src/effects/SkBlendImageFilter.cpp - fp2-dev/platform/external/chromium_org/third_party/skia - Gitiles

 /*
  * Copyright 2012 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "SkBlendImageFilter.h"
 #include "SkCanvas.h"
 #include "SkColorPriv.h"
 #include "SkFlattenableBuffers.h"
 #if SK_SUPPORT_GPU
 #include "SkGr.h"
 #include "SkGrPixelRef.h"
 #include "gl/GrGLProgramStage.h"
 #endif

 namespace {

 SkXfermode::Mode modeToXfermode(SkBlendImageFilter::Mode mode)
 {
     switch (mode) {
       case SkBlendImageFilter::kNormal_Mode:
         return SkXfermode::kSrcOver_Mode;
       case SkBlendImageFilter::kMultiply_Mode:
         return SkXfermode::kMultiply_Mode;
       case SkBlendImageFilter::kScreen_Mode:
         return SkXfermode::kScreen_Mode;
       case SkBlendImageFilter::kDarken_Mode:
         return SkXfermode::kDarken_Mode;
       case SkBlendImageFilter::kLighten_Mode:
         return SkXfermode::kLighten_Mode;
     }
     SkASSERT(0);
     return SkXfermode::kSrcOver_Mode;
 }

 SkPMColor multiply_proc(SkPMColor src, SkPMColor dst) {
     int omsa = 255 - SkGetPackedA32(src);
     int sr = SkGetPackedR32(src), sg = SkGetPackedG32(src), sb = SkGetPackedB32(src);
     int omda = 255 - SkGetPackedA32(dst);
     int dr = SkGetPackedR32(dst), dg = SkGetPackedG32(dst), db = SkGetPackedB32(dst);
     int a = 255 - SkMulDiv255Round(omsa, omda);
     int r = SkMulDiv255Round(omsa, dr) + SkMulDiv255Round(omda, sr) + SkMulDiv255Round(sr, dr);
     int g = SkMulDiv255Round(omsa, dg) + SkMulDiv255Round(omda, sg) + SkMulDiv255Round(sg, dg);
     int b = SkMulDiv255Round(omsa, db) + SkMulDiv255Round(omda, sb) + SkMulDiv255Round(sb, db);
     return SkPackARGB32(a, r, g, b);
 }

 };

 ///////////////////////////////////////////////////////////////////////////////

 SkBlendImageFilter::SkBlendImageFilter(SkBlendImageFilter::Mode mode, SkImageFilter* background, SkImageFilter* foreground)
   : INHERITED(2, background, foreground), fMode(mode)
 {
 }

 SkBlendImageFilter::~SkBlendImageFilter() {
 }

 SkBlendImageFilter::SkBlendImageFilter(SkFlattenableReadBuffer& buffer)
   : INHERITED(buffer)
 {
     fMode = (SkBlendImageFilter::Mode) buffer.readInt();
 }

 void SkBlendImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeInt((int) fMode);
 }

 bool SkBlendImageFilter::onFilterImage(Proxy* proxy,
                                        const SkBitmap& src,
                                        const SkMatrix& ctm,
                                        SkBitmap* dst,
                                        SkIPoint* offset) {
     SkBitmap background, foreground = src;
     SkImageFilter* backgroundInput = getBackgroundInput();
     SkImageFilter* foregroundInput = getForegroundInput();
     SkASSERT(NULL != backgroundInput);
     if (!backgroundInput->filterImage(proxy, src, ctm, &background, offset)) {
         return false;
     }
     if (foregroundInput && !foregroundInput->filterImage(proxy, src, ctm, &foreground, offset)) {
         return false;
     }
     SkAutoLockPixels alp_foreground(foreground), alp_background(background);
     if (!foreground.getPixels() || !background.getPixels()) {
         return false;
     }
     dst->setConfig(background.config(), background.width(), background.height());
     dst->allocPixels();
     SkCanvas canvas(*dst);
     SkPaint paint;
     paint.setXfermodeMode(SkXfermode::kSrc_Mode);
     canvas.drawBitmap(background, 0, 0, &paint);
     // FEBlend's multiply mode is (1 - Sa) * Da + (1 - Da) * Sc + Sc * Dc
     // Skia's is just Sc * Dc.  So we use a custom proc to implement FEBlend's
     // version.
     if (fMode == SkBlendImageFilter::kMultiply_Mode) {
         paint.setXfermode(new SkProcXfermode(multiply_proc))->unref();
     } else {
         paint.setXfermodeMode(modeToXfermode(fMode));
     }
     canvas.drawBitmap(foreground, 0, 0, &paint);
     return true;
 }

 ///////////////////////////////////////////////////////////////////////////////

 #if SK_SUPPORT_GPU
 class GrGLBlendEffect  : public GrGLProgramStage {
 public:
     GrGLBlendEffect(const GrProgramStageFactory& factory,
                     const GrCustomStage& stage);
     virtual ~GrGLBlendEffect();

     virtual void emitFS(GrGLShaderBuilder* builder,
                         const char* outputColor,
                         const char* inputColor,
                         const TextureSamplerArray&) SK_OVERRIDE;

     virtual void emitVS(GrGLShaderBuilder* builder,
                         const char* vertexCoords) SK_OVERRIDE {}

     static inline StageKey GenKey(const GrCustomStage& s, const GrGLCaps&);

 private:
     typedef GrGLProgramStage INHERITED;
     SkBlendImageFilter::Mode fMode;
 };

 ///////////////////////////////////////////////////////////////////////////////

 class GrBlendEffect : public GrSingleTextureEffect {
 public:
     GrBlendEffect(SkBlendImageFilter::Mode mode, GrTexture* foreground);
     virtual ~GrBlendEffect();

     virtual bool isEqual(const GrCustomStage&) const SK_OVERRIDE;
     const GrProgramStageFactory& getFactory() const;
     SkBlendImageFilter::Mode mode() const { return fMode; }

     typedef GrGLBlendEffect GLProgramStage;
     static const char* Name() { return "Blend"; }

 private:
     typedef GrSingleTextureEffect INHERITED;
     SkBlendImageFilter::Mode fMode;
 };

 // FIXME:  This should be refactored with SkSingleInputImageFilter's version.
 static GrTexture* getInputResultAsTexture(SkImageFilter::Proxy* proxy,
                                           SkImageFilter* input,
                                           GrTexture* src,
                                           const SkRect& rect) {
     GrTexture* resultTex;
     if (!input) {
         resultTex = src;
     } else if (input->canFilterImageGPU()) {
         // onFilterImageGPU() already refs the result, so just return it here.
         return input->onFilterImageGPU(proxy, src, rect);
     } else {
         SkBitmap srcBitmap, result;
         srcBitmap.setConfig(SkBitmap::kARGB_8888_Config, src->width(), src->height());
         srcBitmap.setPixelRef(new SkGrPixelRef(src))->unref();
         SkIPoint offset;
         if (input->filterImage(proxy, srcBitmap, SkMatrix(), &result, &offset)) {
             if (result.getTexture()) {
                 resultTex = (GrTexture*) result.getTexture();
             } else {
                 resultTex = GrLockCachedBitmapTexture(src->getContext(), result, NULL);
                 SkSafeRef(resultTex);
                 GrUnlockCachedBitmapTexture(resultTex);
                 return resultTex;
             }
         } else {
             resultTex = src;
         }
     }
     SkSafeRef(resultTex);
     return resultTex;
 }

 GrTexture* SkBlendImageFilter::onFilterImageGPU(Proxy* proxy, GrTexture* src, const SkRect& rect) {
     SkAutoTUnref<GrTexture> background(getInputResultAsTexture(proxy, getBackgroundInput(), src, rect));
     SkAutoTUnref<GrTexture> foreground(getInputResultAsTexture(proxy, getForegroundInput(), src, rect));
     GrContext* context = src->getContext();

     GrTextureDesc desc;
     desc.fFlags = kRenderTarget_GrTextureFlagBit | kNoStencil_GrTextureFlagBit;
     desc.fWidth = SkScalarCeilToInt(rect.width());
     desc.fHeight = SkScalarCeilToInt(rect.height());
     desc.fConfig = kRGBA_8888_GrPixelConfig;

     GrAutoScratchTexture ast(context, desc);
     GrTexture* dst = ast.detach();

     GrContext::AutoMatrix am;
     am.setIdentity(context);

     GrContext::AutoRenderTarget art(context, dst->asRenderTarget());
     GrContext::AutoClip ac(context, rect);

     GrMatrix sampleM;
     sampleM.setIDiv(background->width(), background->height());
     GrPaint paint;
     paint.colorSampler(0)->reset(sampleM);
     paint.colorSampler(0)->setCustomStage(SkNEW_ARGS(GrSingleTextureEffect, (background.get())))->unref();
     paint.colorSampler(1)->reset(sampleM);
     paint.colorSampler(1)->setCustomStage(SkNEW_ARGS(GrBlendEffect, (fMode, foreground.get())))->unref();
     context->drawRect(paint, rect);
     return dst;
 }

 ///////////////////////////////////////////////////////////////////////////////

 GrBlendEffect::GrBlendEffect(SkBlendImageFilter::Mode mode, GrTexture* foreground)
     : INHERITED(foreground), fMode(mode) {
 }

 GrBlendEffect::~GrBlendEffect() {
 }

 bool GrBlendEffect::isEqual(const GrCustomStage& sBase) const {
     const GrBlendEffect& s = static_cast<const GrBlendEffect&>(sBase);
     return INHERITED::isEqual(sBase) &&
            fMode == s.fMode;
 }

 const GrProgramStageFactory& GrBlendEffect::getFactory() const {
     return GrTProgramStageFactory<GrBlendEffect>::getInstance();
 }

 ///////////////////////////////////////////////////////////////////////////////

 GrGLBlendEffect::GrGLBlendEffect(const GrProgramStageFactory& factory,
                                  const GrCustomStage& stage)
     : GrGLProgramStage(factory),
       fMode(static_cast<const GrBlendEffect&>(stage).mode()) {
 }

 GrGLBlendEffect::~GrGLBlendEffect() {
 }

 void GrGLBlendEffect::emitFS(GrGLShaderBuilder* builder,
                              const char* outputColor,
                              const char* inputColor,
                              const TextureSamplerArray& samplers) {
     SkString* code = &builder->fFSCode;
     const char* bgColor = inputColor;
     const char* fgColor = "fgColor";
     code->appendf("\t\tvec4 %s = ", fgColor);
     builder->appendTextureLookup(code, samplers[0]);
     code->append(";\n");
     code->appendf("\t\t%s.a = 1.0 - (1.0 - %s.a) * (1.0 - %s.b);\n", outputColor, bgColor, fgColor);
     switch (fMode) {
       case SkBlendImageFilter::kNormal_Mode:
         code->appendf("\t\t%s.rgb = (1.0 - %s.a) * %s.rgb + %s.rgb;\n", outputColor, fgColor, bgColor, fgColor);
         break;
       case SkBlendImageFilter::kMultiply_Mode:
         code->appendf("\t\t%s.rgb = (1.0 - %s.a) * %s.rgb + (1.0 - %s.a) * %s.rgb + %s.rgb * %s.rgb;\n", outputColor, fgColor, bgColor, bgColor, fgColor, fgColor, bgColor);
         break;
       case SkBlendImageFilter::kScreen_Mode:
         code->appendf("\t\t%s.rgb = %s.rgb + %s.rgb - %s.rgb * %s.rgb;\n", outputColor, bgColor, fgColor, fgColor, bgColor);
         break;
       case SkBlendImageFilter::kDarken_Mode:
         code->appendf("\t\t%s.rgb = min((1.0 - %s.a) * %s.rgb + %s.rgb, (1.0 - %s.a) * %s.rgb + %s.rgb);\n", outputColor, fgColor, bgColor, fgColor, bgColor, fgColor, bgColor);
         break;
       case SkBlendImageFilter::kLighten_Mode:
         code->appendf("\t\t%s.rgb = max((1.0 - %s.a) * %s.rgb + %s.rgb, (1.0 - %s.a) * %s.rgb + %s.rgb);\n", outputColor, fgColor, bgColor, fgColor, bgColor, fgColor, bgColor);
         break;
     }
 }

 GrGLProgramStage::StageKey GrGLBlendEffect::GenKey(const GrCustomStage& s, const GrGLCaps&) {
     return static_cast<const GrBlendEffect&>(s).mode();
 }
 #endif
	/*
	* Copyright 2012 The Android Open Source Project
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "SkBlendImageFilter.h"
	#include "SkCanvas.h"
	#include "SkColorPriv.h"
	#include "SkFlattenableBuffers.h"
	#if SK_SUPPORT_GPU
	#include "SkGr.h"
	#include "SkGrPixelRef.h"
	#include "gl/GrGLProgramStage.h"
	#endif

	namespace {

	SkXfermode::Mode modeToXfermode(SkBlendImageFilter::Mode mode)
	{
	switch (mode) {
	case SkBlendImageFilter::kNormal_Mode:
	return SkXfermode::kSrcOver_Mode;
	case SkBlendImageFilter::kMultiply_Mode:
	return SkXfermode::kMultiply_Mode;
	case SkBlendImageFilter::kScreen_Mode:
	return SkXfermode::kScreen_Mode;
	case SkBlendImageFilter::kDarken_Mode:
	return SkXfermode::kDarken_Mode;
	case SkBlendImageFilter::kLighten_Mode:
	return SkXfermode::kLighten_Mode;
	}
	SkASSERT(0);
	return SkXfermode::kSrcOver_Mode;
	}

	SkPMColor multiply_proc(SkPMColor src, SkPMColor dst) {
	int omsa = 255 - SkGetPackedA32(src);
	int sr = SkGetPackedR32(src), sg = SkGetPackedG32(src), sb = SkGetPackedB32(src);
	int omda = 255 - SkGetPackedA32(dst);
	int dr = SkGetPackedR32(dst), dg = SkGetPackedG32(dst), db = SkGetPackedB32(dst);
	int a = 255 - SkMulDiv255Round(omsa, omda);
	int r = SkMulDiv255Round(omsa, dr) + SkMulDiv255Round(omda, sr) + SkMulDiv255Round(sr, dr);
	int g = SkMulDiv255Round(omsa, dg) + SkMulDiv255Round(omda, sg) + SkMulDiv255Round(sg, dg);
	int b = SkMulDiv255Round(omsa, db) + SkMulDiv255Round(omda, sb) + SkMulDiv255Round(sb, db);
	return SkPackARGB32(a, r, g, b);
	}

	};

	///////////////////////////////////////////////////////////////////////////////

	SkBlendImageFilter::SkBlendImageFilter(SkBlendImageFilter::Mode mode, SkImageFilter* background, SkImageFilter* foreground)
	: INHERITED(2, background, foreground), fMode(mode)
	{
	}

	SkBlendImageFilter::~SkBlendImageFilter() {
	}

	SkBlendImageFilter::SkBlendImageFilter(SkFlattenableReadBuffer& buffer)
	: INHERITED(buffer)
	{
	fMode = (SkBlendImageFilter::Mode) buffer.readInt();
	}

	void SkBlendImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
	this->INHERITED::flatten(buffer);
	buffer.writeInt((int) fMode);
	}

	bool SkBlendImageFilter::onFilterImage(Proxy* proxy,
	const SkBitmap& src,
	const SkMatrix& ctm,
	SkBitmap* dst,
	SkIPoint* offset) {
	SkBitmap background, foreground = src;
	SkImageFilter* backgroundInput = getBackgroundInput();
	SkImageFilter* foregroundInput = getForegroundInput();
	SkASSERT(NULL != backgroundInput);
	if (!backgroundInput->filterImage(proxy, src, ctm, &background, offset)) {
	return false;
	}
	if (foregroundInput && !foregroundInput->filterImage(proxy, src, ctm, &foreground, offset)) {
	return false;
	}
	SkAutoLockPixels alp_foreground(foreground), alp_background(background);
	if (!foreground.getPixels() \|\| !background.getPixels()) {
	return false;
	}
	dst->setConfig(background.config(), background.width(), background.height());
	dst->allocPixels();
	SkCanvas canvas(*dst);
	SkPaint paint;
	paint.setXfermodeMode(SkXfermode::kSrc_Mode);
	canvas.drawBitmap(background, 0, 0, &paint);
	// FEBlend's multiply mode is (1 - Sa) * Da + (1 - Da) * Sc + Sc * Dc
	// Skia's is just Sc * Dc. So we use a custom proc to implement FEBlend's
	// version.
	if (fMode == SkBlendImageFilter::kMultiply_Mode) {
	paint.setXfermode(new SkProcXfermode(multiply_proc))->unref();
	} else {
	paint.setXfermodeMode(modeToXfermode(fMode));
	}
	canvas.drawBitmap(foreground, 0, 0, &paint);
	return true;
	}

	///////////////////////////////////////////////////////////////////////////////

	#if SK_SUPPORT_GPU
	class GrGLBlendEffect : public GrGLProgramStage {
	public:
	GrGLBlendEffect(const GrProgramStageFactory& factory,
	const GrCustomStage& stage);
	virtual ~GrGLBlendEffect();

	virtual void emitFS(GrGLShaderBuilder* builder,
	const char* outputColor,
	const char* inputColor,
	const TextureSamplerArray&) SK_OVERRIDE;

	virtual void emitVS(GrGLShaderBuilder* builder,
	const char* vertexCoords) SK_OVERRIDE {}

	static inline StageKey GenKey(const GrCustomStage& s, const GrGLCaps&);

	private:
	typedef GrGLProgramStage INHERITED;
	SkBlendImageFilter::Mode fMode;
	};

	///////////////////////////////////////////////////////////////////////////////

	class GrBlendEffect : public GrSingleTextureEffect {
	public:
	GrBlendEffect(SkBlendImageFilter::Mode mode, GrTexture* foreground);
	virtual ~GrBlendEffect();

	virtual bool isEqual(const GrCustomStage&) const SK_OVERRIDE;
	const GrProgramStageFactory& getFactory() const;
	SkBlendImageFilter::Mode mode() const { return fMode; }

	typedef GrGLBlendEffect GLProgramStage;
	static const char* Name() { return "Blend"; }

	private:
	typedef GrSingleTextureEffect INHERITED;
	SkBlendImageFilter::Mode fMode;
	};

	// FIXME: This should be refactored with SkSingleInputImageFilter's version.
	static GrTexture* getInputResultAsTexture(SkImageFilter::Proxy* proxy,
	SkImageFilter* input,
	GrTexture* src,
	const SkRect& rect) {
	GrTexture* resultTex;
	if (!input) {
	resultTex = src;
	} else if (input->canFilterImageGPU()) {
	// onFilterImageGPU() already refs the result, so just return it here.
	return input->onFilterImageGPU(proxy, src, rect);
	} else {
	SkBitmap srcBitmap, result;
	srcBitmap.setConfig(SkBitmap::kARGB_8888_Config, src->width(), src->height());
	srcBitmap.setPixelRef(new SkGrPixelRef(src))->unref();
	SkIPoint offset;
	if (input->filterImage(proxy, srcBitmap, SkMatrix(), &result, &offset)) {
	if (result.getTexture()) {
	resultTex = (GrTexture*) result.getTexture();
	} else {
	resultTex = GrLockCachedBitmapTexture(src->getContext(), result, NULL);
	SkSafeRef(resultTex);
	GrUnlockCachedBitmapTexture(resultTex);
	return resultTex;
	}
	} else {
	resultTex = src;
	}
	}
	SkSafeRef(resultTex);
	return resultTex;
	}

	GrTexture* SkBlendImageFilter::onFilterImageGPU(Proxy* proxy, GrTexture* src, const SkRect& rect) {
	SkAutoTUnref<GrTexture> background(getInputResultAsTexture(proxy, getBackgroundInput(), src, rect));
	SkAutoTUnref<GrTexture> foreground(getInputResultAsTexture(proxy, getForegroundInput(), src, rect));
	GrContext* context = src->getContext();

	GrTextureDesc desc;
	desc.fFlags = kRenderTarget_GrTextureFlagBit \| kNoStencil_GrTextureFlagBit;
	desc.fWidth = SkScalarCeilToInt(rect.width());
	desc.fHeight = SkScalarCeilToInt(rect.height());
	desc.fConfig = kRGBA_8888_GrPixelConfig;

	GrAutoScratchTexture ast(context, desc);
	GrTexture* dst = ast.detach();

	GrContext::AutoMatrix am;
	am.setIdentity(context);

	GrContext::AutoRenderTarget art(context, dst->asRenderTarget());
	GrContext::AutoClip ac(context, rect);

	GrMatrix sampleM;
	sampleM.setIDiv(background->width(), background->height());
	GrPaint paint;
	paint.colorSampler(0)->reset(sampleM);
	paint.colorSampler(0)->setCustomStage(SkNEW_ARGS(GrSingleTextureEffect, (background.get())))->unref();
	paint.colorSampler(1)->reset(sampleM);
	paint.colorSampler(1)->setCustomStage(SkNEW_ARGS(GrBlendEffect, (fMode, foreground.get())))->unref();
	context->drawRect(paint, rect);
	return dst;
	}

	///////////////////////////////////////////////////////////////////////////////

	GrBlendEffect::GrBlendEffect(SkBlendImageFilter::Mode mode, GrTexture* foreground)
	: INHERITED(foreground), fMode(mode) {
	}

	GrBlendEffect::~GrBlendEffect() {
	}

	bool GrBlendEffect::isEqual(const GrCustomStage& sBase) const {
	const GrBlendEffect& s = static_cast<const GrBlendEffect&>(sBase);
	return INHERITED::isEqual(sBase) &&
	fMode == s.fMode;
	}

	const GrProgramStageFactory& GrBlendEffect::getFactory() const {
	return GrTProgramStageFactory<GrBlendEffect>::getInstance();
	}

	///////////////////////////////////////////////////////////////////////////////

	GrGLBlendEffect::GrGLBlendEffect(const GrProgramStageFactory& factory,
	const GrCustomStage& stage)
	: GrGLProgramStage(factory),
	fMode(static_cast<const GrBlendEffect&>(stage).mode()) {
	}

	GrGLBlendEffect::~GrGLBlendEffect() {
	}

	void GrGLBlendEffect::emitFS(GrGLShaderBuilder* builder,
	const char* outputColor,
	const char* inputColor,
	const TextureSamplerArray& samplers) {
	SkString* code = &builder->fFSCode;
	const char* bgColor = inputColor;
	const char* fgColor = "fgColor";
	code->appendf("\t\tvec4 %s = ", fgColor);
	builder->appendTextureLookup(code, samplers[0]);
	code->append(";\n");
	code->appendf("\t\t%s.a = 1.0 - (1.0 - %s.a) * (1.0 - %s.b);\n", outputColor, bgColor, fgColor);
	switch (fMode) {
	case SkBlendImageFilter::kNormal_Mode:
	code->appendf("\t\t%s.rgb = (1.0 - %s.a) * %s.rgb + %s.rgb;\n", outputColor, fgColor, bgColor, fgColor);
	break;
	case SkBlendImageFilter::kMultiply_Mode:
	code->appendf("\t\t%s.rgb = (1.0 - %s.a) * %s.rgb + (1.0 - %s.a) * %s.rgb + %s.rgb * %s.rgb;\n", outputColor, fgColor, bgColor, bgColor, fgColor, fgColor, bgColor);
	break;
	case SkBlendImageFilter::kScreen_Mode:
	code->appendf("\t\t%s.rgb = %s.rgb + %s.rgb - %s.rgb * %s.rgb;\n", outputColor, bgColor, fgColor, fgColor, bgColor);
	break;
	case SkBlendImageFilter::kDarken_Mode:
	code->appendf("\t\t%s.rgb = min((1.0 - %s.a) * %s.rgb + %s.rgb, (1.0 - %s.a) * %s.rgb + %s.rgb);\n", outputColor, fgColor, bgColor, fgColor, bgColor, fgColor, bgColor);
	break;
	case SkBlendImageFilter::kLighten_Mode:
	code->appendf("\t\t%s.rgb = max((1.0 - %s.a) * %s.rgb + %s.rgb, (1.0 - %s.a) * %s.rgb + %s.rgb);\n", outputColor, fgColor, bgColor, fgColor, bgColor, fgColor, bgColor);
	break;
	}
	}

	GrGLProgramStage::StageKey GrGLBlendEffect::GenKey(const GrCustomStage& s, const GrGLCaps&) {
	return static_cast<const GrBlendEffect&>(s).mode();
	}
	#endif