| /* |
| * 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/GrGLSL.h" |
| #include "gl/GrGLTexture.h" |
| #include "gl/GrGLVertexEffect.h" |
| #include "GrTBackendEffectFactory.h" |
| #include "GrTexture.h" |
| |
| #include "SkDistanceFieldGen.h" |
| |
| 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, |
| EffectKey key, |
| const char* outputColor, |
| const char* inputColor, |
| const TransformedCoordsArray&, |
| const TextureSamplerArray& samplers) SK_OVERRIDE { |
| SkASSERT(1 == drawEffect.castEffect<GrDistanceFieldTextureEffect>().numVertexAttribs()); |
| |
| SkAssertResult(builder->enableFeature(GrGLShaderBuilder::kStandardDerivatives_GLSLFeature)); |
| const GrDistanceFieldTextureEffect& dfTexEffect = |
| drawEffect.castEffect<GrDistanceFieldTextureEffect>(); |
| |
| 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 ");\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 |
| // (assuming a radius of the diagonal of the fragment, hence a factor of sqrt(2)/2) |
| builder->fsCodeAppend("\tafwidth = 0.7071*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 |
| // (assuming a radius of the diagonal of the fragment, hence a factor of sqrt(2)/2) |
| builder->fsCodeAppend("\tafwidth = 0.7071*length(grad);\n"); |
| } |
| |
| builder->fsCodeAppend("\tfloat val = smoothstep(-afwidth, afwidth, distance);\n"); |
| |
| builder->fsCodeAppendf("\t%s = %s;\n", outputColor, |
| (GrGLSLExpr4(inputColor) * GrGLSLExpr1("val")).c_str()); |
| } |
| |
| virtual void setData(const GrGLUniformManager& uman, |
| const GrDrawEffect& drawEffect) SK_OVERRIDE { |
| SkASSERT(fTextureSizeUni.isValid()); |
| |
| GrTexture* texture = drawEffect.effect()->get()->texture(0); |
| if (texture->width() != fTextureSize.width() || |
| texture->height() != fTextureSize.height()) { |
| fTextureSize = SkISize::Make(texture->width(), texture->height()); |
| uman.set2f(fTextureSizeUni, |
| SkIntToScalar(fTextureSize.width()), |
| SkIntToScalar(fTextureSize.height())); |
| } |
| } |
| |
| static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) { |
| const GrDistanceFieldTextureEffect& dfTexEffect = |
| drawEffect.castEffect<GrDistanceFieldTextureEffect>(); |
| |
| return dfTexEffect.isSimilarity() ? 0x1 : 0x0; |
| } |
| |
| private: |
| GrGLUniformManager::UniformHandle fTextureSizeUni; |
| SkISize fTextureSize; |
| |
| typedef GrGLVertexEffect INHERITED; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| GrDistanceFieldTextureEffect::GrDistanceFieldTextureEffect(GrTexture* texture, |
| const GrTextureParams& params, |
| bool similarity) |
| : fTextureAccess(texture, params) |
| , fIsSimilarity(similarity) { |
| this->addTextureAccess(&fTextureAccess); |
| this->addVertexAttrib(kVec2f_GrSLType); |
| } |
| |
| bool GrDistanceFieldTextureEffect::onIsEqual(const GrEffect& other) const { |
| const GrDistanceFieldTextureEffect& cte = CastEffect<GrDistanceFieldTextureEffect>(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<GrDistanceFieldTextureEffect>::getInstance(); |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| GR_DEFINE_EFFECT_TEST(GrDistanceFieldTextureEffect); |
| |
| GrEffectRef* GrDistanceFieldTextureEffect::TestCreate(SkRandom* random, |
| GrContext*, |
| const GrDrawTargetCaps&, |
| GrTexture* textures[]) { |
| int texIdx = 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); |
| |
| return GrDistanceFieldTextureEffect::Create(textures[texIdx], params, |
| 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, |
| EffectKey key, |
| const char* outputColor, |
| const char* inputColor, |
| const TransformedCoordsArray&, |
| const TextureSamplerArray& samplers) SK_OVERRIDE { |
| SkASSERT(1 == drawEffect.castEffect<GrDistanceFieldLCDTextureEffect>().numVertexAttribs()); |
| |
| SkAssertResult(builder->enableFeature(GrGLShaderBuilder::kStandardDerivatives_GLSLFeature)); |
| const GrDistanceFieldLCDTextureEffect& dfTexEffect = |
| drawEffect.castEffect<GrDistanceFieldLCDTextureEffect>(); |
| |
| 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 = " |
| SK_DistanceFieldMultiplier "*(texColor.r - " SK_DistanceFieldThreshold ");\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 = " |
| SK_DistanceFieldMultiplier "*(texColor.r - " SK_DistanceFieldThreshold ");\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 = " |
| SK_DistanceFieldMultiplier "*(texColor.r - " SK_DistanceFieldThreshold ");\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 |
| // (assuming a radius of the diagonal of the fragment, hence a factor of sqrt(2)/2) |
| builder->fsCodeAppend("\tafwidth = 0.7071*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 |
| // (assuming a radius of the diagonal of the fragment, hence a factor of sqrt(2)/2) |
| builder->fsCodeAppend("\tafwidth = 0.7071*length(grad);\n"); |
| } |
| |
| builder->fsCodeAppend("\tvec4 val = vec4(smoothstep(vec3(-afwidth), vec3(afwidth), distance), 1.0);\n"); |
| |
| builder->fsCodeAppendf("\t%s = %s;\n", outputColor, |
| (GrGLSLExpr4(inputColor) * GrGLSLExpr4("val")).c_str()); |
| } |
| |
| virtual void setData(const GrGLUniformManager& uman, |
| const GrDrawEffect& drawEffect) SK_OVERRIDE { |
| SkASSERT(fTextureSizeUni.isValid()); |
| |
| GrTexture* texture = drawEffect.effect()->get()->texture(0); |
| if (texture->width() != fTextureSize.width() || |
| texture->height() != fTextureSize.height()) { |
| const GrDistanceFieldLCDTextureEffect& dfTexEffect = |
| drawEffect.castEffect<GrDistanceFieldLCDTextureEffect>(); |
| fTextureSize = SkISize::Make(texture->width(), texture->height()); |
| float delta = 1.0f/(3.0f*texture->width()); |
| if (dfTexEffect.useBGR()) { |
| delta = -delta; |
| } |
| uman.set3f(fTextureSizeUni, |
| SkIntToScalar(fTextureSize.width()), |
| SkIntToScalar(fTextureSize.height()), |
| delta); |
| } |
| } |
| |
| static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) { |
| const GrDistanceFieldLCDTextureEffect& dfTexEffect = |
| drawEffect.castEffect<GrDistanceFieldLCDTextureEffect>(); |
| |
| int uniformScale = dfTexEffect.isUniformScale() ? 0x01 : 0x00; |
| int useBGR = dfTexEffect.useBGR() ? 0x10 : 0x00; |
| return uniformScale | useBGR; |
| } |
| |
| private: |
| GrGLUniformManager::UniformHandle fTextureSizeUni; |
| SkISize fTextureSize; |
| |
| typedef GrGLVertexEffect INHERITED; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| GrDistanceFieldLCDTextureEffect::GrDistanceFieldLCDTextureEffect(GrTexture* texture, |
| const GrTextureParams& params, |
| bool uniformScale, |
| bool useBGR) |
| : fTextureAccess(texture, params) |
| , fUniformScale(uniformScale) |
| , fUseBGR(useBGR) { |
| this->addTextureAccess(&fTextureAccess); |
| this->addVertexAttrib(kVec2f_GrSLType); |
| } |
| |
| bool GrDistanceFieldLCDTextureEffect::onIsEqual(const GrEffect& other) const { |
| const GrDistanceFieldLCDTextureEffect& cte = CastEffect<GrDistanceFieldLCDTextureEffect>(other); |
| return fTextureAccess == cte.fTextureAccess; |
| } |
| |
| 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<GrDistanceFieldLCDTextureEffect>::getInstance(); |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| GR_DEFINE_EFFECT_TEST(GrDistanceFieldLCDTextureEffect); |
| |
| GrEffectRef* GrDistanceFieldLCDTextureEffect::TestCreate(SkRandom* random, |
| GrContext*, |
| const GrDrawTargetCaps&, |
| GrTexture* textures[]) { |
| int texIdx = 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); |
| |
| return GrDistanceFieldLCDTextureEffect::Create(textures[texIdx], params, |
| random->nextBool(), random->nextBool()); |
| } |