1 #ifndef SkLayerDrawLooper_DEFINED 2 #define SkLayerDrawLooper_DEFINED 3 4 #include "SkDrawLooper.h" 5 #include "SkXfermode.h" 6 7 struct SkPoint; 8 9 class SK_API SkLayerDrawLooper : public SkDrawLooper { 10 public: 11 SkLayerDrawLooper(); 12 virtual ~SkLayerDrawLooper(); 13 14 /** 15 * Bits specifies which aspects of the layer's paint should replace the 16 * corresponding aspects on the draw's paint. 17 * kEntirePaint_Bits means use the layer's paint completely. 18 * 0 means ignore the layer's paint. 19 */ 20 enum Bits { 21 kStyle_Bit = 1 << 0, //!< use this layer's Style/stroke settings 22 kTextSkewX_Bit = 1 << 1, //!< use this layer's textskewx 23 kPathEffect_Bit = 1 << 2, //!< use this layer's patheffect 24 kMaskFilter_Bit = 1 << 3, //!< use this layer's maskfilter 25 kShader_Bit = 1 << 4, //!< use this layer's shader 26 kColorFilter_Bit = 1 << 5, //!< use this layer's colorfilter 27 kXfermode_Bit = 1 << 6, //!< use this layer's xfermode 28 29 kEntirePaint_Bits = -1, //!< use this layer's paint entirely 30 }; 31 typedef int32_t BitFlags; 32 33 /** 34 * Info for how to apply the layer's paint and offset. 35 * 36 * fFlagsMask selects which flags in the layer's paint should be applied. 37 * result = (draw-flags & ~fFlagsMask) | (layer-flags & fFlagsMask) 38 * In the extreme: 39 * If fFlagsMask is 0, we ignore all of the layer's flags 40 * If fFlagsMask is -1, we use all of the layer's flags 41 * 42 * fColorMode controls how we compute the final color for the layer: 43 * The layer's paint's color is treated as the SRC 44 * The draw's paint's color is treated as the DST 45 * final-color = Mode(layers-color, draws-color); 46 * Any SkXfermode::Mode will work. Two common choices are: 47 * kSrc_Mode: to use the layer's color, ignoring the draw's 48 * kDst_Mode: to just keep the draw's color, ignoring the layer's 49 */ 50 struct SK_API LayerInfo { 51 uint32_t fFlagsMask; // SkPaint::Flags 52 BitFlags fPaintBits; 53 SkXfermode::Mode fColorMode; 54 SkVector fOffset; 55 bool fPostTranslate; //!< applies to fOffset 56 57 /** 58 * Initial the LayerInfo. Defaults to settings that will draw the 59 * layer with no changes: e.g. 60 * fPaintBits == 0 61 * fColorMode == kDst_Mode 62 * fOffset == (0, 0) 63 */ 64 LayerInfo(); 65 }; 66 67 /** 68 * Call for each layer you want to add (from top to bottom). 69 * This returns a paint you can modify, but that ptr is only valid until 70 * the next call made to addLayer(). 71 */ 72 SkPaint* addLayer(const LayerInfo&); 73 74 /** 75 * This layer will draw with the original paint, ad the specified offset 76 */ 77 void addLayer(SkScalar dx, SkScalar dy); 78 79 /** 80 * This layer will with the original paint and no offset. 81 */ addLayer()82 void addLayer() { this->addLayer(0, 0); } 83 84 // overrides from SkDrawLooper 85 virtual void init(SkCanvas*); 86 virtual bool next(SkCanvas*, SkPaint* paint); 87 88 // must be public for Registrar :( CreateProc(SkFlattenableReadBuffer & buffer)89 static SkFlattenable* CreateProc(SkFlattenableReadBuffer& buffer) { 90 return SkNEW_ARGS(SkLayerDrawLooper, (buffer)); 91 } 92 93 protected: 94 SkLayerDrawLooper(SkFlattenableReadBuffer&); 95 96 // overrides from SkFlattenable 97 virtual void flatten(SkFlattenableWriteBuffer& ); getFactory()98 virtual Factory getFactory() { return CreateProc; } 99 100 private: 101 struct Rec { 102 Rec* fNext; 103 SkPaint fPaint; 104 LayerInfo fInfo; 105 106 static Rec* Reverse(Rec*); 107 }; 108 Rec* fRecs; 109 int fCount; 110 111 // state-machine during the init/next cycle 112 Rec* fCurrRec; 113 114 static void ApplyInfo(SkPaint* dst, const SkPaint& src, const LayerInfo&); 115 116 class MyRegistrar : public SkFlattenable::Registrar { 117 public: 118 MyRegistrar(); 119 }; 120 121 typedef SkDrawLooper INHERITED; 122 }; 123 124 125 #endif 126