SkPath Reference
===
---
class SkPath {
enum Direction : int {
kCW_Direction,
kCCW_Direction,
};
SkPath();
SkPath(const SkPath& path);
~SkPath();
SkPath& operator=(const SkPath& path);
friend bool operator==(const SkPath& a, const SkPath& b);
friend bool operator!=(const SkPath& a, const SkPath& b);
bool isInterpolatable(const SkPath& compare) const;
bool interpolate(const SkPath& ending, SkScalar weight, SkPath* out) const;
enum FillType {
kWinding_FillType,
kEvenOdd_FillType,
kInverseWinding_FillType,
kInverseEvenOdd_FillType,
};
FillType getFillType() const;
void setFillType(FillType ft);
bool isInverseFillType() const;
void toggleInverseFillType();
enum Convexity : uint8_t {
kUnknown_Convexity,
kConvex_Convexity,
kConcave_Convexity,
};
Convexity getConvexity() const;
Convexity getConvexityOrUnknown() const;
void setConvexity(Convexity convexity);
bool isConvex() const;
bool isOval(SkRect* bounds) const;
bool isRRect(SkRRect* rrect) const;
SkPath& reset();
SkPath& rewind();
bool isEmpty() const;
bool isLastContourClosed() const;
bool isFinite() const;
bool isVolatile() const;
void setIsVolatile(bool isVolatile);
static bool IsLineDegenerate(const SkPoint& p1, const SkPoint& p2, bool exact);
static bool IsQuadDegenerate(const SkPoint& p1, const SkPoint& p2,
const SkPoint& p3, bool exact);
static bool IsCubicDegenerate(const SkPoint& p1, const SkPoint& p2,
const SkPoint& p3, const SkPoint& p4, bool exact);
bool isLine(SkPoint line[2]) const;
int countPoints() const;
SkPoint getPoint(int index) const;
int getPoints(SkPoint points[], int max) const;
int countVerbs() const;
int getVerbs(uint8_t verbs[], int max) const;
void swap(SkPath& other);
const SkRect& getBounds() const;
void updateBoundsCache() const;
SkRect computeTightBounds() const;
bool conservativelyContainsRect(const SkRect& rect) const;
void incReserve(int extraPtCount);
void shrinkToFit();
SkPath& moveTo(SkScalar x, SkScalar y);
SkPath& moveTo(const SkPoint& p);
SkPath& rMoveTo(SkScalar dx, SkScalar dy);
SkPath& lineTo(SkScalar x, SkScalar y);
SkPath& lineTo(const SkPoint& p);
SkPath& rLineTo(SkScalar dx, SkScalar dy);
SkPath& quadTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2);
SkPath& quadTo(const SkPoint& p1, const SkPoint& p2);
SkPath& rQuadTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2);
SkPath& conicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2,
SkScalar w);
SkPath& conicTo(const SkPoint& p1, const SkPoint& p2, SkScalar w);
SkPath& rConicTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2,
SkScalar w);
SkPath& cubicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2,
SkScalar x3, SkScalar y3);
SkPath& cubicTo(const SkPoint& p1, const SkPoint& p2, const SkPoint& p3);
SkPath& rCubicTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2,
SkScalar dx3, SkScalar dy3);
SkPath& arcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo);
SkPath& arcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius);
SkPath& arcTo(const SkPoint p1, const SkPoint p2, SkScalar radius);
enum ArcSize {
kSmall_ArcSize,
kLarge_ArcSize,
};
SkPath& arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc,
Direction sweep, SkScalar x, SkScalar y);
SkPath& arcTo(const SkPoint r, SkScalar xAxisRotate, ArcSize largeArc, Direction sweep,
const SkPoint xy);
SkPath& rArcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc,
Direction sweep, SkScalar dx, SkScalar dy);
SkPath& close();
static bool IsInverseFillType(FillType fill);
static FillType ConvertToNonInverseFillType(FillType fill);
static int ConvertConicToQuads(const SkPoint& p0, const SkPoint& p1, const SkPoint& p2,
SkScalar w, SkPoint pts[], int pow2);
bool isRect(SkRect* rect, bool* isClosed = nullptr, Direction* direction = nullptr) const;
bool isNestedFillRects(SkRect rect[2], Direction dirs[2] = nullptr) const;
SkPath& addRect(const SkRect& rect, Direction dir = kCW_Direction);
SkPath& addRect(const SkRect& rect, Direction dir, unsigned start);
SkPath& addRect(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom,
Direction dir = kCW_Direction);
SkPath& addOval(const SkRect& oval, Direction dir = kCW_Direction);
SkPath& addOval(const SkRect& oval, Direction dir, unsigned start);
SkPath& addCircle(SkScalar x, SkScalar y, SkScalar radius,
Direction dir = kCW_Direction);
SkPath& addArc(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle);
SkPath& addRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry,
Direction dir = kCW_Direction);
SkPath& addRoundRect(const SkRect& rect, const SkScalar radii[],
Direction dir = kCW_Direction);
SkPath& addRRect(const SkRRect& rrect, Direction dir = kCW_Direction);
SkPath& addRRect(const SkRRect& rrect, Direction dir, unsigned start);
SkPath& addPoly(const SkPoint pts[], int count, bool close);
SkPath& addPoly(const std::initializer_list<SkPoint>& list, bool close);
enum AddPathMode {
kAppend_AddPathMode,
kExtend_AddPathMode,
};
SkPath& addPath(const SkPath& src, SkScalar dx, SkScalar dy,
AddPathMode mode = kAppend_AddPathMode);
SkPath& addPath(const SkPath& src, AddPathMode mode = kAppend_AddPathMode);
SkPath& addPath(const SkPath& src, const SkMatrix& matrix,
AddPathMode mode = kAppend_AddPathMode);
SkPath& reverseAddPath(const SkPath& src);
void offset(SkScalar dx, SkScalar dy, SkPath* dst) const;
void offset(SkScalar dx, SkScalar dy);
void transform(const SkMatrix& matrix, SkPath* dst) const;
void transform(const SkMatrix& matrix);
bool getLastPt(SkPoint* lastPt) const;
void setLastPt(SkScalar x, SkScalar y);
void setLastPt(const SkPoint& p);
enum SegmentMask {
kLine_SegmentMask = 1 << 0,
kQuad_SegmentMask = 1 << 1,
kConic_SegmentMask = 1 << 2,
kCubic_SegmentMask = 1 << 3,
};
uint32_t getSegmentMasks() const;
enum Verb {
kMove_Verb,
kLine_Verb,
kQuad_Verb,
kConic_Verb,
kCubic_Verb,
kClose_Verb,
kDone_Verb,
};
bool contains(SkScalar x, SkScalar y) const;
void dump(SkWStream* stream, bool forceClose, bool dumpAsHex) const;
void dump() const;
void dumpHex() const;
size_t writeToMemory(void* buffer) const;
sk_sp<SkData> serialize() const;
size_t readFromMemory(const void* buffer, size_t length);
uint32_t getGenerationID() const;
bool isValid() const;
};
Paths contain geometry. Paths may be empty, or contain one or more Verbs that
outline a figure. Path always starts with a move verb to a Cartesian_Coordinate,
and may be followed by additional verbs that add lines or curves.
Adding a close verb makes the geometry into a continuous loop, a closed contour.
Paths may contain any number of contours, each beginning with a move verb.
Path contours may contain only a move verb, or may also contain lines,
Quadratic_Beziers, Conics, and Cubic_Beziers. Path contours may be open or
closed.
When used to draw a filled area, Path describes whether the fill is inside or
outside the geometry. Path also describes the winding rule used to fill
overlapping contours.
Internally, Path lazily computes metrics likes bounds and convexity. Call
SkPath::updateBoundsCache to make Path thread safe.
---
enum Verb {
kMove_Verb,
kLine_Verb,
kQuad_Verb,
kConic_Verb,
kCubic_Verb,
kClose_Verb,
kDone_Verb,
};
Verb instructs Path how to interpret one or more Point and optional Conic_Weight;
manage Contour, and terminate Path.
### Constants
| Const |
Value |
Description |
|---|
SkPath::kMove_Verb |
0 |
Consecutive kMove_Verb are preserved but all but the last kMove_Verb is
ignored. kMove_Verb after other Verbs implicitly closes the previous Contour
if SkPaint::kFill_Style is set when drawn; otherwise, stroke is drawn open.
kMove_Verb as the last Verb is preserved but ignored.
|
SkPath::kLine_Verb |
1 |
Line is a straight segment from Point to Point. Consecutive kLine_Verb
extend Contour. kLine_Verb at same position as prior kMove_Verb is
preserved, and draws Point if SkPaint::kStroke_Style is set, and
SkPaint::Cap is SkPaint::kSquare_Cap or SkPaint::kRound_Cap. kLine_Verb
at same position as prior line or curve Verb is preserved but is ignored.
|
SkPath::kQuad_Verb |
2 |
Adds Quad from Last_Point, using control Point, and end Point.
Quad is a parabolic section within tangents from Last_Point to control Point,
and control Point to end Point.
|
SkPath::kConic_Verb |
3 |
Adds Conic from Last_Point, using control Point, end Point, and Conic_Weight.
Conic is a elliptical, parabolic, or hyperbolic section within tangents
from Last_Point to control Point, and control Point to end Point, constrained
by Conic_Weight. Conic_Weight less than one is elliptical; equal to one is
parabolic (and identical to Quad); greater than one hyperbolic.
|
SkPath::kCubic_Verb |
4 |
Adds Cubic from Last_Point, using two control Points, and end Point.
Cubic is a third-order Bezier_Curve section within tangents from Last_Point
to first control Point, and from second control Point to end Point.
|
SkPath::kClose_Verb |
5 |
Closes Contour, connecting Last_Point to kMove_Verb Point. Consecutive
kClose_Verb are preserved but only first has an effect. kClose_Verb after
kMove_Verb has no effect.
|
SkPath::kDone_Verb |
6 |
Not in Verb_Array, but returned by Path iterator.
|
Each Verb has zero or more Points stored in Path.
Path iterator returns complete curve descriptions, duplicating shared Points
for consecutive entries.
| Verb | Allocated Points | Iterated Points | Weights |
| --- | --- | --- | --- |
| kMove_Verb | 1 | 1 | 0 |
| kLine_Verb | 1 | 2 | 0 |
| kQuad_Verb | 2 | 3 | 0 |
| kConic_Verb | 2 | 3 | 1 |
| kCubic_Verb | 3 | 4 | 0 |
| kClose_Verb | 0 | 1 | 0 |
| kDone_Verb | -- | 0 | 0 |
### Example
#### Example Output
~~~~
verb count: 7
verbs: kMove_Verb kLine_Verb kQuad_Verb kClose_Verb kMove_Verb kCubic_Verb kConic_Verb
~~~~
---
enum Direction : int {
kCW_Direction,
kCCW_Direction,
};
Direction describes whether Contour is clockwise or counterclockwise.
When Path contains multiple overlapping Contours, Direction together with
Fill_Type determines whether overlaps are filled or form holes.
Direction also determines how Contour is measured. For instance, dashing
measures along Path to determine where to start and stop stroke; Direction
will change dashed results as it steps clockwise or counterclockwise.
Closed Contours like Rect, Round_Rect, Circle, and Oval added with
kCW_Direction travel clockwise; the same added with kCCW_Direction
travel counterclockwise.
### Constants
### Example
### See Also
arcTo rArcTo isRect isNestedFillRects addRect addOval
---
SkPath()
Constructs an empty SkPath. By default, SkPath has no verbs, no SkPoint, and no weights.
SkPath::FillType is set to kWinding_FillType.
### Return Value
empty SkPath
### Example
#### Example Output
~~~~
path is empty
~~~~
### See Also
reset rewind
---
SkPath(const SkPath& path)
Constructs a copy of an existing path.
Copy constructor makes two paths identical by value. Internally, path and
the returned result share pointer values. The underlying verb array, SkPoint array
and weights are copied when modified.
Creating a SkPath copy is very efficient and never allocates memory.
SkPath are always copied by value from the interface; the underlying shared
pointers are not exposed.
### Parameters
### Return Value
copy of SkPath
### Example
Modifying one
path does not effect another, even if they started as copies
of each other.
~SkPath()
Releases ownership of any shared data and deletes data if SkPath is sole owner.
### Example
delete calls
Path destructor, but copy of original in path2 is unaffected.
SkPath& operator=(const SkPath& path)
Constructs a copy of an existing path.
SkPath assignment makes two paths identical by value. Internally, assignment
shares pointer values. The underlying verb array, SkPoint array and weights
are copied when modified.
Copying SkPath by assignment is very efficient and never allocates memory.
SkPath are always copied by value from the interface; the underlying shared
pointers are not exposed.
### Parameters
### Return Value
SkPath copied by value
### Example
#### Example Output
~~~~
path1 bounds = 10, 20, 30, 40
path2 bounds = 10, 20, 30, 40
~~~~
### See Also
swap SkPath(const SkPath& path)
---
bool operator==(const SkPath& a, const SkPath& b)
Compares a and b; returns true if SkPath::FillType, verb array, SkPoint array, and weights
are equivalent.
### Parameters
### Return Value
true if SkPath pair are equivalent
### Example
#### Example Output
~~~~
empty one == two
moveTo one != two
rewind one == two
reset one == two
~~~~
### See Also
operator!=(const SkPath& a, const SkPath& b) operator=(const SkPath& path)
---
bool operator!=(const SkPath& a, const SkPath& b)
Compares a and b; returns true if SkPath::FillType, verb array, SkPoint array, and weights
are not equivalent.
### Parameters
### Return Value
true if SkPath pair are not equivalent
### Example
Path pair are equal though their convexity is not equal.
#### Example Output
~~~~
empty one == two
add rect one == two
setConvexity one == two
convexity !=
~~~~
bool isInterpolatable(const SkPath& compare)const
Returns true if SkPath contain equal verbs and equal weights.
If SkPath contain one or more conics, the weights must match.
conicTo() may add different verbs depending on conic weight, so it is not
trivial to interpolate a pair of SkPath containing conics with different
conic weight values.
### Parameters
### Return Value
true if SkPath verb array and weights are equivalent
### Example
#### Example Output
~~~~
paths are interpolatable
~~~~
### See Also
isInterpolatable
---
bool interpolate(const SkPath& ending, SkScalar weight, SkPath* out)const
Interpolates between Paths with Point_Array of equal size.
Copy Verb_Array and Weights to out, and set out Point_Array to a weighted
average of this Point_Array and ending Point_Array, using the formula:
(Path Point * weight) + ending Point * (1 - weight).
weight is most useful when between zero (ending Point_Array) and
one (this Point_Array); will work with values outside of this
range.
interpolate() returns false and leaves out unchanged if Point_Array is not
the same size as ending Point_Array. Call isInterpolatable to check Path
compatibility prior to calling interpolate().
### Parameters
### Return Value
true if Paths contain same number of Points
### Example
### See Also
isInterpolatable
---
enum FillType {
kWinding_FillType,
kEvenOdd_FillType,
kInverseWinding_FillType,
kInverseEvenOdd_FillType,
};
Fill_Type selects the rule used to fill Path. Path set to kWinding_FillType
fills if the sum of Contour edges is not zero, where clockwise edges add one, and
counterclockwise edges subtract one. Path set to kEvenOdd_FillType fills if the
number of Contour edges is odd. Each Fill_Type has an inverse variant that
reverses the rule:
kInverseWinding_FillType fills where the sum of Contour edges is zero;
kInverseEvenOdd_FillType fills where the number of Contour edges is even.
### Example
The top row has two clockwise rectangles. The second row has one clockwise and
one counterclockwise rectangle. The even-odd variants draw the same. The
winding variants draw the top rectangle overlap, which has a winding of 2, the
same as the outer parts of the top rectangles, which have a winding of 1.
### See Also
SkPaint::Style Direction getFillType setFillType
---
FillType getFillType()const
Returns FillType, the rule used to fill SkPath. FillType of a new SkPath is
kWinding_FillType.
### Return Value
one of: kWinding_FillType, kEvenOdd_FillType, kInverseWinding_FillType,
kInverseEvenOdd_FillType
### Example
#### Example Output
~~~~
default path fill type is kWinding_FillType
~~~~
### See Also
FillType setFillType isInverseFillType
---
void setFillType(FillType ft)
Sets FillType, the rule used to fill SkPath. While there is no check
that ft is legal, values outside of FillType are not supported.
### Parameters
kInverseEvenOdd_FillType
### Example
If empty
Path is set to inverse
FillType, it fills all pixels.
bool isInverseFillType()const
Returns if FillType describes area outside SkPath geometry. The inverse fill area
extends indefinitely.
### Return Value
true if FillType is kInverseWinding_FillType or kInverseEvenOdd_FillType
### Example
#### Example Output
~~~~
default path fill type is inverse: false
~~~~
### See Also
FillType getFillType setFillType toggleInverseFillType
---
void toggleInverseFillType()
Replaces FillType with its inverse. The inverse of FillType describes the area
unmodified by the original FillType.
| FillType | toggled FillType |
| --- | --- |
| kWinding_FillType | kInverseWinding_FillType |
| kEvenOdd_FillType | kInverseEvenOdd_FillType |
| kInverseWinding_FillType | kWinding_FillType |
| kInverseEvenOdd_FillType | kEvenOdd_FillType |
### Example
Path drawn normally and through its inverse touches every
pixel once.
enum Convexity : uint8_t {
kUnknown_Convexity,
kConvex_Convexity,
kConcave_Convexity,
};
Path is convex if it contains one Contour and Contour loops no more than
360 degrees, and Contour angles all have same Direction. Convex Path
may have better performance and require fewer resources on GPU_Surface.
Path is concave when either at least one Direction change is clockwise and
another is counterclockwise, or the sum of the changes in Direction is not 360
degrees.
Initially Path Convexity is kUnknown_Convexity. Path Convexity is computed
if needed by destination Surface.
### Constants
### Example
### See Also
Contour Direction getConvexity getConvexityOrUnknown setConvexity isConvex
---
Convexity getConvexity()const
Computes SkPath::Convexity if required, and returns stored value.
SkPath::Convexity is computed if stored value is kUnknown_Convexity,
or if SkPath has been altered since SkPath::Convexity was computed or set.
### Return Value
computed or stored SkPath::Convexity
### Example
### See Also
Convexity Contour Direction getConvexityOrUnknown setConvexity isConvex
---
Convexity getConvexityOrUnknown()const
Returns last computed SkPath::Convexity, or kUnknown_Convexity if
SkPath has been altered since SkPath::Convexity was computed or set.
### Return Value
stored SkPath::Convexity
### Example
### See Also
Convexity Contour Direction getConvexity setConvexity isConvex
---
void setConvexity(Convexity convexity)
Stores convexity so that it is later returned by getConvexity() or getConvexityOrUnknown().
convexity may differ from getConvexity(), although setting an incorrect value may
cause incorrect or inefficient drawing.
If convexity is kUnknown_Convexity: getConvexity() will
compute SkPath::Convexity, and getConvexityOrUnknown() will return kUnknown_Convexity.
If convexity is kConvex_Convexity or kConcave_Convexity, getConvexity()
and getConvexityOrUnknown() will return convexity until the path is
altered.
### Parameters
### Example
### See Also
Convexity Contour Direction getConvexity getConvexityOrUnknown isConvex
---
bool isConvex()const
Computes SkPath::Convexity if required, and returns true if value is kConvex_Convexity.
If setConvexity() was called with kConvex_Convexity or kConcave_Convexity, and
the path has not been altered, SkPath::Convexity is not recomputed.
### Return Value
true if SkPath::Convexity stored or computed is kConvex_Convexity
### Example
Concave shape is erroneously considered convex after a forced call to
setConvexity.
bool isOval(SkRect* bounds)const
Returns true if this path is recognized as an oval or circle.
bounds receives bounds of oval.
bounds is unmodified if oval is not found.
### Parameters
### Return Value
true if SkPath is recognized as an oval or circle
### Example
### See Also
Oval addCircle addOval
---
bool isRRect(SkRRect* rrect)const
Returns true if path is representable as SkRRect.
Returns false if path is representable as oval, circle, or SkRect.
rrect receives bounds of SkRRect.
rrect is unmodified if SkRRect is not found.
### Parameters
### Return Value
true if SkPath contains only SkRRect
### Example
Draw rounded rectangle and its bounds.
SkPath& reset()
Sets SkPath to its initial state.
Removes verb array, SkPoint array, and weights, and sets FillType to kWinding_FillType.
Internal storage associated with SkPath is released.
### Return Value
reference to SkPath
### Example
### See Also
rewind()
---
SkPath& rewind()
Sets SkPath to its initial state, preserving internal storage.
Removes verb array, SkPoint array, and weights, and sets FillType to kWinding_FillType.
Internal storage associated with SkPath is retained.
Use rewind() instead of reset() if SkPath storage will be reused and performance
is critical.
### Return Value
reference to SkPath
### Example
Although path1 retains its internal storage, it is indistinguishable from
a newly initialized
path.
bool isEmpty()const
Returns if SkPath is empty.
Empty SkPath may have FillType but has no SkPoint, SkPath::Verb, or conic weight.
SkPath() constructs empty SkPath; reset() and rewind() make SkPath empty.
### Return Value
true if the path contains no SkPath::Verb array
### Example
#### Example Output
~~~~
initial path is empty
after moveTo path is not empty
after rewind path is empty
after lineTo path is not empty
after reset path is empty
~~~~
### See Also
SkPath() reset() rewind()
---
bool isLastContourClosed()const
Returns if contour is closed.
Contour is closed if SkPath SkPath::Verb array was last modified by close(). When stroked,
closed contour draws SkPaint::Join instead of SkPaint::Cap at first and last SkPoint.
### Return Value
true if the last contour ends with a kClose_Verb
### Example
#### Example Output
~~~~
initial last contour is not closed
after close last contour is not closed
after lineTo last contour is not closed
after close last contour is closed
~~~~
### See Also
close()
---
bool isFinite()const
Returns true for finite SkPoint array values between negative SK_ScalarMax and
positive SK_ScalarMax. Returns false for any SkPoint array value of
SK_ScalarInfinity, SK_ScalarNegativeInfinity, or SK_ScalarNaN.
### Return Value
true if all SkPoint values are finite
### Example
#### Example Output
~~~~
initial path is finite
after line path is finite
after scale path is not finite
~~~~
### See Also
SkScalar
---
bool isVolatile()const
Returns true if the path is volatile; it will not be altered or discarded
by the caller after it is drawn. SkPath by default have volatile set false, allowing
SkSurface to attach a cache of data which speeds repeated drawing. If true, SkSurface
may not speed repeated drawing.
### Return Value
true if caller will alter SkPath after drawing
### Example
#### Example Output
~~~~
volatile by default is false
~~~~
### See Also
setIsVolatile
---
void setIsVolatile(bool isVolatile)
Specifies whether SkPath is volatile; whether it will be altered or discarded
by the caller after it is drawn. SkPath by default have volatile set false, allowing
SkBaseDevice to attach a cache of data which speeds repeated drawing.
Mark temporary paths, discarded or modified after use, as volatile
to inform SkBaseDevice that the path need not be cached.
Mark animating SkPath volatile to improve performance.
Mark unchanging SkPath non-volatile to improve repeated rendering.
raster surface SkPath draws are affected by volatile for some shadows.
GPU surface SkPath draws are affected by volatile for some shadows and concave geometries.
### Parameters
### Example
### See Also
isVolatile
---
static bool IsLineDegenerate(const SkPoint& p1, const SkPoint& p2, bool exact)
Tests if line between SkPoint pair is degenerate.
Line with no length or that moves a very short distance is degenerate; it is
treated as a point.
exact changes the equality test. If true, returns true only if p1 equals p2.
If false, returns true if p1 equals or nearly equals p2.
### Parameters
### Return Value
true if line is degenerate; its length is effectively zero
### Example
As single precision floats, 100 and 100.000001 have the same bit representation,
and are exactly equal. 100 and 100.0001 have different bit representations, and
are not exactly equal, but are nearly equal.
#### Example Output
~~~~
line from (100,100) to (100,100) is degenerate, nearly
line from (100,100) to (100,100) is degenerate, exactly
line from (100,100) to (100.0001,100.0001) is degenerate, nearly
line from (100,100) to (100.0001,100.0001) is not degenerate, exactly
~~~~
static bool IsQuadDegenerate(const SkPoint& p1, const SkPoint& p2, const SkPoint& p3, bool exact)
Tests if quad is degenerate.
Quad with no length or that moves a very short distance is degenerate; it is
treated as a point.
### Parameters
if false, returns true if p1, p2, and p3 are equal or nearly equal
### Return Value
true if quad is degenerate; its length is effectively zero
### Example
As single precision floats: 100, 100.00001, and 100.00002 have different bit representations
but nearly the same value. Translating all three by 1000 gives them the same bit representation;
the fractional portion of the number can not be represented by the float and is lost.
#### Example Output
~~~~
quad (100,100), (100.00001,100.00001), (100.00002,100.00002) is degenerate, nearly
quad (1100,1100), (1100,1100), (1100,1100) is degenerate, nearly
quad (100,100), (100.00001,100.00001), (100.00002,100.00002) is not degenerate, exactly
quad (1100,1100), (1100,1100), (1100,1100) is degenerate, exactly
~~~~
static bool IsCubicDegenerate(const SkPoint& p1, const SkPoint& p2, const SkPoint& p3,
const SkPoint& p4, bool exact)
Tests if cubic is degenerate.
Cubic with no length or that moves a very short distance is degenerate; it is
treated as a point.
### Parameters
if false, returns true if p1, p2, p3, and p4 are equal or nearly equal
### Return Value
true if cubic is degenerate; its length is effectively zero
### Example
#### Example Output
~~~~
0.00024414062 is degenerate
0.00024414065 is length
~~~~
---
bool isLine(SkPoint line[2])const
Returns true if SkPath contains only one line;
SkPath::Verb array has two entries: kMove_Verb, kLine_Verb.
If SkPath contains one line and line is not nullptr, line is set to
line start point and line end point.
Returns false if SkPath is not one line; line is unaltered.
### Parameters
### Return Value
true if SkPath contains exactly one line
### Example
#### Example Output
~~~~
empty is not line
zero line is line (0,0) (0,0)
line is line (10,10) (20,20)
second move is not line
~~~~
Point_Array contains Points satisfying the allocated Points for
each Verb in Verb_Array. For instance, Path containing one Contour with Line
and Quad is described by Verb_Array: kMove_Verb, kLine_Verb, kQuad_Verb; and
one Point for move, one Point for Line, two Points for Quad; totaling four Points.
Point_Array may be read directly from Path with getPoints, or inspected with
getPoint, with Iter, or with RawIter.
---
int getPoints(SkPoint points[], int max)const
Returns number of points in SkPath. Up to max points are copied.
points may be nullptr; then, max must be zero.
If max is greater than number of points, excess points storage is unaltered.
### Parameters
### Return Value
SkPath SkPoint array length
### Example
#### Example Output
~~~~
no points point count: 3
zero max point count: 3
too small point count: 3 (0,0) (20,20)
just right point count: 3 (0,0) (20,20) (-10,-10)
~~~~
### See Also
countPoints getPoint
---
int countPoints()const
Returns the number of points in SkPath.
SkPoint count is initially zero.
### Return Value
SkPath SkPoint array length
### Example
#### Example Output
~~~~
empty point count: 0
zero line point count: 2
line point count: 2
second move point count: 3
~~~~
### See Also
getPoints
---
SkPoint getPoint(int index)const
Returns SkPoint at index in SkPoint array. Valid range for index is
0 to countPoints() - 1.
Returns (0, 0) if index is out of range.
### Parameters
### Return Value
SkPoint array value or (0, 0)
### Example
#### Example Output
~~~~
point 0: (-10,-10)
point 1: (10,10)
~~~~
### See Also
countPoints getPoints
Verb_Array always starts with kMove_Verb.
If kClose_Verb is not the last entry, it is always followed by kMove_Verb;
the quantity of kMove_Verb equals the Contour count.
Verb_Array does not include or count kDone_Verb; it is a convenience
returned when iterating through Verb_Array.
Verb_Array may be read directly from Path with getVerbs, or inspected with Iter,
or with RawIter.
---
int countVerbs()const
Returns the number of verbs: kMove_Verb, kLine_Verb, kQuad_Verb, kConic_Verb,
kCubic_Verb, and kClose_Verb; added to SkPath.
### Return Value
length of verb array
### Example
#### Example Output
~~~~
empty verb count: 0
round rect verb count: 10
~~~~
### See Also
getVerbs Iter RawIter
---
int getVerbs(uint8_t verbs[], int max)const
Returns the number of verbs in the path. Up to max verbs are copied. The
verbs are copied as one byte per verb.
### Parameters
### Return Value
the actual number of verbs in the path
### Example
#### Example Output
~~~~
no verbs verb count: 3
zero max verb count: 3
too small verb count: 3 move line
just right verb count: 3 move line line
~~~~
### See Also
countVerbs getPoints Iter RawIter
---
void swap(SkPath& other)
Exchanges the verb array, SkPoint array, weights, and SkPath::FillType with other.
Cached state is also exchanged. swap() internally exchanges pointers, so
it is lightweight and does not allocate memory.
swap() usage has largely been replaced by operator=(const SkPath& path).
SkPath do not copy their content on assignment until they are written to,
making assignment as efficient as swap().
### Parameters
### Example
#### Example Output
~~~~
path1 bounds = 0, 0, 0, 0
path2 bounds = 10, 20, 30, 40
~~~~
### See Also
operator=(const SkPath& path)
---
const SkRect& getBounds()const
Returns minimum and maximum axes values of SkPoint array.
Returns (0, 0, 0, 0) if SkPath contains no points. Returned bounds width and height may
be larger or smaller than area affected when SkPath is drawn.
SkRect returned includes all SkPoint added to SkPath, including SkPoint associated with
kMove_Verb that define empty contours.
### Return Value
bounds of all SkPoint in SkPoint array
### Example
Bounds of upright
Circle can be predicted from center and radius.
Bounds of rotated
Circle includes control
Points outside of filled area.
void updateBoundsCache()const
Updates internal bounds so that subsequent calls to getBounds() are instantaneous.
Unaltered copies of SkPath may also access cached bounds through getBounds().
For now, identical to calling getBounds() and ignoring the returned value.
Call to prepare SkPath subsequently drawn from multiple threads,
to avoid a race condition where each draw separately computes the bounds.
### Example
#### Example Output
~~~~
#Volatile
uncached avg: 0.18048 ms
cached avg: 0.182784 ms
~~~~
### See Also
getBounds
---
SkRect computeTightBounds()const
Returns minimum and maximum axes values of the lines and curves in SkPath.
Returns (0, 0, 0, 0) if SkPath contains no points.
Returned bounds width and height may be larger or smaller than area affected
when SkPath is drawn.
Includes SkPoint associated with kMove_Verb that define empty
contours.
Behaves identically to getBounds() when SkPath contains
only lines. If SkPath contains curves, computed bounds includes
the maximum extent of the quad, conic, or cubic; is slower than getBounds();
and unlike getBounds(), does not cache the result.
### Return Value
tight bounds of curves in SkPath
### Example
#### Example Output
~~~~
empty bounds = 0, 0, 0, 0
circle bounds = 25, 20, 75, 70
rotated circle bounds = 25, 20, 75, 70
~~~~
### See Also
getBounds
---
bool conservativelyContainsRect(const SkRect& rect)const
Returns true if rect is contained by SkPath.
May return false when rect is contained by SkPath.
For now, only returns true if SkPath has one contour and is convex.
rect may share points and edges with SkPath and be contained.
Returns true if rect is empty, that is, it has zero width or height; and
the SkPoint or line described by rect is contained by SkPath.
### Parameters
### Return Value
true if rect is contained
### Example
Rect is drawn in blue if it is contained by red
Path.
void incReserve(int extraPtCount)
Grows SkPath verb array and SkPoint array to contain extraPtCount additional SkPoint.
May improve performance and use less memory by
reducing the number and size of allocations when creating SkPath.
### Parameters
### Example
### See Also
Point_Array
---
void shrinkToFit()
Shrinks SkPath verb array and SkPoint array storage to discard unused capacity.
May reduce the heap overhead for SkPath known to be fully constructed.
### See Also
incReserve
---
SkPath& moveTo(SkScalar x, SkScalar y)
Adds beginning of contour at SkPoint (x, y).
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
Contour lineTo rMoveTo quadTo conicTo cubicTo close()
---
SkPath& moveTo(const SkPoint& p)
Adds beginning of contour at SkPoint p.
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
Contour lineTo rMoveTo quadTo conicTo cubicTo close()
---
SkPath& rMoveTo(SkScalar dx, SkScalar dy)
Adds beginning of contour relative to last point.
If SkPath is empty, starts contour at (dx, dy).
Otherwise, start contour at last point offset by (dx, dy).
Function name stands for "relative move to".
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
Contour lineTo moveTo quadTo conicTo cubicTo close()
---
SkPath& lineTo(SkScalar x, SkScalar y)
Adds line from last point to (x, y). If SkPath is empty, or last SkPath::Verb is
kClose_Verb, last point is set to (0, 0) before adding line.
lineTo() appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed.
lineTo() then appends kLine_Verb to verb array and (x, y) to SkPoint array.
### Parameters
x |
end of added line on x-axis |
y |
end of added line on y-axis |
### Return Value
reference to SkPath
### Example
### See Also
Contour moveTo rLineTo addRect
---
SkPath& lineTo(const SkPoint& p)
Adds line from last point to SkPoint p. If SkPath is empty, or last SkPath::Verb is
kClose_Verb, last point is set to (0, 0) before adding line.
lineTo() first appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed.
lineTo() then appends kLine_Verb to verb array and SkPoint p to SkPoint array.
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
Contour moveTo rLineTo addRect
---
SkPath& rLineTo(SkScalar dx, SkScalar dy)
Adds line from last point to vector (dx, dy). If SkPath is empty, or last SkPath::Verb is
kClose_Verb, last point is set to (0, 0) before adding line.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed;
then appends kLine_Verb to verb array and line end to SkPoint array.
Line end is last point plus vector (dx, dy).
Function name stands for "relative line to".
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
Contour moveTo lineTo addRect
---
Quad describes a Quadratic_Bezier, a second-order curve identical to a section
of a parabola. Quad begins at a start Point, curves towards a control Point,
and then curves to an end Point.
### Example
Quad is a special case of Conic where Conic_Weight is set to one.
Quad is always contained by the triangle connecting its three Points. Quad
begins tangent to the line between start Point and control Point, and ends
tangent to the line between control Point and end Point.
### Example
---
SkPath& quadTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2)
Adds quad from last point towards (x1, y1), to (x2, y2).
If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to (0, 0)
before adding quad.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed;
then appends kQuad_Verb to verb array; and (x1, y1), (x2, y2)
to SkPoint array.
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
Contour moveTo conicTo rQuadTo
---
SkPath& quadTo(const SkPoint& p1, const SkPoint& p2)
Adds quad from last point towards SkPoint p1, to SkPoint p2.
If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to (0, 0)
before adding quad.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed;
then appends kQuad_Verb to verb array; and SkPoint p1, p2
to SkPoint array.
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
Contour moveTo conicTo rQuadTo
---
SkPath& rQuadTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2)
Adds quad from last point towards vector (dx1, dy1), to vector (dx2, dy2).
If SkPath is empty, or last SkPath::Verb
is kClose_Verb, last point is set to (0, 0) before adding quad.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array,
if needed; then appends kQuad_Verb to verb array; and appends quad
control and quad end to SkPoint array.
Quad control is last point plus vector (dx1, dy1).
Quad end is last point plus vector (dx2, dy2).
Function name stands for "relative quad to".
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
Contour moveTo conicTo quadTo
Conic describes a conical section: a piece of an ellipse, or a piece of a
parabola, or a piece of a hyperbola. Conic begins at a start Point,
curves towards a control Point, and then curves to an end Point. The influence
of the control Point is determined by Conic_Weight.
Each Conic in Path adds two Points and one Conic_Weight. Conic_Weights in Path
may be inspected with Iter, or with RawIter.
---
Weight determines both the strength of the control Point and the type of Conic.
Weight varies from zero to infinity. At zero, Weight causes the control Point to
have no effect; Conic is identical to a line segment from start Point to end
point. If Weight is less than one, Conic follows an elliptical arc.
If Weight is exactly one, then Conic is identical to Quad; Conic follows a
parabolic arc. If Weight is greater than one, Conic follows a hyperbolic
arc. If Weight is infinity, Conic is identical to two line segments, connecting
start Point to control Point, and control Point to end Point.
### Example
#### Example Output
~~~~
move {0, 0},
quad {0, 0}, {20, 30}, {50, 60},
done
~~~~
If weight is less than one, Conic is an elliptical segment.
### Example
A 90 degree circular
arc has the weight
1 / sqrt(2).
#### Example Output
~~~~
move {0, 0},
line {0, 0}, {20, 0},
line {20, 0}, {20, 20},
done
~~~~
---
SkPath& conicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar w)
Adds conic from last point towards (x1, y1), to (x2, y2), weighted by w.
If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to (0, 0)
before adding conic.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed.
If w is finite and not one, appends kConic_Verb to verb array;
and (x1, y1), (x2, y2) to SkPoint array; and w to conic weights.
If w is one, appends kQuad_Verb to verb array, and
(x1, y1), (x2, y2) to SkPoint array.
If w is not finite, appends kLine_Verb twice to verb array, and
(x1, y1), (x2, y2) to SkPoint array.
### Parameters
### Return Value
reference to SkPath
### Example
As weight increases,
curve is pulled towards control
point.
The bottom two
curves are elliptical; the next is parabolic; the
top
curve is hyperbolic.
SkPath& conicTo(const SkPoint& p1, const SkPoint& p2, SkScalar w)
Adds conic from last point towards SkPoint p1, to SkPoint p2, weighted by w.
If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to (0, 0)
before adding conic.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed.
If w is finite and not one, appends kConic_Verb to verb array;
and SkPoint p1, p2 to SkPoint array; and w to conic weights.
If w is one, appends kQuad_Verb to verb array, and SkPoint p1, p2
to SkPoint array.
If w is not finite, appends kLine_Verb twice to verb array, and
SkPoint p1, p2 to SkPoint array.
### Parameters
### Return Value
reference to SkPath
### Example
Conics and
arcs use identical representations. As the
arc sweep increases
the
Conic_Weight also increases, but remains smaller than one.
SkPath& rConicTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2, SkScalar w)
Adds conic from last point towards vector (dx1, dy1), to vector (dx2, dy2),
weighted by w. If SkPath is empty, or last SkPath::Verb
is kClose_Verb, last point is set to (0, 0) before adding conic.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array,
if needed.
If w is finite and not one, next appends kConic_Verb to verb array,
and w is recorded as conic weight; otherwise, if w is one, appends
kQuad_Verb to verb array; or if w is not finite, appends kLine_Verb
twice to verb array.
In all cases appends SkPoint control and end to SkPoint array.
control is last point plus vector (dx1, dy1).
end is last point plus vector (dx2, dy2).
Function name stands for "relative conic to".
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
conicTo arcTo addArc quadTo
---
Cubic describes a Bezier_Curve segment described by a third-order polynomial.
Cubic begins at a start Point, curving towards the first control Point;
and curves from the end Point towards the second control Point.
### Example
---
SkPath& cubicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar x3, SkScalar y3)
Adds cubic from last point towards (x1, y1), then towards (x2, y2), ending at
(x3, y3). If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to
(0, 0) before adding cubic.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed;
then appends kCubic_Verb to verb array; and (x1, y1), (x2, y2), (x3, y3)
to SkPoint array.
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
Contour moveTo rCubicTo quadTo
---
SkPath& cubicTo(const SkPoint& p1, const SkPoint& p2, const SkPoint& p3)
Adds cubic from last point towards SkPoint p1, then towards SkPoint p2, ending at
SkPoint p3. If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to
(0, 0) before adding cubic.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed;
then appends kCubic_Verb to verb array; and SkPoint p1, p2, p3
to SkPoint array.
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
Contour moveTo rCubicTo quadTo
---
SkPath& rCubicTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2, SkScalar dx3, SkScalar dy3)
Adds cubic from last point towards vector (dx1, dy1), then towards
vector (dx2, dy2), to vector (dx3, dy3).
If SkPath is empty, or last SkPath::Verb
is kClose_Verb, last point is set to (0, 0) before adding cubic.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array,
if needed; then appends kCubic_Verb to verb array; and appends cubic
control and cubic end to SkPoint array.
Cubic control is last point plus vector (dx1, dy1).
Cubic end is last point plus vector (dx2, dy2).
Function name stands for "relative cubic to".
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
Contour moveTo cubicTo quadTo
---
Arc can be constructed in a number of ways. Arc may be described by part of Oval and angles,
by start point and end point, and by radius and tangent lines. Each construction has advantages,
and some constructions correspond to Arc drawing in graphics standards.
All Arc draws are implemented by one or more Conic draws. When Conic_Weight is less than one,
Conic describes an Arc of some Oval or Circle.
CirclearcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo)
describes Arc as a piece of Oval, beginning at start angle, sweeping clockwise or counterclockwise,
which may continue Contour or start a new one. This construction is similar to PostScript and
HTML_Canvas arcs. Variation addArc always starts new Contour. SkCanvas::drawArc draws without
requiring Path.
PatharcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius)
describes Arc as tangent to the line segment from last Point added to Path to (x1, y1); and tangent
to the line segment from (x1, y1) to (x2, y2). This construction is similar to PostScript and
HTML_Canvas arcs.
arcsarcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc, Direction sweep, SkScalar x, SkScalar y)
describes Arc as part of Oval with radii (rx, ry), beginning at
last Point added to Path and ending at (x, y). More than one Arc satisfies this criteria,
so additional values choose a single solution. This construction is similar to SVG arcs.
conicTo describes Arc of less than 180 degrees as a pair of tangent lines and Conic_Weight.
conicTo can represent any Arc with a sweep less than 180 degrees at any rotation. All arcTo
constructions are converted to Conic data when added to Path.
| 1 suparcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo) |
| 2 parameter adds move to first point |
| 3 start angle must be multiple of 90 degrees |
| 4 suparcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius) |
| 5 suparcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc, Direction sweep, SkScalar x, SkScalar y) |
### Example
In the example above:
| 1 describes an arc from an oval, a starting angle, and a sweep angle. |
| 2 is similar to 1, but does not require building a path to draw. |
| 3 is similar to 1, but always begins new Contour. |
| 4 describes an arc from a pair of tangent lines and a radius. |
| 5 describes an arc from Oval center, arc start Point and arc end Point. |
| 6 describes an arc from a pair of tangent lines and a Conic_Weight. |
---
SkPath& arcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo)
Appends arc to SkPath. Arc added is part of ellipse
bounded by oval, from startAngle through sweepAngle. Both startAngle and
sweepAngle are measured in degrees, where zero degrees is aligned with the
positive x-axis, and positive sweeps extends arc clockwise.
arcTo() adds line connecting SkPath last SkPoint to initial arc SkPoint if forceMoveTo
is false and SkPath is not empty. Otherwise, added contour begins with first point
of arc. Angles greater than -360 and less than 360 are treated modulo 360.
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
addArc SkCanvas::drawArc conicTo
---
SkPath& arcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius)
Appends arc to SkPath, after appending line if needed. Arc is implemented by conic
weighted to describe part of circle. Arc is contained by tangent from
last SkPath point to (x1, y1), and tangent from (x1, y1) to (x2, y2). Arc
is part of circle sized to radius, positioned so it touches both tangent lines.
If last Path Point does not start Arc, arcTo appends connecting Line to Path.
The length of Vector from (x1, y1) to (x2, y2) does not affect Arc.
Arc sweep is always less than 180 degrees. If radius is zero, or if
tangents are nearly parallel, arcTo appends Line from last Path Point to (x1, y1).
arcTo appends at most one Line and one conic.
arcTo implements the functionality of PostScript arct and HTML Canvas arcTo.
### Parameters
x1 |
x-axis value common to pair of tangents |
y1 |
y-axis value common to pair of tangents |
x2 |
x-axis value end of second tangent |
y2 |
y-axis value end of second tangent |
radius |
distance from arc to circle center |
### Return Value
reference to SkPath
### Example
### Example
### Example
#### Example Output
~~~~
move to (156,20)
line (156,20),(79.2893,20)
conic (79.2893,20),(200,20),(114.645,105.355) weight 0.382683
~~~~
### See Also
conicTo
---
SkPath& arcTo(const SkPoint p1, const SkPoint p2, SkScalar radius)
Appends arc to SkPath, after appending line if needed. Arc is implemented by conic
weighted to describe part of circle. Arc is contained by tangent from
last SkPath point to p1, and tangent from p1 to p2. Arc
is part of circle sized to radius, positioned so it touches both tangent lines.
If last SkPath SkPoint does not start arc, arcTo() appends connecting line to SkPath.
The length of vector from p1 to p2 does not affect arc.
Arc sweep is always less than 180 degrees. If radius is zero, or if
tangents are nearly parallel, arcTo() appends line from last SkPath SkPoint to p1.
arcTo() appends at most one line and one conic.
arcTo() implements the functionality of PostScript arct and HTML Canvas arcTo.
### Parameters
### Return Value
reference to SkPath
### Example
#### Example Output
~~~~
move to (156,20)
line (156,20),(200,20)
~~~~
### See Also
conicTo
---
enum ArcSize {
kSmall_ArcSize,
kLarge_ArcSize,
};
Four axis-aligned Ovals with the same height and width intersect a pair of Points.
ArcSize and Direction select one of the four Ovals, by choosing the larger or smaller
arc between the Points; and by choosing the arc Direction, clockwise
or counterclockwise.
### Constants
### Example
Arc begins at top of
Oval pair and ends at bottom.
Arc can take four routes to get there.
Two routes are large, and two routes are counterclockwise. The one route both large
and counterclockwise is blue.
SkPath& arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc, Direction sweep,
SkScalar x, SkScalar y)
Appends arc to SkPath. Arc is implemented by one or more conics weighted to
describe part of oval with radii (rx, ry) rotated by xAxisRotate degrees. Arc
curves from last SkPath SkPoint to (x, y), choosing one of four possible routes:
clockwise or counterclockwise, and smaller or larger.
Arc sweep is always less than 360 degrees. arcTo() appends line to (x, y) if
either radii are zero, or if last SkPath SkPoint equals (x, y). arcTo() scales radii
(rx, ry) to fit last SkPath SkPoint and (x, y) if both are greater than zero but
too small.
arcTo() appends up to four conic curves.
arcTo() implements the functionality of SVG arc, although SVG sweep-flag value
is opposite the integer value of sweep; SVG sweep-flag uses 1 for clockwise,
while kCW_Direction cast to int is zero.
### Parameters
rx |
radius on x-axis before x-axis rotation |
ry |
radius on y-axis before x-axis rotation |
xAxisRotate |
x-axis rotation in degrees; positive values are clockwise |
largeArc |
chooses smaller or larger arc |
sweep |
chooses clockwise or counterclockwise arc |
x |
end of arc |
y |
end of arc |
### Return Value
reference to SkPath
### Example
### See Also
rArcTo ArcSize Direction
---
SkPath& arcTo(const SkPoint r, SkScalar xAxisRotate, ArcSize largeArc, Direction sweep,
const SkPoint xy)
Appends arc to SkPath. Arc is implemented by one or more conic weighted to describe
part of oval with radii (r.fX, r.fY) rotated by xAxisRotate degrees. Arc curves
from last SkPath SkPoint to (xy.fX, xy.fY), choosing one of four possible routes:
clockwise or counterclockwise,
and smaller or larger.
Arc sweep is always less than 360 degrees. arcTo() appends line to xy if either
radii are zero, or if last SkPath SkPoint equals (xy.fX, xy.fY). arcTo() scales radii r to
fit last SkPath SkPoint and xy if both are greater than zero but too small to describe
an arc.
arcTo() appends up to four conic curves.
arcTo() implements the functionality of SVG arc, although SVG sweep-flag value is
opposite the integer value of sweep; SVG sweep-flag uses 1 for clockwise, while
kCW_Direction cast to int is zero.
### Parameters
r |
radii on axes before x-axis rotation |
xAxisRotate |
x-axis rotation in degrees; positive values are clockwise |
largeArc |
chooses smaller or larger arc |
sweep |
chooses clockwise or counterclockwise arc |
xy |
end of arc |
### Return Value
reference to SkPath
### Example
### See Also
rArcTo ArcSize Direction
---
SkPath& rArcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc, Direction sweep,
SkScalar dx, SkScalar dy)
Appends Arc to Path, relative to last Path Point. Arc is implemented by one or
more Conic, weighted to describe part of Oval with radii (rx, ry) rotated by
xAxisRotate degrees. Arc curves from last Path Point to relative end Point
(dx, dy), choosing one of four possible routes: clockwise or
counterclockwise, and smaller or larger. If Path is empty, the start Arc Point
is (0, 0).
Arc sweep is always less than 360 degrees. arcTo appends Line to end Point
if either radii are zero, or if last Path Point equals end Point.
arcTo scales radii (rx, ry) to fit last Path Point and end Point if both are
greater than zero but too small to describe an arc.
arcTo appends up to four Conic curves.
arcTo implements the functionality of SVG_Arc, although SVG "sweep-flag" value is
opposite the integer value of sweep; SVG "sweep-flag" uses 1 for clockwise, while
kCW_Direction cast to int is zero.
### Parameters
rx |
radius before x-axis rotation |
ry |
radius before x-axis rotation |
xAxisRotate |
x-axis rotation in degrees; positive values are clockwise |
largeArc |
chooses smaller or larger Arc |
sweep |
chooses clockwise or counterclockwise Arc |
dx |
x-axis offset end of Arc from last Path Point |
dy |
y-axis offset end of Arc from last Path Point |
### Return Value
reference to Path
### Example
### See Also
arcTo ArcSize Direction
---
SkPath& close()
Appends kClose_Verb to SkPath. A closed contour connects the first and last SkPoint
with line, forming a continuous loop. Open and closed contour draw the same
with SkPaint::kFill_Style. With SkPaint::kStroke_Style, open contour draws
SkPaint::Cap at contour start and end; closed contour draws
SkPaint::Join at contour start and end.
close() has no effect if SkPath is empty or last SkPath SkPath::Verb is kClose_Verb.
### Return Value
reference to SkPath
### Example
### See Also
---
static bool IsInverseFillType(FillType fill)
Returns true if fill is inverted and Path with fill represents area outside
of its geometric bounds.
| FillType | is inverse |
| --- | --- |
| kWinding_FillType | false |
| kEvenOdd_FillType | false |
| kInverseWinding_FillType | true |
| kInverseEvenOdd_FillType | true |
### Parameters
### Return Value
true if Path fills outside its bounds
### Example
#### Example Output
~~~~
IsInverseFillType(kWinding_FillType) == false
IsInverseFillType(kEvenOdd_FillType) == false
IsInverseFillType(kInverseWinding_FillType) == true
IsInverseFillType(kInverseEvenOdd_FillType) == true
~~~~
### See Also
FillType getFillType setFillType ConvertToNonInverseFillType
---
static FillType ConvertToNonInverseFillType(FillType fill)
Returns equivalent Fill_Type representing Path fill inside its bounds.
| FillType | inside FillType |
| --- | --- |
| kWinding_FillType | kWinding_FillType |
| kEvenOdd_FillType | kEvenOdd_FillType |
| kInverseWinding_FillType | kWinding_FillType |
| kInverseEvenOdd_FillType | kEvenOdd_FillType |
### Parameters
### Return Value
fill, or kWinding_FillType or kEvenOdd_FillType if fill is inverted
### Example
#### Example Output
~~~~
ConvertToNonInverseFillType(kWinding_FillType) == kWinding_FillType
ConvertToNonInverseFillType(kEvenOdd_FillType) == kEvenOdd_FillType
ConvertToNonInverseFillType(kInverseWinding_FillType) == kWinding_FillType
ConvertToNonInverseFillType(kInverseEvenOdd_FillType) == kEvenOdd_FillType
~~~~
### See Also
FillType getFillType setFillType IsInverseFillType
---
static int ConvertConicToQuads(const SkPoint& p0, const SkPoint& p1, const SkPoint& p2, SkScalar w,
SkPoint pts[], int pow2)
Approximates Conic with Quad array. Conic is constructed from start Point p0,
control Point p1, end Point p2, and weight w.
Quad array is stored in pts; this storage is supplied by caller.
Maximum Quad count is 2 to the pow2.
Every third point in array shares last Point of previous Quad and first Point of
next Quad. Maximum pts storage size is given by:
(1 + 2 * (1 << pow2)) * sizeof(SkPoint).
Returns Quad count used the approximation, which may be smaller
than the number requested.
Conic_Weight determines the amount of influence Conic control point has on the curve.
w less than one represents an elliptical section. w greater than one represents
a hyperbolic section. w equal to one represents a parabolic section.
Two Quad curves are sufficient to approximate an elliptical Conic with a sweep
of up to 90 degrees; in this case, set pow2 to one.
### Parameters
### Return Value
number of Quad curves written to pts
### Example
A pair of
Quad curves are drawn in red on top of the elliptical
Conic curve in black.
The middle
curve is nearly circular. The top-right
curve is parabolic, which can
be drawn exactly with a single
Quad.
bool isRect(SkRect* rect, bool* isClosed = nullptr, Direction* direction = nullptr)const
Returns true if SkPath is equivalent to SkRect when filled.
If false: rect, isClosed, and direction are unchanged.
If true: rect, isClosed, and direction are written to if not nullptr.
rect may be smaller than the SkPath bounds. SkPath bounds may include kMove_Verb points
that do not alter the area drawn by the returned rect.
### Parameters
### Return Value
true if SkPath contains SkRect
### Example
#### Example Output
~~~~
empty is not rect
addRect is rect (10, 20, 30, 40); is closed; direction CW
moveTo is rect (10, 20, 30, 40); is closed; direction CW
lineTo is not rect
addPoly is rect (0, 0, 80, 80); is not closed; direction CCW
~~~~
### See Also
computeTightBounds conservativelyContainsRect getBounds isConvex isLastContourClosed isNestedFillRects
---
bool isNestedFillRects(SkRect rect[2], Direction dirs[2] = nullptr)const
Returns true if SkPath is equivalent to nested SkRect pair when filled.
If false, rect and dirs are unchanged.
If true, rect and dirs are written to if not nullptr:
setting rect[0] to outer SkRect, and rect[1] to inner SkRect;
setting dirs[0] to SkPath::Direction of outer SkRect, and dirs[1] to SkPath::Direction of
inner SkRect.
### Parameters
### Return Value
true if SkPath contains nested SkRect pair
### Example
#### Example Output
~~~~
outer (7.5, 17.5, 32.5, 42.5); direction CW
inner (12.5, 22.5, 27.5, 37.5); direction CCW
~~~~
### See Also
computeTightBounds conservativelyContainsRect getBounds isConvex isLastContourClosed isRect
---
SkPath& addRect(const SkRect& rect, Direction dir = kCW_Direction)
Adds SkRect to SkPath, appending kMove_Verb, three kLine_Verb, and kClose_Verb,
starting with top-left corner of SkRect; followed by top-right, bottom-right,
and bottom-left if dir is kCW_Direction; or followed by bottom-left,
bottom-right, and top-right if dir is kCCW_Direction.
### Parameters
### Return Value
reference to SkPath
### Example
The left
Rect dashes starting at the top-left corner, to the right.
The right
Rect dashes starting at the top-left corner, towards the bottom.
SkPath& addRect(const SkRect& rect, Direction dir, unsigned start)
Adds Rect to Path, appending kMove_Verb, three kLine_Verb, and kClose_Verb.
If dir is kCW_Direction, Rect corners are added clockwise; if dir is
kCCW_Direction, Rect corners are added counterclockwise.
start determines the first corner added.
| start | first corner |
| --- | --- |
| 0 | top-left |
| 1 | top-right |
| 2 | bottom-right |
| 3 | bottom-left |
### Parameters
### Return Value
reference to Path
### Example
The arrow is just after the initial corner and
points towards the next
corner appended to
Path.
SkPath& addRect(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom,
Direction dir = kCW_Direction)
Adds SkRect (left, top, right, bottom) to SkPath,
appending kMove_Verb, three kLine_Verb, and kClose_Verb,
starting with top-left corner of SkRect; followed by top-right, bottom-right,
and bottom-left if dir is kCW_Direction; or followed by bottom-left,
bottom-right, and top-right if dir is kCCW_Direction.
### Parameters
### Return Value
reference to SkPath
### Example
The
left Rect dashes start at the top-left corner, and continue to the
right.
The
right Rect dashes start at the top-left corner, and continue down.
SkPath& addOval(const SkRect& oval, Direction dir = kCW_Direction)
Adds oval to path, appending kMove_Verb, four kConic_Verb, and kClose_Verb.
Oval is upright ellipse bounded by SkRect oval with radii equal to half oval width
and half oval height. Oval begins at (oval.fRight, oval.centerY()) and continues
clockwise if dir is kCW_Direction, counterclockwise if dir is kCCW_Direction.
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
SkCanvas::drawOval Direction Oval
---
SkPath& addOval(const SkRect& oval, Direction dir, unsigned start)
Adds Oval to Path, appending kMove_Verb, four kConic_Verb, and kClose_Verb.
Oval is upright ellipse bounded by Rect oval with radii equal to half oval width
and half oval height. Oval begins at start and continues
clockwise if dir is kCW_Direction, counterclockwise if dir is kCCW_Direction.
| start | Point |
| --- | --- |
| 0 | oval.centerX(), oval.fTop |
| 1 | oval.fRight, oval.centerY() |
| 2 | oval.centerX(), oval.fBottom |
| 3 | oval.fLeft, oval.centerY() |
### Parameters
### Return Value
reference to Path
### Example
### See Also
SkCanvas::drawOval Direction Oval
---
SkPath& addCircle(SkScalar x, SkScalar y, SkScalar radius, Direction dir = kCW_Direction)
Adds Circle centered at (x, y) of size radius to Path, appending kMove_Verb,
four kConic_Verb, and kClose_Verb. Circle begins at: (x + radius, y), continuing
clockwise if dir is kCW_Direction, and counterclockwise if dir is kCCW_Direction.
Has no effect if radius is zero or negative.
### Parameters
### Return Value
reference to Path
### Example
### See Also
SkCanvas::drawCircle Direction Circle
---
SkPath& addArc(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle)
Appends arc to SkPath, as the start of new contour. Arc added is part of ellipse
bounded by oval, from startAngle through sweepAngle. Both startAngle and
sweepAngle are measured in degrees, where zero degrees is aligned with the
positive x-axis, and positive sweeps extends arc clockwise.
If sweepAngle <= -360, or sweepAngle >= 360; and startAngle modulo 90 is nearly
zero, append oval instead of arc. Otherwise, sweepAngle values are treated
modulo 360, and arc may or may not draw depending on numeric rounding.
### Parameters
oval |
bounds of ellipse containing arc |
startAngle |
starting angle of arc in degrees |
sweepAngle |
sweep, in degrees. Positive is clockwise; treated modulo 360 |
### Return Value
reference to SkPath
### Example
The middle row of the left and right columns draw differently from the entries
above and below because
sweepAngle is outside of the range of +/-360,
and
startAngle modulo 90 is not zero.
SkPath& addRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry, Direction dir = kCW_Direction)
Appends SkRRect to SkPath, creating a new closed contour. SkRRect has bounds
equal to rect; each corner is 90 degrees of an ellipse with radii (rx, ry). If
dir is kCW_Direction, SkRRect starts at top-left of the lower-left corner and
winds clockwise. If dir is kCCW_Direction, SkRRect starts at the bottom-left
of the upper-left corner and winds counterclockwise.
If either rx or ry is too large, rx and ry are scaled uniformly until the
corners fit. If rx or ry is less than or equal to zero, addRoundRect() appends
SkRect rect to SkPath.
After appending, SkPath may be empty, or may contain: SkRect, oval, or SkRRect.
### Parameters
### Return Value
reference to SkPath
### Example
If either radius is zero,
path contains
Rect and is drawn red.
If sides are only radii,
path contains
Oval and is drawn blue.
All remaining
path draws are convex, and are drawn in gray; no
paths constructed from
addRoundRect are concave, so none are
drawn in green.
SkPath& addRoundRect(const SkRect& rect, const SkScalar radii[], Direction dir = kCW_Direction)
Appends Round_Rect to Path, creating a new closed Contour. Round_Rect has bounds
equal to rect; each corner is 90 degrees of an ellipse with radii from the
array.
| radii index | location |
| --- | --- |
| 0 | x-axis radius of top-left corner |
| 1 | y-axis radius of top-left corner |
| 2 | x-axis radius of top-right corner |
| 3 | y-axis radius of top-right corner |
| 4 | x-axis radius of bottom-right corner |
| 5 | y-axis radius of bottom-right corner |
| 6 | x-axis radius of bottom-left corner |
| 7 | y-axis radius of bottom-left corner |
If dir is kCW_Direction, Round_Rect starts at top-left of the lower-left corner
and winds clockwise. If dir is kCCW_Direction, Round_Rect starts at the
bottom-left of the upper-left corner and winds counterclockwise.
If both radii on any side of rect exceed its length, all radii are scaled
uniformly until the corners fit. If either radius of a corner is less than or
equal to zero, both are treated as zero.
After appending, Path may be empty, or may contain: Rect, Oval, or Round_Rect.
### Parameters
### Return Value
reference to Path
### Example
### See Also
addRRect SkCanvas::drawRoundRect
---
SkPath& addRRect(const SkRRect& rrect, Direction dir = kCW_Direction)
Adds rrect to SkPath, creating a new closed contour. If
dir is kCW_Direction, rrect starts at top-left of the lower-left corner and
winds clockwise. If dir is kCCW_Direction, rrect starts at the bottom-left
of the upper-left corner and winds counterclockwise.
After appending, SkPath may be empty, or may contain: SkRect, oval, or SkRRect.
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
addRoundRect SkCanvas::drawRRect
---
SkPath& addRRect(const SkRRect& rrect, Direction dir, unsigned start)
Adds rrect to Path, creating a new closed Contour. If dir is kCW_Direction, rrect
winds clockwise; if dir is kCCW_Direction, rrect winds counterclockwise.
start determines the first point of rrect to add.
| start | location |
| --- | --- |
| 0 | right of top-left corner |
| 1 | left of top-right corner |
| 2 | bottom of top-right corner |
| 3 | top of bottom-right corner |
| 4 | left of bottom-right corner |
| 5 | right of bottom-left corner |
| 6 | top of bottom-left corner |
| 7 | bottom of top-left corner |
After appending, Path may be empty, or may contain: Rect, Oval, or Round_Rect.
### Parameters
### Return Value
reference to Path
### Example
### See Also
addRoundRect SkCanvas::drawRRect
---
SkPath& addPoly(const SkPoint pts[], int count, bool close)
Adds contour created from line array, adding (count - 1) line segments.
Contour added starts at pts[0], then adds a line for every additional SkPoint
in pts array. If close is true, appends kClose_Verb to SkPath, connecting
pts[count - 1] and pts[0].
If count is zero, append kMove_Verb to path.
Has no effect if count is less than one.
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
SkCanvas::drawPoints
---
SkPath& addPoly(const std::initializer_list<SkPoint>& list, bool close)
Adds contour created from list. Contour added starts at list[0], then adds a line
for every additional SkPoint in list. If close is true, appends kClose_Verb to SkPath,
connecting last and first SkPoint in list.
If list is empty, append kMove_Verb to path.
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
SkCanvas::drawPoints
---
enum AddPathMode {
kAppend_AddPathMode,
kExtend_AddPathMode,
};
AddPathMode chooses how addPath appends. Adding one Path to another can extend
the last Contour or start a new Contour.
### Constants
### Example
### See Also
addPath reverseAddPath
---
SkPath& addPath(const SkPath& src, SkScalar dx, SkScalar dy, AddPathMode mode = kAppend_AddPathMode)
Appends src to SkPath, offset by (dx, dy).
If mode is kAppend_AddPathMode, src verb array, SkPoint array, and conic weights are
added unaltered. If mode is kExtend_AddPathMode, add line before appending
verbs, SkPoint, and conic weights.
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
AddPathMode offset reverseAddPath
---
SkPath& addPath(const SkPath& src, AddPathMode mode = kAppend_AddPathMode)
Appends src to SkPath.
If mode is kAppend_AddPathMode, src verb array, SkPoint array, and conic weights are
added unaltered. If mode is kExtend_AddPathMode, add line before appending
verbs, SkPoint, and conic weights.
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
AddPathMode reverseAddPath
---
SkPath& addPath(const SkPath& src, const SkMatrix& matrix, AddPathMode mode = kAppend_AddPathMode)
Appends src to SkPath, transformed by matrix. Transformed curves may have different
verbs, SkPoint, and conic weights.
If mode is kAppend_AddPathMode, src verb array, SkPoint array, and conic weights are
added unaltered. If mode is kExtend_AddPathMode, add line before appending
verbs, SkPoint, and conic weights.
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
AddPathMode transform offset reverseAddPath
---
SkPath& reverseAddPath(const SkPath& src)
Appends src to SkPath, from back to front.
Reversed src always appends a new contour to SkPath.
### Parameters
### Return Value
reference to SkPath
### Example
### See Also
AddPathMode transform offset addPath
---
void offset(SkScalar dx, SkScalar dy, SkPath* dst)const
Offsets SkPoint array by (dx, dy). Offset SkPath replaces dst.
If dst is nullptr, SkPath is replaced by offset data.
### Parameters
### Example
### See Also
addPath transform
---
void offset(SkScalar dx, SkScalar dy)
Offsets SkPoint array by (dx, dy). SkPath is replaced by offset data.
### Parameters
### Example
### See Also
addPath transform SkCanvas::translate()
---
void transform(const SkMatrix& matrix, SkPath* dst)const
Transforms verb array, SkPoint array, and weight by matrix.
transform may change verbs and increase their number.
Transformed SkPath replaces dst; if dst is nullptr, original data
is replaced.
### Parameters
### Example
### See Also
addPath offset SkCanvas::concat() SkMatrix
---
void transform(const SkMatrix& matrix)
Transforms verb array, SkPoint array, and weight by matrix.
transform may change verbs and increase their number.
SkPath is replaced by transformed data.
### Parameters
### Example
### See Also
addPath offset SkCanvas::concat() SkMatrix
Path is defined cumulatively, often by adding a segment to the end of last
Contour. Last_Point of Contour is shared as first Point of added Line or Curve.
Last_Point can be read and written directly with getLastPt and setLastPt.
---
bool getLastPt(SkPoint* lastPt)const
Returns last point on SkPath in lastPt. Returns false if SkPoint array is empty,
storing (0, 0) if lastPt is not nullptr.
### Parameters
### Return Value
true if SkPoint array contains one or more SkPoint
### Example
#### Example Output
~~~~
last point: 35.2786, 52.9772
~~~~
### See Also
setLastPt
---
void setLastPt(SkScalar x, SkScalar y)
Sets last point to (x, y). If SkPoint array is empty, append kMove_Verb to
verb array and append (x, y) to SkPoint array.
### Parameters
### Example
### See Also
getLastPt
---
void setLastPt(const SkPoint& p)
Sets the last point on the path. If SkPoint array is empty, append kMove_Verb to
verb array and append p to SkPoint array.
### Parameters
### Example
### See Also
getLastPt
---
enum SegmentMask {
kLine_SegmentMask = 1 << 0,
kQuad_SegmentMask = 1 << 1,
kConic_SegmentMask = 1 << 2,
kCubic_SegmentMask = 1 << 3,
};
SegmentMask constants correspond to each drawing Verb type in Path; for
instance, if Path only contains Lines, only the kLine_SegmentMask bit is set.
### Constants
### Example
#### Example Output
~~~~
Path kConic_SegmentMask is clear
Path kQuad_SegmentMask is set
~~~~
### See Also
getSegmentMasks Verb
---
uint32_t getSegmentMasks()const
Returns a mask, where each set bit corresponds to a SegmentMask constant
if SkPath contains one or more verbs of that type.
Returns zero if SkPath contains no lines, or curves: quads, conics, or cubics.
getSegmentMasks() returns a cached result; it is very fast.
### Return Value
SegmentMask bits or zero
### Example
#### Example Output
~~~~
mask quad set
~~~~
### See Also
getSegmentMasks Verb
---
bool contains(SkScalar x, SkScalar y)const
Returns true if the point (x, y) is contained by Path, taking into
account FillType.
| FillType | contains() returns true if Point is enclosed by |
| --- | --- |
| kWinding_FillType | a non-zero sum of Contour Directions. |
| kEvenOdd_FillType | an odd number of Contours. |
| kInverseWinding_FillType | a zero sum of Contour Directions. |
| kInverseEvenOdd_FillType | and even number of Contours. |
### Parameters
x |
x-axis value of containment test |
y |
y-axis value of containment test |
### Return Value
true if Point is in Path
### Example
### See Also
conservativelyContainsRect Fill_Type Op
---
void dump(SkWStream* stream, bool forceClose, bool dumpAsHex)const
Writes text representation of SkPath to stream. If stream is nullptr, writes to
standard output. Set forceClose to true to get edges used to fill SkPath.
Set dumpAsHex true to generate exact binary representations
of floating point numbers used in SkPoint array and conic weights.
### Parameters
### Example
#### Example Output
~~~~
path.setFillType(SkPath::kWinding_FillType);
path.moveTo(0, 0);
path.quadTo(20, 30, 40, 50);
path.setFillType(SkPath::kWinding_FillType);
path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
path.quadTo(SkBits2Float(0x41a00000), SkBits2Float(0x41f00000), SkBits2Float(0x42200000), SkBits2Float(0x42480000)); // 20, 30, 40, 50
path.setFillType(SkPath::kWinding_FillType);
path.moveTo(0, 0);
path.quadTo(20, 30, 40, 50);
path.lineTo(0, 0);
path.close();
path.setFillType(SkPath::kWinding_FillType);
path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
path.quadTo(SkBits2Float(0x41a00000), SkBits2Float(0x41f00000), SkBits2Float(0x42200000), SkBits2Float(0x42480000)); // 20, 30, 40, 50
path.lineTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
path.close();
~~~~
### See Also
dumpHex SkRect::dump() SkRRect::dump() SkPathMeasure::dump()
---
void dump()const
Writes text representation of SkPath to standard output. The representation may be
directly compiled as C++ code. Floating point values are written
with limited precision; it may not be possible to reconstruct original SkPath
from output.
### Example
#### Example Output
~~~~
path.setFillType(SkPath::kWinding_FillType);
path.moveTo(0, 0);
path.lineTo(0.857143f, 0.666667f);
path is not equal to copy
~~~~
### See Also
dumpHex SkRect::dump() SkRRect::dump() SkPathMeasure::dump() writeToMemory
---
void dumpHex()const
Writes text representation of Path to standard output. The representation may be
directly compiled as C++ code. Floating point values are written
in hexadecimal to preserve their exact bit pattern. The output reconstructs the
original Path.
Use instead of dump() when submitting
bug reports against Skia .
### Example
#### Example Output
~~~~
path.setFillType(SkPath::kWinding_FillType);
path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
path.lineTo(SkBits2Float(0x3f5b6db7), SkBits2Float(0x3f2aaaab)); // 0.857143f, 0.666667f
path is equal to copy
~~~~
### See Also
dump SkRect::dumpHex SkRRect::dumpHex writeToMemory
---
size_t writeToMemory(void* buffer)const
Writes SkPath to buffer, returning the number of bytes written.
Pass nullptr to obtain the storage size.
Writes SkPath::FillType, verb array, SkPoint array, conic weight, and
additionally writes computed information like SkPath::Convexity and bounds.
Use only be used in concert with readFromMemory();
the format used for SkPath in memory is not guaranteed.
### Parameters
### Return Value
size of storage required for SkPath; always a multiple of 4
### Example
#### Example Output
~~~~
path is equal to copy
~~~~
### See Also
serialize readFromMemory dump dumpHex
---
sk_sp<SkData> serialize()const
Writes SkPath to buffer, returning the buffer written to, wrapped in SkData.
serialize() writes SkPath::FillType, verb array, SkPoint array, conic weight, and
additionally writes computed information like SkPath::Convexity and bounds.
serialize() should only be used in concert with readFromMemory().
The format used for SkPath in memory is not guaranteed.
### Return Value
SkPath data wrapped in SkData buffer
### Example
#### Example Output
~~~~
path is equal to copy
~~~~
### See Also
writeToMemory readFromMemory dump dumpHex
---
size_t readFromMemory(const void* buffer, size_t length)
Initializes SkPath from buffer of size length. Returns zero if the buffer is
data is inconsistent, or the length is too small.
Reads SkPath::FillType, verb array, SkPoint array, conic weight, and
additionally reads computed information like SkPath::Convexity and bounds.
Used only in concert with writeToMemory();
the format used for SkPath in memory is not guaranteed.
### Parameters
### Return Value
number of bytes read, or zero on failure
### Example
#### Example Output
~~~~
length = 32; returned by readFromMemory = 0
length = 40; returned by readFromMemory = 36
~~~~
### See Also
writeToMemory
Generation_ID provides a quick way to check if Verb_Array, Point_Array, or
Conic_Weight has changed. Generation_ID is not a hash; identical Paths will
not necessarily have matching Generation_IDs.
Empty Paths have a Generation_ID of one.
---
uint32_t getGenerationID()const
(See Skia bug 1762.)
Returns a non-zero, globally unique value. A different value is returned
if verb array, SkPoint array, or conic weight changes.
Setting SkPath::FillType does not change generation identifier.
Each time the path is modified, a different generation identifier will be returned.
SkPath::FillType does affect generation identifier on Android framework.
### Return Value
non-zero, globally unique value
### Example
#### Example Output
~~~~
empty genID = 1
1st lineTo genID = 2
empty genID = 1
2nd lineTo genID = 3
~~~~
### See Also
operator==(const SkPath& a, const SkPath& b)
---
bool isValid()const
Returns if SkPath data is consistent. Corrupt SkPath data is detected if
internal values are out of range or internal storage does not match
array dimensions.
### Return Value
true if SkPath data is consistent
---
class Iter {
Iter();
Iter(const SkPath& path, bool forceClose);
void setPath(const SkPath& path, bool forceClose);
Verb next(SkPoint pts[4], bool doConsumeDegenerates = true, bool exact = false);
SkScalar conicWeight() const;
bool isCloseLine() const;
bool isClosedContour() const;
};
Iterates through Verb_Array, and associated Point_Array and Conic_Weight.
Provides options to treat open Contours as closed, and to ignore
degenerate data.
### Example
### See Also
RawIter
---
Iter()
Initializes SkPath::Iter with an empty SkPath. next() on SkPath::Iter returns
kDone_Verb.
Call setPath to initialize SkPath::Iter at a later time.
### Return Value
SkPath::Iter of empty SkPath
### Example
#### Example Output
~~~~
iter is done
iter is done
~~~~
### See Also
setPath
---
Iter(const SkPath& path, bool forceClose)
Sets SkPath::Iter to return elements of verb array, SkPoint array, and conic weight in
path. If forceClose is true, SkPath::Iter will add kLine_Verb and kClose_Verb after each
open contour. path is not altered.
### Parameters
### Return Value
SkPath::Iter of path
### Example
#### Example Output
~~~~
open:
kMove_Verb {0, 0},
kQuad_Verb {0, 0}, {10, 20}, {30, 40},
kDone_Verb
closed:
kMove_Verb {0, 0},
kQuad_Verb {0, 0}, {10, 20}, {30, 40},
kLine_Verb {30, 40}, {0, 0},
kClose_Verb {0, 0},
kDone_Verb
~~~~
### See Also
setPath
---
void setPath(const SkPath& path, bool forceClose)
Sets SkPath::Iter to return elements of verb array, SkPoint array, and conic weight in
path. If forceClose is true, SkPath::Iter will add kLine_Verb and kClose_Verb after each
open contour. path is not altered.
### Parameters
### Example
#### Example Output
~~~~
quad open:
kMove_Verb {0, 0},
kQuad_Verb {0, 0}, {10, 20}, {30, 40},
kDone_Verb
conic closed:
kMove_Verb {0, 0},
kConic_Verb {0, 0}, {1, 2}, {3, 4}, weight = 0.5
kLine_Verb {3, 4}, {0, 0},
kClose_Verb {0, 0},
kDone_Verb
~~~~
### See Also
Iter(const SkPath& path, bool forceClose)
---
Verb next(SkPoint pts[4], bool doConsumeDegenerates = true, bool exact = false)
Returns next SkPath::Verb in verb array, and advances SkPath::Iter.
When verb array is exhausted, returns kDone_Verb.
Zero to four SkPoint are stored in pts, depending on the returned SkPath::Verb.
If doConsumeDegenerates is true, skip consecutive kMove_Verb entries, returning
only the last in the series; and skip very small lines, quads, and conics; and
skip kClose_Verb following kMove_Verb.
if doConsumeDegenerates is true and exact is true, only skip lines, quads, and
conics with zero lengths.
### Parameters
### Return Value
next SkPath::Verb from verb array
### Example
#### Example Output
~~~~
skip degenerate:
kMove_Verb {20, 20},
kQuad_Verb {20, 20}, {10, 20}, {30, 40},
kDone_Verb
skip degenerate if exact:
kMove_Verb {20, 20},
kQuad_Verb {20, 20}, {10, 20}, {30, 40},
kMove_Verb {30, 30},
kLine_Verb {30, 30}, {30.00001, 30},
kDone_Verb
skip none:
kMove_Verb {10, 10},
kMove_Verb {20, 20},
kQuad_Verb {20, 20}, {10, 20}, {30, 40},
kMove_Verb {1, 1},
kClose_Verb {1, 1},
kMove_Verb {30, 30},
kLine_Verb {30, 30}, {30, 30},
kMove_Verb {30, 30},
kLine_Verb {30, 30}, {30.00001, 30},
kDone_Verb
~~~~
### See Also
Verb IsLineDegenerate IsCubicDegenerate IsQuadDegenerate
---
SkScalar conicWeight()const
Returns conic weight if next() returned kConic_Verb.
If next() has not been called, or next() did not return kConic_Verb,
result is undefined.
### Return Value
conic weight for conic SkPoint returned by next()
### Example
#### Example Output
~~~~
first verb is move
next verb is conic
conic points: {0,0}, {1,2}, {3,4}
conic weight: 0.5
~~~~
### See Also
Conic_Weight
---
bool isCloseLine()const
Returns true if last kLine_Verb returned by next() was generated
by kClose_Verb. When true, the end point returned by next() is
also the start point of contour.
If next() has not been called, or next() did not return kLine_Verb,
result is undefined.
### Return Value
true if last kLine_Verb was generated by kClose_Verb
### Example
#### Example Output
~~~~
1st verb is move
moveTo point: {6,7}
2nd verb is conic
3rd verb is line
line points: {3,4}, {6,7}
line generated by close
4th verb is close
~~~~
### See Also
close()
---
bool isClosedContour()const
Returns true if subsequent calls to next() return kClose_Verb before returning
kMove_Verb. if true, contour SkPath::Iter is processing may end with kClose_Verb, or
SkPath::Iter may have been initialized with force close set to true.
### Return Value
true if contour is closed
### Example
#### Example Output
~~~~
without close(), forceClose is false: isClosedContour returns false
with close(), forceClose is false: isClosedContour returns true
without close(), forceClose is true : isClosedContour returns true
with close(), forceClose is true : isClosedContour returns true
~~~~
### See Also
Iter(const SkPath& path, bool forceClose)
---
class RawIter {
RawIter();
RawIter(const SkPath& path);
void setPath(const SkPath& path);
Verb next(SkPoint pts[4]);
Verb peek() const;
SkScalar conicWeight() const;
};
Iterates through Verb_Array, and associated Point_Array and Conic_Weight.
Verb_Array, Point_Array, and Conic_Weight are returned unaltered.
---
RawIter()
Initializes RawIter with an empty SkPath. next() on RawIter returns kDone_Verb.
Call setPath to initialize SkPath::Iter at a later time.
### Return Value
RawIter of empty SkPath
---
RawIter(const SkPath& path)
Sets RawIter to return elements of verb array, SkPoint array, and conic weight in path.
### Parameters
### Return Value
RawIter of path
---
void setPath(const SkPath& path)
Sets SkPath::Iter to return elements of verb array, SkPoint array, and conic weight in
path.
### Parameters
---
Verb next(SkPoint pts[4])
Returns next SkPath::Verb in verb array, and advances RawIter.
When verb array is exhausted, returns kDone_Verb.
Zero to four SkPoint are stored in pts, depending on the returned SkPath::Verb.
### Parameters
### Return Value
next SkPath::Verb from verb array
### Example
#### Example Output
~~~~
kMove_Verb {50, 60},
kQuad_Verb {50, 60}, {10, 20}, {30, 40},
kClose_Verb {50, 60},
kMove_Verb {50, 60},
kLine_Verb {50, 60}, {30, 30},
kConic_Verb {30, 30}, {1, 2}, {3, 4}, weight = 0.5
kCubic_Verb {3, 4}, {-1, -2}, {-3, -4}, {-5, -6},
kDone_Verb
~~~~
### See Also
peek()
---
Verb peek()const
Returns next SkPath::Verb, but does not advance RawIter.
### Return Value
next SkPath::Verb from verb array
### Example
#### Example Output
~~~~
#Volatile
peek Move == verb Move
peek Quad == verb Quad
peek Conic == verb Conic
peek Cubic == verb Cubic
peek Done == verb Done
peek Done == verb Done
~~~~
### See Also
next
---
SkScalar conicWeight()const
Returns conic weight if next() returned kConic_Verb.
If next() has not been called, or next() did not return kConic_Verb,
result is undefined.
### Return Value
conic weight for conic SkPoint returned by next()
### Example
#### Example Output
~~~~
first verb is move
next verb is conic
conic points: {0,0}, {1,2}, {3,4}
conic weight: 0.5
~~~~
### See Also
Conic_Weight