1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/include/effects/SkLayerDrawLooper.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,180 @@
1.4 +/*
1.5 + * Copyright 2011 Google Inc.
1.6 + *
1.7 + * Use of this source code is governed by a BSD-style license that can be
1.8 + * found in the LICENSE file.
1.9 + */
1.10 +
1.11 +#ifndef SkLayerDrawLooper_DEFINED
1.12 +#define SkLayerDrawLooper_DEFINED
1.13 +
1.14 +#include "SkDrawLooper.h"
1.15 +#include "SkPaint.h"
1.16 +#include "SkPoint.h"
1.17 +#include "SkXfermode.h"
1.18 +
1.19 +class SK_API SkLayerDrawLooper : public SkDrawLooper {
1.20 +public:
1.21 + SK_DECLARE_INST_COUNT(SkLayerDrawLooper)
1.22 +
1.23 + SkLayerDrawLooper();
1.24 + virtual ~SkLayerDrawLooper();
1.25 +
1.26 + /**
1.27 + * Bits specifies which aspects of the layer's paint should replace the
1.28 + * corresponding aspects on the draw's paint.
1.29 + * kEntirePaint_Bits means use the layer's paint completely.
1.30 + * 0 means ignore the layer's paint... except for fColorMode, which is
1.31 + * always applied.
1.32 + */
1.33 + enum Bits {
1.34 + kStyle_Bit = 1 << 0, //!< use this layer's Style/stroke settings
1.35 + kTextSkewX_Bit = 1 << 1, //!< use this layer's textskewx
1.36 + kPathEffect_Bit = 1 << 2, //!< use this layer's patheffect
1.37 + kMaskFilter_Bit = 1 << 3, //!< use this layer's maskfilter
1.38 + kShader_Bit = 1 << 4, //!< use this layer's shader
1.39 + kColorFilter_Bit = 1 << 5, //!< use this layer's colorfilter
1.40 + kXfermode_Bit = 1 << 6, //!< use this layer's xfermode
1.41 +
1.42 + /**
1.43 + * Use the layer's paint entirely, with these exceptions:
1.44 + * - We never override the draw's paint's text_encoding, since that is
1.45 + * used to interpret the text/len parameters in draw[Pos]Text.
1.46 + * - Color is always computed using the LayerInfo's fColorMode.
1.47 + */
1.48 + kEntirePaint_Bits = -1
1.49 +
1.50 + };
1.51 + typedef int32_t BitFlags;
1.52 +
1.53 + /**
1.54 + * Info for how to apply the layer's paint and offset.
1.55 + *
1.56 + * fColorMode controls how we compute the final color for the layer:
1.57 + * The layer's paint's color is treated as the SRC
1.58 + * The draw's paint's color is treated as the DST
1.59 + * final-color = Mode(layers-color, draws-color);
1.60 + * Any SkXfermode::Mode will work. Two common choices are:
1.61 + * kSrc_Mode: to use the layer's color, ignoring the draw's
1.62 + * kDst_Mode: to just keep the draw's color, ignoring the layer's
1.63 + */
1.64 + struct SK_API LayerInfo {
1.65 + BitFlags fPaintBits;
1.66 + SkXfermode::Mode fColorMode;
1.67 + SkVector fOffset;
1.68 + bool fPostTranslate; //!< applies to fOffset
1.69 +
1.70 + /**
1.71 + * Initial the LayerInfo. Defaults to settings that will draw the
1.72 + * layer with no changes: e.g.
1.73 + * fPaintBits == 0
1.74 + * fColorMode == kDst_Mode
1.75 + * fOffset == (0, 0)
1.76 + */
1.77 + LayerInfo();
1.78 + };
1.79 +
1.80 + /**
1.81 + * Call for each layer you want to add (from top to bottom).
1.82 + * This returns a paint you can modify, but that ptr is only valid until
1.83 + * the next call made to addLayer().
1.84 + */
1.85 + SkPaint* addLayer(const LayerInfo&);
1.86 +
1.87 + /**
1.88 + * This layer will draw with the original paint, at the specified offset
1.89 + */
1.90 + void addLayer(SkScalar dx, SkScalar dy);
1.91 +
1.92 + /**
1.93 + * This layer will with the original paint and no offset.
1.94 + */
1.95 + void addLayer() { this->addLayer(0, 0); }
1.96 +
1.97 + /// Similar to addLayer, but adds a layer to the top.
1.98 + SkPaint* addLayerOnTop(const LayerInfo&);
1.99 +
1.100 + virtual SkDrawLooper::Context* createContext(SkCanvas*, void* storage) const SK_OVERRIDE;
1.101 +
1.102 + virtual size_t contextSize() const SK_OVERRIDE { return sizeof(LayerDrawLooperContext); }
1.103 +
1.104 + SK_TO_STRING_OVERRIDE()
1.105 +
1.106 + /// Implements Flattenable.
1.107 + virtual Factory getFactory() const SK_OVERRIDE { return CreateProc; }
1.108 + static SkFlattenable* CreateProc(SkReadBuffer& buffer);
1.109 +
1.110 +protected:
1.111 + virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
1.112 +
1.113 +private:
1.114 + struct Rec {
1.115 + Rec* fNext;
1.116 + SkPaint fPaint;
1.117 + LayerInfo fInfo;
1.118 + };
1.119 + Rec* fRecs;
1.120 + Rec* fTopRec;
1.121 + int fCount;
1.122 +
1.123 + // state-machine during the init/next cycle
1.124 + class LayerDrawLooperContext : public SkDrawLooper::Context {
1.125 + public:
1.126 + explicit LayerDrawLooperContext(const SkLayerDrawLooper* looper);
1.127 +
1.128 + protected:
1.129 + virtual bool next(SkCanvas*, SkPaint* paint) SK_OVERRIDE;
1.130 +
1.131 + private:
1.132 + Rec* fCurrRec;
1.133 +
1.134 + static void ApplyInfo(SkPaint* dst, const SkPaint& src, const LayerInfo&);
1.135 + };
1.136 +
1.137 + class MyRegistrar : public SkFlattenable::Registrar {
1.138 + public:
1.139 + MyRegistrar();
1.140 + };
1.141 +
1.142 + typedef SkDrawLooper INHERITED;
1.143 +
1.144 +public:
1.145 + class SK_API Builder {
1.146 + public:
1.147 + Builder();
1.148 + ~Builder();
1.149 +
1.150 + /**
1.151 + * Call for each layer you want to add (from top to bottom).
1.152 + * This returns a paint you can modify, but that ptr is only valid until
1.153 + * the next call made to addLayer().
1.154 + */
1.155 + SkPaint* addLayer(const LayerInfo&);
1.156 +
1.157 + /**
1.158 + * This layer will draw with the original paint, at the specified offset
1.159 + */
1.160 + void addLayer(SkScalar dx, SkScalar dy);
1.161 +
1.162 + /**
1.163 + * This layer will with the original paint and no offset.
1.164 + */
1.165 + void addLayer() { this->addLayer(0, 0); }
1.166 +
1.167 + /// Similar to addLayer, but adds a layer to the top.
1.168 + SkPaint* addLayerOnTop(const LayerInfo&);
1.169 +
1.170 + /**
1.171 + * Pass list of layers on to newly built looper and return it. This will
1.172 + * also reset the builder, so it can be used to build another looper.
1.173 + */
1.174 + SkLayerDrawLooper* detachLooper();
1.175 +
1.176 + private:
1.177 + Rec* fRecs;
1.178 + Rec* fTopRec;
1.179 + int fCount;
1.180 + };
1.181 +};
1.182 +
1.183 +#endif
