1SkMatrix Reference 2=== 3 4 5<a name='SkMatrix'></a> 6 7--- 8 9<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0"> 10class <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> { 11 12 static <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_MakeScale'>MakeScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy); 13 static <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_MakeScale'>MakeScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> scale); 14 static <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_MakeTrans'>MakeTrans</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy); 15 static <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_MakeAll'>MakeAll</a>(<a href='undocumented#SkScalar'>SkScalar</a> scaleX, <a href='undocumented#SkScalar'>SkScalar</a> skewX, <a href='undocumented#SkScalar'>SkScalar</a> transX, 16 <a href='undocumented#SkScalar'>SkScalar</a> skewY, <a href='undocumented#SkScalar'>SkScalar</a> scaleY, <a href='undocumented#SkScalar'>SkScalar</a> transY, 17 <a href='undocumented#SkScalar'>SkScalar</a> pers0, <a href='undocumented#SkScalar'>SkScalar</a> pers1, <a href='undocumented#SkScalar'>SkScalar</a> pers2); 18 19 enum <a href='#SkMatrix_TypeMask'>TypeMask</a> { 20 <a href='#SkMatrix_kIdentity_Mask'>kIdentity_Mask</a> = 0, 21 <a href='#SkMatrix_kTranslate_Mask'>kTranslate_Mask</a> = 0x01, 22 <a href='#SkMatrix_kScale_Mask'>kScale_Mask</a> = 0x02, 23 <a href='#SkMatrix_kAffine_Mask'>kAffine_Mask</a> = 0x04, 24 <a href='#SkMatrix_kPerspective_Mask'>kPerspective_Mask</a> = 0x08, 25 }; 26 27 <a href='#SkMatrix_TypeMask'>TypeMask</a> <a href='#SkMatrix_getType'>getType</a>() const; 28 bool <a href='#SkMatrix_isIdentity'>isIdentity</a>() const; 29 bool <a href='#SkMatrix_isScaleTranslate'>isScaleTranslate</a>() const; 30 bool <a href='#SkMatrix_isTranslate'>isTranslate</a>() const; 31 bool <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a>() const; 32 bool <a href='#SkMatrix_preservesAxisAlignment'>preservesAxisAlignment</a>() const; 33 bool <a href='#SkMatrix_hasPerspective'>hasPerspective</a>() const; 34 bool <a href='#SkMatrix_isSimilarity'>isSimilarity</a>(<a href='undocumented#SkScalar'>SkScalar</a> tol = <a href='undocumented#SK_ScalarNearlyZero'>SK_ScalarNearlyZero</a>) const; 35 bool <a href='#SkMatrix_preservesRightAngles'>preservesRightAngles</a>(<a href='undocumented#SkScalar'>SkScalar</a> tol = <a href='undocumented#SK_ScalarNearlyZero'>SK_ScalarNearlyZero</a>) const; 36 37 static constexpr int <a href='#SkMatrix_kMScaleX'>kMScaleX</a> = 0 static constexpr int <a href='#SkMatrix_kMSkewX'>kMSkewX</a> = 1 static constexpr int <a href='#SkMatrix_kMTransX'>kMTransX</a> = 2 static constexpr int <a href='#SkMatrix_kMSkewY'>kMSkewY</a> = 3 static constexpr int <a href='#SkMatrix_kMScaleY'>kMScaleY</a> = 4 static constexpr int <a href='#SkMatrix_kMTransY'>kMTransY</a> = 5 static constexpr int <a href='#SkMatrix_kMPersp0'>kMPersp0</a> = 6 static constexpr int <a href='#SkMatrix_kMPersp1'>kMPersp1</a> = 7 static constexpr int <a href='#SkMatrix_kMPersp2'>kMPersp2</a> = 8 static constexpr int <a href='#SkMatrix_kAScaleX'>kAScaleX</a> = 0 static constexpr int <a href='#SkMatrix_kASkewY'>kASkewY</a> = 1 static constexpr int <a href='#SkMatrix_kASkewX'>kASkewX</a> = 2 static constexpr int <a href='#SkMatrix_kAScaleY'>kAScaleY</a> = 3 static constexpr int <a href='#SkMatrix_kATransX'>kATransX</a> = 4 static constexpr int <a href='#SkMatrix_kATransY'>kATransY</a> = 5 38 <a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_array_operator'>operator[]</a>(int index) const; 39 <a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_get'>get</a>(int index) const; 40 <a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getScaleX'>getScaleX</a>() const; 41 <a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getScaleY'>getScaleY</a>() const; 42 <a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getSkewY'>getSkewY</a>() const; 43 <a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getSkewX'>getSkewX</a>() const; 44 <a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getTranslateX'>getTranslateX</a>() const; 45 <a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getTranslateY'>getTranslateY</a>() const; 46 <a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getPerspX'>getPerspX</a>() const; 47 <a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getPerspY'>getPerspY</a>() const; 48 <a href='undocumented#SkScalar'>SkScalar</a>& <a href='#SkMatrix_array1_operator'>operator[]</a>(int index); 49 void <a href='#SkMatrix_set'>set</a>(int index, <a href='undocumented#SkScalar'>SkScalar</a> value); 50 void <a href='#SkMatrix_setScaleX'>setScaleX</a>(<a href='undocumented#SkScalar'>SkScalar</a> v); 51 void <a href='#SkMatrix_setScaleY'>setScaleY</a>(<a href='undocumented#SkScalar'>SkScalar</a> v); 52 void <a href='#SkMatrix_setSkewY'>setSkewY</a>(<a href='undocumented#SkScalar'>SkScalar</a> v); 53 void <a href='#SkMatrix_setSkewX'>setSkewX</a>(<a href='undocumented#SkScalar'>SkScalar</a> v); 54 void <a href='#SkMatrix_setTranslateX'>setTranslateX</a>(<a href='undocumented#SkScalar'>SkScalar</a> v); 55 void <a href='#SkMatrix_setTranslateY'>setTranslateY</a>(<a href='undocumented#SkScalar'>SkScalar</a> v); 56 void <a href='#SkMatrix_setPerspX'>setPerspX</a>(<a href='undocumented#SkScalar'>SkScalar</a> v); 57 void <a href='#SkMatrix_setPerspY'>setPerspY</a>(<a href='undocumented#SkScalar'>SkScalar</a> v); 58 void <a href='#SkMatrix_setAll'>setAll</a>(<a href='undocumented#SkScalar'>SkScalar</a> scaleX, <a href='undocumented#SkScalar'>SkScalar</a> skewX, <a href='undocumented#SkScalar'>SkScalar</a> transX, 59 <a href='undocumented#SkScalar'>SkScalar</a> skewY, <a href='undocumented#SkScalar'>SkScalar</a> scaleY, <a href='undocumented#SkScalar'>SkScalar</a> transY, 60 <a href='undocumented#SkScalar'>SkScalar</a> persp0, <a href='undocumented#SkScalar'>SkScalar</a> persp1, <a href='undocumented#SkScalar'>SkScalar</a> persp2); 61 void <a href='#SkMatrix_get9'>get9</a>(<a href='undocumented#SkScalar'>SkScalar</a> buffer[9]) const; 62 void <a href='#SkMatrix_set9'>set9</a>(const <a href='undocumented#SkScalar'>SkScalar</a> buffer[9]); 63 void <a href='#SkMatrix_reset'>reset()</a>; 64 void <a href='#SkMatrix_setIdentity'>setIdentity</a>(); 65 void <a href='#SkMatrix_setTranslate'>setTranslate</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy); 66 void <a href='#SkMatrix_setTranslate'>setTranslate</a>(const <a href='SkPoint_Reference#SkVector'>SkVector</a>& v); 67 void <a href='#SkMatrix_setScale'>setScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py); 68 void <a href='#SkMatrix_setScale'>setScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy); 69 void <a href='#SkMatrix_setRotate'>setRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py); 70 void <a href='#SkMatrix_setRotate'>setRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees); 71 void <a href='#SkMatrix_setSinCos'>setSinCos</a>(<a href='undocumented#SkScalar'>SkScalar</a> sinValue, <a href='undocumented#SkScalar'>SkScalar</a> cosValue, 72 <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py); 73 void <a href='#SkMatrix_setSinCos'>setSinCos</a>(<a href='undocumented#SkScalar'>SkScalar</a> sinValue, <a href='undocumented#SkScalar'>SkScalar</a> cosValue); 74 <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& <a href='#SkMatrix_setRSXform'>setRSXform</a>(const <a href='undocumented#SkRSXform'>SkRSXform</a>& rsxForm); 75 void <a href='#SkMatrix_setSkew'>setSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py); 76 void <a href='#SkMatrix_setSkew'>setSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky); 77 void <a href='#SkMatrix_setConcat'>setConcat</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& a, const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& b); 78 void <a href='#SkMatrix_preTranslate'>preTranslate</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy); 79 void <a href='#SkMatrix_preScale'>preScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py); 80 void <a href='#SkMatrix_preScale'>preScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy); 81 void <a href='#SkMatrix_preRotate'>preRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py); 82 void <a href='#SkMatrix_preRotate'>preRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees); 83 void <a href='#SkMatrix_preSkew'>preSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py); 84 void <a href='#SkMatrix_preSkew'>preSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky); 85 void <a href='#SkMatrix_preConcat'>preConcat</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& other); 86 void <a href='#SkMatrix_postTranslate'>postTranslate</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy); 87 void <a href='#SkMatrix_postScale'>postScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py); 88 void <a href='#SkMatrix_postScale'>postScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy); 89 bool <a href='#SkMatrix_postIDiv'>postIDiv</a>(int divx, int divy); 90 void <a href='#SkMatrix_postRotate'>postRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py); 91 void <a href='#SkMatrix_postRotate'>postRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees); 92 void <a href='#SkMatrix_postSkew'>postSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py); 93 void <a href='#SkMatrix_postSkew'>postSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky); 94 void <a href='#SkMatrix_postConcat'>postConcat</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& other); 95 96 enum <a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> { 97 <a href='#SkMatrix_kFill_ScaleToFit'>kFill_ScaleToFit</a>, 98 <a href='#SkMatrix_kStart_ScaleToFit'>kStart_ScaleToFit</a>, 99 <a href='#SkMatrix_kCenter_ScaleToFit'>kCenter_ScaleToFit</a>, 100 <a href='#SkMatrix_kEnd_ScaleToFit'>kEnd_ScaleToFit</a>, 101 }; 102 103 bool <a href='#SkMatrix_setRectToRect'>setRectToRect</a>(const <a href='SkRect_Reference#SkRect'>SkRect</a>& src, const <a href='SkRect_Reference#SkRect'>SkRect</a>& dst, <a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> stf); 104 static <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_MakeRectToRect'>MakeRectToRect</a>(const <a href='SkRect_Reference#SkRect'>SkRect</a>& src, const <a href='SkRect_Reference#SkRect'>SkRect</a>& dst, <a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> stf); 105 bool <a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a>(const <a href='SkPoint_Reference#SkPoint'>SkPoint</a> src[], const <a href='SkPoint_Reference#SkPoint'>SkPoint</a> dst[], int count); 106 bool <a href='#SkMatrix_invert'>invert</a>(<a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>* inverse) const; 107 static void <a href='#SkMatrix_SetAffineIdentity'>SetAffineIdentity</a>(<a href='undocumented#SkScalar'>SkScalar</a> affine[6]); 108 bool <a href='#SkMatrix_asAffine'>asAffine</a>(<a href='undocumented#SkScalar'>SkScalar</a> affine[6]) const; 109 void <a href='#SkMatrix_setAffine'>setAffine</a>(const <a href='undocumented#SkScalar'>SkScalar</a> affine[6]); 110 void <a href='#SkMatrix_mapPoints'>mapPoints</a>(<a href='SkPoint_Reference#SkPoint'>SkPoint</a> dst[], const <a href='SkPoint_Reference#SkPoint'>SkPoint</a> src[], int count) const; 111 void <a href='#SkMatrix_mapPoints'>mapPoints</a>(<a href='SkPoint_Reference#SkPoint'>SkPoint</a> pts[], int count) const; 112 void <a href='#SkMatrix_mapHomogeneousPoints'>mapHomogeneousPoints</a>(<a href='undocumented#SkPoint3'>SkPoint3</a> dst[], const <a href='undocumented#SkPoint3'>SkPoint3</a> src[], int count) const; 113 void <a href='#SkMatrix_mapXY'>mapXY</a>(<a href='undocumented#SkScalar'>SkScalar</a> x, <a href='undocumented#SkScalar'>SkScalar</a> y, <a href='SkPoint_Reference#SkPoint'>SkPoint</a>* result) const; 114 <a href='SkPoint_Reference#SkPoint'>SkPoint</a> <a href='#SkMatrix_mapXY'>mapXY</a>(<a href='undocumented#SkScalar'>SkScalar</a> x, <a href='undocumented#SkScalar'>SkScalar</a> y) const; 115 void <a href='#SkMatrix_mapVectors'>mapVectors</a>(<a href='SkPoint_Reference#SkVector'>SkVector</a> dst[], const <a href='SkPoint_Reference#SkVector'>SkVector</a> src[], int count) const; 116 void <a href='#SkMatrix_mapVectors'>mapVectors</a>(<a href='SkPoint_Reference#SkVector'>SkVector</a> vecs[], int count) const; 117 void <a href='#SkMatrix_mapVector'>mapVector</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy, <a href='SkPoint_Reference#SkVector'>SkVector</a>* result) const; 118 <a href='SkPoint_Reference#SkVector'>SkVector</a> <a href='#SkMatrix_mapVector'>mapVector</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy) const; 119 bool <a href='#SkMatrix_mapRect'>mapRect</a>(<a href='SkRect_Reference#SkRect'>SkRect</a>* dst, const <a href='SkRect_Reference#SkRect'>SkRect</a>& src) const; 120 bool <a href='#SkMatrix_mapRect'>mapRect</a>(<a href='SkRect_Reference#SkRect'>SkRect</a>* <a href='SkRect_Reference#Rect'>rect</a>) const; 121 <a href='SkRect_Reference#SkRect'>SkRect</a> <a href='#SkMatrix_mapRect'>mapRect</a>(const <a href='SkRect_Reference#SkRect'>SkRect</a>& src) const; 122 void <a href='#SkMatrix_mapRectToQuad'>mapRectToQuad</a>(<a href='SkPoint_Reference#SkPoint'>SkPoint</a> dst[4], const <a href='SkRect_Reference#SkRect'>SkRect</a>& <a href='SkRect_Reference#Rect'>rect</a>) const; 123 void <a href='#SkMatrix_mapRectScaleTranslate'>mapRectScaleTranslate</a>(<a href='SkRect_Reference#SkRect'>SkRect</a>* dst, const <a href='SkRect_Reference#SkRect'>SkRect</a>& src) const; 124 <a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_mapRadius'>mapRadius</a>(<a href='undocumented#SkScalar'>SkScalar</a> radius) const; 125 bool <a href='#SkMatrix_isFixedStepInX'>isFixedStepInX</a>() const; 126 <a href='SkPoint_Reference#SkVector'>SkVector</a> <a href='#SkMatrix_fixedStepInX'>fixedStepInX</a>(<a href='undocumented#SkScalar'>SkScalar</a> y) const; 127 bool <a href='#SkMatrix_cheapEqualTo'>cheapEqualTo</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& m) const; 128 friend bool <a href='#SkMatrix_equal_operator'>operator==</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& a, const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& b); 129 friend bool <a href='#SkMatrix_notequal_operator'>operator!=</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& a, const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& b); 130 void <a href='#SkMatrix_dump'>dump()</a> const; 131 <a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getMinScale'>getMinScale</a>() const; 132 <a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getMaxScale'>getMaxScale</a>() const; 133 bool <a href='#SkMatrix_getMinMaxScales'>getMinMaxScales</a>(<a href='undocumented#SkScalar'>SkScalar</a> scaleFactors[2]) const; 134 bool <a href='#SkMatrix_decomposeScale'>decomposeScale</a>(<a href='undocumented#SkSize'>SkSize</a>* scale, <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>* remaining = nullptr) const; 135 static const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& <a href='#SkMatrix_I'>I</a>(); 136 static const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& <a href='#SkMatrix_InvalidMatrix'>InvalidMatrix</a>(); 137 static <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_Concat'>Concat</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& a, const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& b); 138 void <a href='#SkMatrix_dirtyMatrixTypeCache'>dirtyMatrixTypeCache</a>(); 139 void <a href='#SkMatrix_setScaleTranslate'>setScaleTranslate</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy, <a href='undocumented#SkScalar'>SkScalar</a> tx, <a href='undocumented#SkScalar'>SkScalar</a> ty); 140 bool <a href='#SkMatrix_isFinite'>isFinite</a>() const; 141}; 142 143</pre> 144 145<a href='SkMatrix_Reference#Matrix'>Matrix</a> holds a 3 by 3 <a href='SkMatrix_Reference#Matrix'>matrix</a> for transforming coordinates. This allows mapping 146<a href='SkPoint_Reference#Point'>Points</a> and <a href='SkPoint_Reference#Vector'>Vectors</a> with translation, scaling, skewing, rotation, and 147perspective. 148 149<a href='SkMatrix_Reference#Matrix'>Matrix</a> elements are in row major order. <a href='SkMatrix_Reference#Matrix'>Matrix</a> does not have a constructor, 150so it must be explicitly initialized. <a href='#SkMatrix_setIdentity'>setIdentity</a> initializes <a href='SkMatrix_Reference#Matrix'>Matrix</a> 151so it has no effect. <a href='#SkMatrix_setTranslate'>setTranslate</a>, <a href='#SkMatrix_setScale'>setScale</a>, <a href='#SkMatrix_setSkew'>setSkew</a>, <a href='#SkMatrix_setRotate'>setRotate</a>, <a href='#SkMatrix_set9'>set9</a> and <a href='#SkMatrix_setAll'>setAll</a> 152initializes all <a href='SkMatrix_Reference#Matrix'>Matrix</a> elements with the corresponding mapping. 153 154<a href='SkMatrix_Reference#Matrix'>Matrix</a> includes a hidden variable that classifies the type of <a href='SkMatrix_Reference#Matrix'>matrix</a> to 155improve performance. <a href='SkMatrix_Reference#Matrix'>Matrix</a> is not thread safe unless <a href='#SkMatrix_getType'>getType</a> is called first. 156 157<a name='SkMatrix_MakeScale'></a> 158 159--- 160 161<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 162static <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_MakeScale'>MakeScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy) 163</pre> 164 165Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to scale by (<a href='#SkMatrix_MakeScale_sx'>sx</a>, <a href='#SkMatrix_MakeScale_sy'>sy</a>). Returned <a href='SkMatrix_Reference#Matrix'>matrix</a> is: 166 167| <a href='#SkMatrix_MakeScale_sx'>sx</a> 0 0 | 168| 0 <a href='#SkMatrix_MakeScale_sy'>sy</a> 0 | 169| 0 0 1 | 170 171### Parameters 172 173<table> <tr> <td><a name='SkMatrix_MakeScale_sx'><code><strong>sx</strong></code></a></td> 174 <td>horizontal scale factor</td> 175 </tr> 176 <tr> <td><a name='SkMatrix_MakeScale_sy'><code><strong>sy</strong></code></a></td> 177 <td>vertical scale factor</td> 178 </tr> 179</table> 180 181### Return Value 182 183<a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> with scale 184 185### Example 186 187<div><fiddle-embed name="7ff17718111df6d6f95381d8a8f1b389"></fiddle-embed></div> 188 189### See Also 190 191<a href='#SkMatrix_setScale'>setScale</a> <a href='#SkMatrix_postScale'>postScale</a> <a href='#SkMatrix_preScale'>preScale</a> 192 193<a name='SkMatrix_MakeScale_2'></a> 194 195--- 196 197<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 198static <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_MakeScale'>MakeScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> scale) 199</pre> 200 201Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='#SkMatrix_MakeScale_2_scale'>scale</a> by (<a href='#SkMatrix_MakeScale_2_scale'>scale</a>, <a href='#SkMatrix_MakeScale_2_scale'>scale</a>). Returned <a href='SkMatrix_Reference#Matrix'>matrix</a> is: 202 203| <a href='#SkMatrix_MakeScale_2_scale'>scale</a> 0 0 | 204| 0 <a href='#SkMatrix_MakeScale_2_scale'>scale</a> 0 | 205| 0 0 1 | 206 207### Parameters 208 209<table> <tr> <td><a name='SkMatrix_MakeScale_2_scale'><code><strong>scale</strong></code></a></td> 210 <td>horizontal and vertical <a href='#SkMatrix_MakeScale_2_scale'>scale</a> factor</td> 211 </tr> 212</table> 213 214### Return Value 215 216<a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> with <a href='#SkMatrix_MakeScale_2_scale'>scale</a> 217 218### Example 219 220<div><fiddle-embed name="2956aeb50fa862cdb13995e1e56a4bc8"></fiddle-embed></div> 221 222### See Also 223 224<a href='#SkMatrix_setScale'>setScale</a> <a href='#SkMatrix_postScale'>postScale</a> <a href='#SkMatrix_preScale'>preScale</a> 225 226<a name='SkMatrix_MakeTrans'></a> 227 228--- 229 230<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 231static <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_MakeTrans'>MakeTrans</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy) 232</pre> 233 234Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to translate by (<a href='#SkMatrix_MakeTrans_dx'>dx</a>, <a href='#SkMatrix_MakeTrans_dy'>dy</a>). Returned <a href='SkMatrix_Reference#Matrix'>matrix</a> is: 235 236| 1 0 <a href='#SkMatrix_MakeTrans_dx'>dx</a> | 237| 0 1 <a href='#SkMatrix_MakeTrans_dy'>dy</a> | 238| 0 0 1 | 239 240### Parameters 241 242<table> <tr> <td><a name='SkMatrix_MakeTrans_dx'><code><strong>dx</strong></code></a></td> 243 <td>horizontal translation</td> 244 </tr> 245 <tr> <td><a name='SkMatrix_MakeTrans_dy'><code><strong>dy</strong></code></a></td> 246 <td>vertical translation</td> 247 </tr> 248</table> 249 250### Return Value 251 252<a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> with translation 253 254### Example 255 256<div><fiddle-embed name="b2479df0d9cf296ff64ac31e36684557"></fiddle-embed></div> 257 258### See Also 259 260<a href='#SkMatrix_setTranslate'>setTranslate</a> <a href='#SkMatrix_postTranslate'>postTranslate</a> <a href='#SkMatrix_preTranslate'>preTranslate</a> 261 262<a name='SkMatrix_MakeAll'></a> 263 264--- 265 266<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 267static <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_MakeAll'>MakeAll</a>(<a href='undocumented#SkScalar'>SkScalar</a> scaleX, <a href='undocumented#SkScalar'>SkScalar</a> skewX, <a href='undocumented#SkScalar'>SkScalar</a> transX, <a href='undocumented#SkScalar'>SkScalar</a> skewY, 268 <a href='undocumented#SkScalar'>SkScalar</a> scaleY, <a href='undocumented#SkScalar'>SkScalar</a> transY, <a href='undocumented#SkScalar'>SkScalar</a> pers0, <a href='undocumented#SkScalar'>SkScalar</a> pers1, 269 <a href='undocumented#SkScalar'>SkScalar</a> pers2) 270</pre> 271 272Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 273 274| <a href='#SkMatrix_MakeAll_scaleX'>scaleX</a> <a href='#SkMatrix_MakeAll_skewX'>skewX</a> <a href='#SkMatrix_MakeAll_transX'>transX</a> | 275| <a href='#SkMatrix_MakeAll_skewY'>skewY</a> <a href='#SkMatrix_MakeAll_scaleY'>scaleY</a> <a href='#SkMatrix_MakeAll_transY'>transY</a> | 276| <a href='#SkMatrix_MakeAll_pers0'>pers0</a> <a href='#SkMatrix_MakeAll_pers1'>pers1</a> <a href='#SkMatrix_MakeAll_pers2'>pers2</a> | 277 278### Parameters 279 280<table> <tr> <td><a name='SkMatrix_MakeAll_scaleX'><code><strong>scaleX</strong></code></a></td> 281 <td>horizontal scale factor</td> 282 </tr> 283 <tr> <td><a name='SkMatrix_MakeAll_skewX'><code><strong>skewX</strong></code></a></td> 284 <td>horizontal skew factor</td> 285 </tr> 286 <tr> <td><a name='SkMatrix_MakeAll_transX'><code><strong>transX</strong></code></a></td> 287 <td>horizontal translation</td> 288 </tr> 289 <tr> <td><a name='SkMatrix_MakeAll_skewY'><code><strong>skewY</strong></code></a></td> 290 <td>vertical skew factor</td> 291 </tr> 292 <tr> <td><a name='SkMatrix_MakeAll_scaleY'><code><strong>scaleY</strong></code></a></td> 293 <td>vertical scale factor</td> 294 </tr> 295 <tr> <td><a name='SkMatrix_MakeAll_transY'><code><strong>transY</strong></code></a></td> 296 <td>vertical translation</td> 297 </tr> 298 <tr> <td><a name='SkMatrix_MakeAll_pers0'><code><strong>pers0</strong></code></a></td> 299 <td>input x-axis perspective factor</td> 300 </tr> 301 <tr> <td><a name='SkMatrix_MakeAll_pers1'><code><strong>pers1</strong></code></a></td> 302 <td>input y-axis perspective factor</td> 303 </tr> 304 <tr> <td><a name='SkMatrix_MakeAll_pers2'><code><strong>pers2</strong></code></a></td> 305 <td>perspective scale factor</td> 306 </tr> 307</table> 308 309### Return Value 310 311<a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> constructed from parameters 312 313### Example 314 315<div><fiddle-embed name="6bad83b64de9266e323c29d550e04188"></fiddle-embed></div> 316 317### See Also 318 319<a href='#SkMatrix_setAll'>setAll</a> <a href='#SkMatrix_set9'>set9</a> <a href='#SkMatrix_postConcat'>postConcat</a> <a href='#SkMatrix_preConcat'>preConcat</a> 320 321<a name='SkMatrix_TypeMask'></a> 322 323--- 324 325<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0"> 326 enum <a href='#SkMatrix_TypeMask'>TypeMask</a> { 327 <a href='#SkMatrix_kIdentity_Mask'>kIdentity_Mask</a> = 0, 328 <a href='#SkMatrix_kTranslate_Mask'>kTranslate_Mask</a> = 0x01, 329 <a href='#SkMatrix_kScale_Mask'>kScale_Mask</a> = 0x02, 330 <a href='#SkMatrix_kAffine_Mask'>kAffine_Mask</a> = 0x04, 331 <a href='#SkMatrix_kPerspective_Mask'>kPerspective_Mask</a> = 0x08, 332 }; 333 334</pre> 335 336Enumeration of bit fields for mask returned by <a href='#SkMatrix_getType'>getType</a>. 337Used to identify the complexity of <a href='SkMatrix_Reference#Matrix'>Matrix</a>, to optimize performance. 338 339### Constants 340 341<table style='border-collapse: collapse; width: 62.5em'> 342 <tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Const</th> 343<th style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>Value</th> 344<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr> 345 <tr style='background-color: #f0f0f0; '> 346 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kIdentity_Mask'><code>SkMatrix::kIdentity_Mask</code></a></td> 347 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>0</td> 348 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 349all bits clear if <a href='SkMatrix_Reference#Matrix'>Matrix</a> is identity 350</td> 351 </tr> 352 <tr> 353 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kTranslate_Mask'><code>SkMatrix::kTranslate_Mask</code></a></td> 354 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>1</td> 355 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 356set if <a href='SkMatrix_Reference#Matrix'>Matrix</a> has translation 357</td> 358 </tr> 359 <tr style='background-color: #f0f0f0; '> 360 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kScale_Mask'><code>SkMatrix::kScale_Mask</code></a></td> 361 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>2</td> 362 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 363set if <a href='SkMatrix_Reference#Matrix'>Matrix</a> scales x-axis or y-axis 364</td> 365 </tr> 366 <tr> 367 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kAffine_Mask'><code>SkMatrix::kAffine_Mask</code></a></td> 368 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>4</td> 369 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 370set if <a href='SkMatrix_Reference#Matrix'>Matrix</a> skews or rotates 371</td> 372 </tr> 373 <tr style='background-color: #f0f0f0; '> 374 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kPerspective_Mask'><code>SkMatrix::kPerspective_Mask</code></a></td> 375 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>8</td> 376 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 377set if <a href='SkMatrix_Reference#Matrix'>Matrix</a> has perspective 378</td> 379 </tr> 380</table> 381 382### Example 383 384<div><fiddle-embed name="ba19b36df8cd78586f3dff54e2d4c093"> 385 386#### Example Output 387 388~~~~ 389after reset: kIdentity_Mask 390after postTranslate: kTranslate_Mask 391after postScale: kTranslate_Mask kScale_Mask 392after postScale: kTranslate_Mask kScale_Mask kAffine_Mask 393after setPolyToPoly: kTranslate_Mask kScale_Mask kAffine_Mask kPerspective_Mask 394~~~~ 395 396</fiddle-embed></div> 397 398### See Also 399 400<a href='#SkMatrix_getType'>getType</a> 401 402<a name='Property'></a> 403 404<a name='SkMatrix_getType'></a> 405 406--- 407 408<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 409<a href='#SkMatrix_TypeMask'>TypeMask</a> <a href='#SkMatrix_getType'>getType</a>()const 410</pre> 411 412Returns a bit field describing the transformations the <a href='SkMatrix_Reference#Matrix'>matrix</a> may 413perform. The bit field is computed conservatively, so it may include 414false positives. For example, when <a href='#SkMatrix_kPerspective_Mask'>kPerspective_Mask</a> is set, all 415other bits are set. 416 417### Return Value 418 419<a href='#SkMatrix_kIdentity_Mask'>kIdentity_Mask</a>, or combinations of: <a href='#SkMatrix_kTranslate_Mask'>kTranslate_Mask</a>, <a href='#SkMatrix_kScale_Mask'>kScale_Mask</a>, 420 421<a href='#SkMatrix_kAffine_Mask'>kAffine_Mask</a>, <a href='#SkMatrix_kPerspective_Mask'>kPerspective_Mask</a> 422 423### Example 424 425<div><fiddle-embed name="8e45fe2dd52731bb2d4318686257e1d7"> 426 427#### Example Output 428 429~~~~ 430identity flags hex: 0 decimal: 0 431set all flags hex: f decimal: 15 432~~~~ 433 434</fiddle-embed></div> 435 436### See Also 437 438<a href='#SkMatrix_TypeMask'>TypeMask</a> 439 440<a name='SkMatrix_isIdentity'></a> 441 442--- 443 444<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 445bool <a href='#SkMatrix_isIdentity'>isIdentity</a>()const 446</pre> 447 448Returns true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> is identity. Identity <a href='SkMatrix_Reference#Matrix'>matrix</a> is: 449 450| 1 0 0 | 451| 0 1 0 | 452| 0 0 1 | 453 454### Return Value 455 456true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> has no effect 457 458### Example 459 460<div><fiddle-embed name="780ab376325b3cfa889ea26c0769ec11"> 461 462#### Example Output 463 464~~~~ 465is identity: true 466is identity: false 467~~~~ 468 469</fiddle-embed></div> 470 471### See Also 472 473<a href='#SkMatrix_reset'>reset()</a> <a href='#SkMatrix_setIdentity'>setIdentity</a> <a href='#SkMatrix_getType'>getType</a> 474 475<a name='SkMatrix_isScaleTranslate'></a> 476 477--- 478 479<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 480bool <a href='#SkMatrix_isScaleTranslate'>isScaleTranslate</a>()const 481</pre> 482 483Returns true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> at most scales and translates. <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> may be identity, 484contain only scale elements, only translate elements, or both. <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> form is: 485 486| scale-x 0 translate-x | 487| 0 scale-y translate-y | 488| 0 0 1 | 489 490### Return Value 491 492true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> is identity; or scales, translates, or both 493 494### Example 495 496<div><fiddle-embed name="6287e29674a487eb94174992d45b9a34"> 497 498#### Example Output 499 500~~~~ 501is scale-translate: true 502is scale-translate: true 503is scale-translate: true 504is scale-translate: true 505~~~~ 506 507</fiddle-embed></div> 508 509### See Also 510 511<a href='#SkMatrix_setScale'>setScale</a> <a href='#SkMatrix_isTranslate'>isTranslate</a> <a href='#SkMatrix_setTranslate'>setTranslate</a> <a href='#SkMatrix_getType'>getType</a> 512 513<a name='SkMatrix_isTranslate'></a> 514 515--- 516 517<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 518bool <a href='#SkMatrix_isTranslate'>isTranslate</a>()const 519</pre> 520 521Returns true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> is identity, or translates. <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> form is: 522 523| 1 0 translate-x | 524| 0 1 translate-y | 525| 0 0 1 | 526 527### Return Value 528 529true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> is identity, or translates 530 531### Example 532 533<div><fiddle-embed name="73ac71a8a30841873577c11c6c9b38ee"> 534 535#### Example Output 536 537~~~~ 538is translate: true 539is translate: true 540is translate: false 541is translate: false 542~~~~ 543 544</fiddle-embed></div> 545 546### See Also 547 548<a href='#SkMatrix_setTranslate'>setTranslate</a> <a href='#SkMatrix_getType'>getType</a> 549 550<a name='SkMatrix_rectStaysRect'></a> 551 552--- 553 554<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 555bool <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a>()const 556</pre> 557 558Returns true <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> maps <a href='SkRect_Reference#SkRect'>SkRect</a> to another <a href='SkRect_Reference#SkRect'>SkRect</a>. If true, <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> is identity, 559or scales, or rotates a multiple of 90 degrees, or mirrors on axes. In all 560cases, <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> may also have translation. <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> form is either: 561 562| scale-x 0 translate-x | 563| 0 scale-y translate-y | 564| 0 0 1 | 565 566or 567 568| 0 rotate-x translate-x | 569| rotate-y 0 translate-y | 570| 0 0 1 | 571 572for non-zero values of scale-x, scale-y, rotate-x, and rotate-y. 573 574Also called <a href='#SkMatrix_preservesAxisAlignment'>preservesAxisAlignment</a>(); use the one that provides better inline 575documentation. 576 577### Return Value 578 579true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> maps one <a href='SkRect_Reference#SkRect'>SkRect</a> into another 580 581### Example 582 583<div><fiddle-embed name="ce5319c036c9b5086da8a0009fe409f8"> 584 585#### Example Output 586 587~~~~ 588rectStaysRect: true 589rectStaysRect: true 590rectStaysRect: true 591rectStaysRect: true 592~~~~ 593 594</fiddle-embed></div> 595 596### See Also 597 598<a href='#SkMatrix_preservesAxisAlignment'>preservesAxisAlignment</a> <a href='#SkMatrix_preservesRightAngles'>preservesRightAngles</a> 599 600<a name='SkMatrix_preservesAxisAlignment'></a> 601 602--- 603 604<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 605bool <a href='#SkMatrix_preservesAxisAlignment'>preservesAxisAlignment</a>()const 606</pre> 607 608Returns true <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> maps <a href='SkRect_Reference#SkRect'>SkRect</a> to another <a href='SkRect_Reference#SkRect'>SkRect</a>. If true, <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> is identity, 609or scales, or rotates a multiple of 90 degrees, or mirrors on axes. In all 610cases, <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> may also have translation. <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> form is either: 611 612| scale-x 0 translate-x | 613| 0 scale-y translate-y | 614| 0 0 1 | 615 616or 617 618| 0 rotate-x translate-x | 619| rotate-y 0 translate-y | 620| 0 0 1 | 621 622for non-zero values of scale-x, scale-y, rotate-x, and rotate-y. 623 624Also called <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a>(); use the one that provides better inline 625documentation. 626 627### Return Value 628 629true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> maps one <a href='SkRect_Reference#SkRect'>SkRect</a> into another 630 631### Example 632 633<div><fiddle-embed name="7a234c96608fb7cb8135b9940b0b15f7"> 634 635#### Example Output 636 637~~~~ 638preservesAxisAlignment: true 639preservesAxisAlignment: true 640preservesAxisAlignment: true 641preservesAxisAlignment: true 642~~~~ 643 644</fiddle-embed></div> 645 646### See Also 647 648<a href='#SkMatrix_rectStaysRect'>rectStaysRect</a> <a href='#SkMatrix_preservesRightAngles'>preservesRightAngles</a> 649 650<a name='SkMatrix_hasPerspective'></a> 651 652--- 653 654<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 655bool <a href='#SkMatrix_hasPerspective'>hasPerspective</a>()const 656</pre> 657 658Returns true if the <a href='SkMatrix_Reference#Matrix'>matrix</a> contains perspective elements. <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> form is: 659 660| -- -- -- | 661| -- -- -- | 662| perspective-x perspective-y perspective-scale | 663 664where perspective-x or perspective-y is non-zero, or perspective-scale is 665not one. All other elements may have any value. 666 667### Return Value 668 669true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> is in most general form 670 671### Example 672 673<div><fiddle-embed name="688123908c733169bbbfaf11f41ecff6"></fiddle-embed></div> 674 675### See Also 676 677<a href='#SkMatrix_setAll'>setAll</a> <a href='#SkMatrix_set9'>set9</a> <a href='#SkMatrix_MakeAll'>MakeAll</a> 678 679<a name='SkMatrix_isSimilarity'></a> 680 681--- 682 683<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 684bool <a href='#SkMatrix_isSimilarity'>isSimilarity</a>(<a href='undocumented#SkScalar'>SkScalar</a> tol = <a href='undocumented#SK_ScalarNearlyZero'>SK_ScalarNearlyZero</a>)const 685</pre> 686 687Returns true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> contains only translation, rotation, reflection, and 688uniform scale. 689Returns false if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> contains different scales, skewing, perspective, or 690degenerate forms that collapse to a <a href='undocumented#Line'>line</a> or <a href='SkPoint_Reference#Point'>point</a>. 691 692Describes that the <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> makes rendering with and without the <a href='SkMatrix_Reference#Matrix'>matrix</a> are 693visually alike; a transformed <a href='undocumented#Circle'>circle</a> remains a <a href='undocumented#Circle'>circle</a>. Mathematically, this is 694referred to as similarity of a <a href='undocumented#Euclidean_Space'>Euclidean space</a>, or a similarity transformation. 695 696Preserves right angles, keeping the arms of the angle equal lengths. 697 698### Parameters 699 700<table> <tr> <td><a name='SkMatrix_isSimilarity_tol'><code><strong>tol</strong></code></a></td> 701 <td>to be deprecated</td> 702 </tr> 703</table> 704 705### Return Value 706 707true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> only rotates, uniformly scales, translates 708 709### Example 710 711<div><fiddle-embed name="8b37f4ae7fec1756433c0f984175fb14"><div><a href='undocumented#String'>String</a> is drawn four times through but only two are visible. Drawing the pair 712with <a href='#SkMatrix_isSimilarity'>isSimilarity</a> false reveals the pair not visible through the <a href='SkMatrix_Reference#Matrix'>matrix</a>. 713</div></fiddle-embed></div> 714 715### See Also 716 717<a href='#SkMatrix_isScaleTranslate'>isScaleTranslate</a> <a href='#SkMatrix_preservesRightAngles'>preservesRightAngles</a> <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a> <a href='#SkMatrix_isFixedStepInX'>isFixedStepInX</a> 718 719<a name='SkMatrix_preservesRightAngles'></a> 720 721--- 722 723<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 724bool <a href='#SkMatrix_preservesRightAngles'>preservesRightAngles</a>(<a href='undocumented#SkScalar'>SkScalar</a> tol = <a href='undocumented#SK_ScalarNearlyZero'>SK_ScalarNearlyZero</a>)const 725</pre> 726 727Returns true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> contains only translation, rotation, reflection, and 728scale. Scale may differ along rotated axes. 729Returns false if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> skewing, perspective, or degenerate forms that collapse 730to a <a href='undocumented#Line'>line</a> or <a href='SkPoint_Reference#Point'>point</a>. 731 732Preserves right angles, but not requiring that the arms of the angle 733retain equal lengths. 734 735### Parameters 736 737<table> <tr> <td><a name='SkMatrix_preservesRightAngles_tol'><code><strong>tol</strong></code></a></td> 738 <td>to be deprecated</td> 739 </tr> 740</table> 741 742### Return Value 743 744true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> only rotates, scales, translates 745 746### Example 747 748<div><fiddle-embed name="b9becf0dc24a9f00726e24a81fb72f16"><div>Equal scale is both similar and preserves right angles. 749Unequal scale is not similar but preserves right angles. 750Skews are not similar and do not preserve right angles. 751</div></fiddle-embed></div> 752 753### See Also 754 755<a href='#SkMatrix_isScaleTranslate'>isScaleTranslate</a> <a href='#SkMatrix_isSimilarity'>isSimilarity</a> <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a> <a href='#SkMatrix_isFixedStepInX'>isFixedStepInX</a> 756 757<a name='MemberIndex'></a> 758 759--- 760 761<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0"> 762 static constexpr int <a href='#SkMatrix_kMScaleX'>kMScaleX</a> = 0; 763 static constexpr int <a href='#SkMatrix_kMSkewX'>kMSkewX</a> = 1; 764 static constexpr int <a href='#SkMatrix_kMTransX'>kMTransX</a> = 2; 765 static constexpr int <a href='#SkMatrix_kMSkewY'>kMSkewY</a> = 3; 766 static constexpr int <a href='#SkMatrix_kMScaleY'>kMScaleY</a> = 4; 767 static constexpr int <a href='#SkMatrix_kMTransY'>kMTransY</a> = 5; 768 static constexpr int <a href='#SkMatrix_kMPersp0'>kMPersp0</a> = 6; 769 static constexpr int <a href='#SkMatrix_kMPersp1'>kMPersp1</a> = 7; 770 static constexpr int <a href='#SkMatrix_kMPersp2'>kMPersp2</a> = 8; 771</pre> 772 773<a href='SkMatrix_Reference#Matrix'>Matrix</a> organizes its values in row order. These members correspond to 774each value in <a href='SkMatrix_Reference#Matrix'>Matrix</a>. 775 776### Constants 777 778<table style='border-collapse: collapse; width: 62.5em'> 779 <tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Const</th> 780<th style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>Value</th> 781<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr> 782 <tr style='background-color: #f0f0f0; '> 783 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMScaleX'><code>SkMatrix::kMScaleX</code></a></td> 784 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>0</td> 785 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 786horizontal scale factor</td> 787 </tr> 788 <tr> 789 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMSkewX'><code>SkMatrix::kMSkewX</code></a></td> 790 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>1</td> 791 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 792horizontal skew factor</td> 793 </tr> 794 <tr style='background-color: #f0f0f0; '> 795 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMTransX'><code>SkMatrix::kMTransX</code></a></td> 796 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>2</td> 797 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 798horizontal translation</td> 799 </tr> 800 <tr> 801 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMSkewY'><code>SkMatrix::kMSkewY</code></a></td> 802 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>3</td> 803 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 804vertical skew factor</td> 805 </tr> 806 <tr style='background-color: #f0f0f0; '> 807 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMScaleY'><code>SkMatrix::kMScaleY</code></a></td> 808 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>4</td> 809 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 810vertical scale factor</td> 811 </tr> 812 <tr> 813 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMTransY'><code>SkMatrix::kMTransY</code></a></td> 814 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>5</td> 815 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 816vertical translation</td> 817 </tr> 818 <tr style='background-color: #f0f0f0; '> 819 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMPersp0'><code>SkMatrix::kMPersp0</code></a></td> 820 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>6</td> 821 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 822input x perspective factor</td> 823 </tr> 824 <tr> 825 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMPersp1'><code>SkMatrix::kMPersp1</code></a></td> 826 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>7</td> 827 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 828input y perspective factor</td> 829 </tr> 830 <tr style='background-color: #f0f0f0; '> 831 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMPersp2'><code>SkMatrix::kMPersp2</code></a></td> 832 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>8</td> 833 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 834perspective bias</td> 835 </tr> 836</table> 837 838### Example 839 840<div><fiddle-embed name="3bbf75f4748420810aa2586e3c8548d9"></fiddle-embed></div> 841 842### See Also 843 844<a href='#SkMatrix_get'>get()</a> <a href='#SkMatrix_set'>set()</a> 845 846<a name='AffineIndex'></a> 847 848--- 849 850<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0"> 851</pre> 852 853Affine arrays are in column major order to match the <a href='SkMatrix_Reference#Matrix'>matrix</a> used by 854PDF and XPS. 855 856### Constants 857 858<table style='border-collapse: collapse; width: 62.5em'> 859 <tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Const</th> 860<th style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>Value</th> 861<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr> 862 <tr style='background-color: #f0f0f0; '> 863 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kAScaleX'><code>SkMatrix::kAScaleX</code></a></td> 864 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>0</td> 865 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 866horizontal scale factor</td> 867 </tr> 868 <tr> 869 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kASkewY'><code>SkMatrix::kASkewY</code></a></td> 870 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>1</td> 871 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 872vertical skew factor</td> 873 </tr> 874 <tr style='background-color: #f0f0f0; '> 875 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kASkewX'><code>SkMatrix::kASkewX</code></a></td> 876 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>2</td> 877 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 878horizontal skew factor</td> 879 </tr> 880 <tr> 881 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kAScaleY'><code>SkMatrix::kAScaleY</code></a></td> 882 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>3</td> 883 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 884vertical scale factor</td> 885 </tr> 886 <tr style='background-color: #f0f0f0; '> 887 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kATransX'><code>SkMatrix::kATransX</code></a></td> 888 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>4</td> 889 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 890horizontal translation</td> 891 </tr> 892 <tr> 893 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kATransY'><code>SkMatrix::kATransY</code></a></td> 894 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>5</td> 895 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 896vertical translation</td> 897 </tr> 898</table> 899 900### See Also 901 902<a href='#SkMatrix_SetAffineIdentity'>SetAffineIdentity</a> <a href='#SkMatrix_asAffine'>asAffine</a> <a href='#SkMatrix_setAffine'>setAffine</a> 903 904<a name='SkMatrix_array_operator'></a> 905 906--- 907 908<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 909<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_array1_operator'>operator[]</a>(int index)const 910</pre> 911 912### Example 913 914<div><fiddle-embed name="e8740493abdf0c6341762db9cee56b89"> 915 916#### Example Output 917 918~~~~ 919matrix[SkMatrix::kMScaleX] == 42 920matrix[SkMatrix::kMScaleY] == 24 921~~~~ 922 923</fiddle-embed></div> 924 925### See Also 926 927<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_set'>set</a> 928 929<a name='SkMatrix_get'></a> 930 931--- 932 933<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 934<a href='undocumented#SkScalar'>SkScalar</a> get(int index)const 935</pre> 936 937Returns one <a href='SkMatrix_Reference#Matrix'>matrix</a> value. Asserts if <a href='#SkMatrix_get_index'>index</a> is out of range and SK_DEBUG is 938defined. 939 940### Parameters 941 942<table> <tr> <td><a name='SkMatrix_get_index'><code><strong>index</strong></code></a></td> 943 <td>one of: <a href='#SkMatrix_kMScaleX'>kMScaleX</a>, <a href='#SkMatrix_kMSkewX'>kMSkewX</a>, <a href='#SkMatrix_kMTransX'>kMTransX</a>, <a href='#SkMatrix_kMSkewY'>kMSkewY</a>, <a href='#SkMatrix_kMScaleY'>kMScaleY</a>, <a href='#SkMatrix_kMTransY'>kMTransY</a>,</td> 944 </tr> 945</table> 946 947<a href='#SkMatrix_kMPersp0'>kMPersp0</a>, <a href='#SkMatrix_kMPersp1'>kMPersp1</a>, <a href='#SkMatrix_kMPersp2'>kMPersp2</a> 948 949### Return Value 950 951value corresponding to <a href='#SkMatrix_get_index'>index</a> 952 953### Example 954 955<div><fiddle-embed name="f5ed382bd04fa7d50b2398cce2fca23a"> 956 957#### Example Output 958 959~~~~ 960matrix.get(SkMatrix::kMSkewX) == 42 961matrix.get(SkMatrix::kMSkewY) == 24 962~~~~ 963 964</fiddle-embed></div> 965 966### See Also 967 968<a href='#SkMatrix_array1_operator'>operator[]</a>(int <a href='#SkMatrix_get_index'>index</a>) <a href='#SkMatrix_set'>set</a> 969 970<a name='SkMatrix_getScaleX'></a> 971 972--- 973 974<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 975<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getScaleX'>getScaleX</a>()const 976</pre> 977 978Returns scale factor multiplied by x-axis input, contributing to x-axis output. 979With <a href='#SkMatrix_mapPoints'>mapPoints</a>(), scales <a href='SkPoint_Reference#SkPoint'>SkPoint</a> along the x-axis. 980 981### Return Value 982 983horizontal scale factor 984 985### Example 986 987<div><fiddle-embed name="ab746d9be63975041ae8e50cba84dc3d"> 988 989#### Example Output 990 991~~~~ 992matrix.getScaleX() == 42 993~~~~ 994 995</fiddle-embed></div> 996 997### See Also 998 999<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_getScaleY'>getScaleY</a> <a href='#SkMatrix_setScaleX'>setScaleX</a> <a href='#SkMatrix_setScale'>setScale</a> 1000 1001<a name='SkMatrix_getScaleY'></a> 1002 1003--- 1004 1005<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1006<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getScaleY'>getScaleY</a>()const 1007</pre> 1008 1009Returns scale factor multiplied by y-axis input, contributing to y-axis output. 1010With <a href='#SkMatrix_mapPoints'>mapPoints</a>(), scales <a href='SkPoint_Reference#SkPoint'>SkPoint</a> along the y-axis. 1011 1012### Return Value 1013 1014vertical scale factor 1015 1016### Example 1017 1018<div><fiddle-embed name="708b1a548a2f8661b2ab570782fbc751"> 1019 1020#### Example Output 1021 1022~~~~ 1023matrix.getScaleY() == 24 1024~~~~ 1025 1026</fiddle-embed></div> 1027 1028### See Also 1029 1030<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_getScaleX'>getScaleX</a> <a href='#SkMatrix_setScaleY'>setScaleY</a> <a href='#SkMatrix_setScale'>setScale</a> 1031 1032<a name='SkMatrix_getSkewY'></a> 1033 1034--- 1035 1036<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1037<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getSkewY'>getSkewY</a>()const 1038</pre> 1039 1040Returns scale factor multiplied by x-axis input, contributing to y-axis output. 1041With <a href='#SkMatrix_mapPoints'>mapPoints</a>(), skews <a href='SkPoint_Reference#SkPoint'>SkPoint</a> along the y-axis. 1042Skewing both axes can rotate <a href='SkPoint_Reference#SkPoint'>SkPoint</a>. 1043 1044### Return Value 1045 1046vertical skew factor 1047 1048### Example 1049 1050<div><fiddle-embed name="6be5704506d029ffc91ba03b1d3e674b"> 1051 1052#### Example Output 1053 1054~~~~ 1055matrix.getSkewY() == 24 1056~~~~ 1057 1058</fiddle-embed></div> 1059 1060### See Also 1061 1062<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_getSkewX'>getSkewX</a> <a href='#SkMatrix_setSkewY'>setSkewY</a> <a href='#SkMatrix_setSkew'>setSkew</a> 1063 1064<a name='SkMatrix_getSkewX'></a> 1065 1066--- 1067 1068<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1069<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getSkewX'>getSkewX</a>()const 1070</pre> 1071 1072Returns scale factor multiplied by y-axis input, contributing to x-axis output. 1073With <a href='#SkMatrix_mapPoints'>mapPoints</a>(), skews <a href='SkPoint_Reference#SkPoint'>SkPoint</a> along the x-axis. 1074Skewing both axes can rotate <a href='SkPoint_Reference#SkPoint'>SkPoint</a>. 1075 1076### Return Value 1077 1078horizontal scale factor 1079 1080### Example 1081 1082<div><fiddle-embed name="df3a5d3c688e7597eae1e4e07bf91ae6"> 1083 1084#### Example Output 1085 1086~~~~ 1087matrix.getSkewX() == 42 1088~~~~ 1089 1090</fiddle-embed></div> 1091 1092### See Also 1093 1094<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_getSkewY'>getSkewY</a> <a href='#SkMatrix_setSkewX'>setSkewX</a> <a href='#SkMatrix_setSkew'>setSkew</a> 1095 1096<a name='SkMatrix_getTranslateX'></a> 1097 1098--- 1099 1100<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1101<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getTranslateX'>getTranslateX</a>()const 1102</pre> 1103 1104Returns translation contributing to x-axis output. 1105With <a href='#SkMatrix_mapPoints'>mapPoints</a>(), moves <a href='SkPoint_Reference#SkPoint'>SkPoint</a> along the x-axis. 1106 1107### Return Value 1108 1109horizontal translation factor 1110 1111### Example 1112 1113<div><fiddle-embed name="6236f7f2b91aff977a66ba2ee2558ca4"> 1114 1115#### Example Output 1116 1117~~~~ 1118matrix.getTranslateX() == 42 1119~~~~ 1120 1121</fiddle-embed></div> 1122 1123### See Also 1124 1125<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_getTranslateY'>getTranslateY</a> <a href='#SkMatrix_setTranslateX'>setTranslateX</a> <a href='#SkMatrix_setTranslate'>setTranslate</a> 1126 1127<a name='SkMatrix_getTranslateY'></a> 1128 1129--- 1130 1131<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1132<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getTranslateY'>getTranslateY</a>()const 1133</pre> 1134 1135Returns translation contributing to y-axis output. 1136With <a href='#SkMatrix_mapPoints'>mapPoints</a>(), moves <a href='SkPoint_Reference#SkPoint'>SkPoint</a> along the y-axis. 1137 1138### Return Value 1139 1140vertical translation factor 1141 1142### Example 1143 1144<div><fiddle-embed name="08464e32d22421d2b254c71a84545ef5"> 1145 1146#### Example Output 1147 1148~~~~ 1149matrix.getTranslateY() == 24 1150~~~~ 1151 1152</fiddle-embed></div> 1153 1154### See Also 1155 1156<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_getTranslateX'>getTranslateX</a> <a href='#SkMatrix_setTranslateY'>setTranslateY</a> <a href='#SkMatrix_setTranslate'>setTranslate</a> 1157 1158<a name='SkMatrix_getPerspX'></a> 1159 1160--- 1161 1162<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1163<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getPerspX'>getPerspX</a>()const 1164</pre> 1165 1166Returns factor scaling input x-axis relative to input y-axis. 1167 1168### Return Value 1169 1170input x-axis perspective factor 1171 1172### Example 1173 1174<div><fiddle-embed name="a0f5bf4b55e8c33bfda29bf67e34306f"></fiddle-embed></div> 1175 1176### See Also 1177 1178<a href='#SkMatrix_kMPersp0'>kMPersp0</a> <a href='#SkMatrix_getPerspY'>getPerspY</a> 1179 1180<a name='SkMatrix_getPerspY'></a> 1181 1182--- 1183 1184<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1185<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getPerspY'>getPerspY</a>()const 1186</pre> 1187 1188Returns factor scaling input y-axis relative to input x-axis. 1189 1190### Return Value 1191 1192input y-axis perspective factor 1193 1194### Example 1195 1196<div><fiddle-embed name="424a00a73675dbd99ad20feb0267442b"></fiddle-embed></div> 1197 1198### See Also 1199 1200<a href='#SkMatrix_kMPersp1'>kMPersp1</a> <a href='#SkMatrix_getPerspX'>getPerspX</a> 1201 1202<a name='SkMatrix_array1_operator'></a> 1203 1204--- 1205 1206<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1207<a href='undocumented#SkScalar'>SkScalar</a>& <a href='#SkMatrix_array1_operator'>operator[]</a>(int index) 1208</pre> 1209 1210### Example 1211 1212<div><fiddle-embed name="f4365ef332f51f7fd25040e0771ba9a2"> 1213 1214#### Example Output 1215 1216~~~~ 1217with identity matrix: x = 24 1218after skew x mod: x = 24 1219after 2nd skew x mod: x = 24 1220after dirty cache: x = 66 1221~~~~ 1222 1223</fiddle-embed></div> 1224 1225### See Also 1226 1227<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_dirtyMatrixTypeCache'>dirtyMatrixTypeCache</a> <a href='#SkMatrix_set'>set</a> 1228 1229<a name='Set'></a> 1230 1231<a name='SkMatrix_set'></a> 1232 1233--- 1234 1235<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1236void set(int index, <a href='undocumented#SkScalar'>SkScalar</a> value) 1237</pre> 1238 1239Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_set_value'>value</a>. Asserts if <a href='#SkMatrix_set_index'>index</a> is out of range and SK_DEBUG is 1240defined. Safer than operator[]; internal cache is always maintained. 1241 1242### Parameters 1243 1244<table> <tr> <td><a name='SkMatrix_set_index'><code><strong>index</strong></code></a></td> 1245 <td>one of: <a href='#SkMatrix_kMScaleX'>kMScaleX</a>, <a href='#SkMatrix_kMSkewX'>kMSkewX</a>, <a href='#SkMatrix_kMTransX'>kMTransX</a>, <a href='#SkMatrix_kMSkewY'>kMSkewY</a>, <a href='#SkMatrix_kMScaleY'>kMScaleY</a>, <a href='#SkMatrix_kMTransY'>kMTransY</a>,</td> 1246 </tr> 1247</table> 1248 1249<a href='#SkMatrix_kMPersp0'>kMPersp0</a>, <a href='#SkMatrix_kMPersp1'>kMPersp1</a>, <a href='#SkMatrix_kMPersp2'>kMPersp2</a> 1250 1251### Parameters 1252 1253<table> <tr> <td><a name='SkMatrix_set_value'><code><strong>value</strong></code></a></td> 1254 <td><a href='undocumented#Scalar'>scalar</a> to store in <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a></td> 1255 </tr> 1256</table> 1257 1258### Example 1259 1260<div><fiddle-embed name="1d400a92ca826cc89bcb88ea051f28c8"> 1261 1262#### Example Output 1263 1264~~~~ 1265with identity matrix: x = 24 1266after skew x mod: x = 24 1267after 2nd skew x mod: x = 66 1268~~~~ 1269 1270</fiddle-embed></div> 1271 1272### See Also 1273 1274operator[] <a href='#SkMatrix_get'>get</a> 1275 1276<a name='SkMatrix_setScaleX'></a> 1277 1278--- 1279 1280<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1281void <a href='#SkMatrix_setScaleX'>setScaleX</a>(<a href='undocumented#SkScalar'>SkScalar</a> v) 1282</pre> 1283 1284Sets horizontal scale factor. 1285 1286### Parameters 1287 1288<table> <tr> <td><a name='SkMatrix_setScaleX_v'><code><strong>v</strong></code></a></td> 1289 <td>horizontal scale factor to store</td> 1290 </tr> 1291</table> 1292 1293### Example 1294 1295<div><fiddle-embed name="a39dfed98c3c3c3a56be9ad59fe4e21e"></fiddle-embed></div> 1296 1297### See Also 1298 1299<a href='#SkMatrix_set'>set</a> <a href='#SkMatrix_setScale'>setScale</a> <a href='#SkMatrix_setScaleY'>setScaleY</a> 1300 1301<a name='SkMatrix_setScaleY'></a> 1302 1303--- 1304 1305<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1306void <a href='#SkMatrix_setScaleY'>setScaleY</a>(<a href='undocumented#SkScalar'>SkScalar</a> v) 1307</pre> 1308 1309Sets vertical scale factor. 1310 1311### Parameters 1312 1313<table> <tr> <td><a name='SkMatrix_setScaleY_v'><code><strong>v</strong></code></a></td> 1314 <td>vertical scale factor to store</td> 1315 </tr> 1316</table> 1317 1318### Example 1319 1320<div><fiddle-embed name="f040c6dd85a02e94eaca00d5c2832604"></fiddle-embed></div> 1321 1322### See Also 1323 1324<a href='#SkMatrix_set'>set</a> <a href='#SkMatrix_setScale'>setScale</a> <a href='#SkMatrix_setScaleX'>setScaleX</a> 1325 1326<a name='SkMatrix_setSkewY'></a> 1327 1328--- 1329 1330<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1331void <a href='#SkMatrix_setSkewY'>setSkewY</a>(<a href='undocumented#SkScalar'>SkScalar</a> v) 1332</pre> 1333 1334Sets vertical skew factor. 1335 1336### Parameters 1337 1338<table> <tr> <td><a name='SkMatrix_setSkewY_v'><code><strong>v</strong></code></a></td> 1339 <td>vertical skew factor to store</td> 1340 </tr> 1341</table> 1342 1343### Example 1344 1345<div><fiddle-embed name="b418d15df9829aefcc6aca93a37428bb"></fiddle-embed></div> 1346 1347### See Also 1348 1349<a href='#SkMatrix_set'>set</a> <a href='#SkMatrix_setSkew'>setSkew</a> <a href='#SkMatrix_setSkewX'>setSkewX</a> 1350 1351<a name='SkMatrix_setSkewX'></a> 1352 1353--- 1354 1355<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1356void <a href='#SkMatrix_setSkewX'>setSkewX</a>(<a href='undocumented#SkScalar'>SkScalar</a> v) 1357</pre> 1358 1359Sets horizontal skew factor. 1360 1361### Parameters 1362 1363<table> <tr> <td><a name='SkMatrix_setSkewX_v'><code><strong>v</strong></code></a></td> 1364 <td>horizontal skew factor to store</td> 1365 </tr> 1366</table> 1367 1368### Example 1369 1370<div><fiddle-embed name="c7177a6fbc1545be95a5ebca87e0cd0d"></fiddle-embed></div> 1371 1372### See Also 1373 1374<a href='#SkMatrix_set'>set</a> <a href='#SkMatrix_setSkew'>setSkew</a> <a href='#SkMatrix_setSkewX'>setSkewX</a> 1375 1376<a name='SkMatrix_setTranslateX'></a> 1377 1378--- 1379 1380<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1381void <a href='#SkMatrix_setTranslateX'>setTranslateX</a>(<a href='undocumented#SkScalar'>SkScalar</a> v) 1382</pre> 1383 1384Sets horizontal translation. 1385 1386### Parameters 1387 1388<table> <tr> <td><a name='SkMatrix_setTranslateX_v'><code><strong>v</strong></code></a></td> 1389 <td>horizontal translation to store</td> 1390 </tr> 1391</table> 1392 1393### Example 1394 1395<div><fiddle-embed name="a18bc2e3607ac3a8e438bcb61fb13130"></fiddle-embed></div> 1396 1397### See Also 1398 1399<a href='#SkMatrix_set'>set</a> <a href='#SkMatrix_setTranslate'>setTranslate</a> <a href='#SkMatrix_setTranslateY'>setTranslateY</a> 1400 1401<a name='SkMatrix_setTranslateY'></a> 1402 1403--- 1404 1405<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1406void <a href='#SkMatrix_setTranslateY'>setTranslateY</a>(<a href='undocumented#SkScalar'>SkScalar</a> v) 1407</pre> 1408 1409Sets vertical translation. 1410 1411### Parameters 1412 1413<table> <tr> <td><a name='SkMatrix_setTranslateY_v'><code><strong>v</strong></code></a></td> 1414 <td>vertical translation to store</td> 1415 </tr> 1416</table> 1417 1418### Example 1419 1420<div><fiddle-embed name="34e3c70a72b836abf7f4858d35eecc98"></fiddle-embed></div> 1421 1422### See Also 1423 1424<a href='#SkMatrix_set'>set</a> <a href='#SkMatrix_setTranslate'>setTranslate</a> <a href='#SkMatrix_setTranslateX'>setTranslateX</a> 1425 1426<a name='SkMatrix_setPerspX'></a> 1427 1428--- 1429 1430<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1431void <a href='#SkMatrix_setPerspX'>setPerspX</a>(<a href='undocumented#SkScalar'>SkScalar</a> v) 1432</pre> 1433 1434Sets input x-axis perspective factor, which causes <a href='#SkMatrix_mapXY'>mapXY</a>() to vary input x-axis values 1435inversely proportional to input y-axis values. 1436 1437### Parameters 1438 1439<table> <tr> <td><a name='SkMatrix_setPerspX_v'><code><strong>v</strong></code></a></td> 1440 <td>perspective factor</td> 1441 </tr> 1442</table> 1443 1444### Example 1445 1446<div><fiddle-embed name="830a9e4e4bb93d25afd83b2fea63929e"></fiddle-embed></div> 1447 1448### See Also 1449 1450<a href='#SkMatrix_getPerspX'>getPerspX</a> <a href='#SkMatrix_set'>set</a> <a href='#SkMatrix_setAll'>setAll</a> <a href='#SkMatrix_set9'>set9</a> <a href='#SkMatrix_MakeAll'>MakeAll</a> 1451 1452<a name='SkMatrix_setPerspY'></a> 1453 1454--- 1455 1456<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1457void <a href='#SkMatrix_setPerspY'>setPerspY</a>(<a href='undocumented#SkScalar'>SkScalar</a> v) 1458</pre> 1459 1460Sets input y-axis perspective factor, which causes <a href='#SkMatrix_mapXY'>mapXY</a>() to vary input y-axis values 1461inversely proportional to input x-axis values. 1462 1463### Parameters 1464 1465<table> <tr> <td><a name='SkMatrix_setPerspY_v'><code><strong>v</strong></code></a></td> 1466 <td>perspective factor</td> 1467 </tr> 1468</table> 1469 1470### Example 1471 1472<div><fiddle-embed name="aeb258b7922c1a11b698b00f562182ec"></fiddle-embed></div> 1473 1474### See Also 1475 1476<a href='#SkMatrix_getPerspY'>getPerspY</a> <a href='#SkMatrix_set'>set</a> <a href='#SkMatrix_setAll'>setAll</a> <a href='#SkMatrix_set9'>set9</a> <a href='#SkMatrix_MakeAll'>MakeAll</a> 1477 1478<a name='SkMatrix_setAll'></a> 1479 1480--- 1481 1482<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1483void <a href='#SkMatrix_setAll'>setAll</a>(<a href='undocumented#SkScalar'>SkScalar</a> scaleX, <a href='undocumented#SkScalar'>SkScalar</a> skewX, <a href='undocumented#SkScalar'>SkScalar</a> transX, <a href='undocumented#SkScalar'>SkScalar</a> skewY, <a href='undocumented#SkScalar'>SkScalar</a> scaleY, 1484 <a href='undocumented#SkScalar'>SkScalar</a> transY, <a href='undocumented#SkScalar'>SkScalar</a> persp0, <a href='undocumented#SkScalar'>SkScalar</a> persp1, <a href='undocumented#SkScalar'>SkScalar</a> persp2) 1485</pre> 1486 1487Sets all values from parameters. Sets <a href='SkMatrix_Reference#Matrix'>matrix</a> to: 1488 1489| <a href='#SkMatrix_setAll_scaleX'>scaleX</a> <a href='#SkMatrix_setAll_skewX'>skewX</a> <a href='#SkMatrix_setAll_transX'>transX</a> | 1490| <a href='#SkMatrix_setAll_skewY'>skewY</a> <a href='#SkMatrix_setAll_scaleY'>scaleY</a> <a href='#SkMatrix_setAll_transY'>transY</a> | 1491| <a href='#SkMatrix_setAll_persp0'>persp0</a> <a href='#SkMatrix_setAll_persp1'>persp1</a> <a href='#SkMatrix_setAll_persp2'>persp2</a> | 1492 1493### Parameters 1494 1495<table> <tr> <td><a name='SkMatrix_setAll_scaleX'><code><strong>scaleX</strong></code></a></td> 1496 <td>horizontal scale factor to store</td> 1497 </tr> 1498 <tr> <td><a name='SkMatrix_setAll_skewX'><code><strong>skewX</strong></code></a></td> 1499 <td>horizontal skew factor to store</td> 1500 </tr> 1501 <tr> <td><a name='SkMatrix_setAll_transX'><code><strong>transX</strong></code></a></td> 1502 <td>horizontal translation to store</td> 1503 </tr> 1504 <tr> <td><a name='SkMatrix_setAll_skewY'><code><strong>skewY</strong></code></a></td> 1505 <td>vertical skew factor to store</td> 1506 </tr> 1507 <tr> <td><a name='SkMatrix_setAll_scaleY'><code><strong>scaleY</strong></code></a></td> 1508 <td>vertical scale factor to store</td> 1509 </tr> 1510 <tr> <td><a name='SkMatrix_setAll_transY'><code><strong>transY</strong></code></a></td> 1511 <td>vertical translation to store</td> 1512 </tr> 1513 <tr> <td><a name='SkMatrix_setAll_persp0'><code><strong>persp0</strong></code></a></td> 1514 <td>input x-axis values perspective factor to store</td> 1515 </tr> 1516 <tr> <td><a name='SkMatrix_setAll_persp1'><code><strong>persp1</strong></code></a></td> 1517 <td>input y-axis values perspective factor to store</td> 1518 </tr> 1519 <tr> <td><a name='SkMatrix_setAll_persp2'><code><strong>persp2</strong></code></a></td> 1520 <td>perspective scale factor to store</td> 1521 </tr> 1522</table> 1523 1524### Example 1525 1526<div><fiddle-embed name="95ccfc2a89ce593e6b7a9f992a844bc0"></fiddle-embed></div> 1527 1528### See Also 1529 1530<a href='#SkMatrix_set9'>set9</a> <a href='#SkMatrix_MakeAll'>MakeAll</a> 1531 1532<a name='SkMatrix_get9'></a> 1533 1534--- 1535 1536<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1537void <a href='#SkMatrix_get9'>get9</a>(<a href='undocumented#SkScalar'>SkScalar</a> buffer[9])const 1538</pre> 1539 1540Copies nine <a href='undocumented#Scalar'>scalar</a> values contained by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> into <a href='#SkMatrix_get9_buffer'>buffer</a>, in member value 1541ascending order: <a href='#SkMatrix_kMScaleX'>kMScaleX</a>, <a href='#SkMatrix_kMSkewX'>kMSkewX</a>, <a href='#SkMatrix_kMTransX'>kMTransX</a>, <a href='#SkMatrix_kMSkewY'>kMSkewY</a>, <a href='#SkMatrix_kMScaleY'>kMScaleY</a>, <a href='#SkMatrix_kMTransY'>kMTransY</a>, 1542<a href='#SkMatrix_kMPersp0'>kMPersp0</a>, <a href='#SkMatrix_kMPersp1'>kMPersp1</a>, <a href='#SkMatrix_kMPersp2'>kMPersp2</a>. 1543 1544### Parameters 1545 1546<table> <tr> <td><a name='SkMatrix_get9_buffer'><code><strong>buffer</strong></code></a></td> 1547 <td>storage for nine <a href='undocumented#Scalar'>scalar</a> values</td> 1548 </tr> 1549</table> 1550 1551### Example 1552 1553<div><fiddle-embed name="379fc375e011050b54ed9df83c0996a7"> 1554 1555#### Example Output 1556 1557~~~~ 1558{4, 0, 3}, 1559{0, 5, 4}, 1560{0, 0, 1} 1561~~~~ 1562 1563</fiddle-embed></div> 1564 1565### See Also 1566 1567<a href='#SkMatrix_set9'>set9</a> 1568 1569<a name='SkMatrix_set9'></a> 1570 1571--- 1572 1573<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1574void <a href='#SkMatrix_set9'>set9</a>(const <a href='undocumented#SkScalar'>SkScalar</a> buffer[9]) 1575</pre> 1576 1577Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to nine <a href='undocumented#Scalar'>scalar</a> values in <a href='#SkMatrix_set9_buffer'>buffer</a>, in member value ascending order: 1578<a href='#SkMatrix_kMScaleX'>kMScaleX</a>, <a href='#SkMatrix_kMSkewX'>kMSkewX</a>, <a href='#SkMatrix_kMTransX'>kMTransX</a>, <a href='#SkMatrix_kMSkewY'>kMSkewY</a>, <a href='#SkMatrix_kMScaleY'>kMScaleY</a>, <a href='#SkMatrix_kMTransY'>kMTransY</a>, <a href='#SkMatrix_kMPersp0'>kMPersp0</a>, <a href='#SkMatrix_kMPersp1'>kMPersp1</a>, 1579<a href='#SkMatrix_kMPersp2'>kMPersp2</a>. 1580 1581Sets <a href='SkMatrix_Reference#Matrix'>matrix</a> to: 1582 1583| <a href='#SkMatrix_set9_buffer'>buffer</a>[0] <a href='#SkMatrix_set9_buffer'>buffer</a>[1] <a href='#SkMatrix_set9_buffer'>buffer</a>[2] | 1584| <a href='#SkMatrix_set9_buffer'>buffer</a>[3] <a href='#SkMatrix_set9_buffer'>buffer</a>[4] <a href='#SkMatrix_set9_buffer'>buffer</a>[5] | 1585| <a href='#SkMatrix_set9_buffer'>buffer</a>[6] <a href='#SkMatrix_set9_buffer'>buffer</a>[7] <a href='#SkMatrix_set9_buffer'>buffer</a>[8] | 1586 1587In the future, <a href='#SkMatrix_set9'>set9</a> followed by <a href='#SkMatrix_get9'>get9</a> may not return the same values. Since <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> 1588maps non-homogeneous coordinates, scaling all nine values produces an equivalent 1589transformation, possibly improving precision. 1590 1591### Parameters 1592 1593<table> <tr> <td><a name='SkMatrix_set9_buffer'><code><strong>buffer</strong></code></a></td> 1594 <td>nine <a href='undocumented#Scalar'>scalar</a> values</td> 1595 </tr> 1596</table> 1597 1598### Example 1599 1600<div><fiddle-embed name="ec5de0d23e5fe28ba7628625d1402e85"></fiddle-embed></div> 1601 1602### See Also 1603 1604<a href='#SkMatrix_setAll'>setAll</a> <a href='#SkMatrix_get9'>get9</a> <a href='#SkMatrix_MakeAll'>MakeAll</a> 1605 1606<a name='SkMatrix_reset'></a> 1607 1608--- 1609 1610<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1611void <a href='#SkMatrix_reset'>reset()</a> 1612</pre> 1613 1614Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to identity; which has no effect on mapped <a href='SkPoint_Reference#SkPoint'>SkPoint</a>. Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 1615 1616| 1 0 0 | 1617| 0 1 0 | 1618| 0 0 1 | 1619 1620Also called <a href='#SkMatrix_setIdentity'>setIdentity</a>(); use the one that provides better inline 1621documentation. 1622 1623### Example 1624 1625<div><fiddle-embed name="ca94f7922bc37ef03bbc51ad70536fcf"> 1626 1627#### Example Output 1628 1629~~~~ 1630m.isIdentity(): true 1631~~~~ 1632 1633</fiddle-embed></div> 1634 1635### See Also 1636 1637<a href='#SkMatrix_isIdentity'>isIdentity</a> <a href='#SkMatrix_setIdentity'>setIdentity</a> 1638 1639<a name='SkMatrix_setIdentity'></a> 1640 1641--- 1642 1643<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1644void <a href='#SkMatrix_setIdentity'>setIdentity</a>() 1645</pre> 1646 1647Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to identity; which has no effect on mapped <a href='SkPoint_Reference#SkPoint'>SkPoint</a>. Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 1648 1649| 1 0 0 | 1650| 0 1 0 | 1651| 0 0 1 | 1652 1653Also called <a href='#SkMatrix_reset'>reset()</a>; use the one that provides better inline 1654documentation. 1655 1656### Example 1657 1658<div><fiddle-embed name="3979c865bb482e6ef1fafc71e56bbb91"> 1659 1660#### Example Output 1661 1662~~~~ 1663m.isIdentity(): true 1664~~~~ 1665 1666</fiddle-embed></div> 1667 1668### See Also 1669 1670<a href='#SkMatrix_isIdentity'>isIdentity</a> <a href='#SkMatrix_reset'>reset</a> 1671 1672<a name='SkMatrix_setTranslate'></a> 1673 1674--- 1675 1676<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1677void <a href='#SkMatrix_setTranslate'>setTranslate</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy) 1678</pre> 1679 1680Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to translate by (<a href='#SkMatrix_setTranslate_dx'>dx</a>, <a href='#SkMatrix_setTranslate_dy'>dy</a>). 1681 1682### Parameters 1683 1684<table> <tr> <td><a name='SkMatrix_setTranslate_dx'><code><strong>dx</strong></code></a></td> 1685 <td>horizontal translation</td> 1686 </tr> 1687 <tr> <td><a name='SkMatrix_setTranslate_dy'><code><strong>dy</strong></code></a></td> 1688 <td>vertical translation</td> 1689 </tr> 1690</table> 1691 1692### Example 1693 1694<div><fiddle-embed name="63ca62985741b1bccb5e8b9cf734874e"></fiddle-embed></div> 1695 1696### See Also 1697 1698<a href='#SkMatrix_setTranslateX'>setTranslateX</a> <a href='#SkMatrix_setTranslateY'>setTranslateY</a> 1699 1700<a name='SkMatrix_setTranslate_2'></a> 1701 1702--- 1703 1704<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1705void <a href='#SkMatrix_setTranslate'>setTranslate</a>(const <a href='SkPoint_Reference#SkVector'>SkVector</a>& v) 1706</pre> 1707 1708Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to translate by (<a href='#SkMatrix_setTranslate_2_v'>v</a>.<a href='#SkPoint_fX'>fX</a>, <a href='#SkMatrix_setTranslate_2_v'>v</a>.<a href='#SkPoint_fY'>fY</a>). 1709 1710### Parameters 1711 1712<table> <tr> <td><a name='SkMatrix_setTranslate_2_v'><code><strong>v</strong></code></a></td> 1713 <td><a href='SkPoint_Reference#Vector'>vector</a> containing horizontal and vertical translation</td> 1714 </tr> 1715</table> 1716 1717### Example 1718 1719<div><fiddle-embed name="ccfc734aff2ddea0b097c83f5621de5e"></fiddle-embed></div> 1720 1721### See Also 1722 1723<a href='#SkMatrix_setTranslateX'>setTranslateX</a> <a href='#SkMatrix_setTranslateY'>setTranslateY</a> <a href='#SkMatrix_MakeTrans'>MakeTrans</a> 1724 1725<a name='SkMatrix_setScale'></a> 1726 1727--- 1728 1729<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1730void <a href='#SkMatrix_setScale'>setScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py) 1731</pre> 1732 1733Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to scale by <a href='#SkMatrix_setScale_sx'>sx</a> and <a href='#SkMatrix_setScale_sy'>sy</a>, about a pivot <a href='SkPoint_Reference#Point'>point</a> at (<a href='#SkMatrix_setScale_px'>px</a>, <a href='#SkMatrix_setScale_py'>py</a>). 1734The pivot <a href='SkPoint_Reference#Point'>point</a> is unchanged when mapped with <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 1735 1736### Parameters 1737 1738<table> <tr> <td><a name='SkMatrix_setScale_sx'><code><strong>sx</strong></code></a></td> 1739 <td>horizontal scale factor</td> 1740 </tr> 1741 <tr> <td><a name='SkMatrix_setScale_sy'><code><strong>sy</strong></code></a></td> 1742 <td>vertical scale factor</td> 1743 </tr> 1744 <tr> <td><a name='SkMatrix_setScale_px'><code><strong>px</strong></code></a></td> 1745 <td>pivot on x-axis</td> 1746 </tr> 1747 <tr> <td><a name='SkMatrix_setScale_py'><code><strong>py</strong></code></a></td> 1748 <td>pivot on y-axis</td> 1749 </tr> 1750</table> 1751 1752### Example 1753 1754<div><fiddle-embed name="4565a0792058178c88e0a129a87272d6"></fiddle-embed></div> 1755 1756### See Also 1757 1758<a href='#SkMatrix_setScaleX'>setScaleX</a> <a href='#SkMatrix_setScaleY'>setScaleY</a> <a href='#SkMatrix_MakeScale'>MakeScale</a> <a href='#SkMatrix_preScale'>preScale</a> <a href='#SkMatrix_postScale'>postScale</a> 1759 1760<a name='SkMatrix_setScale_2'></a> 1761 1762--- 1763 1764<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1765void <a href='#SkMatrix_setScale'>setScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy) 1766</pre> 1767 1768Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to scale by <a href='#SkMatrix_setScale_2_sx'>sx</a> and <a href='#SkMatrix_setScale_2_sy'>sy</a> about at pivot <a href='SkPoint_Reference#Point'>point</a> at (0, 0). 1769 1770### Parameters 1771 1772<table> <tr> <td><a name='SkMatrix_setScale_2_sx'><code><strong>sx</strong></code></a></td> 1773 <td>horizontal scale factor</td> 1774 </tr> 1775 <tr> <td><a name='SkMatrix_setScale_2_sy'><code><strong>sy</strong></code></a></td> 1776 <td>vertical scale factor</td> 1777 </tr> 1778</table> 1779 1780### Example 1781 1782<div><fiddle-embed name="1579d0cc109c26e69f66f73abd35fb0e"></fiddle-embed></div> 1783 1784### See Also 1785 1786<a href='#SkMatrix_setScaleX'>setScaleX</a> <a href='#SkMatrix_setScaleY'>setScaleY</a> <a href='#SkMatrix_MakeScale'>MakeScale</a> <a href='#SkMatrix_preScale'>preScale</a> <a href='#SkMatrix_postScale'>postScale</a> 1787 1788<a name='SkMatrix_setRotate'></a> 1789 1790--- 1791 1792<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1793void <a href='#SkMatrix_setRotate'>setRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py) 1794</pre> 1795 1796Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to rotate by <a href='#SkMatrix_setRotate_degrees'>degrees</a> about a pivot <a href='SkPoint_Reference#Point'>point</a> at (<a href='#SkMatrix_setRotate_px'>px</a>, <a href='#SkMatrix_setRotate_py'>py</a>). 1797The pivot <a href='SkPoint_Reference#Point'>point</a> is unchanged when mapped with <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 1798 1799Positive <a href='#SkMatrix_setRotate_degrees'>degrees</a> rotates clockwise. 1800 1801### Parameters 1802 1803<table> <tr> <td><a name='SkMatrix_setRotate_degrees'><code><strong>degrees</strong></code></a></td> 1804 <td>angle of axes relative to upright axes</td> 1805 </tr> 1806 <tr> <td><a name='SkMatrix_setRotate_px'><code><strong>px</strong></code></a></td> 1807 <td>pivot on x-axis</td> 1808 </tr> 1809 <tr> <td><a name='SkMatrix_setRotate_py'><code><strong>py</strong></code></a></td> 1810 <td>pivot on y-axis</td> 1811 </tr> 1812</table> 1813 1814### Example 1815 1816<div><fiddle-embed name="8c28db3add9cd0177225088f6df6bbb5"></fiddle-embed></div> 1817 1818### See Also 1819 1820<a href='#SkMatrix_setSinCos'>setSinCos</a> <a href='#SkMatrix_preRotate'>preRotate</a> <a href='#SkMatrix_postRotate'>postRotate</a> 1821 1822<a name='SkMatrix_setRotate_2'></a> 1823 1824--- 1825 1826<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1827void <a href='#SkMatrix_setRotate'>setRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees) 1828</pre> 1829 1830Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to rotate by <a href='#SkMatrix_setRotate_2_degrees'>degrees</a> about a pivot <a href='SkPoint_Reference#Point'>point</a> at (0, 0). 1831Positive <a href='#SkMatrix_setRotate_2_degrees'>degrees</a> rotates clockwise. 1832 1833### Parameters 1834 1835<table> <tr> <td><a name='SkMatrix_setRotate_2_degrees'><code><strong>degrees</strong></code></a></td> 1836 <td>angle of axes relative to upright axes</td> 1837 </tr> 1838</table> 1839 1840### Example 1841 1842<div><fiddle-embed name="93efb9d191bf1b9710c173513e014d6c"></fiddle-embed></div> 1843 1844### See Also 1845 1846<a href='#SkMatrix_setSinCos'>setSinCos</a> <a href='#SkMatrix_preRotate'>preRotate</a> <a href='#SkMatrix_postRotate'>postRotate</a> 1847 1848<a name='SkMatrix_setSinCos'></a> 1849 1850--- 1851 1852<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1853void <a href='#SkMatrix_setSinCos'>setSinCos</a>(<a href='undocumented#SkScalar'>SkScalar</a> sinValue, <a href='undocumented#SkScalar'>SkScalar</a> cosValue, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py) 1854</pre> 1855 1856Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to rotate by <a href='#SkMatrix_setSinCos_sinValue'>sinValue</a> and <a href='#SkMatrix_setSinCos_cosValue'>cosValue</a>, about a pivot <a href='SkPoint_Reference#Point'>point</a> at (<a href='#SkMatrix_setSinCos_px'>px</a>, <a href='#SkMatrix_setSinCos_py'>py</a>). 1857The pivot <a href='SkPoint_Reference#Point'>point</a> is unchanged when mapped with <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 1858 1859<a href='SkPoint_Reference#Vector'>Vector</a> (<a href='#SkMatrix_setSinCos_sinValue'>sinValue</a>, <a href='#SkMatrix_setSinCos_cosValue'>cosValue</a>) describes the angle of rotation relative to (0, 1). 1860<a href='SkPoint_Reference#Vector'>Vector</a> length specifies scale. 1861 1862### Parameters 1863 1864<table> <tr> <td><a name='SkMatrix_setSinCos_sinValue'><code><strong>sinValue</strong></code></a></td> 1865 <td>rotation <a href='SkPoint_Reference#Vector'>vector</a> x-axis component</td> 1866 </tr> 1867 <tr> <td><a name='SkMatrix_setSinCos_cosValue'><code><strong>cosValue</strong></code></a></td> 1868 <td>rotation <a href='SkPoint_Reference#Vector'>vector</a> y-axis component</td> 1869 </tr> 1870 <tr> <td><a name='SkMatrix_setSinCos_px'><code><strong>px</strong></code></a></td> 1871 <td>pivot on x-axis</td> 1872 </tr> 1873 <tr> <td><a name='SkMatrix_setSinCos_py'><code><strong>py</strong></code></a></td> 1874 <td>pivot on y-axis</td> 1875 </tr> 1876</table> 1877 1878### Example 1879 1880<div><fiddle-embed name="187e1d9228e2e4341ef820bd77b6fda9"></fiddle-embed></div> 1881 1882### See Also 1883 1884<a href='#SkMatrix_setRotate'>setRotate</a> <a href='#SkMatrix_setScale'>setScale</a> <a href='#SkMatrix_setRSXform'>setRSXform</a> 1885 1886<a name='SkMatrix_setSinCos_2'></a> 1887 1888--- 1889 1890<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1891void <a href='#SkMatrix_setSinCos'>setSinCos</a>(<a href='undocumented#SkScalar'>SkScalar</a> sinValue, <a href='undocumented#SkScalar'>SkScalar</a> cosValue) 1892</pre> 1893 1894Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to rotate by <a href='#SkMatrix_setSinCos_2_sinValue'>sinValue</a> and <a href='#SkMatrix_setSinCos_2_cosValue'>cosValue</a>, about a pivot <a href='SkPoint_Reference#Point'>point</a> at (0, 0). 1895 1896<a href='SkPoint_Reference#Vector'>Vector</a> (<a href='#SkMatrix_setSinCos_2_sinValue'>sinValue</a>, <a href='#SkMatrix_setSinCos_2_cosValue'>cosValue</a>) describes the angle of rotation relative to (0, 1). 1897<a href='SkPoint_Reference#Vector'>Vector</a> length specifies scale. 1898 1899### Parameters 1900 1901<table> <tr> <td><a name='SkMatrix_setSinCos_2_sinValue'><code><strong>sinValue</strong></code></a></td> 1902 <td>rotation <a href='SkPoint_Reference#Vector'>vector</a> x-axis component</td> 1903 </tr> 1904 <tr> <td><a name='SkMatrix_setSinCos_2_cosValue'><code><strong>cosValue</strong></code></a></td> 1905 <td>rotation <a href='SkPoint_Reference#Vector'>vector</a> y-axis component</td> 1906 </tr> 1907</table> 1908 1909### Example 1910 1911<div><fiddle-embed name="e37a94a53c959951b059fcd624639ef6"><div><a href='SkCanvas_Reference#Canvas'>Canvas</a> needs offset after applying <a href='SkMatrix_Reference#Matrix'>Matrix</a> to pivot about <a href='SkRect_Reference#Rect'>Rect</a> center. 1912</div></fiddle-embed></div> 1913 1914### See Also 1915 1916<a href='#SkMatrix_setRotate'>setRotate</a> <a href='#SkMatrix_setScale'>setScale</a> <a href='#SkMatrix_setRSXform'>setRSXform</a> 1917 1918<a name='SkMatrix_setRSXform'></a> 1919 1920--- 1921 1922<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1923<a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& <a href='#SkMatrix_setRSXform'>setRSXform</a>(const <a href='undocumented#SkRSXform'>SkRSXform</a>& rsxForm) 1924</pre> 1925 1926Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to rotate, scale, and translate using a compressed <a href='SkMatrix_Reference#Matrix'>matrix</a> form. 1927 1928<a href='SkPoint_Reference#Vector'>Vector</a> (<a href='#SkMatrix_setRSXform_rsxForm'>rsxForm</a>.<a href='#SkRSXform_fSSin'>fSSin</a>, <a href='#SkMatrix_setRSXform_rsxForm'>rsxForm</a>.<a href='#SkRSXform_fSCos'>fSCos</a>) describes the angle of rotation relative 1929to (0, 1). <a href='SkPoint_Reference#Vector'>Vector</a> length specifies scale. Mapped <a href='SkPoint_Reference#Point'>point</a> is rotated and scaled 1930by <a href='SkPoint_Reference#Vector'>vector</a>, then translated by (<a href='#SkMatrix_setRSXform_rsxForm'>rsxForm</a>.<a href='#SkRSXform_fTx'>fTx</a>, <a href='#SkMatrix_setRSXform_rsxForm'>rsxForm</a>.<a href='#SkRSXform_fTy'>fTy</a>). 1931 1932### Parameters 1933 1934<table> <tr> <td><a name='SkMatrix_setRSXform_rsxForm'><code><strong>rsxForm</strong></code></a></td> 1935 <td>compressed <a href='undocumented#SkRSXform'>SkRSXform</a> <a href='SkMatrix_Reference#Matrix'>matrix</a></td> 1936 </tr> 1937</table> 1938 1939### Return Value 1940 1941reference to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> 1942 1943### Example 1944 1945<div><fiddle-embed name="c3f5faddca466f78278b32b88fd5f5eb"><div><a href='SkCanvas_Reference#Canvas'>Canvas</a> needs offset after applying <a href='SkMatrix_Reference#Matrix'>Matrix</a> to pivot about <a href='SkRect_Reference#Rect'>Rect</a> center. 1946</div></fiddle-embed></div> 1947 1948### See Also 1949 1950<a href='#SkMatrix_setSinCos'>setSinCos</a> <a href='#SkMatrix_setScale'>setScale</a> <a href='#SkMatrix_setTranslate'>setTranslate</a> 1951 1952<a name='SkMatrix_setSkew'></a> 1953 1954--- 1955 1956<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1957void <a href='#SkMatrix_setSkew'>setSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py) 1958</pre> 1959 1960Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to skew by <a href='#SkMatrix_setSkew_kx'>kx</a> and <a href='#SkMatrix_setSkew_ky'>ky</a>, about a pivot <a href='SkPoint_Reference#Point'>point</a> at (<a href='#SkMatrix_setSkew_px'>px</a>, <a href='#SkMatrix_setSkew_py'>py</a>). 1961The pivot <a href='SkPoint_Reference#Point'>point</a> is unchanged when mapped with <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 1962 1963### Parameters 1964 1965<table> <tr> <td><a name='SkMatrix_setSkew_kx'><code><strong>kx</strong></code></a></td> 1966 <td>horizontal skew factor</td> 1967 </tr> 1968 <tr> <td><a name='SkMatrix_setSkew_ky'><code><strong>ky</strong></code></a></td> 1969 <td>vertical skew factor</td> 1970 </tr> 1971 <tr> <td><a name='SkMatrix_setSkew_px'><code><strong>px</strong></code></a></td> 1972 <td>pivot on x-axis</td> 1973 </tr> 1974 <tr> <td><a name='SkMatrix_setSkew_py'><code><strong>py</strong></code></a></td> 1975 <td>pivot on y-axis</td> 1976 </tr> 1977</table> 1978 1979### Example 1980 1981<div><fiddle-embed name="55e0431adc6c5b1987ebb8123cc10342"></fiddle-embed></div> 1982 1983### See Also 1984 1985<a href='#SkMatrix_setSkewX'>setSkewX</a> <a href='#SkMatrix_setSkewY'>setSkewY</a> <a href='#SkMatrix_preSkew'>preSkew</a> <a href='#SkMatrix_postSkew'>postSkew</a> 1986 1987<a name='SkMatrix_setSkew_2'></a> 1988 1989--- 1990 1991<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 1992void <a href='#SkMatrix_setSkew'>setSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky) 1993</pre> 1994 1995Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to skew by <a href='#SkMatrix_setSkew_2_kx'>kx</a> and <a href='#SkMatrix_setSkew_2_ky'>ky</a>, about a pivot <a href='SkPoint_Reference#Point'>point</a> at (0, 0). 1996 1997### Parameters 1998 1999<table> <tr> <td><a name='SkMatrix_setSkew_2_kx'><code><strong>kx</strong></code></a></td> 2000 <td>horizontal skew factor</td> 2001 </tr> 2002 <tr> <td><a name='SkMatrix_setSkew_2_ky'><code><strong>ky</strong></code></a></td> 2003 <td>vertical skew factor</td> 2004 </tr> 2005</table> 2006 2007### Example 2008 2009<div><fiddle-embed name="05be7844e9afdd7b9bfc31c5423a70a2"></fiddle-embed></div> 2010 2011### See Also 2012 2013<a href='#SkMatrix_setSkewX'>setSkewX</a> <a href='#SkMatrix_setSkewY'>setSkewY</a> <a href='#SkMatrix_preSkew'>preSkew</a> <a href='#SkMatrix_postSkew'>postSkew</a> 2014 2015<a name='SkMatrix_setConcat'></a> 2016 2017--- 2018 2019<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2020void <a href='#SkMatrix_setConcat'>setConcat</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& a, const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& b) 2021</pre> 2022 2023Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_setConcat_a'>a</a> multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_setConcat_b'>b</a>. Either <a href='#SkMatrix_setConcat_a'>a</a> or <a href='#SkMatrix_setConcat_b'>b</a> may be this. 2024 2025Given: 2026 2027| A B C | | J K L | 2028<a href='#SkMatrix_setConcat_a'>a</a> = | D E F |, <a href='#SkMatrix_setConcat_b'>b</a> = | M N O | 2029| G H <a href='#SkMatrix_I'>I</a> | | P Q R | 2030 2031sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2032 2033| A B C | | J K L | | AJ+BM+CP AK+BN+CQ AL+BO+CR | 2034<a href='#SkMatrix_setConcat_a'>a</a> * <a href='#SkMatrix_setConcat_b'>b</a> = | D E F | * | M N O | = | DJ+EM+FP DK+EN+FQ DL+EO+FR | 2035| G H <a href='#SkMatrix_I'>I</a> | | P Q R | | GJ+HM+IP GK+HN+IQ GL+HO+IR | 2036 2037### Parameters 2038 2039<table> <tr> <td><a name='SkMatrix_setConcat_a'><code><strong>a</strong></code></a></td> 2040 <td><a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> on left side of multiply expression</td> 2041 </tr> 2042 <tr> <td><a name='SkMatrix_setConcat_b'><code><strong>b</strong></code></a></td> 2043 <td><a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> on right side of multiply expression</td> 2044 </tr> 2045</table> 2046 2047### Example 2048 2049<div><fiddle-embed name="0381a10ac69bdefdf9d15b47cbb9fefe"><div><a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a> creates perspective <a href='SkMatrix_Reference#Matrix'>matrices</a>, one the inverse of the other. 2050Multiplying the <a href='SkMatrix_Reference#Matrix'>matrix</a> by its inverse turns into an identity <a href='SkMatrix_Reference#Matrix'>matrix</a>. 2051</div></fiddle-embed></div> 2052 2053### See Also 2054 2055<a href='#SkMatrix_Concat'>Concat</a> <a href='#SkMatrix_preConcat'>preConcat</a> <a href='#SkMatrix_postConcat'>postConcat</a> <a href='SkCanvas_Reference#SkCanvas'>SkCanvas</a>::<a href='#SkCanvas_concat'>concat</a> 2056 2057<a name='SkMatrix_preTranslate'></a> 2058 2059--- 2060 2061<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2062void <a href='#SkMatrix_preTranslate'>preTranslate</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy) 2063</pre> 2064 2065Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> constructed from translation (<a href='#SkMatrix_preTranslate_dx'>dx</a>, <a href='#SkMatrix_preTranslate_dy'>dy</a>). 2066This can be thought of as moving the <a href='SkPoint_Reference#Point'>point</a> to be mapped before applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2067 2068Given: 2069 2070| A B C | | 1 0 <a href='#SkMatrix_preTranslate_dx'>dx</a> | 2071<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E F |, T(<a href='#SkMatrix_preTranslate_dx'>dx</a>, <a href='#SkMatrix_preTranslate_dy'>dy</a>) = | 0 1 <a href='#SkMatrix_preTranslate_dy'>dy</a> | 2072| G H <a href='#SkMatrix_I'>I</a> | | 0 0 1 | 2073 2074sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2075 2076| A B C | | 1 0 <a href='#SkMatrix_preTranslate_dx'>dx</a> | | A B A*<a href='#SkMatrix_preTranslate_dx'>dx</a>+B*<a href='#SkMatrix_preTranslate_dy'>dy</a>+C | 2077<a href='SkMatrix_Reference#Matrix'>Matrix</a> * T(<a href='#SkMatrix_preTranslate_dx'>dx</a>, <a href='#SkMatrix_preTranslate_dy'>dy</a>) = | D E F | | 0 1 <a href='#SkMatrix_preTranslate_dy'>dy</a> | = | D E D*<a href='#SkMatrix_preTranslate_dx'>dx</a>+E*<a href='#SkMatrix_preTranslate_dy'>dy</a>+F | 2078| G H <a href='#SkMatrix_I'>I</a> | | 0 0 1 | | G H G*<a href='#SkMatrix_preTranslate_dx'>dx</a>+H*<a href='#SkMatrix_preTranslate_dy'>dy</a>+<a href='#SkMatrix_I'>I</a> | 2079 2080### Parameters 2081 2082<table> <tr> <td><a name='SkMatrix_preTranslate_dx'><code><strong>dx</strong></code></a></td> 2083 <td>x-axis translation before applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a></td> 2084 </tr> 2085 <tr> <td><a name='SkMatrix_preTranslate_dy'><code><strong>dy</strong></code></a></td> 2086 <td>y-axis translation before applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a></td> 2087 </tr> 2088</table> 2089 2090### Example 2091 2092<div><fiddle-embed name="f75a9b629aa6c51ed888f8799b5ba5f7"></fiddle-embed></div> 2093 2094### See Also 2095 2096<a href='#SkMatrix_postTranslate'>postTranslate</a> <a href='#SkMatrix_setTranslate'>setTranslate</a> <a href='#SkMatrix_MakeTrans'>MakeTrans</a> 2097 2098<a name='SkMatrix_preScale'></a> 2099 2100--- 2101 2102<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2103void <a href='#SkMatrix_preScale'>preScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py) 2104</pre> 2105 2106Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> constructed from scaling by (<a href='#SkMatrix_preScale_sx'>sx</a>, <a href='#SkMatrix_preScale_sy'>sy</a>) 2107about pivot <a href='SkPoint_Reference#Point'>point</a> (<a href='#SkMatrix_preScale_px'>px</a>, <a href='#SkMatrix_preScale_py'>py</a>). 2108This can be thought of as scaling about a pivot <a href='SkPoint_Reference#Point'>point</a> before applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2109 2110Given: 2111 2112| A B C | | <a href='#SkMatrix_preScale_sx'>sx</a> 0 dx | 2113<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E F |, S(<a href='#SkMatrix_preScale_sx'>sx</a>, <a href='#SkMatrix_preScale_sy'>sy</a>, <a href='#SkMatrix_preScale_px'>px</a>, <a href='#SkMatrix_preScale_py'>py</a>) = | 0 <a href='#SkMatrix_preScale_sy'>sy</a> dy | 2114| G H <a href='#SkMatrix_I'>I</a> | | 0 0 1 | 2115 2116where 2117 2118dx = <a href='#SkMatrix_preScale_px'>px</a> - <a href='#SkMatrix_preScale_sx'>sx</a> * <a href='#SkMatrix_preScale_px'>px</a> 2119dy = <a href='#SkMatrix_preScale_py'>py</a> - <a href='#SkMatrix_preScale_sy'>sy</a> * <a href='#SkMatrix_preScale_py'>py</a> 2120 2121sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2122 2123| A B C | | <a href='#SkMatrix_preScale_sx'>sx</a> 0 dx | | A*<a href='#SkMatrix_preScale_sx'>sx</a> B*<a href='#SkMatrix_preScale_sy'>sy</a> A*dx+B*dy+C | 2124<a href='SkMatrix_Reference#Matrix'>Matrix</a> * S(<a href='#SkMatrix_preScale_sx'>sx</a>, <a href='#SkMatrix_preScale_sy'>sy</a>, <a href='#SkMatrix_preScale_px'>px</a>, <a href='#SkMatrix_preScale_py'>py</a>) = | D E F | | 0 <a href='#SkMatrix_preScale_sy'>sy</a> dy | = | D*<a href='#SkMatrix_preScale_sx'>sx</a> E*<a href='#SkMatrix_preScale_sy'>sy</a> D*dx+E*dy+F | 2125| G H <a href='#SkMatrix_I'>I</a> | | 0 0 1 | | G*<a href='#SkMatrix_preScale_sx'>sx</a> H*<a href='#SkMatrix_preScale_sy'>sy</a> G*dx+H*dy+<a href='#SkMatrix_I'>I</a> | 2126 2127### Parameters 2128 2129<table> <tr> <td><a name='SkMatrix_preScale_sx'><code><strong>sx</strong></code></a></td> 2130 <td>horizontal scale factor</td> 2131 </tr> 2132 <tr> <td><a name='SkMatrix_preScale_sy'><code><strong>sy</strong></code></a></td> 2133 <td>vertical scale factor</td> 2134 </tr> 2135 <tr> <td><a name='SkMatrix_preScale_px'><code><strong>px</strong></code></a></td> 2136 <td>pivot on x-axis</td> 2137 </tr> 2138 <tr> <td><a name='SkMatrix_preScale_py'><code><strong>py</strong></code></a></td> 2139 <td>pivot on y-axis</td> 2140 </tr> 2141</table> 2142 2143### Example 2144 2145<div><fiddle-embed name="2531f8d1e05d7b6dc22f3efcd2fb84e4"></fiddle-embed></div> 2146 2147### See Also 2148 2149<a href='#SkMatrix_postScale'>postScale</a> <a href='#SkMatrix_setScale'>setScale</a> <a href='#SkMatrix_MakeScale'>MakeScale</a> 2150 2151<a name='SkMatrix_preScale_2'></a> 2152 2153--- 2154 2155<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2156void <a href='#SkMatrix_preScale'>preScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy) 2157</pre> 2158 2159Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> constructed from scaling by (<a href='#SkMatrix_preScale_2_sx'>sx</a>, <a href='#SkMatrix_preScale_2_sy'>sy</a>) 2160about pivot <a href='SkPoint_Reference#Point'>point</a> (0, 0). 2161This can be thought of as scaling about the origin before applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2162 2163Given: 2164 2165| A B C | | <a href='#SkMatrix_preScale_2_sx'>sx</a> 0 0 | 2166<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E F |, S(<a href='#SkMatrix_preScale_2_sx'>sx</a>, <a href='#SkMatrix_preScale_2_sy'>sy</a>) = | 0 <a href='#SkMatrix_preScale_2_sy'>sy</a> 0 | 2167| G H <a href='#SkMatrix_I'>I</a> | | 0 0 1 | 2168 2169sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2170 2171| A B C | | <a href='#SkMatrix_preScale_2_sx'>sx</a> 0 0 | | A*<a href='#SkMatrix_preScale_2_sx'>sx</a> B*<a href='#SkMatrix_preScale_2_sy'>sy</a> C | 2172<a href='SkMatrix_Reference#Matrix'>Matrix</a> * S(<a href='#SkMatrix_preScale_2_sx'>sx</a>, <a href='#SkMatrix_preScale_2_sy'>sy</a>) = | D E F | | 0 <a href='#SkMatrix_preScale_2_sy'>sy</a> 0 | = | D*<a href='#SkMatrix_preScale_2_sx'>sx</a> E*<a href='#SkMatrix_preScale_2_sy'>sy</a> F | 2173| G H <a href='#SkMatrix_I'>I</a> | | 0 0 1 | | G*<a href='#SkMatrix_preScale_2_sx'>sx</a> H*<a href='#SkMatrix_preScale_2_sy'>sy</a> <a href='#SkMatrix_I'>I</a> | 2174 2175### Parameters 2176 2177<table> <tr> <td><a name='SkMatrix_preScale_2_sx'><code><strong>sx</strong></code></a></td> 2178 <td>horizontal scale factor</td> 2179 </tr> 2180 <tr> <td><a name='SkMatrix_preScale_2_sy'><code><strong>sy</strong></code></a></td> 2181 <td>vertical scale factor</td> 2182 </tr> 2183</table> 2184 2185### Example 2186 2187<div><fiddle-embed name="3edbdea8e43d06086abf33ec4a9b415b"></fiddle-embed></div> 2188 2189### See Also 2190 2191<a href='#SkMatrix_postScale'>postScale</a> <a href='#SkMatrix_setScale'>setScale</a> <a href='#SkMatrix_MakeScale'>MakeScale</a> 2192 2193<a name='SkMatrix_preRotate'></a> 2194 2195--- 2196 2197<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2198void <a href='#SkMatrix_preRotate'>preRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py) 2199</pre> 2200 2201Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> constructed from rotating by <a href='#SkMatrix_preRotate_degrees'>degrees</a> 2202about pivot <a href='SkPoint_Reference#Point'>point</a> (<a href='#SkMatrix_preRotate_px'>px</a>, <a href='#SkMatrix_preRotate_py'>py</a>). 2203This can be thought of as rotating about a pivot <a href='SkPoint_Reference#Point'>point</a> before applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2204 2205Positive <a href='#SkMatrix_preRotate_degrees'>degrees</a> rotates clockwise. 2206 2207Given: 2208 2209| A B C | | c -s dx | 2210<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E F |, R(<a href='#SkMatrix_preRotate_degrees'>degrees</a>, <a href='#SkMatrix_preRotate_px'>px</a>, <a href='#SkMatrix_preRotate_py'>py</a>) = | s c dy | 2211| G H <a href='#SkMatrix_I'>I</a> | | 0 0 1 | 2212 2213where 2214 2215c = cos(<a href='#SkMatrix_preRotate_degrees'>degrees</a>) 2216s = sin(<a href='#SkMatrix_preRotate_degrees'>degrees</a>) 2217dx = s * <a href='#SkMatrix_preRotate_py'>py</a> + (1 - c) * <a href='#SkMatrix_preRotate_px'>px</a> 2218dy = -s * <a href='#SkMatrix_preRotate_px'>px</a> + (1 - c) * <a href='#SkMatrix_preRotate_py'>py</a> 2219 2220sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2221 2222| A B C | | c -s dx | | Ac+Bs -As+Bc A*dx+B*dy+C | 2223<a href='SkMatrix_Reference#Matrix'>Matrix</a> * R(<a href='#SkMatrix_preRotate_degrees'>degrees</a>, <a href='#SkMatrix_preRotate_px'>px</a>, <a href='#SkMatrix_preRotate_py'>py</a>) = | D E F | | s c dy | = | Dc+Es -Ds+Ec D*dx+E*dy+F | 2224| G H <a href='#SkMatrix_I'>I</a> | | 0 0 1 | | Gc+Hs -Gs+Hc G*dx+H*dy+<a href='#SkMatrix_I'>I</a> | 2225 2226### Parameters 2227 2228<table> <tr> <td><a name='SkMatrix_preRotate_degrees'><code><strong>degrees</strong></code></a></td> 2229 <td>angle of axes relative to upright axes</td> 2230 </tr> 2231 <tr> <td><a name='SkMatrix_preRotate_px'><code><strong>px</strong></code></a></td> 2232 <td>pivot on x-axis</td> 2233 </tr> 2234 <tr> <td><a name='SkMatrix_preRotate_py'><code><strong>py</strong></code></a></td> 2235 <td>pivot on y-axis</td> 2236 </tr> 2237</table> 2238 2239### Example 2240 2241<div><fiddle-embed name="a70bb18d67c06a20ab514e7a47924e5a"></fiddle-embed></div> 2242 2243### See Also 2244 2245<a href='#SkMatrix_postRotate'>postRotate</a> <a href='#SkMatrix_setRotate'>setRotate</a> 2246 2247<a name='SkMatrix_preRotate_2'></a> 2248 2249--- 2250 2251<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2252void <a href='#SkMatrix_preRotate'>preRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees) 2253</pre> 2254 2255Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> constructed from rotating by <a href='#SkMatrix_preRotate_2_degrees'>degrees</a> 2256about pivot <a href='SkPoint_Reference#Point'>point</a> (0, 0). 2257This can be thought of as rotating about the origin before applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2258 2259Positive <a href='#SkMatrix_preRotate_2_degrees'>degrees</a> rotates clockwise. 2260 2261Given: 2262 2263| A B C | | c -s 0 | 2264<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E F |, R(<a href='#SkMatrix_preRotate_2_degrees'>degrees</a>, px, py) = | s c 0 | 2265| G H <a href='#SkMatrix_I'>I</a> | | 0 0 1 | 2266 2267where 2268 2269c = cos(<a href='#SkMatrix_preRotate_2_degrees'>degrees</a>) 2270s = sin(<a href='#SkMatrix_preRotate_2_degrees'>degrees</a>) 2271 2272sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2273 2274| A B C | | c -s 0 | | Ac+Bs -As+Bc C | 2275<a href='SkMatrix_Reference#Matrix'>Matrix</a> * R(<a href='#SkMatrix_preRotate_2_degrees'>degrees</a>, px, py) = | D E F | | s c 0 | = | Dc+Es -Ds+Ec F | 2276| G H <a href='#SkMatrix_I'>I</a> | | 0 0 1 | | Gc+Hs -Gs+Hc <a href='#SkMatrix_I'>I</a> | 2277 2278### Parameters 2279 2280<table> <tr> <td><a name='SkMatrix_preRotate_2_degrees'><code><strong>degrees</strong></code></a></td> 2281 <td>angle of axes relative to upright axes</td> 2282 </tr> 2283</table> 2284 2285### Example 2286 2287<div><fiddle-embed name="5acd49bd931c79a808dd6c7cc0e92f72"></fiddle-embed></div> 2288 2289### See Also 2290 2291<a href='#SkMatrix_postRotate'>postRotate</a> <a href='#SkMatrix_setRotate'>setRotate</a> 2292 2293<a name='SkMatrix_preSkew'></a> 2294 2295--- 2296 2297<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2298void <a href='#SkMatrix_preSkew'>preSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py) 2299</pre> 2300 2301Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> constructed from skewing by (<a href='#SkMatrix_preSkew_kx'>kx</a>, <a href='#SkMatrix_preSkew_ky'>ky</a>) 2302about pivot <a href='SkPoint_Reference#Point'>point</a> (<a href='#SkMatrix_preSkew_px'>px</a>, <a href='#SkMatrix_preSkew_py'>py</a>). 2303This can be thought of as skewing about a pivot <a href='SkPoint_Reference#Point'>point</a> before applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2304 2305Given: 2306 2307| A B C | | 1 <a href='#SkMatrix_preSkew_kx'>kx</a> dx | 2308<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E F |, K(<a href='#SkMatrix_preSkew_kx'>kx</a>, <a href='#SkMatrix_preSkew_ky'>ky</a>, <a href='#SkMatrix_preSkew_px'>px</a>, <a href='#SkMatrix_preSkew_py'>py</a>) = | <a href='#SkMatrix_preSkew_ky'>ky</a> 1 dy | 2309| G H <a href='#SkMatrix_I'>I</a> | | 0 0 1 | 2310 2311where 2312 2313dx = -<a href='#SkMatrix_preSkew_kx'>kx</a> * <a href='#SkMatrix_preSkew_py'>py</a> 2314dy = -<a href='#SkMatrix_preSkew_ky'>ky</a> * <a href='#SkMatrix_preSkew_px'>px</a> 2315 2316sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2317 2318| A B C | | 1 <a href='#SkMatrix_preSkew_kx'>kx</a> dx | | A+B*<a href='#SkMatrix_preSkew_ky'>ky</a> A*<a href='#SkMatrix_preSkew_kx'>kx</a>+B A*dx+B*dy+C | 2319<a href='SkMatrix_Reference#Matrix'>Matrix</a> * K(<a href='#SkMatrix_preSkew_kx'>kx</a>, <a href='#SkMatrix_preSkew_ky'>ky</a>, <a href='#SkMatrix_preSkew_px'>px</a>, <a href='#SkMatrix_preSkew_py'>py</a>) = | D E F | | <a href='#SkMatrix_preSkew_ky'>ky</a> 1 dy | = | D+E*<a href='#SkMatrix_preSkew_ky'>ky</a> D*<a href='#SkMatrix_preSkew_kx'>kx</a>+E D*dx+E*dy+F | 2320| G H <a href='#SkMatrix_I'>I</a> | | 0 0 1 | | G+H*<a href='#SkMatrix_preSkew_ky'>ky</a> G*<a href='#SkMatrix_preSkew_kx'>kx</a>+H G*dx+H*dy+<a href='#SkMatrix_I'>I</a> | 2321 2322### Parameters 2323 2324<table> <tr> <td><a name='SkMatrix_preSkew_kx'><code><strong>kx</strong></code></a></td> 2325 <td>horizontal skew factor</td> 2326 </tr> 2327 <tr> <td><a name='SkMatrix_preSkew_ky'><code><strong>ky</strong></code></a></td> 2328 <td>vertical skew factor</td> 2329 </tr> 2330 <tr> <td><a name='SkMatrix_preSkew_px'><code><strong>px</strong></code></a></td> 2331 <td>pivot on x-axis</td> 2332 </tr> 2333 <tr> <td><a name='SkMatrix_preSkew_py'><code><strong>py</strong></code></a></td> 2334 <td>pivot on y-axis</td> 2335 </tr> 2336</table> 2337 2338### Example 2339 2340<div><fiddle-embed name="199a18ad61d702664ce6df1d7037aa48"></fiddle-embed></div> 2341 2342### See Also 2343 2344<a href='#SkMatrix_postSkew'>postSkew</a> <a href='#SkMatrix_setSkew'>setSkew</a> 2345 2346<a name='SkMatrix_preSkew_2'></a> 2347 2348--- 2349 2350<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2351void <a href='#SkMatrix_preSkew'>preSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky) 2352</pre> 2353 2354Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> constructed from skewing by (<a href='#SkMatrix_preSkew_2_kx'>kx</a>, <a href='#SkMatrix_preSkew_2_ky'>ky</a>) 2355about pivot <a href='SkPoint_Reference#Point'>point</a> (0, 0). 2356This can be thought of as skewing about the origin before applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2357 2358Given: 2359 2360| A B C | | 1 <a href='#SkMatrix_preSkew_2_kx'>kx</a> 0 | 2361<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E F |, K(<a href='#SkMatrix_preSkew_2_kx'>kx</a>, <a href='#SkMatrix_preSkew_2_ky'>ky</a>) = | <a href='#SkMatrix_preSkew_2_ky'>ky</a> 1 0 | 2362| G H <a href='#SkMatrix_I'>I</a> | | 0 0 1 | 2363 2364sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2365 2366| A B C | | 1 <a href='#SkMatrix_preSkew_2_kx'>kx</a> 0 | | A+B*<a href='#SkMatrix_preSkew_2_ky'>ky</a> A*<a href='#SkMatrix_preSkew_2_kx'>kx</a>+B C | 2367<a href='SkMatrix_Reference#Matrix'>Matrix</a> * K(<a href='#SkMatrix_preSkew_2_kx'>kx</a>, <a href='#SkMatrix_preSkew_2_ky'>ky</a>) = | D E F | | <a href='#SkMatrix_preSkew_2_ky'>ky</a> 1 0 | = | D+E*<a href='#SkMatrix_preSkew_2_ky'>ky</a> D*<a href='#SkMatrix_preSkew_2_kx'>kx</a>+E F | 2368| G H <a href='#SkMatrix_I'>I</a> | | 0 0 1 | | G+H*<a href='#SkMatrix_preSkew_2_ky'>ky</a> G*<a href='#SkMatrix_preSkew_2_kx'>kx</a>+H <a href='#SkMatrix_I'>I</a> | 2369 2370### Parameters 2371 2372<table> <tr> <td><a name='SkMatrix_preSkew_2_kx'><code><strong>kx</strong></code></a></td> 2373 <td>horizontal skew factor</td> 2374 </tr> 2375 <tr> <td><a name='SkMatrix_preSkew_2_ky'><code><strong>ky</strong></code></a></td> 2376 <td>vertical skew factor</td> 2377 </tr> 2378</table> 2379 2380### Example 2381 2382<div><fiddle-embed name="e100c543869fe8fd516ba69de79444ba"></fiddle-embed></div> 2383 2384### See Also 2385 2386<a href='#SkMatrix_postSkew'>postSkew</a> <a href='#SkMatrix_setSkew'>setSkew</a> 2387 2388<a name='SkMatrix_preConcat'></a> 2389 2390--- 2391 2392<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2393void <a href='#SkMatrix_preConcat'>preConcat</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& other) 2394</pre> 2395 2396Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_preConcat_other'>other</a>. 2397This can be thought of mapping by <a href='#SkMatrix_preConcat_other'>other</a> before applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2398 2399Given: 2400 2401| A B C | | J K L | 2402<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E F |, <a href='#SkMatrix_preConcat_other'>other</a> = | M N O | 2403| G H <a href='#SkMatrix_I'>I</a> | | P Q R | 2404 2405sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2406 2407| A B C | | J K L | | AJ+BM+CP AK+BN+CQ AL+BO+CR | 2408<a href='SkMatrix_Reference#Matrix'>Matrix</a> * <a href='#SkMatrix_preConcat_other'>other</a> = | D E F | * | M N O | = | DJ+EM+FP DK+EN+FQ DL+EO+FR | 2409| G H <a href='#SkMatrix_I'>I</a> | | P Q R | | GJ+HM+IP GK+HN+IQ GL+HO+IR | 2410 2411### Parameters 2412 2413<table> <tr> <td><a name='SkMatrix_preConcat_other'><code><strong>other</strong></code></a></td> 2414 <td><a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> on right side of multiply expression</td> 2415 </tr> 2416</table> 2417 2418### Example 2419 2420<div><fiddle-embed name="b07e62298e7b0ab5683db199faffceb2"><div><a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a> creates perspective <a href='SkMatrix_Reference#Matrix'>matrices</a>, one the inverse of the <a href='#SkMatrix_preConcat_other'>other</a>. 2421Multiplying the <a href='SkMatrix_Reference#Matrix'>matrix</a> by its inverse turns into an identity <a href='SkMatrix_Reference#Matrix'>matrix</a>. 2422</div></fiddle-embed></div> 2423 2424### See Also 2425 2426<a href='#SkMatrix_postConcat'>postConcat</a> <a href='#SkMatrix_setConcat'>setConcat</a> <a href='#SkMatrix_Concat'>Concat</a> 2427 2428<a name='SkMatrix_postTranslate'></a> 2429 2430--- 2431 2432<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2433void <a href='#SkMatrix_postTranslate'>postTranslate</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy) 2434</pre> 2435 2436Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> constructed from translation (<a href='#SkMatrix_postTranslate_dx'>dx</a>, <a href='#SkMatrix_postTranslate_dy'>dy</a>) multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2437This can be thought of as moving the <a href='SkPoint_Reference#Point'>point</a> to be mapped after applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2438 2439Given: 2440 2441| J K L | | 1 0 <a href='#SkMatrix_postTranslate_dx'>dx</a> | 2442<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | M N O |, T(<a href='#SkMatrix_postTranslate_dx'>dx</a>, <a href='#SkMatrix_postTranslate_dy'>dy</a>) = | 0 1 <a href='#SkMatrix_postTranslate_dy'>dy</a> | 2443| P Q R | | 0 0 1 | 2444 2445sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2446 2447| 1 0 <a href='#SkMatrix_postTranslate_dx'>dx</a> | | J K L | | J+<a href='#SkMatrix_postTranslate_dx'>dx</a>*P K+<a href='#SkMatrix_postTranslate_dx'>dx</a>*Q L+<a href='#SkMatrix_postTranslate_dx'>dx</a>*R | 2448T(<a href='#SkMatrix_postTranslate_dx'>dx</a>, <a href='#SkMatrix_postTranslate_dy'>dy</a>) * <a href='SkMatrix_Reference#Matrix'>Matrix</a> = | 0 1 <a href='#SkMatrix_postTranslate_dy'>dy</a> | | M N O | = | M+<a href='#SkMatrix_postTranslate_dy'>dy</a>*P N+<a href='#SkMatrix_postTranslate_dy'>dy</a>*Q O+<a href='#SkMatrix_postTranslate_dy'>dy</a>*R | 2449| 0 0 1 | | P Q R | | P Q R | 2450 2451### Parameters 2452 2453<table> <tr> <td><a name='SkMatrix_postTranslate_dx'><code><strong>dx</strong></code></a></td> 2454 <td>x-axis translation after applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a></td> 2455 </tr> 2456 <tr> <td><a name='SkMatrix_postTranslate_dy'><code><strong>dy</strong></code></a></td> 2457 <td>y-axis translation after applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a></td> 2458 </tr> 2459</table> 2460 2461### Example 2462 2463<div><fiddle-embed name="f5144ef4bd7cea294fad2f756ed335af"><div>Compare with <a href='#SkMatrix_preTranslate'>preTranslate</a> example. 2464</div></fiddle-embed></div> 2465 2466### See Also 2467 2468<a href='#SkMatrix_preTranslate'>preTranslate</a> <a href='#SkMatrix_setTranslate'>setTranslate</a> <a href='#SkMatrix_MakeTrans'>MakeTrans</a> 2469 2470<a name='SkMatrix_postScale'></a> 2471 2472--- 2473 2474<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2475void <a href='#SkMatrix_postScale'>postScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py) 2476</pre> 2477 2478Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> constructed from scaling by (<a href='#SkMatrix_postScale_sx'>sx</a>, <a href='#SkMatrix_postScale_sy'>sy</a>) about pivot <a href='SkPoint_Reference#Point'>point</a> 2479(<a href='#SkMatrix_postScale_px'>px</a>, <a href='#SkMatrix_postScale_py'>py</a>), multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2480This can be thought of as scaling about a pivot <a href='SkPoint_Reference#Point'>point</a> after applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2481 2482Given: 2483 2484| J K L | | <a href='#SkMatrix_postScale_sx'>sx</a> 0 dx | 2485<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | M N O |, S(<a href='#SkMatrix_postScale_sx'>sx</a>, <a href='#SkMatrix_postScale_sy'>sy</a>, <a href='#SkMatrix_postScale_px'>px</a>, <a href='#SkMatrix_postScale_py'>py</a>) = | 0 <a href='#SkMatrix_postScale_sy'>sy</a> dy | 2486| P Q R | | 0 0 1 | 2487 2488where 2489 2490dx = <a href='#SkMatrix_postScale_px'>px</a> - <a href='#SkMatrix_postScale_sx'>sx</a> * <a href='#SkMatrix_postScale_px'>px</a> 2491dy = <a href='#SkMatrix_postScale_py'>py</a> - <a href='#SkMatrix_postScale_sy'>sy</a> * <a href='#SkMatrix_postScale_py'>py</a> 2492 2493sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2494 2495| <a href='#SkMatrix_postScale_sx'>sx</a> 0 dx | | J K L | | <a href='#SkMatrix_postScale_sx'>sx</a>*J+dx*P <a href='#SkMatrix_postScale_sx'>sx</a>*K+dx*Q <a href='#SkMatrix_postScale_sx'>sx</a>*L+dx+R | 2496S(<a href='#SkMatrix_postScale_sx'>sx</a>, <a href='#SkMatrix_postScale_sy'>sy</a>, <a href='#SkMatrix_postScale_px'>px</a>, <a href='#SkMatrix_postScale_py'>py</a>) * <a href='SkMatrix_Reference#Matrix'>Matrix</a> = | 0 <a href='#SkMatrix_postScale_sy'>sy</a> dy | | M N O | = | <a href='#SkMatrix_postScale_sy'>sy</a>*M+dy*P <a href='#SkMatrix_postScale_sy'>sy</a>*N+dy*Q <a href='#SkMatrix_postScale_sy'>sy</a>*O+dy*R | 2497| 0 0 1 | | P Q R | | P Q R | 2498 2499### Parameters 2500 2501<table> <tr> <td><a name='SkMatrix_postScale_sx'><code><strong>sx</strong></code></a></td> 2502 <td>horizontal scale factor</td> 2503 </tr> 2504 <tr> <td><a name='SkMatrix_postScale_sy'><code><strong>sy</strong></code></a></td> 2505 <td>vertical scale factor</td> 2506 </tr> 2507 <tr> <td><a name='SkMatrix_postScale_px'><code><strong>px</strong></code></a></td> 2508 <td>pivot on x-axis</td> 2509 </tr> 2510 <tr> <td><a name='SkMatrix_postScale_py'><code><strong>py</strong></code></a></td> 2511 <td>pivot on y-axis</td> 2512 </tr> 2513</table> 2514 2515### Example 2516 2517<div><fiddle-embed name="ed3aa18ba0ea95c85cc49aa3829fe384"></fiddle-embed></div> 2518 2519### See Also 2520 2521<a href='#SkMatrix_preScale'>preScale</a> <a href='#SkMatrix_setScale'>setScale</a> <a href='#SkMatrix_MakeScale'>MakeScale</a> 2522 2523<a name='SkMatrix_postScale_2'></a> 2524 2525--- 2526 2527<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2528void <a href='#SkMatrix_postScale'>postScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy) 2529</pre> 2530 2531Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> constructed from scaling by (<a href='#SkMatrix_postScale_2_sx'>sx</a>, <a href='#SkMatrix_postScale_2_sy'>sy</a>) about pivot <a href='SkPoint_Reference#Point'>point</a> 2532(0, 0), multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2533This can be thought of as scaling about the origin after applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2534 2535Given: 2536 2537| J K L | | <a href='#SkMatrix_postScale_2_sx'>sx</a> 0 0 | 2538<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | M N O |, S(<a href='#SkMatrix_postScale_2_sx'>sx</a>, <a href='#SkMatrix_postScale_2_sy'>sy</a>) = | 0 <a href='#SkMatrix_postScale_2_sy'>sy</a> 0 | 2539| P Q R | | 0 0 1 | 2540 2541sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2542 2543| <a href='#SkMatrix_postScale_2_sx'>sx</a> 0 0 | | J K L | | <a href='#SkMatrix_postScale_2_sx'>sx</a>*J <a href='#SkMatrix_postScale_2_sx'>sx</a>*K <a href='#SkMatrix_postScale_2_sx'>sx</a>*L | 2544S(<a href='#SkMatrix_postScale_2_sx'>sx</a>, <a href='#SkMatrix_postScale_2_sy'>sy</a>) * <a href='SkMatrix_Reference#Matrix'>Matrix</a> = | 0 <a href='#SkMatrix_postScale_2_sy'>sy</a> 0 | | M N O | = | <a href='#SkMatrix_postScale_2_sy'>sy</a>*M <a href='#SkMatrix_postScale_2_sy'>sy</a>*N <a href='#SkMatrix_postScale_2_sy'>sy</a>*O | 2545| 0 0 1 | | P Q R | | P Q R | 2546 2547### Parameters 2548 2549<table> <tr> <td><a name='SkMatrix_postScale_2_sx'><code><strong>sx</strong></code></a></td> 2550 <td>horizontal scale factor</td> 2551 </tr> 2552 <tr> <td><a name='SkMatrix_postScale_2_sy'><code><strong>sy</strong></code></a></td> 2553 <td>vertical scale factor</td> 2554 </tr> 2555</table> 2556 2557### Example 2558 2559<div><fiddle-embed name="1931017698766a67d3a26423453b8095"></fiddle-embed></div> 2560 2561### See Also 2562 2563<a href='#SkMatrix_preScale'>preScale</a> <a href='#SkMatrix_setScale'>setScale</a> <a href='#SkMatrix_MakeScale'>MakeScale</a> 2564 2565<a name='SkMatrix_postIDiv'></a> 2566 2567--- 2568 2569<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2570bool <a href='#SkMatrix_postIDiv'>postIDiv</a>(int divx, int divy) 2571</pre> 2572 2573Sets <a href='SkMatrix_Reference#Matrix'>Matrix</a> to <a href='SkMatrix_Reference#Matrix'>Matrix</a> constructed from scaling by (1/<a href='#SkMatrix_postIDiv_divx'>divx</a>, 1/<a href='#SkMatrix_postIDiv_divy'>divy</a>), 2574multiplied by <a href='SkMatrix_Reference#Matrix'>Matrix</a>. 2575 2576Returns false if either <a href='#SkMatrix_postIDiv_divx'>divx</a> or <a href='#SkMatrix_postIDiv_divy'>divy</a> is zero. 2577 2578Given: 2579 2580<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0"> 2581 | J K L | | sx 0 0 | 2582Matrix = | M N O |, I(divx, divy) = | 0 sy 0 | 2583 | P Q R | | 0 0 1 | 2584</pre> 2585 2586where 2587 2588<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0"> 2589sx = 1 / divx 2590sy = 1 / divy 2591</pre> 2592 2593sets <a href='SkMatrix_Reference#Matrix'>Matrix</a> to: 2594 2595<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0"> 2596 | sx 0 0 | | J K L | | sx*J sx*K sx*L | 2597I(divx, divy) * Matrix = | 0 sy 0 | | M N O | = | sy*M sy*N sy*O | 2598 | 0 0 1 | | P Q R | | P Q R | 2599</pre> 2600 2601### Parameters 2602 2603<table> <tr> <td><a name='SkMatrix_postIDiv_divx'><code><strong>divx</strong></code></a></td> 2604 <td>integer divisor for inverse scale on x-axis</td> 2605 </tr> 2606 <tr> <td><a name='SkMatrix_postIDiv_divy'><code><strong>divy</strong></code></a></td> 2607 <td>integer divisor for inverse scale on y-axis</td> 2608 </tr> 2609</table> 2610 2611### Return Value 2612 2613true on successful scale 2614 2615### Example 2616 2617<div><fiddle-embed name="e6ad0bd2999613d9e4758b661d45070c"></fiddle-embed></div> 2618 2619### See Also 2620 2621<a href='#SkMatrix_postScale'>postScale</a> <a href='#SkMatrix_MakeScale'>MakeScale</a> 2622 2623<a name='SkMatrix_postRotate'></a> 2624 2625--- 2626 2627<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2628void <a href='#SkMatrix_postRotate'>postRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py) 2629</pre> 2630 2631Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> constructed from rotating by <a href='#SkMatrix_postRotate_degrees'>degrees</a> about pivot <a href='SkPoint_Reference#Point'>point</a> 2632(<a href='#SkMatrix_postRotate_px'>px</a>, <a href='#SkMatrix_postRotate_py'>py</a>), multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2633This can be thought of as rotating about a pivot <a href='SkPoint_Reference#Point'>point</a> after applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2634 2635Positive <a href='#SkMatrix_postRotate_degrees'>degrees</a> rotates clockwise. 2636 2637Given: 2638 2639| J K L | | c -s dx | 2640<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | M N O |, R(<a href='#SkMatrix_postRotate_degrees'>degrees</a>, <a href='#SkMatrix_postRotate_px'>px</a>, <a href='#SkMatrix_postRotate_py'>py</a>) = | s c dy | 2641| P Q R | | 0 0 1 | 2642 2643where 2644 2645c = cos(<a href='#SkMatrix_postRotate_degrees'>degrees</a>) 2646s = sin(<a href='#SkMatrix_postRotate_degrees'>degrees</a>) 2647dx = s * <a href='#SkMatrix_postRotate_py'>py</a> + (1 - c) * <a href='#SkMatrix_postRotate_px'>px</a> 2648dy = -s * <a href='#SkMatrix_postRotate_px'>px</a> + (1 - c) * <a href='#SkMatrix_postRotate_py'>py</a> 2649 2650sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2651 2652|c -s dx| |J K L| |cJ-sM+dx*P cK-sN+dx*Q cL-sO+dx+R| 2653R(<a href='#SkMatrix_postRotate_degrees'>degrees</a>, <a href='#SkMatrix_postRotate_px'>px</a>, <a href='#SkMatrix_postRotate_py'>py</a>) * <a href='SkMatrix_Reference#Matrix'>Matrix</a> = |s c dy| |M N O| = |sJ+cM+dy*P sK+cN+dy*Q sL+cO+dy*R| 2654|0 0 1| |P Q R| | P Q R| 2655 2656### Parameters 2657 2658<table> <tr> <td><a name='SkMatrix_postRotate_degrees'><code><strong>degrees</strong></code></a></td> 2659 <td>angle of axes relative to upright axes</td> 2660 </tr> 2661 <tr> <td><a name='SkMatrix_postRotate_px'><code><strong>px</strong></code></a></td> 2662 <td>pivot on x-axis</td> 2663 </tr> 2664 <tr> <td><a name='SkMatrix_postRotate_py'><code><strong>py</strong></code></a></td> 2665 <td>pivot on y-axis</td> 2666 </tr> 2667</table> 2668 2669### Example 2670 2671<div><fiddle-embed name="e09194ee48a81e7b375ade473d340f0d"></fiddle-embed></div> 2672 2673### See Also 2674 2675<a href='#SkMatrix_preRotate'>preRotate</a> <a href='#SkMatrix_setRotate'>setRotate</a> 2676 2677<a name='SkMatrix_postRotate_2'></a> 2678 2679--- 2680 2681<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2682void <a href='#SkMatrix_postRotate'>postRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees) 2683</pre> 2684 2685Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> constructed from rotating by <a href='#SkMatrix_postRotate_2_degrees'>degrees</a> about pivot <a href='SkPoint_Reference#Point'>point</a> 2686(0, 0), multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2687This can be thought of as rotating about the origin after applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2688 2689Positive <a href='#SkMatrix_postRotate_2_degrees'>degrees</a> rotates clockwise. 2690 2691Given: 2692 2693| J K L | | c -s 0 | 2694<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | M N O |, R(<a href='#SkMatrix_postRotate_2_degrees'>degrees</a>, px, py) = | s c 0 | 2695| P Q R | | 0 0 1 | 2696 2697where 2698 2699c = cos(<a href='#SkMatrix_postRotate_2_degrees'>degrees</a>) 2700s = sin(<a href='#SkMatrix_postRotate_2_degrees'>degrees</a>) 2701 2702sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2703 2704| c -s dx | | J K L | | cJ-sM cK-sN cL-sO | 2705R(<a href='#SkMatrix_postRotate_2_degrees'>degrees</a>, px, py) * <a href='SkMatrix_Reference#Matrix'>Matrix</a> = | s c dy | | M N O | = | sJ+cM sK+cN sL+cO | 2706| 0 0 1 | | P Q R | | P Q R | 2707 2708### Parameters 2709 2710<table> <tr> <td><a name='SkMatrix_postRotate_2_degrees'><code><strong>degrees</strong></code></a></td> 2711 <td>angle of axes relative to upright axes</td> 2712 </tr> 2713</table> 2714 2715### Example 2716 2717<div><fiddle-embed name="52e4c53e26971af5576b30de60fa70c2"></fiddle-embed></div> 2718 2719### See Also 2720 2721<a href='#SkMatrix_preRotate'>preRotate</a> <a href='#SkMatrix_setRotate'>setRotate</a> 2722 2723<a name='SkMatrix_postSkew'></a> 2724 2725--- 2726 2727<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2728void <a href='#SkMatrix_postSkew'>postSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py) 2729</pre> 2730 2731Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> constructed from skewing by (<a href='#SkMatrix_postSkew_kx'>kx</a>, <a href='#SkMatrix_postSkew_ky'>ky</a>) about pivot <a href='SkPoint_Reference#Point'>point</a> 2732(<a href='#SkMatrix_postSkew_px'>px</a>, <a href='#SkMatrix_postSkew_py'>py</a>), multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2733This can be thought of as skewing about a pivot <a href='SkPoint_Reference#Point'>point</a> after applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2734 2735Given: 2736 2737| J K L | | 1 <a href='#SkMatrix_postSkew_kx'>kx</a> dx | 2738<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | M N O |, K(<a href='#SkMatrix_postSkew_kx'>kx</a>, <a href='#SkMatrix_postSkew_ky'>ky</a>, <a href='#SkMatrix_postSkew_px'>px</a>, <a href='#SkMatrix_postSkew_py'>py</a>) = | <a href='#SkMatrix_postSkew_ky'>ky</a> 1 dy | 2739| P Q R | | 0 0 1 | 2740 2741where 2742 2743dx = -<a href='#SkMatrix_postSkew_kx'>kx</a> * <a href='#SkMatrix_postSkew_py'>py</a> 2744dy = -<a href='#SkMatrix_postSkew_ky'>ky</a> * <a href='#SkMatrix_postSkew_px'>px</a> 2745 2746sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2747 2748| 1 <a href='#SkMatrix_postSkew_kx'>kx</a> dx| |J K L| |J+<a href='#SkMatrix_postSkew_kx'>kx</a>*M+dx*P K+<a href='#SkMatrix_postSkew_kx'>kx</a>*N+dx*Q L+<a href='#SkMatrix_postSkew_kx'>kx</a>*O+dx+R| 2749K(<a href='#SkMatrix_postSkew_kx'>kx</a>, <a href='#SkMatrix_postSkew_ky'>ky</a>, <a href='#SkMatrix_postSkew_px'>px</a>, <a href='#SkMatrix_postSkew_py'>py</a>) * <a href='SkMatrix_Reference#Matrix'>Matrix</a> = |<a href='#SkMatrix_postSkew_ky'>ky</a> 1 dy| |M N O| = |<a href='#SkMatrix_postSkew_ky'>ky</a>*J+M+dy*P <a href='#SkMatrix_postSkew_ky'>ky</a>*K+N+dy*Q <a href='#SkMatrix_postSkew_ky'>ky</a>*L+O+dy*R| 2750| 0 0 1| |P Q R| | P Q R| 2751 2752### Parameters 2753 2754<table> <tr> <td><a name='SkMatrix_postSkew_kx'><code><strong>kx</strong></code></a></td> 2755 <td>horizontal skew factor</td> 2756 </tr> 2757 <tr> <td><a name='SkMatrix_postSkew_ky'><code><strong>ky</strong></code></a></td> 2758 <td>vertical skew factor</td> 2759 </tr> 2760 <tr> <td><a name='SkMatrix_postSkew_px'><code><strong>px</strong></code></a></td> 2761 <td>pivot on x-axis</td> 2762 </tr> 2763 <tr> <td><a name='SkMatrix_postSkew_py'><code><strong>py</strong></code></a></td> 2764 <td>pivot on y-axis</td> 2765 </tr> 2766</table> 2767 2768### Example 2769 2770<div><fiddle-embed name="8c34ae3a2b7e2742bb969819737365ec"></fiddle-embed></div> 2771 2772### See Also 2773 2774<a href='#SkMatrix_preSkew'>preSkew</a> <a href='#SkMatrix_setSkew'>setSkew</a> 2775 2776<a name='SkMatrix_postSkew_2'></a> 2777 2778--- 2779 2780<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2781void <a href='#SkMatrix_postSkew'>postSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky) 2782</pre> 2783 2784Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> constructed from skewing by (<a href='#SkMatrix_postSkew_2_kx'>kx</a>, <a href='#SkMatrix_postSkew_2_ky'>ky</a>) about pivot <a href='SkPoint_Reference#Point'>point</a> 2785(0, 0), multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2786This can be thought of as skewing about the origin after applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2787 2788Given: 2789 2790| J K L | | 1 <a href='#SkMatrix_postSkew_2_kx'>kx</a> 0 | 2791<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | M N O |, K(<a href='#SkMatrix_postSkew_2_kx'>kx</a>, <a href='#SkMatrix_postSkew_2_ky'>ky</a>) = | <a href='#SkMatrix_postSkew_2_ky'>ky</a> 1 0 | 2792| P Q R | | 0 0 1 | 2793 2794sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2795 2796| 1 <a href='#SkMatrix_postSkew_2_kx'>kx</a> 0 | | J K L | | J+<a href='#SkMatrix_postSkew_2_kx'>kx</a>*M K+<a href='#SkMatrix_postSkew_2_kx'>kx</a>*N L+<a href='#SkMatrix_postSkew_2_kx'>kx</a>*O | 2797K(<a href='#SkMatrix_postSkew_2_kx'>kx</a>, <a href='#SkMatrix_postSkew_2_ky'>ky</a>) * <a href='SkMatrix_Reference#Matrix'>Matrix</a> = | <a href='#SkMatrix_postSkew_2_ky'>ky</a> 1 0 | | M N O | = | <a href='#SkMatrix_postSkew_2_ky'>ky</a>*J+M <a href='#SkMatrix_postSkew_2_ky'>ky</a>*K+N <a href='#SkMatrix_postSkew_2_ky'>ky</a>*L+O | 2798| 0 0 1 | | P Q R | | P Q R | 2799 2800### Parameters 2801 2802<table> <tr> <td><a name='SkMatrix_postSkew_2_kx'><code><strong>kx</strong></code></a></td> 2803 <td>horizontal skew factor</td> 2804 </tr> 2805 <tr> <td><a name='SkMatrix_postSkew_2_ky'><code><strong>ky</strong></code></a></td> 2806 <td>vertical skew factor</td> 2807 </tr> 2808</table> 2809 2810### Example 2811 2812<div><fiddle-embed name="3aa2603225dff72ac53dd359f897f494"></fiddle-embed></div> 2813 2814### See Also 2815 2816<a href='#SkMatrix_preSkew'>preSkew</a> <a href='#SkMatrix_setSkew'>setSkew</a> 2817 2818<a name='SkMatrix_postConcat'></a> 2819 2820--- 2821 2822<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2823void <a href='#SkMatrix_postConcat'>postConcat</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& other) 2824</pre> 2825 2826Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_postConcat_other'>other</a> multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2827This can be thought of mapping by <a href='#SkMatrix_postConcat_other'>other</a> after applying <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 2828 2829Given: 2830 2831| J K L | | A B C | 2832<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | M N O |, <a href='#SkMatrix_postConcat_other'>other</a> = | D E F | 2833| P Q R | | G H <a href='#SkMatrix_I'>I</a> | 2834 2835sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2836 2837| A B C | | J K L | | AJ+BM+CP AK+BN+CQ AL+BO+CR | 2838<a href='#SkMatrix_postConcat_other'>other</a> * <a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E F | * | M N O | = | DJ+EM+FP DK+EN+FQ DL+EO+FR | 2839| G H <a href='#SkMatrix_I'>I</a> | | P Q R | | GJ+HM+IP GK+HN+IQ GL+HO+IR | 2840 2841### Parameters 2842 2843<table> <tr> <td><a name='SkMatrix_postConcat_other'><code><strong>other</strong></code></a></td> 2844 <td><a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> on left side of multiply expression</td> 2845 </tr> 2846</table> 2847 2848### Example 2849 2850<div><fiddle-embed name="e4226c55d9bdbc119264bd372b2b9835"></fiddle-embed></div> 2851 2852### See Also 2853 2854<a href='#SkMatrix_preConcat'>preConcat</a> <a href='#SkMatrix_setConcat'>setConcat</a> <a href='#SkMatrix_Concat'>Concat</a> 2855 2856<a name='SkMatrix_ScaleToFit'></a> 2857 2858--- 2859 2860<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0"> 2861 enum <a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> { 2862 <a href='#SkMatrix_kFill_ScaleToFit'>kFill_ScaleToFit</a>, 2863 <a href='#SkMatrix_kStart_ScaleToFit'>kStart_ScaleToFit</a>, 2864 <a href='#SkMatrix_kCenter_ScaleToFit'>kCenter_ScaleToFit</a>, 2865 <a href='#SkMatrix_kEnd_ScaleToFit'>kEnd_ScaleToFit</a>, 2866 }; 2867</pre> 2868 2869<a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> describes how <a href='SkMatrix_Reference#Matrix'>Matrix</a> is constructed to map one <a href='SkRect_Reference#Rect'>Rect</a> to another. 2870<a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> may allow <a href='SkMatrix_Reference#Matrix'>Matrix</a> to have unequal horizontal and vertical scaling, 2871or may restrict <a href='SkMatrix_Reference#Matrix'>Matrix</a> to square scaling. If restricted, <a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> specifies 2872how <a href='SkMatrix_Reference#Matrix'>Matrix</a> maps to the side or center of the destination <a href='SkRect_Reference#Rect'>Rect</a>. 2873 2874### Constants 2875 2876<table style='border-collapse: collapse; width: 62.5em'> 2877 <tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Const</th> 2878<th style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>Value</th> 2879<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr> 2880 <tr style='background-color: #f0f0f0; '> 2881 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kFill_ScaleToFit'><code>SkMatrix::kFill_ScaleToFit</code></a></td> 2882 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>0</td> 2883 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 2884Computes <a href='SkMatrix_Reference#Matrix'>Matrix</a> that scales about x-axis and y-axis independently, so that 2885source <a href='SkRect_Reference#Rect'>Rect</a> is mapped to completely fill destination <a href='SkRect_Reference#Rect'>Rect</a>. The aspect ratio 2886of source <a href='SkRect_Reference#Rect'>Rect</a> may change. 2887</td> 2888 </tr> 2889 <tr> 2890 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kStart_ScaleToFit'><code>SkMatrix::kStart_ScaleToFit</code></a></td> 2891 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>1</td> 2892 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 2893Computes <a href='SkMatrix_Reference#Matrix'>Matrix</a> that maintains source <a href='SkRect_Reference#Rect'>Rect</a> aspect ratio, mapping source <a href='SkRect_Reference#Rect'>Rect</a> 2894width or height to destination <a href='SkRect_Reference#Rect'>Rect</a>. Aligns mapping to left and top edges 2895of destination <a href='SkRect_Reference#Rect'>Rect</a>. 2896</td> 2897 </tr> 2898 <tr style='background-color: #f0f0f0; '> 2899 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kCenter_ScaleToFit'><code>SkMatrix::kCenter_ScaleToFit</code></a></td> 2900 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>2</td> 2901 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 2902Computes <a href='SkMatrix_Reference#Matrix'>Matrix</a> that maintains source <a href='SkRect_Reference#Rect'>Rect</a> aspect ratio, mapping source <a href='SkRect_Reference#Rect'>Rect</a> 2903width or height to destination <a href='SkRect_Reference#Rect'>Rect</a>. Aligns mapping to center of destination 2904<a href='SkRect_Reference#Rect'>Rect</a>. 2905</td> 2906 </tr> 2907 <tr> 2908 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kEnd_ScaleToFit'><code>SkMatrix::kEnd_ScaleToFit</code></a></td> 2909 <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>3</td> 2910 <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> 2911Computes <a href='SkMatrix_Reference#Matrix'>Matrix</a> that maintains source <a href='SkRect_Reference#Rect'>Rect</a> aspect ratio, mapping source <a href='SkRect_Reference#Rect'>Rect</a> 2912width or height to destination <a href='SkRect_Reference#Rect'>Rect</a>. Aligns mapping to right and bottom 2913edges of destination <a href='SkRect_Reference#Rect'>Rect</a>. 2914</td> 2915 </tr> 2916</table> 2917 2918### Example 2919 2920<div><fiddle-embed name="17c3070b31b700ea8f52e48af9a66b6e"></fiddle-embed></div> 2921 2922### See Also 2923 2924<a href='#SkMatrix_setRectToRect'>setRectToRect</a> <a href='#SkMatrix_MakeRectToRect'>MakeRectToRect</a> <a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a> 2925 2926<a name='SkMatrix_setRectToRect'></a> 2927 2928--- 2929 2930<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2931bool <a href='#SkMatrix_setRectToRect'>setRectToRect</a>(const <a href='SkRect_Reference#SkRect'>SkRect</a>& src, const <a href='SkRect_Reference#SkRect'>SkRect</a>& dst, <a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> stf) 2932</pre> 2933 2934Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to scale and translate <a href='#SkMatrix_setRectToRect_src'>src</a> <a href='SkRect_Reference#SkRect'>SkRect</a> to <a href='#SkMatrix_setRectToRect_dst'>dst</a> <a href='SkRect_Reference#SkRect'>SkRect</a>. <a href='#SkMatrix_setRectToRect_stf'>stf</a> selects whether 2935mapping completely fills <a href='#SkMatrix_setRectToRect_dst'>dst</a> or preserves the aspect ratio, and how to align 2936<a href='#SkMatrix_setRectToRect_src'>src</a> within <a href='#SkMatrix_setRectToRect_dst'>dst</a>. Returns false if <a href='#SkMatrix_setRectToRect_src'>src</a> is empty, and sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to identity. 2937Returns true if <a href='#SkMatrix_setRectToRect_dst'>dst</a> is empty, and sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 2938 2939| 0 0 0 | 2940| 0 0 0 | 2941| 0 0 1 | 2942 2943### Parameters 2944 2945<table> <tr> <td><a name='SkMatrix_setRectToRect_src'><code><strong>src</strong></code></a></td> 2946 <td><a href='SkRect_Reference#SkRect'>SkRect</a> to map from</td> 2947 </tr> 2948 <tr> <td><a name='SkMatrix_setRectToRect_dst'><code><strong>dst</strong></code></a></td> 2949 <td><a href='SkRect_Reference#SkRect'>SkRect</a> to map to</td> 2950 </tr> 2951 <tr> <td><a name='SkMatrix_setRectToRect_stf'><code><strong>stf</strong></code></a></td> 2952 <td>one of: <a href='#SkMatrix_kFill_ScaleToFit'>kFill_ScaleToFit</a>, <a href='#SkMatrix_kStart_ScaleToFit'>kStart_ScaleToFit</a>,</td> 2953 </tr> 2954</table> 2955 2956<a href='#SkMatrix_kCenter_ScaleToFit'>kCenter_ScaleToFit</a>, <a href='#SkMatrix_kEnd_ScaleToFit'>kEnd_ScaleToFit</a> 2957 2958### Return Value 2959 2960true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> can represent <a href='SkRect_Reference#SkRect'>SkRect</a> mapping 2961 2962### Example 2963 2964<div><fiddle-embed name="69cdea599dcaaec35efcb24403f4287b"> 2965 2966#### Example Output 2967 2968~~~~ 2969src: 0, 0, 0, 0 dst: 0, 0, 0, 0 success: false 2970[ 1.0000 0.0000 0.0000][ 0.0000 1.0000 0.0000][ 0.0000 0.0000 1.0000] 2971src: 0, 0, 0, 0 dst: 5, 6, 8, 9 success: false 2972[ 1.0000 0.0000 0.0000][ 0.0000 1.0000 0.0000][ 0.0000 0.0000 1.0000] 2973src: 1, 2, 3, 4 dst: 0, 0, 0, 0 success: true 2974[ 0.0000 0.0000 0.0000][ 0.0000 0.0000 0.0000][ 0.0000 0.0000 1.0000] 2975src: 1, 2, 3, 4 dst: 5, 6, 8, 9 success: true 2976[ 1.5000 0.0000 3.5000][ 0.0000 1.5000 3.0000][ 0.0000 0.0000 1.0000] 2977~~~~ 2978 2979</fiddle-embed></div> 2980 2981### See Also 2982 2983<a href='#SkMatrix_MakeRectToRect'>MakeRectToRect</a> <a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> <a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a> <a href='SkRect_Reference#SkRect'>SkRect</a>::<a href='#SkRect_isEmpty'>isEmpty</a> 2984 2985<a name='SkMatrix_MakeRectToRect'></a> 2986 2987--- 2988 2989<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 2990static <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_MakeRectToRect'>MakeRectToRect</a>(const <a href='SkRect_Reference#SkRect'>SkRect</a>& src, const <a href='SkRect_Reference#SkRect'>SkRect</a>& dst, <a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> stf) 2991</pre> 2992 2993Returns <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> set to scale and translate <a href='#SkMatrix_MakeRectToRect_src'>src</a> <a href='SkRect_Reference#SkRect'>SkRect</a> to <a href='#SkMatrix_MakeRectToRect_dst'>dst</a> <a href='SkRect_Reference#SkRect'>SkRect</a>. <a href='#SkMatrix_MakeRectToRect_stf'>stf</a> selects 2994whether mapping completely fills <a href='#SkMatrix_MakeRectToRect_dst'>dst</a> or preserves the aspect ratio, and how to 2995align <a href='#SkMatrix_MakeRectToRect_src'>src</a> within <a href='#SkMatrix_MakeRectToRect_dst'>dst</a>. Returns the identity <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> if <a href='#SkMatrix_MakeRectToRect_src'>src</a> is empty. If <a href='#SkMatrix_MakeRectToRect_dst'>dst</a> is 2996empty, returns <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> set to: 2997 2998| 0 0 0 | 2999| 0 0 0 | 3000| 0 0 1 | 3001 3002### Parameters 3003 3004<table> <tr> <td><a name='SkMatrix_MakeRectToRect_src'><code><strong>src</strong></code></a></td> 3005 <td><a href='SkRect_Reference#SkRect'>SkRect</a> to map from</td> 3006 </tr> 3007 <tr> <td><a name='SkMatrix_MakeRectToRect_dst'><code><strong>dst</strong></code></a></td> 3008 <td><a href='SkRect_Reference#SkRect'>SkRect</a> to map to</td> 3009 </tr> 3010 <tr> <td><a name='SkMatrix_MakeRectToRect_stf'><code><strong>stf</strong></code></a></td> 3011 <td>one of: <a href='#SkMatrix_kFill_ScaleToFit'>kFill_ScaleToFit</a>, <a href='#SkMatrix_kStart_ScaleToFit'>kStart_ScaleToFit</a>,</td> 3012 </tr> 3013</table> 3014 3015<a href='#SkMatrix_kCenter_ScaleToFit'>kCenter_ScaleToFit</a>, <a href='#SkMatrix_kEnd_ScaleToFit'>kEnd_ScaleToFit</a> 3016 3017### Return Value 3018 3019<a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> mapping <a href='#SkMatrix_MakeRectToRect_src'>src</a> to <a href='#SkMatrix_MakeRectToRect_dst'>dst</a> 3020 3021### Example 3022 3023<div><fiddle-embed name="a1d6a6721b39350f81021f71a1b93208"> 3024 3025#### Example Output 3026 3027~~~~ 3028src: 0, 0, 0, 0 dst: 0, 0, 0, 0 3029[ 1.0000 0.0000 0.0000][ 0.0000 1.0000 0.0000][ 0.0000 0.0000 1.0000] 3030src: 0, 0, 0, 0 dst: 5, 6, 8, 9 3031[ 1.0000 0.0000 0.0000][ 0.0000 1.0000 0.0000][ 0.0000 0.0000 1.0000] 3032src: 1, 2, 3, 4 dst: 0, 0, 0, 0 3033[ 0.0000 0.0000 0.0000][ 0.0000 0.0000 0.0000][ 0.0000 0.0000 1.0000] 3034src: 1, 2, 3, 4 dst: 5, 6, 8, 9 3035[ 1.5000 0.0000 3.5000][ 0.0000 1.5000 3.0000][ 0.0000 0.0000 1.0000] 3036~~~~ 3037 3038</fiddle-embed></div> 3039 3040### See Also 3041 3042<a href='#SkMatrix_setRectToRect'>setRectToRect</a> <a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> <a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a> <a href='SkRect_Reference#SkRect'>SkRect</a>::<a href='#SkRect_isEmpty'>isEmpty</a> 3043 3044<a name='SkMatrix_setPolyToPoly'></a> 3045 3046--- 3047 3048<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3049bool <a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a>(const <a href='SkPoint_Reference#SkPoint'>SkPoint</a> src[], const <a href='SkPoint_Reference#SkPoint'>SkPoint</a> dst[], int count) 3050</pre> 3051 3052Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to map <a href='#SkMatrix_setPolyToPoly_src'>src</a> to <a href='#SkMatrix_setPolyToPoly_dst'>dst</a>. <a href='#SkMatrix_setPolyToPoly_count'>count</a> must be zero or greater, and four or less. 3053 3054If <a href='#SkMatrix_setPolyToPoly_count'>count</a> is zero, sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to identity and returns true. 3055If <a href='#SkMatrix_setPolyToPoly_count'>count</a> is one, sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to translate and returns true. 3056If <a href='#SkMatrix_setPolyToPoly_count'>count</a> is two or more, sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to map <a href='SkPoint_Reference#SkPoint'>SkPoint</a> if possible; returns false 3057if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> cannot be constructed. If <a href='#SkMatrix_setPolyToPoly_count'>count</a> is four, <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> may include 3058perspective. 3059 3060### Parameters 3061 3062<table> <tr> <td><a name='SkMatrix_setPolyToPoly_src'><code><strong>src</strong></code></a></td> 3063 <td><a href='SkPoint_Reference#SkPoint'>SkPoint</a> to map from</td> 3064 </tr> 3065 <tr> <td><a name='SkMatrix_setPolyToPoly_dst'><code><strong>dst</strong></code></a></td> 3066 <td><a href='SkPoint_Reference#SkPoint'>SkPoint</a> to map to</td> 3067 </tr> 3068 <tr> <td><a name='SkMatrix_setPolyToPoly_count'><code><strong>count</strong></code></a></td> 3069 <td>number of <a href='SkPoint_Reference#SkPoint'>SkPoint</a> in <a href='#SkMatrix_setPolyToPoly_src'>src</a> and <a href='#SkMatrix_setPolyToPoly_dst'>dst</a></td> 3070 </tr> 3071</table> 3072 3073### Return Value 3074 3075true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> was constructed successfully 3076 3077### Example 3078 3079<div><fiddle-embed name="c851d1313e8909aaea4f0591699fdb7b"></fiddle-embed></div> 3080 3081### See Also 3082 3083<a href='#SkMatrix_setRectToRect'>setRectToRect</a> <a href='#SkMatrix_MakeRectToRect'>MakeRectToRect</a> 3084 3085<a name='SkMatrix_invert'></a> 3086 3087--- 3088 3089<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3090bool <a href='#SkMatrix_invert'>invert</a>(<a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>* inverse)const 3091</pre> 3092 3093Sets <a href='#SkMatrix_invert_inverse'>inverse</a> to reciprocal <a href='SkMatrix_Reference#Matrix'>matrix</a>, returning true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> can be inverted. 3094Geometrically, if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> maps from source to destination, <a href='#SkMatrix_invert_inverse'>inverse</a> <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> 3095maps from destination to source. If <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> can not be inverted, <a href='#SkMatrix_invert_inverse'>inverse</a> is 3096unchanged. 3097 3098### Parameters 3099 3100<table> <tr> <td><a name='SkMatrix_invert_inverse'><code><strong>inverse</strong></code></a></td> 3101 <td>storage for inverted <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>; may be nullptr</td> 3102 </tr> 3103</table> 3104 3105### Return Value 3106 3107true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> can be inverted 3108 3109### Example 3110 3111<div><fiddle-embed name="0e03cd9f154603ed4b21ca56d69dae44"></fiddle-embed></div> 3112 3113### See Also 3114 3115<a href='#SkMatrix_Concat'>Concat</a> 3116 3117<a name='SkMatrix_SetAffineIdentity'></a> 3118 3119--- 3120 3121<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3122static void <a href='#SkMatrix_SetAffineIdentity'>SetAffineIdentity</a>(<a href='undocumented#SkScalar'>SkScalar</a> affine[6]) 3123</pre> 3124 3125Fills <a href='#SkMatrix_SetAffineIdentity_affine'>affine</a> with identity values in column major order. 3126Sets <a href='#SkMatrix_SetAffineIdentity_affine'>affine</a> to: 3127 3128| 1 0 0 | 3129| 0 1 0 | 3130 3131Affine 3 by 2 <a href='SkMatrix_Reference#Matrix'>matrices</a> in column major order are used by OpenGL and XPS. 3132 3133### Parameters 3134 3135<table> <tr> <td><a name='SkMatrix_SetAffineIdentity_affine'><code><strong>affine</strong></code></a></td> 3136 <td>storage for 3 by 2 <a href='#SkMatrix_SetAffineIdentity_affine'>affine</a> <a href='SkMatrix_Reference#Matrix'>matrix</a></td> 3137 </tr> 3138</table> 3139 3140### Example 3141 3142<div><fiddle-embed name="e10adbd0bcc940c5d4d872db0e78e892"> 3143 3144#### Example Output 3145 3146~~~~ 3147ScaleX: 1 SkewY: 0 SkewX: 0 ScaleY: 1 TransX: 0 TransY: 0 3148~~~~ 3149 3150</fiddle-embed></div> 3151 3152### See Also 3153 3154<a href='#SkMatrix_setAffine'>setAffine</a> <a href='#SkMatrix_asAffine'>asAffine</a> 3155 3156<a name='SkMatrix_asAffine'></a> 3157 3158--- 3159 3160<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3161bool <a href='#SkMatrix_asAffine'>asAffine</a>(<a href='undocumented#SkScalar'>SkScalar</a> affine[6])const 3162</pre> 3163 3164Fills <a href='#SkMatrix_asAffine_affine'>affine</a> in column major order. Sets <a href='#SkMatrix_asAffine_affine'>affine</a> to: 3165 3166| scale-x skew-x translate-x | 3167| skew-y scale-y translate-y | 3168 3169If <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> contains perspective, returns false and leaves <a href='#SkMatrix_asAffine_affine'>affine</a> unchanged. 3170 3171### Parameters 3172 3173<table> <tr> <td><a name='SkMatrix_asAffine_affine'><code><strong>affine</strong></code></a></td> 3174 <td>storage for 3 by 2 <a href='#SkMatrix_asAffine_affine'>affine</a> <a href='SkMatrix_Reference#Matrix'>matrix</a>; may be nullptr</td> 3175 </tr> 3176</table> 3177 3178### Return Value 3179 3180true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> does not contain perspective 3181 3182### Example 3183 3184<div><fiddle-embed name="3325bdf82bd86d9fbc4199f248afa82c"> 3185 3186#### Example Output 3187 3188~~~~ 3189ScaleX: 2 SkewY: 5 SkewX: 3 ScaleY: 6 TransX: 4 TransY: 7 3190~~~~ 3191 3192</fiddle-embed></div> 3193 3194### See Also 3195 3196<a href='#SkMatrix_setAffine'>setAffine</a> <a href='#SkMatrix_SetAffineIdentity'>SetAffineIdentity</a> 3197 3198<a name='SkMatrix_setAffine'></a> 3199 3200--- 3201 3202<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3203void <a href='#SkMatrix_setAffine'>setAffine</a>(const <a href='undocumented#SkScalar'>SkScalar</a> affine[6]) 3204</pre> 3205 3206Sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to <a href='#SkMatrix_setAffine_affine'>affine</a> values, passed in column major order. Given <a href='#SkMatrix_setAffine_affine'>affine</a>, 3207column, then row, as: 3208 3209| scale-x skew-x translate-x | 3210| skew-y scale-y translate-y | 3211 3212<a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> is set, row, then column, to: 3213 3214| scale-x skew-x translate-x | 3215| skew-y scale-y translate-y | 3216| 0 0 1 | 3217 3218### Parameters 3219 3220<table> <tr> <td><a name='SkMatrix_setAffine_affine'><code><strong>affine</strong></code></a></td> 3221 <td>3 by 2 <a href='#SkMatrix_setAffine_affine'>affine</a> <a href='SkMatrix_Reference#Matrix'>matrix</a></td> 3222 </tr> 3223</table> 3224 3225### Example 3226 3227<div><fiddle-embed name="f5b6d371c4d65e5b5ac6eebdd4b237d8"> 3228 3229#### Example Output 3230 3231~~~~ 3232ScaleX: 2 SkewY: 5 SkewX: 3 ScaleY: 6 TransX: 4 TransY: 7 3233[ 2.0000 3.0000 4.0000][ 5.0000 6.0000 7.0000][ 0.0000 0.0000 1.0000] 3234~~~~ 3235 3236</fiddle-embed></div> 3237 3238### See Also 3239 3240<a href='#SkMatrix_asAffine'>asAffine</a> <a href='#SkMatrix_SetAffineIdentity'>SetAffineIdentity</a> 3241 3242<a name='Transform'></a> 3243 3244<a name='SkMatrix_mapPoints'></a> 3245 3246--- 3247 3248<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3249void <a href='#SkMatrix_mapPoints'>mapPoints</a>(<a href='SkPoint_Reference#SkPoint'>SkPoint</a> dst[], const <a href='SkPoint_Reference#SkPoint'>SkPoint</a> src[], int count)const 3250</pre> 3251 3252Maps <a href='#SkMatrix_mapPoints_src'>src</a> <a href='SkPath_Reference#Point_Array'>SkPoint array</a> of length <a href='#SkMatrix_mapPoints_count'>count</a> to <a href='#SkMatrix_mapPoints_dst'>dst</a> <a href='SkPath_Reference#Point_Array'>SkPoint array</a> of equal or greater 3253length. <a href='SkPoint_Reference#SkPoint'>SkPoint</a> are mapped by multiplying each <a href='SkPoint_Reference#SkPoint'>SkPoint</a> by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. Given: 3254 3255| A B C | | x | 3256<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E F |, pt = | y | 3257| G H <a href='#SkMatrix_I'>I</a> | | 1 | 3258 3259where 3260 3261for (i = 0; i < <a href='#SkMatrix_mapPoints_count'>count</a>; ++i) { 3262x = <a href='#SkMatrix_mapPoints_src'>src</a>[i].fX 3263y = <a href='#SkMatrix_mapPoints_src'>src</a>[i].fY 3264} 3265 3266each <a href='#SkMatrix_mapPoints_dst'>dst</a> <a href='SkPoint_Reference#SkPoint'>SkPoint</a> is computed as: 3267 3268|A B C| |x| Ax+By+C Dx+Ey+F 3269<a href='SkMatrix_Reference#Matrix'>Matrix</a> * pt = |D E F| |y| = |Ax+By+C Dx+Ey+F Gx+Hy+<a href='#SkMatrix_I'>I</a>| = ------- , ------- 3270|G H <a href='#SkMatrix_I'>I</a>| |1| Gx+Hy+<a href='#SkMatrix_I'>I</a> Gx+Hy+<a href='#SkMatrix_I'>I</a> 3271 3272<a href='#SkMatrix_mapPoints_src'>src</a> and <a href='#SkMatrix_mapPoints_dst'>dst</a> may <a href='SkPoint_Reference#Point'>point</a> to the same storage. 3273 3274### Parameters 3275 3276<table> <tr> <td><a name='SkMatrix_mapPoints_dst'><code><strong>dst</strong></code></a></td> 3277 <td>storage for mapped <a href='SkPoint_Reference#SkPoint'>SkPoint</a></td> 3278 </tr> 3279 <tr> <td><a name='SkMatrix_mapPoints_src'><code><strong>src</strong></code></a></td> 3280 <td><a href='SkPoint_Reference#SkPoint'>SkPoint</a> to transform</td> 3281 </tr> 3282 <tr> <td><a name='SkMatrix_mapPoints_count'><code><strong>count</strong></code></a></td> 3283 <td>number of <a href='SkPoint_Reference#SkPoint'>SkPoint</a> to transform</td> 3284 </tr> 3285</table> 3286 3287### Example 3288 3289<div><fiddle-embed name="f99dcb00296d0c56b6c0e178e94b3534"></fiddle-embed></div> 3290 3291### See Also 3292 3293<a href='#SkMatrix_mapXY'>mapXY</a> <a href='#SkMatrix_mapHomogeneousPoints'>mapHomogeneousPoints</a> <a href='#SkMatrix_mapVectors'>mapVectors</a> 3294 3295<a name='SkMatrix_mapPoints_2'></a> 3296 3297--- 3298 3299<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3300void <a href='#SkMatrix_mapPoints'>mapPoints</a>(<a href='SkPoint_Reference#SkPoint'>SkPoint</a> pts[], int count)const 3301</pre> 3302 3303Maps <a href='#SkMatrix_mapPoints_2_pts'>pts</a> <a href='SkPath_Reference#Point_Array'>SkPoint array</a> of length <a href='#SkMatrix_mapPoints_2_count'>count</a> in place. <a href='SkPoint_Reference#SkPoint'>SkPoint</a> are mapped by multiplying 3304each <a href='SkPoint_Reference#SkPoint'>SkPoint</a> by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. Given: 3305 3306| A B C | | x | 3307<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E F |, pt = | y | 3308| G H <a href='#SkMatrix_I'>I</a> | | 1 | 3309 3310where 3311 3312for (i = 0; i < <a href='#SkMatrix_mapPoints_2_count'>count</a>; ++i) { 3313x = <a href='#SkMatrix_mapPoints_2_pts'>pts</a>[i].fX 3314y = <a href='#SkMatrix_mapPoints_2_pts'>pts</a>[i].fY 3315} 3316 3317each resulting <a href='#SkMatrix_mapPoints_2_pts'>pts</a> <a href='SkPoint_Reference#SkPoint'>SkPoint</a> is computed as: 3318 3319|A B C| |x| Ax+By+C Dx+Ey+F 3320<a href='SkMatrix_Reference#Matrix'>Matrix</a> * pt = |D E F| |y| = |Ax+By+C Dx+Ey+F Gx+Hy+<a href='#SkMatrix_I'>I</a>| = ------- , ------- 3321|G H <a href='#SkMatrix_I'>I</a>| |1| Gx+Hy+<a href='#SkMatrix_I'>I</a> Gx+Hy+<a href='#SkMatrix_I'>I</a> 3322 3323### Parameters 3324 3325<table> <tr> <td><a name='SkMatrix_mapPoints_2_pts'><code><strong>pts</strong></code></a></td> 3326 <td>storage for mapped <a href='SkPoint_Reference#SkPoint'>SkPoint</a></td> 3327 </tr> 3328 <tr> <td><a name='SkMatrix_mapPoints_2_count'><code><strong>count</strong></code></a></td> 3329 <td>number of <a href='SkPoint_Reference#SkPoint'>SkPoint</a> to transform</td> 3330 </tr> 3331</table> 3332 3333### Example 3334 3335<div><fiddle-embed name="428ca171ae3bd0d3f992458ac598b97b"></fiddle-embed></div> 3336 3337### See Also 3338 3339<a href='#SkMatrix_mapXY'>mapXY</a> <a href='#SkMatrix_mapHomogeneousPoints'>mapHomogeneousPoints</a> <a href='#SkMatrix_mapVectors'>mapVectors</a> 3340 3341<a name='SkMatrix_mapHomogeneousPoints'></a> 3342 3343--- 3344 3345<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3346void <a href='#SkMatrix_mapHomogeneousPoints'>mapHomogeneousPoints</a>(<a href='undocumented#SkPoint3'>SkPoint3</a> dst[], const <a href='undocumented#SkPoint3'>SkPoint3</a> src[], int count)const 3347</pre> 3348 3349Maps <a href='#SkMatrix_mapHomogeneousPoints_src'>src</a> <a href='undocumented#SkPoint3'>SkPoint3</a> array of length <a href='#SkMatrix_mapHomogeneousPoints_count'>count</a> to <a href='#SkMatrix_mapHomogeneousPoints_dst'>dst</a> <a href='undocumented#SkPoint3'>SkPoint3</a> array, which must of length <a href='#SkMatrix_mapHomogeneousPoints_count'>count</a> or 3350greater. <a href='undocumented#SkPoint3'>SkPoint3</a> array is mapped by multiplying each <a href='undocumented#SkPoint3'>SkPoint3</a> by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. Given: 3351 3352| A B C | | x | 3353<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E F |, <a href='#SkMatrix_mapHomogeneousPoints_src'>src</a> = | y | 3354| G H <a href='#SkMatrix_I'>I</a> | | z | 3355 3356each resulting <a href='#SkMatrix_mapHomogeneousPoints_dst'>dst</a> <a href='SkPoint_Reference#SkPoint'>SkPoint</a> is computed as: 3357 3358|A B C| |x| 3359<a href='SkMatrix_Reference#Matrix'>Matrix</a> * <a href='#SkMatrix_mapHomogeneousPoints_src'>src</a> = |D E F| |y| = |Ax+By+Cz Dx+Ey+Fz Gx+Hy+Iz| 3360|G H <a href='#SkMatrix_I'>I</a>| |z| 3361 3362### Parameters 3363 3364<table> <tr> <td><a name='SkMatrix_mapHomogeneousPoints_dst'><code><strong>dst</strong></code></a></td> 3365 <td>storage for mapped <a href='undocumented#SkPoint3'>SkPoint3</a> array</td> 3366 </tr> 3367 <tr> <td><a name='SkMatrix_mapHomogeneousPoints_src'><code><strong>src</strong></code></a></td> 3368 <td><a href='undocumented#SkPoint3'>SkPoint3</a> array to transform</td> 3369 </tr> 3370 <tr> <td><a name='SkMatrix_mapHomogeneousPoints_count'><code><strong>count</strong></code></a></td> 3371 <td>items in <a href='undocumented#SkPoint3'>SkPoint3</a> array to transform</td> 3372 </tr> 3373</table> 3374 3375### Example 3376 3377<div><fiddle-embed name="d56f93e4bc763c7ba4914321ed07a8b5"></fiddle-embed></div> 3378 3379### See Also 3380 3381<a href='#SkMatrix_mapPoints'>mapPoints</a> <a href='#SkMatrix_mapXY'>mapXY</a> <a href='#SkMatrix_mapVectors'>mapVectors</a> 3382 3383<a name='SkMatrix_mapXY'></a> 3384 3385--- 3386 3387<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3388void <a href='#SkMatrix_mapXY'>mapXY</a>(<a href='undocumented#SkScalar'>SkScalar</a> x, <a href='undocumented#SkScalar'>SkScalar</a> y, <a href='SkPoint_Reference#SkPoint'>SkPoint</a>* result)const 3389</pre> 3390 3391Maps <a href='SkPoint_Reference#SkPoint'>SkPoint</a> (<a href='#SkMatrix_mapXY_x'>x</a>, <a href='#SkMatrix_mapXY_y'>y</a>) to <a href='#SkMatrix_mapXY_result'>result</a>. <a href='SkPoint_Reference#SkPoint'>SkPoint</a> is mapped by multiplying by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. Given: 3392 3393| A B C | | <a href='#SkMatrix_mapXY_x'>x</a> | 3394<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E F |, pt = | <a href='#SkMatrix_mapXY_y'>y</a> | 3395| G H <a href='#SkMatrix_I'>I</a> | | 1 | 3396 3397<a href='#SkMatrix_mapXY_result'>result</a> is computed as: 3398 3399|A B C| |<a href='#SkMatrix_mapXY_x'>x</a>| Ax+By+C Dx+Ey+F 3400<a href='SkMatrix_Reference#Matrix'>Matrix</a> * pt = |D E F| |<a href='#SkMatrix_mapXY_y'>y</a>| = |Ax+By+C Dx+Ey+F Gx+Hy+<a href='#SkMatrix_I'>I</a>| = ------- , ------- 3401|G H <a href='#SkMatrix_I'>I</a>| |1| Gx+Hy+<a href='#SkMatrix_I'>I</a> Gx+Hy+<a href='#SkMatrix_I'>I</a> 3402 3403### Parameters 3404 3405<table> <tr> <td><a name='SkMatrix_mapXY_x'><code><strong>x</strong></code></a></td> 3406 <td>x-axis value of <a href='SkPoint_Reference#SkPoint'>SkPoint</a> to map</td> 3407 </tr> 3408 <tr> <td><a name='SkMatrix_mapXY_y'><code><strong>y</strong></code></a></td> 3409 <td>y-axis value of <a href='SkPoint_Reference#SkPoint'>SkPoint</a> to map</td> 3410 </tr> 3411 <tr> <td><a name='SkMatrix_mapXY_result'><code><strong>result</strong></code></a></td> 3412 <td>storage for mapped <a href='SkPoint_Reference#SkPoint'>SkPoint</a></td> 3413 </tr> 3414</table> 3415 3416### Example 3417 3418<div><fiddle-embed name="9e50185d502dc6903783679a84106089"></fiddle-embed></div> 3419 3420### See Also 3421 3422<a href='#SkMatrix_mapPoints'>mapPoints</a> <a href='#SkMatrix_mapVectors'>mapVectors</a> 3423 3424<a name='SkMatrix_mapXY_2'></a> 3425 3426--- 3427 3428<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3429<a href='SkPoint_Reference#SkPoint'>SkPoint</a> <a href='#SkMatrix_mapXY'>mapXY</a>(<a href='undocumented#SkScalar'>SkScalar</a> x, <a href='undocumented#SkScalar'>SkScalar</a> y)const 3430</pre> 3431 3432Returns <a href='SkPoint_Reference#SkPoint'>SkPoint</a> (<a href='#SkMatrix_mapXY_2_x'>x</a>, <a href='#SkMatrix_mapXY_2_y'>y</a>) multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. Given: 3433 3434| A B C | | <a href='#SkMatrix_mapXY_2_x'>x</a> | 3435<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E F |, pt = | <a href='#SkMatrix_mapXY_2_y'>y</a> | 3436| G H <a href='#SkMatrix_I'>I</a> | | 1 | 3437 3438result is computed as: 3439 3440|A B C| |<a href='#SkMatrix_mapXY_2_x'>x</a>| Ax+By+C Dx+Ey+F 3441<a href='SkMatrix_Reference#Matrix'>Matrix</a> * pt = |D E F| |<a href='#SkMatrix_mapXY_2_y'>y</a>| = |Ax+By+C Dx+Ey+F Gx+Hy+<a href='#SkMatrix_I'>I</a>| = ------- , ------- 3442|G H <a href='#SkMatrix_I'>I</a>| |1| Gx+Hy+<a href='#SkMatrix_I'>I</a> Gx+Hy+<a href='#SkMatrix_I'>I</a> 3443 3444### Parameters 3445 3446<table> <tr> <td><a name='SkMatrix_mapXY_2_x'><code><strong>x</strong></code></a></td> 3447 <td>x-axis value of <a href='SkPoint_Reference#SkPoint'>SkPoint</a> to map</td> 3448 </tr> 3449 <tr> <td><a name='SkMatrix_mapXY_2_y'><code><strong>y</strong></code></a></td> 3450 <td>y-axis value of <a href='SkPoint_Reference#SkPoint'>SkPoint</a> to map</td> 3451 </tr> 3452</table> 3453 3454### Return Value 3455 3456mapped <a href='SkPoint_Reference#SkPoint'>SkPoint</a> 3457 3458### Example 3459 3460<div><fiddle-embed name="b1ead09c67a177ab8eace12b061610a7"></fiddle-embed></div> 3461 3462### See Also 3463 3464<a href='#SkMatrix_mapPoints'>mapPoints</a> <a href='#SkMatrix_mapVectors'>mapVectors</a> 3465 3466<a name='SkMatrix_mapVectors'></a> 3467 3468--- 3469 3470<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3471void <a href='#SkMatrix_mapVectors'>mapVectors</a>(<a href='SkPoint_Reference#SkVector'>SkVector</a> dst[], const <a href='SkPoint_Reference#SkVector'>SkVector</a> src[], int count)const 3472</pre> 3473 3474Maps <a href='#SkMatrix_mapVectors_src'>src</a> <a href='SkPoint_Reference#Vector'>vector</a> array of length <a href='#SkMatrix_mapVectors_count'>count</a> to <a href='SkPoint_Reference#Vector'>vector</a> <a href='SkPath_Reference#Point_Array'>SkPoint array</a> of equal or greater 3475length. <a href='SkPoint_Reference#Vector'>Vectors</a> are mapped by multiplying each <a href='SkPoint_Reference#Vector'>vector</a> by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>, treating 3476<a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> translation as zero. Given: 3477 3478| A B 0 | | x | 3479<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E 0 |, <a href='#SkMatrix_mapVectors_src'>src</a> = | y | 3480| G H <a href='#SkMatrix_I'>I</a> | | 1 | 3481 3482where 3483 3484for (i = 0; i < <a href='#SkMatrix_mapVectors_count'>count</a>; ++i) { 3485x = <a href='#SkMatrix_mapVectors_src'>src</a>[i].fX 3486y = <a href='#SkMatrix_mapVectors_src'>src</a>[i].fY 3487} 3488 3489each <a href='#SkMatrix_mapVectors_dst'>dst</a> <a href='SkPoint_Reference#Vector'>vector</a> is computed as: 3490 3491|A B 0| |x| Ax+By Dx+Ey 3492<a href='SkMatrix_Reference#Matrix'>Matrix</a> * <a href='#SkMatrix_mapVectors_src'>src</a> = |D E 0| |y| = |Ax+By Dx+Ey Gx+Hy+<a href='#SkMatrix_I'>I</a>| = ------- , ------- 3493|G H <a href='#SkMatrix_I'>I</a>| |1| Gx+Hy+<a href='#SkMatrix_I'>I</a> Gx+Hy+<a href='#SkMatrix_I'>I</a> 3494 3495<a href='#SkMatrix_mapVectors_src'>src</a> and <a href='#SkMatrix_mapVectors_dst'>dst</a> may <a href='SkPoint_Reference#Point'>point</a> to the same storage. 3496 3497### Parameters 3498 3499<table> <tr> <td><a name='SkMatrix_mapVectors_dst'><code><strong>dst</strong></code></a></td> 3500 <td>storage for mapped <a href='SkPoint_Reference#Vector'>vectors</a></td> 3501 </tr> 3502 <tr> <td><a name='SkMatrix_mapVectors_src'><code><strong>src</strong></code></a></td> 3503 <td><a href='SkPoint_Reference#Vector'>vectors</a> to transform</td> 3504 </tr> 3505 <tr> <td><a name='SkMatrix_mapVectors_count'><code><strong>count</strong></code></a></td> 3506 <td>number of <a href='SkPoint_Reference#Vector'>vectors</a> to transform</td> 3507 </tr> 3508</table> 3509 3510### Example 3511 3512<div><fiddle-embed name="918a9778c3d7d5cb306692784399f6dc"></fiddle-embed></div> 3513 3514### See Also 3515 3516<a href='#SkMatrix_mapVector'>mapVector</a> <a href='#SkMatrix_mapPoints'>mapPoints</a> <a href='#SkMatrix_mapXY'>mapXY</a> 3517 3518<a name='SkMatrix_mapVectors_2'></a> 3519 3520--- 3521 3522<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3523void <a href='#SkMatrix_mapVectors'>mapVectors</a>(<a href='SkPoint_Reference#SkVector'>SkVector</a> vecs[], int count)const 3524</pre> 3525 3526Maps <a href='#SkMatrix_mapVectors_2_vecs'>vecs</a> <a href='SkPoint_Reference#Vector'>vector</a> array of length <a href='#SkMatrix_mapVectors_2_count'>count</a> in place, multiplying each <a href='SkPoint_Reference#Vector'>vector</a> by 3527<a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>, treating <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> translation as zero. Given: 3528 3529| A B 0 | | x | 3530<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E 0 |, vec = | y | 3531| G H <a href='#SkMatrix_I'>I</a> | | 1 | 3532 3533where 3534 3535for (i = 0; i < <a href='#SkMatrix_mapVectors_2_count'>count</a>; ++i) { 3536x = <a href='#SkMatrix_mapVectors_2_vecs'>vecs</a>[i].fX 3537y = <a href='#SkMatrix_mapVectors_2_vecs'>vecs</a>[i].fY 3538} 3539 3540each result <a href='SkPoint_Reference#Vector'>vector</a> is computed as: 3541 3542|A B 0| |x| Ax+By Dx+Ey 3543<a href='SkMatrix_Reference#Matrix'>Matrix</a> * vec = |D E 0| |y| = |Ax+By Dx+Ey Gx+Hy+<a href='#SkMatrix_I'>I</a>| = ------- , ------- 3544|G H <a href='#SkMatrix_I'>I</a>| |1| Gx+Hy+<a href='#SkMatrix_I'>I</a> Gx+Hy+<a href='#SkMatrix_I'>I</a> 3545 3546### Parameters 3547 3548<table> <tr> <td><a name='SkMatrix_mapVectors_2_vecs'><code><strong>vecs</strong></code></a></td> 3549 <td><a href='SkPoint_Reference#Vector'>vectors</a> to transform, and storage for mapped <a href='SkPoint_Reference#Vector'>vectors</a></td> 3550 </tr> 3551 <tr> <td><a name='SkMatrix_mapVectors_2_count'><code><strong>count</strong></code></a></td> 3552 <td>number of <a href='SkPoint_Reference#Vector'>vectors</a> to transform</td> 3553 </tr> 3554</table> 3555 3556### Example 3557 3558<div><fiddle-embed name="5754501a00a1323e76353fb53153e939"></fiddle-embed></div> 3559 3560### See Also 3561 3562<a href='#SkMatrix_mapVector'>mapVector</a> <a href='#SkMatrix_mapPoints'>mapPoints</a> <a href='#SkMatrix_mapXY'>mapXY</a> 3563 3564<a name='SkMatrix_mapVector'></a> 3565 3566--- 3567 3568<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3569void <a href='#SkMatrix_mapVector'>mapVector</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy, <a href='SkPoint_Reference#SkVector'>SkVector</a>* result)const 3570</pre> 3571 3572Maps <a href='SkPoint_Reference#Vector'>vector</a> (<a href='#SkMatrix_mapVector_dx'>dx</a>, <a href='#SkMatrix_mapVector_dy'>dy</a>) to <a href='#SkMatrix_mapVector_result'>result</a>. <a href='SkPoint_Reference#Vector'>Vector</a> is mapped by multiplying by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>, 3573treating <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> translation as zero. Given: 3574 3575| A B 0 | | <a href='#SkMatrix_mapVector_dx'>dx</a> | 3576<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E 0 |, vec = | <a href='#SkMatrix_mapVector_dy'>dy</a> | 3577| G H <a href='#SkMatrix_I'>I</a> | | 1 | 3578 3579each <a href='#SkMatrix_mapVector_result'>result</a> <a href='SkPoint_Reference#Vector'>vector</a> is computed as: 3580 3581|A B 0| |<a href='#SkMatrix_mapVector_dx'>dx</a>| A*<a href='#SkMatrix_mapVector_dx'>dx</a>+B*<a href='#SkMatrix_mapVector_dy'>dy</a> D*<a href='#SkMatrix_mapVector_dx'>dx</a>+E*<a href='#SkMatrix_mapVector_dy'>dy</a> 3582<a href='SkMatrix_Reference#Matrix'>Matrix</a> * vec = |D E 0| |<a href='#SkMatrix_mapVector_dy'>dy</a>| = |A*<a href='#SkMatrix_mapVector_dx'>dx</a>+B*<a href='#SkMatrix_mapVector_dy'>dy</a> D*<a href='#SkMatrix_mapVector_dx'>dx</a>+E*<a href='#SkMatrix_mapVector_dy'>dy</a> G*<a href='#SkMatrix_mapVector_dx'>dx</a>+H*<a href='#SkMatrix_mapVector_dy'>dy</a>+<a href='#SkMatrix_I'>I</a>| = ----------- , ----------- 3583|G H <a href='#SkMatrix_I'>I</a>| | 1| G*<a href='#SkMatrix_mapVector_dx'>dx</a>+H*<a href='#SkMatrix_mapVector_dy'>dy</a>+<a href='#SkMatrix_I'>I</a> G*<a href='#SkMatrix_mapVector_dx'>dx</a>+*dHy+<a href='#SkMatrix_I'>I</a> 3584 3585### Parameters 3586 3587<table> <tr> <td><a name='SkMatrix_mapVector_dx'><code><strong>dx</strong></code></a></td> 3588 <td>x-axis value of <a href='SkPoint_Reference#Vector'>vector</a> to map</td> 3589 </tr> 3590 <tr> <td><a name='SkMatrix_mapVector_dy'><code><strong>dy</strong></code></a></td> 3591 <td>y-axis value of <a href='SkPoint_Reference#Vector'>vector</a> to map</td> 3592 </tr> 3593 <tr> <td><a name='SkMatrix_mapVector_result'><code><strong>result</strong></code></a></td> 3594 <td>storage for mapped <a href='SkPoint_Reference#Vector'>vector</a></td> 3595 </tr> 3596</table> 3597 3598### Example 3599 3600<div><fiddle-embed name="aed143fc6cd0bce4ed029b98d1e61f2d"></fiddle-embed></div> 3601 3602### See Also 3603 3604<a href='#SkMatrix_mapVectors'>mapVectors</a> <a href='#SkMatrix_mapPoints'>mapPoints</a> <a href='#SkMatrix_mapXY'>mapXY</a> 3605 3606<a name='SkMatrix_mapVector_2'></a> 3607 3608--- 3609 3610<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3611<a href='SkPoint_Reference#SkVector'>SkVector</a> <a href='#SkMatrix_mapVector'>mapVector</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy)const 3612</pre> 3613 3614Returns <a href='SkPoint_Reference#Vector'>vector</a> (<a href='#SkMatrix_mapVector_2_dx'>dx</a>, <a href='#SkMatrix_mapVector_2_dy'>dy</a>) multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>, treating <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> translation as zero. 3615Given: 3616 3617| A B 0 | | <a href='#SkMatrix_mapVector_2_dx'>dx</a> | 3618<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E 0 |, vec = | <a href='#SkMatrix_mapVector_2_dy'>dy</a> | 3619| G H <a href='#SkMatrix_I'>I</a> | | 1 | 3620 3621each result <a href='SkPoint_Reference#Vector'>vector</a> is computed as: 3622 3623|A B 0| |<a href='#SkMatrix_mapVector_2_dx'>dx</a>| A*<a href='#SkMatrix_mapVector_2_dx'>dx</a>+B*<a href='#SkMatrix_mapVector_2_dy'>dy</a> D*<a href='#SkMatrix_mapVector_2_dx'>dx</a>+E*<a href='#SkMatrix_mapVector_2_dy'>dy</a> 3624<a href='SkMatrix_Reference#Matrix'>Matrix</a> * vec = |D E 0| |<a href='#SkMatrix_mapVector_2_dy'>dy</a>| = |A*<a href='#SkMatrix_mapVector_2_dx'>dx</a>+B*<a href='#SkMatrix_mapVector_2_dy'>dy</a> D*<a href='#SkMatrix_mapVector_2_dx'>dx</a>+E*<a href='#SkMatrix_mapVector_2_dy'>dy</a> G*<a href='#SkMatrix_mapVector_2_dx'>dx</a>+H*<a href='#SkMatrix_mapVector_2_dy'>dy</a>+<a href='#SkMatrix_I'>I</a>| = ----------- , ----------- 3625|G H <a href='#SkMatrix_I'>I</a>| | 1| G*<a href='#SkMatrix_mapVector_2_dx'>dx</a>+H*<a href='#SkMatrix_mapVector_2_dy'>dy</a>+<a href='#SkMatrix_I'>I</a> G*<a href='#SkMatrix_mapVector_2_dx'>dx</a>+*dHy+<a href='#SkMatrix_I'>I</a> 3626 3627### Parameters 3628 3629<table> <tr> <td><a name='SkMatrix_mapVector_2_dx'><code><strong>dx</strong></code></a></td> 3630 <td>x-axis value of <a href='SkPoint_Reference#Vector'>vector</a> to map</td> 3631 </tr> 3632 <tr> <td><a name='SkMatrix_mapVector_2_dy'><code><strong>dy</strong></code></a></td> 3633 <td>y-axis value of <a href='SkPoint_Reference#Vector'>vector</a> to map</td> 3634 </tr> 3635</table> 3636 3637### Return Value 3638 3639mapped <a href='SkPoint_Reference#Vector'>vector</a> 3640 3641### Example 3642 3643<div><fiddle-embed name="8bf1518db3f369696cd3065b541a8bd7"></fiddle-embed></div> 3644 3645### See Also 3646 3647<a href='#SkMatrix_mapVectors'>mapVectors</a> <a href='#SkMatrix_mapPoints'>mapPoints</a> <a href='#SkMatrix_mapXY'>mapXY</a> 3648 3649<a name='SkMatrix_mapRect'></a> 3650 3651--- 3652 3653<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3654bool <a href='#SkMatrix_mapRect'>mapRect</a>(<a href='SkRect_Reference#SkRect'>SkRect</a>* dst, const <a href='SkRect_Reference#SkRect'>SkRect</a>& src)const 3655</pre> 3656 3657Sets <a href='#SkMatrix_mapRect_dst'>dst</a> to bounds of <a href='#SkMatrix_mapRect_src'>src</a> corners mapped by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 3658Returns true if mapped corners are <a href='#SkMatrix_mapRect_dst'>dst</a> corners. 3659 3660Returned value is the same as calling <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a>(). 3661 3662### Parameters 3663 3664<table> <tr> <td><a name='SkMatrix_mapRect_dst'><code><strong>dst</strong></code></a></td> 3665 <td>storage for bounds of mapped <a href='SkPoint_Reference#SkPoint'>SkPoint</a></td> 3666 </tr> 3667 <tr> <td><a name='SkMatrix_mapRect_src'><code><strong>src</strong></code></a></td> 3668 <td><a href='SkRect_Reference#SkRect'>SkRect</a> to map</td> 3669 </tr> 3670</table> 3671 3672### Return Value 3673 3674true if <a href='#SkMatrix_mapRect_dst'>dst</a> is equivalent to mapped <a href='#SkMatrix_mapRect_src'>src</a> 3675 3676### Example 3677 3678<div><fiddle-embed name="dbcf928b035a31ca69c99392e2e2cca9"></fiddle-embed></div> 3679 3680### See Also 3681 3682<a href='#SkMatrix_mapPoints'>mapPoints</a> <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a> 3683 3684<a name='SkMatrix_mapRect_2'></a> 3685 3686--- 3687 3688<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3689bool <a href='#SkMatrix_mapRect'>mapRect</a>(<a href='SkRect_Reference#SkRect'>SkRect</a>* <a href='SkRect_Reference#Rect'>rect</a>)const 3690</pre> 3691 3692Sets <a href='#SkMatrix_mapRect_2_rect'>rect</a> to bounds of <a href='#SkMatrix_mapRect_2_rect'>rect</a> corners mapped by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 3693Returns true if mapped corners are computed <a href='#SkMatrix_mapRect_2_rect'>rect</a> corners. 3694 3695Returned value is the same as calling <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a>(). 3696 3697### Parameters 3698 3699<table> <tr> <td><a name='SkMatrix_mapRect_2_rect'><code><strong>rect</strong></code></a></td> 3700 <td>rectangle to map, and storage for bounds of mapped corners</td> 3701 </tr> 3702</table> 3703 3704### Return Value 3705 3706true if result is equivalent to mapped <a href='#SkMatrix_mapRect_2_rect'>rect</a> 3707 3708### Example 3709 3710<div><fiddle-embed name="5fafd0bd23d1ed37425b970b4a3c6cc9"></fiddle-embed></div> 3711 3712### See Also 3713 3714<a href='#SkMatrix_mapRectScaleTranslate'>mapRectScaleTranslate</a> <a href='#SkMatrix_mapPoints'>mapPoints</a> <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a> 3715 3716<a name='SkMatrix_mapRect_3'></a> 3717 3718--- 3719 3720<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3721<a href='SkRect_Reference#SkRect'>SkRect</a> <a href='#SkMatrix_mapRect'>mapRect</a>(const <a href='SkRect_Reference#SkRect'>SkRect</a>& src)const 3722</pre> 3723 3724Returns bounds of <a href='#SkMatrix_mapRect_3_src'>src</a> corners mapped by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 3725 3726### Parameters 3727 3728<table> <tr> <td><a name='SkMatrix_mapRect_3_src'><code><strong>src</strong></code></a></td> 3729 <td>rectangle to map</td> 3730 </tr> 3731</table> 3732 3733### Return Value 3734 3735mapped bounds 3736 3737### Example 3738 3739<div><fiddle-embed name="3b7b1f884437ab450f986234e4aec27f"></fiddle-embed></div> 3740 3741### See Also 3742 3743<a href='#SkMatrix_mapRectToQuad'>mapRectToQuad</a> <a href='#SkMatrix_mapRectScaleTranslate'>mapRectScaleTranslate</a> 3744 3745<a name='SkMatrix_mapRectToQuad'></a> 3746 3747--- 3748 3749<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3750void <a href='#SkMatrix_mapRectToQuad'>mapRectToQuad</a>(<a href='SkPoint_Reference#SkPoint'>SkPoint</a> dst[4], const <a href='SkRect_Reference#SkRect'>SkRect</a>& <a href='SkRect_Reference#Rect'>rect</a>)const 3751</pre> 3752 3753Maps four corners of <a href='#SkMatrix_mapRectToQuad_rect'>rect</a> to <a href='#SkMatrix_mapRectToQuad_dst'>dst</a>. <a href='SkPoint_Reference#SkPoint'>SkPoint</a> are mapped by multiplying each 3754<a href='#SkMatrix_mapRectToQuad_rect'>rect</a> corner by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. <a href='#SkMatrix_mapRectToQuad_rect'>rect</a> corner is processed in this order: 3755(<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fLeft'>fLeft</a>, <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fTop'>fTop</a>), (<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fRight'>fRight</a>, <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fTop'>fTop</a>), (<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fRight'>fRight</a>, <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fBottom'>fBottom</a>), 3756(<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fLeft'>fLeft</a>, <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fBottom'>fBottom</a>). 3757 3758<a href='#SkMatrix_mapRectToQuad_rect'>rect</a> may be empty: <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fLeft'>fLeft</a> may be greater than or equal to <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fRight'>fRight</a>; 3759<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fTop'>fTop</a> may be greater than or equal to <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fBottom'>fBottom</a>. 3760 3761Given: 3762 3763| A B C | | x | 3764<a href='SkMatrix_Reference#Matrix'>Matrix</a> = | D E F |, pt = | y | 3765| G H <a href='#SkMatrix_I'>I</a> | | 1 | 3766 3767where pt is initialized from each of (<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fLeft'>fLeft</a>, <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fTop'>fTop</a>), 3768(<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fRight'>fRight</a>, <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fTop'>fTop</a>), (<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fRight'>fRight</a>, <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fBottom'>fBottom</a>), (<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fLeft'>fLeft</a>, <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.<a href='#SkRect_fBottom'>fBottom</a>), 3769each <a href='#SkMatrix_mapRectToQuad_dst'>dst</a> <a href='SkPoint_Reference#SkPoint'>SkPoint</a> is computed as: 3770 3771|A B C| |x| Ax+By+C Dx+Ey+F 3772<a href='SkMatrix_Reference#Matrix'>Matrix</a> * pt = |D E F| |y| = |Ax+By+C Dx+Ey+F Gx+Hy+<a href='#SkMatrix_I'>I</a>| = ------- , ------- 3773|G H <a href='#SkMatrix_I'>I</a>| |1| Gx+Hy+<a href='#SkMatrix_I'>I</a> Gx+Hy+<a href='#SkMatrix_I'>I</a> 3774 3775### Parameters 3776 3777<table> <tr> <td><a name='SkMatrix_mapRectToQuad_dst'><code><strong>dst</strong></code></a></td> 3778 <td>storage for mapped corner <a href='SkPoint_Reference#SkPoint'>SkPoint</a></td> 3779 </tr> 3780 <tr> <td><a name='SkMatrix_mapRectToQuad_rect'><code><strong>rect</strong></code></a></td> 3781 <td><a href='SkRect_Reference#SkRect'>SkRect</a> to map</td> 3782 </tr> 3783</table> 3784 3785### Example 3786 3787<div><fiddle-embed name="c69cd2a590b5733c3cbc92cb9ceed3f5"></fiddle-embed></div> 3788 3789### See Also 3790 3791<a href='#SkMatrix_mapRect'>mapRect</a> <a href='#SkMatrix_mapRectScaleTranslate'>mapRectScaleTranslate</a> 3792 3793<a name='SkMatrix_mapRectScaleTranslate'></a> 3794 3795--- 3796 3797<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3798void <a href='#SkMatrix_mapRectScaleTranslate'>mapRectScaleTranslate</a>(<a href='SkRect_Reference#SkRect'>SkRect</a>* dst, const <a href='SkRect_Reference#SkRect'>SkRect</a>& src)const 3799</pre> 3800 3801Sets <a href='#SkMatrix_mapRectScaleTranslate_dst'>dst</a> to bounds of <a href='#SkMatrix_mapRectScaleTranslate_src'>src</a> corners mapped by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. If <a href='SkMatrix_Reference#Matrix'>matrix</a> contains 3802elements other than scale or translate: asserts if SK_DEBUG is defined; 3803otherwise, results are undefined. 3804 3805### Parameters 3806 3807<table> <tr> <td><a name='SkMatrix_mapRectScaleTranslate_dst'><code><strong>dst</strong></code></a></td> 3808 <td>storage for bounds of mapped <a href='SkPoint_Reference#SkPoint'>SkPoint</a></td> 3809 </tr> 3810 <tr> <td><a name='SkMatrix_mapRectScaleTranslate_src'><code><strong>src</strong></code></a></td> 3811 <td><a href='SkRect_Reference#SkRect'>SkRect</a> to map</td> 3812 </tr> 3813</table> 3814 3815### Example 3816 3817<div><fiddle-embed name="62bc26989c2b4c2a54d516596a71dd97"></fiddle-embed></div> 3818 3819### See Also 3820 3821<a href='#SkMatrix_mapRect'>mapRect</a> <a href='#SkMatrix_mapRectToQuad'>mapRectToQuad</a> <a href='#SkMatrix_isScaleTranslate'>isScaleTranslate</a> <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a> 3822 3823<a name='SkMatrix_mapRadius'></a> 3824 3825--- 3826 3827<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3828<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_mapRadius'>mapRadius</a>(<a href='undocumented#SkScalar'>SkScalar</a> radius)const 3829</pre> 3830 3831Returns geometric mean <a href='#SkMatrix_mapRadius_radius'>radius</a> of ellipse formed by constructing <a href='undocumented#Circle'>circle</a> of 3832<a href='undocumented#Size'>size</a> <a href='#SkMatrix_mapRadius_radius'>radius</a>, and mapping constructed <a href='undocumented#Circle'>circle</a> with <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. The result squared is 3833equal to the major axis length times the minor axis length. 3834Result is not meaningful if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> contains perspective elements. 3835 3836### Parameters 3837 3838<table> <tr> <td><a name='SkMatrix_mapRadius_radius'><code><strong>radius</strong></code></a></td> 3839 <td><a href='undocumented#Circle'>circle</a> <a href='undocumented#Size'>size</a> to map</td> 3840 </tr> 3841</table> 3842 3843### Return Value 3844 3845average mapped <a href='#SkMatrix_mapRadius_radius'>radius</a> 3846 3847### Example 3848 3849<div><fiddle-embed name="6d6f2082fcf59d9f02bfb1758b87db69"><div>The area enclosed by a square with sides equal to mappedRadius is the same as 3850the area enclosed by the ellipse major and minor axes. 3851</div></fiddle-embed></div> 3852 3853### See Also 3854 3855<a href='#SkMatrix_mapVector'>mapVector</a> 3856 3857<a name='SkMatrix_isFixedStepInX'></a> 3858 3859--- 3860 3861<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3862bool <a href='#SkMatrix_isFixedStepInX'>isFixedStepInX</a>()const 3863</pre> 3864 3865Returns true if a unit step on x-axis at some y-axis value mapped through <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> 3866can be represented by a constant <a href='SkPoint_Reference#Vector'>vector</a>. Returns true if <a href='#SkMatrix_getType'>getType</a>() returns 3867<a href='#SkMatrix_kIdentity_Mask'>kIdentity_Mask</a>, or combinations of: <a href='#SkMatrix_kTranslate_Mask'>kTranslate_Mask</a>, <a href='#SkMatrix_kScale_Mask'>kScale_Mask</a>, and <a href='#SkMatrix_kAffine_Mask'>kAffine_Mask</a>. 3868 3869May return true if <a href='#SkMatrix_getType'>getType</a>() returns <a href='#SkMatrix_kPerspective_Mask'>kPerspective_Mask</a>, but only when <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> 3870does not include rotation or skewing along the y-axis. 3871 3872### Return Value 3873 3874true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> does not have complex perspective 3875 3876### Example 3877 3878<div><fiddle-embed name="ab57b232acef69f26de9cb23d23c8a1a"> 3879 3880#### Example Output 3881 3882~~~~ 3883[ 1.0000 0.0000 0.0000][ 0.0000 1.0000 0.0000][ 0.0000 0.0000 1.0000] 3884isFixedStepInX: true 3885[ 1.0000 0.0000 0.0000][ 0.0000 2.0000 0.0000][ 0.0000 0.0000 1.0000] 3886isFixedStepInX: true 3887[ 1.0000 0.0000 0.0000][ 0.0000 1.0000 0.0000][ 0.0000 0.1000 1.0000] 3888isFixedStepInX: true 3889[ 1.0000 0.0000 0.0000][ 0.0000 2.0000 0.0000][ 0.0000 0.1000 1.0000] 3890isFixedStepInX: true 3891[ 1.0000 0.0000 0.0000][ 0.0000 1.0000 0.0000][ 0.1000 0.0000 1.0000] 3892isFixedStepInX: false 3893[ 1.0000 0.0000 0.0000][ 0.0000 2.0000 0.0000][ 0.1000 0.0000 1.0000] 3894isFixedStepInX: false 3895[ 1.0000 0.0000 0.0000][ 0.0000 1.0000 0.0000][ 0.1000 0.1000 1.0000] 3896isFixedStepInX: false 3897[ 1.0000 0.0000 0.0000][ 0.0000 2.0000 0.0000][ 0.1000 0.1000 1.0000] 3898isFixedStepInX: false 3899~~~~ 3900 3901</fiddle-embed></div> 3902 3903### See Also 3904 3905<a href='#SkMatrix_fixedStepInX'>fixedStepInX</a> <a href='#SkMatrix_getType'>getType</a> 3906 3907<a name='SkMatrix_fixedStepInX'></a> 3908 3909--- 3910 3911<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3912<a href='SkPoint_Reference#SkVector'>SkVector</a> <a href='#SkMatrix_fixedStepInX'>fixedStepInX</a>(<a href='undocumented#SkScalar'>SkScalar</a> y)const 3913</pre> 3914 3915Returns <a href='SkPoint_Reference#Vector'>vector</a> representing a unit step on x-axis at <a href='#SkMatrix_fixedStepInX_y'>y</a> mapped through <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. 3916If <a href='#SkMatrix_isFixedStepInX'>isFixedStepInX</a>() is false, returned value is undefined. 3917 3918### Parameters 3919 3920<table> <tr> <td><a name='SkMatrix_fixedStepInX_y'><code><strong>y</strong></code></a></td> 3921 <td>position of <a href='undocumented#Line'>line</a> parallel to x-axis</td> 3922 </tr> 3923</table> 3924 3925### Return Value 3926 3927<a href='SkPoint_Reference#Vector'>vector</a> advance of mapped unit step on x-axis 3928 3929### Example 3930 3931<div><fiddle-embed name="fad6b92b21b1e1deeae61978cec2d232"></fiddle-embed></div> 3932 3933### See Also 3934 3935<a href='#SkMatrix_isFixedStepInX'>isFixedStepInX</a> <a href='#SkMatrix_getType'>getType</a> 3936 3937<a name='SkMatrix_cheapEqualTo'></a> 3938 3939--- 3940 3941<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3942bool <a href='#SkMatrix_cheapEqualTo'>cheapEqualTo</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& m)const 3943</pre> 3944 3945Returns true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> equals <a href='#SkMatrix_cheapEqualTo_m'>m</a>, using an efficient comparison. 3946 3947Returns false when the sign of zero values is the different; when one 3948<a href='SkMatrix_Reference#Matrix'>matrix</a> has positive zero value and the other has negative zero value. 3949 3950Returns true even when both <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> contain NaN. 3951 3952NaN never equals any value, including itself. To improve performance, NaN values 3953are treated as bit patterns that are equal if their bit patterns are equal. 3954 3955### Parameters 3956 3957<table> <tr> <td><a name='SkMatrix_cheapEqualTo_m'><code><strong>m</strong></code></a></td> 3958 <td><a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to compare</td> 3959 </tr> 3960</table> 3961 3962### Return Value 3963 3964true if <a href='#SkMatrix_cheapEqualTo_m'>m</a> and <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> are represented by identical bit patterns 3965 3966### Example 3967 3968<div><fiddle-embed name="39016b3cfc6bbabb09348a53822ce508"> 3969 3970#### Example Output 3971 3972~~~~ 3973identity: a == b a.cheapEqualTo(b): true 3974neg zero: a == b a.cheapEqualTo(b): false 3975one NaN: a != b a.cheapEqualTo(b): false 3976both NaN: a != b a.cheapEqualTo(b): true 3977~~~~ 3978 3979</fiddle-embed></div> 3980 3981### See Also 3982 3983<a href='#SkMatrix_equal_operator'>operator==</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& a, const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& b) 3984 3985<a name='SkMatrix_equal_operator'></a> 3986 3987--- 3988 3989<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 3990bool <a href='#SkMatrix_equal_operator'>operator==</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& a, const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& b) 3991</pre> 3992 3993Compares <a href='#SkMatrix_equal_operator_a'>a</a> and <a href='#SkMatrix_equal_operator_b'>b</a>; returns true if <a href='#SkMatrix_equal_operator_a'>a</a> and <a href='#SkMatrix_equal_operator_b'>b</a> are numerically equal. Returns true 3994even if sign of zero values are different. Returns false if either <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> 3995contains NaN, even if the other <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> also contains NaN. 3996 3997### Parameters 3998 3999<table> <tr> <td><a name='SkMatrix_equal_operator_a'><code><strong>a</strong></code></a></td> 4000 <td><a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to compare</td> 4001 </tr> 4002 <tr> <td><a name='SkMatrix_equal_operator_b'><code><strong>b</strong></code></a></td> 4003 <td><a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to compare</td> 4004 </tr> 4005</table> 4006 4007### Return Value 4008 4009true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_equal_operator_a'>a</a> and <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_equal_operator_b'>b</a> are numerically equal 4010 4011### Example 4012 4013<div><fiddle-embed name="3902859150b0f0c4aeb1f25d00434baa"> 4014 4015#### Example Output 4016 4017~~~~ 4018identity: a == b a.cheapEqualTo(b): true 4019~~~~ 4020 4021</fiddle-embed></div> 4022 4023### See Also 4024 4025<a href='#SkMatrix_cheapEqualTo'>cheapEqualTo</a> <a href='#SkMatrix_notequal_operator'>operator!=</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& <a href='#SkMatrix_equal_operator_a'>a</a>, const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& <a href='#SkMatrix_equal_operator_b'>b</a>) 4026 4027<a name='SkMatrix_notequal_operator'></a> 4028 4029--- 4030 4031<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 4032bool <a href='#SkMatrix_notequal_operator'>operator!=</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& a, const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& b) 4033</pre> 4034 4035Compares <a href='#SkMatrix_notequal_operator_a'>a</a> and <a href='#SkMatrix_notequal_operator_b'>b</a>; returns true if <a href='#SkMatrix_notequal_operator_a'>a</a> and <a href='#SkMatrix_notequal_operator_b'>b</a> are not numerically equal. Returns false 4036even if sign of zero values are different. Returns true if either <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> 4037contains NaN, even if the other <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> also contains NaN. 4038 4039### Parameters 4040 4041<table> <tr> <td><a name='SkMatrix_notequal_operator_a'><code><strong>a</strong></code></a></td> 4042 <td><a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to compare</td> 4043 </tr> 4044 <tr> <td><a name='SkMatrix_notequal_operator_b'><code><strong>b</strong></code></a></td> 4045 <td><a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to compare</td> 4046 </tr> 4047</table> 4048 4049### Return Value 4050 4051true if <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_notequal_operator_a'>a</a> and <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_notequal_operator_b'>b</a> are numerically not equal 4052 4053### Example 4054 4055<div><fiddle-embed name="088ab41f877599f980a99523749b0afd"></fiddle-embed></div> 4056 4057### See Also 4058 4059<a href='#SkMatrix_cheapEqualTo'>cheapEqualTo</a> <a href='#SkMatrix_equal_operator'>operator==</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& <a href='#SkMatrix_notequal_operator_a'>a</a>, const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& <a href='#SkMatrix_notequal_operator_b'>b</a>) 4060 4061<a name='Utility'></a> 4062 4063<a name='SkMatrix_dump'></a> 4064 4065--- 4066 4067<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 4068void <a href='#SkMatrix_dump'>dump()</a>const 4069</pre> 4070 4071Writes <a href='undocumented#Text'>text</a> representation of <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to standard output. Floating <a href='SkPoint_Reference#Point'>point</a> values 4072are written with limited precision; it may not be possible to reconstruct 4073original <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> from output. 4074 4075### Example 4076 4077<div><fiddle-embed name="8d72a4818e5a9188348f6c08ab5d8a40"> 4078 4079#### Example Output 4080 4081~~~~ 4082[ 0.7071 -0.7071 0.0000][ 0.7071 0.7071 0.0000][ 0.0000 0.0000 1.0000] 4083[ 0.7071 -0.7071 0.0000][ 0.7071 0.7071 0.0000][ 0.0000 0.0000 1.0000] 4084matrix != nearlyEqual 4085~~~~ 4086 4087</fiddle-embed></div> 4088 4089### See Also 4090 4091<a href='SkPath_Reference#SkPath'>SkPath</a>::<a href='#SkPath_dump'>dump</a> 4092 4093<a name='SkMatrix_getMinScale'></a> 4094 4095--- 4096 4097<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 4098<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getMinScale'>getMinScale</a>()const 4099</pre> 4100 4101Returns the minimum scaling factor of <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> by decomposing the scaling and 4102skewing elements. 4103Returns -1 if scale factor overflows or <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> contains perspective. 4104 4105### Return Value 4106 4107minimum scale factor 4108 4109### Example 4110 4111<div><fiddle-embed name="1d6f67904c88a806c3731879e9af4ae5"> 4112 4113#### Example Output 4114 4115~~~~ 4116matrix.getMinScale() 24 4117~~~~ 4118 4119</fiddle-embed></div> 4120 4121### See Also 4122 4123<a href='#SkMatrix_getMaxScale'>getMaxScale</a> <a href='#SkMatrix_getMinMaxScales'>getMinMaxScales</a> 4124 4125<a name='SkMatrix_getMaxScale'></a> 4126 4127--- 4128 4129<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 4130<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getMaxScale'>getMaxScale</a>()const 4131</pre> 4132 4133Returns the maximum scaling factor of <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> by decomposing the scaling and 4134skewing elements. 4135Returns -1 if scale factor overflows or <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> contains perspective. 4136 4137### Return Value 4138 4139maximum scale factor 4140 4141### Example 4142 4143<div><fiddle-embed name="3fee4364929899649cf9efc37897e964"> 4144 4145#### Example Output 4146 4147~~~~ 4148matrix.getMaxScale() 42 4149~~~~ 4150 4151</fiddle-embed></div> 4152 4153### See Also 4154 4155<a href='#SkMatrix_getMinScale'>getMinScale</a> <a href='#SkMatrix_getMinMaxScales'>getMinMaxScales</a> 4156 4157<a name='SkMatrix_getMinMaxScales'></a> 4158 4159--- 4160 4161<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 4162bool <a href='#SkMatrix_getMinMaxScales'>getMinMaxScales</a>(<a href='undocumented#SkScalar'>SkScalar</a> scaleFactors[2])const 4163</pre> 4164 4165Sets <a href='#SkMatrix_getMinMaxScales_scaleFactors'>scaleFactors</a>[0] to the minimum scaling factor, and <a href='#SkMatrix_getMinMaxScales_scaleFactors'>scaleFactors</a>[1] to the 4166maximum scaling factor. Scaling factors are computed by decomposing 4167the <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> scaling and skewing elements. 4168 4169Returns true if <a href='#SkMatrix_getMinMaxScales_scaleFactors'>scaleFactors</a> are found; otherwise, returns false and sets 4170<a href='#SkMatrix_getMinMaxScales_scaleFactors'>scaleFactors</a> to undefined values. 4171 4172### Parameters 4173 4174<table> <tr> <td><a name='SkMatrix_getMinMaxScales_scaleFactors'><code><strong>scaleFactors</strong></code></a></td> 4175 <td>storage for minimum and maximum scale factors</td> 4176 </tr> 4177</table> 4178 4179### Return Value 4180 4181true if scale factors were computed correctly 4182 4183### Example 4184 4185<div><fiddle-embed name="13adba0ecf5f82247cf051b4fa4d8a9c"> 4186 4187#### Example Output 4188 4189~~~~ 4190matrix.getMinMaxScales() false 2 2 4191~~~~ 4192 4193</fiddle-embed></div> 4194 4195### See Also 4196 4197<a href='#SkMatrix_getMinScale'>getMinScale</a> <a href='#SkMatrix_getMaxScale'>getMaxScale</a> 4198 4199<a name='SkMatrix_decomposeScale'></a> 4200 4201--- 4202 4203<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 4204bool <a href='#SkMatrix_decomposeScale'>decomposeScale</a>(<a href='undocumented#SkSize'>SkSize</a>* scale, <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>* remaining = nullptr)const 4205</pre> 4206 4207Decomposes <a href='SkMatrix_Reference#Matrix'>Matrix</a> into <a href='#SkMatrix_decomposeScale_scale'>scale</a> components and whatever remains. Returns false if 4208<a href='SkMatrix_Reference#Matrix'>Matrix</a> could not be decomposed. 4209 4210Sets <a href='#SkMatrix_decomposeScale_scale'>scale</a> to portion of <a href='SkMatrix_Reference#Matrix'>Matrix</a> that <a href='#SkMatrix_decomposeScale_scale'>scale</a> axes. Sets <a href='#SkMatrix_decomposeScale_remaining'>remaining</a> to <a href='SkMatrix_Reference#Matrix'>Matrix</a> 4211with scaling factored out. <a href='#SkMatrix_decomposeScale_remaining'>remaining</a> may be passed as nullptr 4212to determine if <a href='SkMatrix_Reference#Matrix'>Matrix</a> can be decomposed without computing remainder. 4213 4214Returns true if <a href='#SkMatrix_decomposeScale_scale'>scale</a> components are found. <a href='#SkMatrix_decomposeScale_scale'>scale</a> and <a href='#SkMatrix_decomposeScale_remaining'>remaining</a> are 4215unchanged if <a href='SkMatrix_Reference#Matrix'>Matrix</a> contains perspective; <a href='#SkMatrix_decomposeScale_scale'>scale</a> factors are not finite, or 4216are nearly zero. 4217 4218On success: <code><a href='SkMatrix_Reference#Matrix'>Matrix</a> = <a href='#SkMatrix_decomposeScale_scale'>scale</a> * Remaining</code>. 4219 4220### Parameters 4221 4222<table> <tr> <td><a name='SkMatrix_decomposeScale_scale'><code><strong>scale</strong></code></a></td> 4223 <td>axes scaling factors; may be nullptr</td> 4224 </tr> 4225 <tr> <td><a name='SkMatrix_decomposeScale_remaining'><code><strong>remaining</strong></code></a></td> 4226 <td><a href='SkMatrix_Reference#Matrix'>Matrix</a> without scaling; may be nullptr</td> 4227 </tr> 4228</table> 4229 4230### Return Value 4231 4232true if <a href='#SkMatrix_decomposeScale_scale'>scale</a> can be computed 4233 4234### Example 4235 4236<div><fiddle-embed name="139b874da0a3ede1f3df88119085c0aa"> 4237 4238#### Example Output 4239 4240~~~~ 4241[ 0.0000 -0.2500 0.0000][ 0.5000 0.0000 0.0000][ 0.0000 0.0000 1.0000] 4242success: true scale: 0.5, 0.25 4243[ 0.0000 -0.5000 0.0000][ 2.0000 0.0000 0.0000][ 0.0000 0.0000 1.0000] 4244[ 0.0000 -0.2500 0.0000][ 0.5000 0.0000 0.0000][ 0.0000 0.0000 1.0000] 4245~~~~ 4246 4247</fiddle-embed></div> 4248 4249### See Also 4250 4251<a href='#SkMatrix_setScale'>setScale</a> <a href='#SkMatrix_MakeScale'>MakeScale</a> 4252 4253<a name='SkMatrix_I'></a> 4254 4255--- 4256 4257<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 4258static const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& <a href='#SkMatrix_I'>I</a>() 4259</pre> 4260 4261Returns reference to const identity <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>. Returned <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> is set to: 4262 4263| 1 0 0 | 4264| 0 1 0 | 4265| 0 0 1 | 4266 4267### Return Value 4268 4269const identity <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> 4270 4271### Example 4272 4273<div><fiddle-embed name="d961d91020f19037204a8c3fd8cb1060"> 4274 4275#### Example Output 4276 4277~~~~ 4278m1 == m2 4279m2 == m3 4280~~~~ 4281 4282</fiddle-embed></div> 4283 4284### See Also 4285 4286<a href='#SkMatrix_reset'>reset()</a> <a href='#SkMatrix_setIdentity'>setIdentity</a> 4287 4288<a name='SkMatrix_InvalidMatrix'></a> 4289 4290--- 4291 4292<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 4293static const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& <a href='#SkMatrix_InvalidMatrix'>InvalidMatrix</a>() 4294</pre> 4295 4296Returns reference to a const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> with invalid values. Returned <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> is set 4297to: 4298 4299| <a href='undocumented#SK_ScalarMax'>SK_ScalarMax</a> <a href='undocumented#SK_ScalarMax'>SK_ScalarMax</a> <a href='undocumented#SK_ScalarMax'>SK_ScalarMax</a> | 4300| <a href='undocumented#SK_ScalarMax'>SK_ScalarMax</a> <a href='undocumented#SK_ScalarMax'>SK_ScalarMax</a> <a href='undocumented#SK_ScalarMax'>SK_ScalarMax</a> | 4301| <a href='undocumented#SK_ScalarMax'>SK_ScalarMax</a> <a href='undocumented#SK_ScalarMax'>SK_ScalarMax</a> <a href='undocumented#SK_ScalarMax'>SK_ScalarMax</a> | 4302 4303### Return Value 4304 4305const invalid <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> 4306 4307### Example 4308 4309<div><fiddle-embed name="af0b72360c1c7a25b4754bfa47011dd5"> 4310 4311#### Example Output 4312 4313~~~~ 4314scaleX 3.40282e+38 4315~~~~ 4316 4317</fiddle-embed></div> 4318 4319### See Also 4320 4321<a href='#SkMatrix_getType'>getType</a> 4322 4323<a name='SkMatrix_Concat'></a> 4324 4325--- 4326 4327<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 4328static <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_Concat'>Concat</a>(const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& a, const <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a>& b) 4329</pre> 4330 4331Returns <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_Concat_a'>a</a> multiplied by <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_Concat_b'>b</a>. 4332 4333Given: 4334 4335| A B C | | J K L | 4336<a href='#SkMatrix_Concat_a'>a</a> = | D E F |, <a href='#SkMatrix_Concat_b'>b</a> = | M N O | 4337| G H <a href='#SkMatrix_I'>I</a> | | P Q R | 4338 4339sets <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> to: 4340 4341| A B C | | J K L | | AJ+BM+CP AK+BN+CQ AL+BO+CR | 4342<a href='#SkMatrix_Concat_a'>a</a> * <a href='#SkMatrix_Concat_b'>b</a> = | D E F | * | M N O | = | DJ+EM+FP DK+EN+FQ DL+EO+FR | 4343| G H <a href='#SkMatrix_I'>I</a> | | P Q R | | GJ+HM+IP GK+HN+IQ GL+HO+IR | 4344 4345### Parameters 4346 4347<table> <tr> <td><a name='SkMatrix_Concat_a'><code><strong>a</strong></code></a></td> 4348 <td><a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> on left side of multiply expression</td> 4349 </tr> 4350 <tr> <td><a name='SkMatrix_Concat_b'><code><strong>b</strong></code></a></td> 4351 <td><a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> on right side of multiply expression</td> 4352 </tr> 4353</table> 4354 4355### Return Value 4356 4357<a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> computed from <a href='#SkMatrix_Concat_a'>a</a> times <a href='#SkMatrix_Concat_b'>b</a> 4358 4359### Example 4360 4361<div><fiddle-embed name="6b4562c7052da94f3d5b2412dca41946"><div><a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a> creates perspective <a href='SkMatrix_Reference#Matrix'>matrices</a>, one the inverse of the other. 4362Multiplying the <a href='SkMatrix_Reference#Matrix'>matrix</a> by its inverse turns into an identity <a href='SkMatrix_Reference#Matrix'>matrix</a>. 4363</div></fiddle-embed></div> 4364 4365### See Also 4366 4367<a href='#SkMatrix_preConcat'>preConcat</a> <a href='#SkMatrix_postConcat'>postConcat</a> 4368 4369<a name='SkMatrix_dirtyMatrixTypeCache'></a> 4370 4371--- 4372 4373<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 4374void <a href='#SkMatrix_dirtyMatrixTypeCache'>dirtyMatrixTypeCache</a>() 4375</pre> 4376 4377Sets internal cache to unknown state. Use to force update after repeated 4378modifications to <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> element reference returned by <a href='#SkMatrix_array1_operator'>operator[]</a>(int index). 4379 4380### Example 4381 4382<div><fiddle-embed name="f4365ef332f51f7fd25040e0771ba9a2"> 4383 4384#### Example Output 4385 4386~~~~ 4387with identity matrix: x = 24 4388after skew x mod: x = 24 4389after 2nd skew x mod: x = 24 4390after dirty cache: x = 66 4391~~~~ 4392 4393</fiddle-embed></div> 4394 4395### See Also 4396 4397<a href='#SkMatrix_array1_operator'>operator[]</a>(int index) <a href='#SkMatrix_getType'>getType</a> 4398 4399<a name='SkMatrix_setScaleTranslate'></a> 4400 4401--- 4402 4403<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 4404void <a href='#SkMatrix_setScaleTranslate'>setScaleTranslate</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy, <a href='undocumented#SkScalar'>SkScalar</a> tx, <a href='undocumented#SkScalar'>SkScalar</a> ty) 4405</pre> 4406 4407Initializes <a href='SkMatrix_Reference#SkMatrix'>SkMatrix</a> with scale and translate elements. 4408 4409| <a href='#SkMatrix_setScaleTranslate_sx'>sx</a> 0 <a href='#SkMatrix_setScaleTranslate_tx'>tx</a> | 4410| 0 <a href='#SkMatrix_setScaleTranslate_sy'>sy</a> <a href='#SkMatrix_setScaleTranslate_ty'>ty</a> | 4411| 0 0 1 | 4412 4413### Parameters 4414 4415<table> <tr> <td><a name='SkMatrix_setScaleTranslate_sx'><code><strong>sx</strong></code></a></td> 4416 <td>horizontal scale factor to store</td> 4417 </tr> 4418 <tr> <td><a name='SkMatrix_setScaleTranslate_sy'><code><strong>sy</strong></code></a></td> 4419 <td>vertical scale factor to store</td> 4420 </tr> 4421 <tr> <td><a name='SkMatrix_setScaleTranslate_tx'><code><strong>tx</strong></code></a></td> 4422 <td>horizontal translation to store</td> 4423 </tr> 4424 <tr> <td><a name='SkMatrix_setScaleTranslate_ty'><code><strong>ty</strong></code></a></td> 4425 <td>vertical translation to store</td> 4426 </tr> 4427</table> 4428 4429### Example 4430 4431<div><fiddle-embed name="fed43797f13796529cb6731385d6f8f3"> 4432 4433#### Example Output 4434 4435~~~~ 4436[ 1.0000 0.0000 3.0000][ 0.0000 2.0000 4.0000][ 0.0000 0.0000 1.0000] 4437~~~~ 4438 4439</fiddle-embed></div> 4440 4441### See Also 4442 4443<a href='#SkMatrix_setScale'>setScale</a> <a href='#SkMatrix_preTranslate'>preTranslate</a> <a href='#SkMatrix_postTranslate'>postTranslate</a> 4444 4445<a name='SkMatrix_isFinite'></a> 4446 4447--- 4448 4449<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0"> 4450bool <a href='#SkMatrix_isFinite'>isFinite</a>()const 4451</pre> 4452 4453Returns true if all elements of the <a href='SkMatrix_Reference#Matrix'>matrix</a> are finite. Returns false if any 4454element is infinity, or NaN. 4455 4456### Return Value 4457 4458true if <a href='SkMatrix_Reference#Matrix'>matrix</a> has only finite elements 4459 4460### Example 4461 4462<div><fiddle-embed name="bc6c6f6a5df770287120d87f81b922eb"> 4463 4464#### Example Output 4465 4466~~~~ 4467[ 1.0000 0.0000 nan][ 0.0000 1.0000 0.0000][ 0.0000 0.0000 1.0000] 4468matrix is finite: false 4469matrix != matrix 4470~~~~ 4471 4472</fiddle-embed></div> 4473 4474### See Also 4475 4476operator== 4477 4478