/* * Copyright 2013 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #include "GrDistanceFieldTextureEffect.h" #include "gl/GrGLEffect.h" #include "gl/GrGLShaderBuilder.h" #include "gl/GrGLSL.h" #include "gl/GrGLTexture.h" #include "gl/GrGLVertexEffect.h" #include "GrTBackendEffectFactory.h" #include "GrTexture.h" #include "SkDistanceFieldGen.h" // To get optical sizes people don't complain about when we blit correctly, // we need to slightly bold each glyph. On the Mac, we need a larger bold value. #if defined(SK_BUILD_FOR_MAC) #define SK_DistanceFieldLCDFactor "0.33" #define SK_DistanceFieldNonLCDFactor "0.25" #else #define SK_DistanceFieldLCDFactor "0.05" #define SK_DistanceFieldNonLCDFactor "0.05" #endif // Assuming a radius of the diagonal of the fragment, hence a factor of sqrt(2)/2 #define SK_DistanceFieldAAFactor "0.7071" class GrGLDistanceFieldTextureEffect : public GrGLVertexEffect { public: GrGLDistanceFieldTextureEffect(const GrBackendEffectFactory& factory, const GrDrawEffect& drawEffect) : INHERITED (factory) , fTextureSize(SkISize::Make(-1,-1)) {} virtual void emitCode(GrGLFullShaderBuilder* builder, const GrDrawEffect& drawEffect, const GrEffectKey& key, const char* outputColor, const char* inputColor, const TransformedCoordsArray&, const TextureSamplerArray& samplers) SK_OVERRIDE { SkASSERT(1 == drawEffect.castEffect().numVertexAttribs()); SkAssertResult(builder->enableFeature(GrGLShaderBuilder::kStandardDerivatives_GLSLFeature)); const GrDistanceFieldTextureEffect& dfTexEffect = drawEffect.castEffect(); SkString fsCoordName; const char* vsCoordName; const char* fsCoordNamePtr; builder->addVarying(kVec2f_GrSLType, "textureCoords", &vsCoordName, &fsCoordNamePtr); fsCoordName = fsCoordNamePtr; const char* attrName0 = builder->getEffectAttributeName(drawEffect.getVertexAttribIndices()[0])->c_str(); builder->vsCodeAppendf("\t%s = %s;\n", vsCoordName, attrName0); const char* textureSizeUniName = NULL; fTextureSizeUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility, kVec2f_GrSLType, "TextureSize", &textureSizeUniName); builder->fsCodeAppend("\tvec4 texColor = "); builder->fsAppendTextureLookup(samplers[0], fsCoordName.c_str(), kVec2f_GrSLType); builder->fsCodeAppend(";\n"); builder->fsCodeAppend("\tfloat distance = " SK_DistanceFieldMultiplier "*(texColor.r - " SK_DistanceFieldThreshold ")" "+ " SK_DistanceFieldNonLCDFactor ";\n"); // we adjust for the effect of the transformation on the distance by using // the length of the gradient of the texture coordinates. We use st coordinates // to ensure we're mapping 1:1 from texel space to pixel space. builder->fsCodeAppendf("\tvec2 uv = %s;\n", fsCoordName.c_str()); builder->fsCodeAppendf("\tvec2 st = uv*%s;\n", textureSizeUniName); builder->fsCodeAppend("\tfloat afwidth;\n"); if (dfTexEffect.isSimilarity()) { // this gives us a smooth step across approximately one fragment builder->fsCodeAppend("\tafwidth = " SK_DistanceFieldAAFactor "*dFdx(st.x);\n"); } else { builder->fsCodeAppend("\tvec2 Jdx = dFdx(st);\n"); builder->fsCodeAppend("\tvec2 Jdy = dFdy(st);\n"); builder->fsCodeAppend("\tvec2 uv_grad;\n"); if (builder->ctxInfo().caps()->dropsTileOnZeroDivide()) { // this is to compensate for the Adreno, which likes to drop tiles on division by 0 builder->fsCodeAppend("\tfloat uv_len2 = dot(uv, uv);\n"); builder->fsCodeAppend("\tif (uv_len2 < 0.0001) {\n"); builder->fsCodeAppend("\t\tuv_grad = vec2(0.7071, 0.7071);\n"); builder->fsCodeAppend("\t} else {\n"); builder->fsCodeAppend("\t\tuv_grad = uv*inversesqrt(uv_len2);\n"); builder->fsCodeAppend("\t}\n"); } else { builder->fsCodeAppend("\tuv_grad = normalize(uv);\n"); } builder->fsCodeAppend("\tvec2 grad = vec2(uv_grad.x*Jdx.x + uv_grad.y*Jdy.x,\n"); builder->fsCodeAppend("\t uv_grad.x*Jdx.y + uv_grad.y*Jdy.y);\n"); // this gives us a smooth step across approximately one fragment builder->fsCodeAppend("\tafwidth = " SK_DistanceFieldAAFactor "*length(grad);\n"); } builder->fsCodeAppend("\tfloat val = smoothstep(-afwidth, afwidth, distance);\n"); #ifdef SK_GAMMA_APPLY_TO_A8 // adjust based on gamma const char* luminanceUniName = NULL; // width, height, 1/(3*width) fLuminanceUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility, kFloat_GrSLType, "Luminance", &luminanceUniName); builder->fsCodeAppendf("\tuv = vec2(val, %s);\n", luminanceUniName); builder->fsCodeAppend("\tvec4 gammaColor = "); builder->fsAppendTextureLookup(samplers[1], "uv", kVec2f_GrSLType); builder->fsCodeAppend(";\n"); builder->fsCodeAppend("\tval = gammaColor.r;\n"); #endif builder->fsCodeAppendf("\t%s = %s;\n", outputColor, (GrGLSLExpr4(inputColor) * GrGLSLExpr1("val")).c_str()); } virtual void setData(const GrGLProgramDataManager& pdman, const GrDrawEffect& drawEffect) SK_OVERRIDE { SkASSERT(fTextureSizeUni.isValid()); GrTexture* texture = drawEffect.effect()->texture(0); if (texture->width() != fTextureSize.width() || texture->height() != fTextureSize.height()) { fTextureSize = SkISize::Make(texture->width(), texture->height()); pdman.set2f(fTextureSizeUni, SkIntToScalar(fTextureSize.width()), SkIntToScalar(fTextureSize.height())); } #ifdef SK_GAMMA_APPLY_TO_A8 const GrDistanceFieldTextureEffect& dfTexEffect = drawEffect.castEffect(); float luminance = dfTexEffect.getLuminance(); if (luminance != fLuminance) { pdman.set1f(fLuminanceUni, luminance); fLuminance = luminance; } #endif } static inline void GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&, GrEffectKeyBuilder* b) { const GrDistanceFieldTextureEffect& dfTexEffect = drawEffect.castEffect(); b->add32(dfTexEffect.isSimilarity()); } private: GrGLProgramDataManager::UniformHandle fTextureSizeUni; SkISize fTextureSize; GrGLProgramDataManager::UniformHandle fLuminanceUni; float fLuminance; typedef GrGLVertexEffect INHERITED; }; /////////////////////////////////////////////////////////////////////////////// GrDistanceFieldTextureEffect::GrDistanceFieldTextureEffect(GrTexture* texture, const GrTextureParams& params, #ifdef SK_GAMMA_APPLY_TO_A8 GrTexture* gamma, const GrTextureParams& gammaParams, float luminance, #endif bool similarity) : fTextureAccess(texture, params) #ifdef SK_GAMMA_APPLY_TO_A8 , fGammaTextureAccess(gamma, gammaParams) , fLuminance(luminance) #endif , fIsSimilarity(similarity) { this->addTextureAccess(&fTextureAccess); #ifdef SK_GAMMA_APPLY_TO_A8 this->addTextureAccess(&fGammaTextureAccess); #endif this->addVertexAttrib(kVec2f_GrSLType); } bool GrDistanceFieldTextureEffect::onIsEqual(const GrEffect& other) const { const GrDistanceFieldTextureEffect& cte = CastEffect(other); return fTextureAccess == cte.fTextureAccess; } void GrDistanceFieldTextureEffect::getConstantColorComponents(GrColor* color, uint32_t* validFlags) const { if ((*validFlags & kA_GrColorComponentFlag) && 0xFF == GrColorUnpackA(*color) && GrPixelConfigIsOpaque(this->texture(0)->config())) { *validFlags = kA_GrColorComponentFlag; } else { *validFlags = 0; } } const GrBackendEffectFactory& GrDistanceFieldTextureEffect::getFactory() const { return GrTBackendEffectFactory::getInstance(); } /////////////////////////////////////////////////////////////////////////////// GR_DEFINE_EFFECT_TEST(GrDistanceFieldTextureEffect); GrEffect* GrDistanceFieldTextureEffect::TestCreate(SkRandom* random, GrContext*, const GrDrawTargetCaps&, GrTexture* textures[]) { int texIdx = random->nextBool() ? GrEffectUnitTest::kSkiaPMTextureIdx : GrEffectUnitTest::kAlphaTextureIdx; #ifdef SK_GAMMA_APPLY_TO_A8 int texIdx2 = random->nextBool() ? GrEffectUnitTest::kSkiaPMTextureIdx : GrEffectUnitTest::kAlphaTextureIdx; #endif static const SkShader::TileMode kTileModes[] = { SkShader::kClamp_TileMode, SkShader::kRepeat_TileMode, SkShader::kMirror_TileMode, }; SkShader::TileMode tileModes[] = { kTileModes[random->nextULessThan(SK_ARRAY_COUNT(kTileModes))], kTileModes[random->nextULessThan(SK_ARRAY_COUNT(kTileModes))], }; GrTextureParams params(tileModes, random->nextBool() ? GrTextureParams::kBilerp_FilterMode : GrTextureParams::kNone_FilterMode); #ifdef SK_GAMMA_APPLY_TO_A8 GrTextureParams params2(tileModes, random->nextBool() ? GrTextureParams::kBilerp_FilterMode : GrTextureParams::kNone_FilterMode); #endif return GrDistanceFieldTextureEffect::Create(textures[texIdx], params, #ifdef SK_GAMMA_APPLY_TO_A8 textures[texIdx2], params2, random->nextF(), #endif random->nextBool()); } /////////////////////////////////////////////////////////////////////////////// class GrGLDistanceFieldLCDTextureEffect : public GrGLVertexEffect { public: GrGLDistanceFieldLCDTextureEffect(const GrBackendEffectFactory& factory, const GrDrawEffect& drawEffect) : INHERITED (factory) , fTextureSize(SkISize::Make(-1,-1)) {} virtual void emitCode(GrGLFullShaderBuilder* builder, const GrDrawEffect& drawEffect, const GrEffectKey& key, const char* outputColor, const char* inputColor, const TransformedCoordsArray&, const TextureSamplerArray& samplers) SK_OVERRIDE { SkASSERT(1 == drawEffect.castEffect().numVertexAttribs()); SkAssertResult(builder->enableFeature(GrGLShaderBuilder::kStandardDerivatives_GLSLFeature)); const GrDistanceFieldLCDTextureEffect& dfTexEffect = drawEffect.castEffect(); SkString fsCoordName; const char* vsCoordName; const char* fsCoordNamePtr; builder->addVarying(kVec2f_GrSLType, "textureCoords", &vsCoordName, &fsCoordNamePtr); fsCoordName = fsCoordNamePtr; const char* attrName0 = builder->getEffectAttributeName(drawEffect.getVertexAttribIndices()[0])->c_str(); builder->vsCodeAppendf("\t%s = %s;\n", vsCoordName, attrName0); const char* textureSizeUniName = NULL; // width, height, 1/(3*width) fTextureSizeUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility, kVec3f_GrSLType, "TextureSize", &textureSizeUniName); // create LCD offset adjusted by inverse of transform builder->fsCodeAppendf("\tvec2 uv = %s;\n", fsCoordName.c_str()); builder->fsCodeAppendf("\tvec2 st = uv*%s.xy;\n", textureSizeUniName); if (dfTexEffect.isUniformScale()) { builder->fsCodeAppend("\tfloat dx = dFdx(st.x);\n"); builder->fsCodeAppendf("\tvec2 offset = vec2(dx*%s.z, 0.0);\n", textureSizeUniName); } else { builder->fsCodeAppend("\tvec2 Jdx = dFdx(st);\n"); builder->fsCodeAppend("\tvec2 Jdy = dFdy(st);\n"); builder->fsCodeAppendf("\tvec2 offset = %s.z*Jdx;\n", textureSizeUniName); } // green is distance to uv center builder->fsCodeAppend("\tvec4 texColor = "); builder->fsAppendTextureLookup(samplers[0], "uv", kVec2f_GrSLType); builder->fsCodeAppend(";\n"); builder->fsCodeAppend("\tvec3 distance;\n"); builder->fsCodeAppend("\tdistance.y = texColor.r;\n"); // red is distance to left offset builder->fsCodeAppend("\tvec2 uv_adjusted = uv - offset;\n"); builder->fsCodeAppend("\ttexColor = "); builder->fsAppendTextureLookup(samplers[0], "uv_adjusted", kVec2f_GrSLType); builder->fsCodeAppend(";\n"); builder->fsCodeAppend("\tdistance.x = texColor.r;\n"); // blue is distance to right offset builder->fsCodeAppend("\tuv_adjusted = uv + offset;\n"); builder->fsCodeAppend("\ttexColor = "); builder->fsAppendTextureLookup(samplers[0], "uv_adjusted", kVec2f_GrSLType); builder->fsCodeAppend(";\n"); builder->fsCodeAppend("\tdistance.z = texColor.r;\n"); builder->fsCodeAppend("\tdistance = " "vec3(" SK_DistanceFieldMultiplier ")*(distance - vec3(" SK_DistanceFieldThreshold"))" "+ vec3(" SK_DistanceFieldLCDFactor ");\n"); // we adjust for the effect of the transformation on the distance by using // the length of the gradient of the texture coordinates. We use st coordinates // to ensure we're mapping 1:1 from texel space to pixel space. // To be strictly correct, we should compute the anti-aliasing factor separately // for each color component. However, this is only important when using perspective // transformations, and even then using a single factor seems like a reasonable // trade-off between quality and speed. builder->fsCodeAppend("\tfloat afwidth;\n"); if (dfTexEffect.isUniformScale()) { // this gives us a smooth step across approximately one fragment builder->fsCodeAppend("\tafwidth = " SK_DistanceFieldAAFactor "*dx;\n"); } else { builder->fsCodeAppend("\tvec2 uv_grad;\n"); if (builder->ctxInfo().caps()->dropsTileOnZeroDivide()) { // this is to compensate for the Adreno, which likes to drop tiles on division by 0 builder->fsCodeAppend("\tfloat uv_len2 = dot(uv, uv);\n"); builder->fsCodeAppend("\tif (uv_len2 < 0.0001) {\n"); builder->fsCodeAppend("\t\tuv_grad = vec2(0.7071, 0.7071);\n"); builder->fsCodeAppend("\t} else {\n"); builder->fsCodeAppend("\t\tuv_grad = uv*inversesqrt(uv_len2);\n"); builder->fsCodeAppend("\t}\n"); } else { builder->fsCodeAppend("\tuv_grad = normalize(uv);\n"); } builder->fsCodeAppend("\tvec2 grad = vec2(uv_grad.x*Jdx.x + uv_grad.y*Jdy.x,\n"); builder->fsCodeAppend("\t uv_grad.x*Jdx.y + uv_grad.y*Jdy.y);\n"); // this gives us a smooth step across approximately one fragment builder->fsCodeAppend("\tafwidth = " SK_DistanceFieldAAFactor "*length(grad);\n"); } builder->fsCodeAppend("\tvec4 val = vec4(smoothstep(vec3(-afwidth), vec3(afwidth), distance), 1.0);\n"); // adjust based on gamma const char* textColorUniName = NULL; // width, height, 1/(3*width) fTextColorUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility, kVec3f_GrSLType, "TextColor", &textColorUniName); builder->fsCodeAppendf("\tuv = vec2(val.x, %s.x);\n", textColorUniName); builder->fsCodeAppend("\tvec4 gammaColor = "); builder->fsAppendTextureLookup(samplers[1], "uv", kVec2f_GrSLType); builder->fsCodeAppend(";\n"); builder->fsCodeAppend("\tval.x = gammaColor.r;\n"); builder->fsCodeAppendf("\tuv = vec2(val.y, %s.y);\n", textColorUniName); builder->fsCodeAppend("\tgammaColor = "); builder->fsAppendTextureLookup(samplers[1], "uv", kVec2f_GrSLType); builder->fsCodeAppend(";\n"); builder->fsCodeAppend("\tval.y = gammaColor.r;\n"); builder->fsCodeAppendf("\tuv = vec2(val.z, %s.z);\n", textColorUniName); builder->fsCodeAppend("\tgammaColor = "); builder->fsAppendTextureLookup(samplers[1], "uv", kVec2f_GrSLType); builder->fsCodeAppend(";\n"); builder->fsCodeAppend("\tval.z = gammaColor.r;\n"); builder->fsCodeAppendf("\t%s = %s;\n", outputColor, (GrGLSLExpr4(inputColor) * GrGLSLExpr4("val")).c_str()); } virtual void setData(const GrGLProgramDataManager& pdman, const GrDrawEffect& drawEffect) SK_OVERRIDE { SkASSERT(fTextureSizeUni.isValid()); SkASSERT(fTextColorUni.isValid()); const GrDistanceFieldLCDTextureEffect& dfTexEffect = drawEffect.castEffect(); GrTexture* texture = drawEffect.effect()->texture(0); if (texture->width() != fTextureSize.width() || texture->height() != fTextureSize.height()) { fTextureSize = SkISize::Make(texture->width(), texture->height()); float delta = 1.0f/(3.0f*texture->width()); if (dfTexEffect.useBGR()) { delta = -delta; } pdman.set3f(fTextureSizeUni, SkIntToScalar(fTextureSize.width()), SkIntToScalar(fTextureSize.height()), delta); } GrColor textColor = dfTexEffect.getTextColor(); if (textColor != fTextColor) { static const float ONE_OVER_255 = 1.f / 255.f; pdman.set3f(fTextColorUni, GrColorUnpackR(textColor) * ONE_OVER_255, GrColorUnpackG(textColor) * ONE_OVER_255, GrColorUnpackB(textColor) * ONE_OVER_255); fTextColor = textColor; } } static inline void GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&, GrEffectKeyBuilder* b) { const GrDistanceFieldLCDTextureEffect& dfTexEffect = drawEffect.castEffect(); b->add32(dfTexEffect.isUniformScale()); } private: GrGLProgramDataManager::UniformHandle fTextureSizeUni; SkISize fTextureSize; GrGLProgramDataManager::UniformHandle fTextColorUni; SkColor fTextColor; typedef GrGLVertexEffect INHERITED; }; /////////////////////////////////////////////////////////////////////////////// GrDistanceFieldLCDTextureEffect::GrDistanceFieldLCDTextureEffect( GrTexture* texture, const GrTextureParams& params, GrTexture* gamma, const GrTextureParams& gParams, SkColor textColor, bool uniformScale, bool useBGR) : fTextureAccess(texture, params) , fGammaTextureAccess(gamma, gParams) , fTextColor(textColor) , fUniformScale(uniformScale) , fUseBGR(useBGR) { this->addTextureAccess(&fTextureAccess); this->addTextureAccess(&fGammaTextureAccess); this->addVertexAttrib(kVec2f_GrSLType); } bool GrDistanceFieldLCDTextureEffect::onIsEqual(const GrEffect& other) const { const GrDistanceFieldLCDTextureEffect& cte = CastEffect(other); return (fTextureAccess == cte.fTextureAccess && fGammaTextureAccess == cte.fGammaTextureAccess); } void GrDistanceFieldLCDTextureEffect::getConstantColorComponents(GrColor* color, uint32_t* validFlags) const { if ((*validFlags & kA_GrColorComponentFlag) && 0xFF == GrColorUnpackA(*color) && GrPixelConfigIsOpaque(this->texture(0)->config())) { *validFlags = kA_GrColorComponentFlag; } else { *validFlags = 0; } } const GrBackendEffectFactory& GrDistanceFieldLCDTextureEffect::getFactory() const { return GrTBackendEffectFactory::getInstance(); } /////////////////////////////////////////////////////////////////////////////// GR_DEFINE_EFFECT_TEST(GrDistanceFieldLCDTextureEffect); GrEffect* GrDistanceFieldLCDTextureEffect::TestCreate(SkRandom* random, GrContext*, const GrDrawTargetCaps&, GrTexture* textures[]) { int texIdx = random->nextBool() ? GrEffectUnitTest::kSkiaPMTextureIdx : GrEffectUnitTest::kAlphaTextureIdx; int texIdx2 = random->nextBool() ? GrEffectUnitTest::kSkiaPMTextureIdx : GrEffectUnitTest::kAlphaTextureIdx; static const SkShader::TileMode kTileModes[] = { SkShader::kClamp_TileMode, SkShader::kRepeat_TileMode, SkShader::kMirror_TileMode, }; SkShader::TileMode tileModes[] = { kTileModes[random->nextULessThan(SK_ARRAY_COUNT(kTileModes))], kTileModes[random->nextULessThan(SK_ARRAY_COUNT(kTileModes))], }; GrTextureParams params(tileModes, random->nextBool() ? GrTextureParams::kBilerp_FilterMode : GrTextureParams::kNone_FilterMode); GrTextureParams params2(tileModes, random->nextBool() ? GrTextureParams::kBilerp_FilterMode : GrTextureParams::kNone_FilterMode); GrColor textColor = GrColorPackRGBA(random->nextULessThan(256), random->nextULessThan(256), random->nextULessThan(256), random->nextULessThan(256)); return GrDistanceFieldLCDTextureEffect::Create(textures[texIdx], params, textures[texIdx2], params2, textColor, random->nextBool(), random->nextBool()); }