| /* |
| * Copyright 2015 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "src/gpu/effects/GrBlendFragmentProcessor.h" |
| |
| #include "src/gpu/GrFragmentProcessor.h" |
| #include "src/gpu/SkGr.h" |
| #include "src/gpu/glsl/GrGLSLBlend.h" |
| #include "src/gpu/glsl/GrGLSLFragmentProcessor.h" |
| #include "src/gpu/glsl/GrGLSLFragmentShaderBuilder.h" |
| |
| using GrBlendFragmentProcessor::BlendBehavior; |
| |
| // Some of the cpu implementations of blend modes differ too much from the GPU enough that |
| // we can't use the cpu implementation to implement constantOutputForConstantInput. |
| static inline bool does_cpu_blend_impl_match_gpu(SkBlendMode mode) { |
| // The non-seperable modes differ too much. So does SoftLight. ColorBurn differs too much on our |
| // test iOS device (but we just disable it across the aboard since it may happen on untested |
| // GPUs). |
| return mode <= SkBlendMode::kLastSeparableMode && mode != SkBlendMode::kSoftLight && |
| mode != SkBlendMode::kColorBurn; |
| } |
| |
| static const char* BlendBehavior_Name(BlendBehavior behavior) { |
| SkASSERT(unsigned(behavior) <= unsigned(BlendBehavior::kLastBlendBehavior)); |
| static constexpr const char* gStrings[] = { |
| "Default", |
| "Compose-One", |
| "Compose-Two", |
| "SkMode", |
| }; |
| static_assert(SK_ARRAY_COUNT(gStrings) == size_t(BlendBehavior::kLastBlendBehavior) + 1); |
| return gStrings[int(behavior)]; |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| |
| class BlendFragmentProcessor : public GrFragmentProcessor { |
| public: |
| static std::unique_ptr<GrFragmentProcessor> Make(std::unique_ptr<GrFragmentProcessor> src, |
| std::unique_ptr<GrFragmentProcessor> dst, |
| SkBlendMode mode, BlendBehavior behavior) { |
| return std::unique_ptr<GrFragmentProcessor>( |
| new BlendFragmentProcessor(std::move(src), std::move(dst), mode, behavior)); |
| } |
| |
| const char* name() const override { return "Blend"; } |
| |
| std::unique_ptr<GrFragmentProcessor> clone() const override; |
| |
| SkBlendMode getMode() const { return fMode; } |
| BlendBehavior blendBehavior() const { return fBlendBehavior; } |
| |
| private: |
| BlendFragmentProcessor(std::unique_ptr<GrFragmentProcessor> src, |
| std::unique_ptr<GrFragmentProcessor> dst, |
| SkBlendMode mode, BlendBehavior behavior) |
| : INHERITED(kBlendFragmentProcessor_ClassID, OptFlags(src.get(), dst.get(), mode)) |
| , fMode(mode) |
| , fBlendBehavior(behavior) { |
| if (fBlendBehavior == BlendBehavior::kDefault) { |
| fBlendBehavior = (src && dst) ? BlendBehavior::kComposeTwoBehavior |
| : BlendBehavior::kComposeOneBehavior; |
| } |
| this->registerChild(std::move(src)); |
| this->registerChild(std::move(dst)); |
| } |
| |
| BlendFragmentProcessor(const BlendFragmentProcessor& that) |
| : INHERITED(kBlendFragmentProcessor_ClassID, ProcessorOptimizationFlags(&that)) |
| , fMode(that.fMode) |
| , fBlendBehavior(that.fBlendBehavior) { |
| this->cloneAndRegisterAllChildProcessors(that); |
| } |
| |
| #if GR_TEST_UTILS |
| SkString onDumpInfo() const override { |
| return SkStringPrintf("(fMode=%s)", SkBlendMode_Name(fMode)); |
| } |
| #endif |
| |
| static OptimizationFlags OptFlags(const GrFragmentProcessor* src, |
| const GrFragmentProcessor* dst, SkBlendMode mode) { |
| OptimizationFlags flags; |
| switch (mode) { |
| case SkBlendMode::kClear: |
| case SkBlendMode::kSrc: |
| case SkBlendMode::kDst: |
| SK_ABORT("Shouldn't have created a Blend FP as 'clear', 'src', or 'dst'."); |
| flags = kNone_OptimizationFlags; |
| break; |
| |
| // Produces opaque if both src and dst are opaque. These also will modulate the child's |
| // output by either the input color or alpha. However, if the child is not compatible |
| // with the coverage as alpha then it may produce a color that is not valid premul. |
| case SkBlendMode::kSrcIn: |
| case SkBlendMode::kDstIn: |
| case SkBlendMode::kModulate: |
| if (src && dst) { |
| flags = ProcessorOptimizationFlags(src) & ProcessorOptimizationFlags(dst) & |
| kPreservesOpaqueInput_OptimizationFlag; |
| } else if (src) { |
| flags = ProcessorOptimizationFlags(src) & |
| ~kConstantOutputForConstantInput_OptimizationFlag; |
| } else if (dst) { |
| flags = ProcessorOptimizationFlags(dst) & |
| ~kConstantOutputForConstantInput_OptimizationFlag; |
| } else { |
| flags = kNone_OptimizationFlags; |
| } |
| break; |
| |
| // Produces zero when both are opaque, indeterminate if one is opaque. |
| case SkBlendMode::kSrcOut: |
| case SkBlendMode::kDstOut: |
| case SkBlendMode::kXor: |
| flags = kNone_OptimizationFlags; |
| break; |
| |
| // Is opaque if the dst is opaque. |
| case SkBlendMode::kSrcATop: |
| flags = ProcessorOptimizationFlags(dst) & kPreservesOpaqueInput_OptimizationFlag; |
| break; |
| |
| // DstATop is the converse of kSrcATop. Screen is also opaque if the src is a opaque. |
| case SkBlendMode::kDstATop: |
| case SkBlendMode::kScreen: |
| flags = ProcessorOptimizationFlags(src) & kPreservesOpaqueInput_OptimizationFlag; |
| break; |
| |
| // These modes are all opaque if either src or dst is opaque. All the advanced modes |
| // compute alpha as src-over. |
| case SkBlendMode::kSrcOver: |
| case SkBlendMode::kDstOver: |
| case SkBlendMode::kPlus: |
| case SkBlendMode::kOverlay: |
| case SkBlendMode::kDarken: |
| case SkBlendMode::kLighten: |
| case SkBlendMode::kColorDodge: |
| case SkBlendMode::kColorBurn: |
| case SkBlendMode::kHardLight: |
| case SkBlendMode::kSoftLight: |
| case SkBlendMode::kDifference: |
| case SkBlendMode::kExclusion: |
| case SkBlendMode::kMultiply: |
| case SkBlendMode::kHue: |
| case SkBlendMode::kSaturation: |
| case SkBlendMode::kColor: |
| case SkBlendMode::kLuminosity: |
| flags = (ProcessorOptimizationFlags(src) | ProcessorOptimizationFlags(dst)) & |
| kPreservesOpaqueInput_OptimizationFlag; |
| break; |
| } |
| if (does_cpu_blend_impl_match_gpu(mode) && |
| (src ? src->hasConstantOutputForConstantInput() : true) && |
| (dst ? dst->hasConstantOutputForConstantInput() : true)) { |
| flags |= kConstantOutputForConstantInput_OptimizationFlag; |
| } |
| return flags; |
| } |
| |
| void onGetGLSLProcessorKey(const GrShaderCaps& caps, GrProcessorKeyBuilder* b) const override { |
| b->add32((int)fMode); |
| } |
| |
| bool onIsEqual(const GrFragmentProcessor& other) const override { |
| const BlendFragmentProcessor& cs = other.cast<BlendFragmentProcessor>(); |
| return fMode == cs.fMode; |
| } |
| |
| SkPMColor4f constantOutputForConstantInput(const SkPMColor4f& input) const override { |
| const auto* src = this->childProcessor(0); |
| const auto* dst = this->childProcessor(1); |
| |
| switch (fBlendBehavior) { |
| case BlendBehavior::kComposeOneBehavior: { |
| SkPMColor4f srcColor = src ? ConstantOutputForConstantInput(src, SK_PMColor4fWHITE) |
| : input; |
| SkPMColor4f dstColor = dst ? ConstantOutputForConstantInput(dst, SK_PMColor4fWHITE) |
| : input; |
| return SkBlendMode_Apply(fMode, srcColor, dstColor); |
| } |
| |
| case BlendBehavior::kComposeTwoBehavior: { |
| SkPMColor4f opaqueInput = { input.fR, input.fG, input.fB, 1 }; |
| SkPMColor4f srcColor = ConstantOutputForConstantInput(src, opaqueInput); |
| SkPMColor4f dstColor = ConstantOutputForConstantInput(dst, opaqueInput); |
| SkPMColor4f result = SkBlendMode_Apply(fMode, srcColor, dstColor); |
| return result * input.fA; |
| } |
| |
| case BlendBehavior::kSkModeBehavior: { |
| SkPMColor4f srcColor = src ? ConstantOutputForConstantInput(src, SK_PMColor4fWHITE) |
| : input; |
| SkPMColor4f dstColor = dst ? ConstantOutputForConstantInput(dst, input) |
| : input; |
| return SkBlendMode_Apply(fMode, srcColor, dstColor); |
| } |
| |
| default: |
| SK_ABORT("unrecognized blend behavior"); |
| return input; |
| } |
| } |
| |
| std::unique_ptr<GrGLSLFragmentProcessor> onMakeProgramImpl() const override; |
| |
| SkBlendMode fMode; |
| BlendBehavior fBlendBehavior; |
| |
| GR_DECLARE_FRAGMENT_PROCESSOR_TEST |
| |
| using INHERITED = GrFragmentProcessor; |
| }; |
| |
| ///////////////////////////////////////////////////////////////////// |
| |
| class GLBlendFragmentProcessor : public GrGLSLFragmentProcessor { |
| public: |
| void emitCode(EmitArgs&) override; |
| |
| private: |
| using INHERITED = GrGLSLFragmentProcessor; |
| }; |
| |
| ///////////////////////////////////////////////////////////////////// |
| |
| GR_DEFINE_FRAGMENT_PROCESSOR_TEST(BlendFragmentProcessor); |
| |
| #if GR_TEST_UTILS |
| std::unique_ptr<GrFragmentProcessor> BlendFragmentProcessor::TestCreate(GrProcessorTestData* d) { |
| // Create one or two random fragment processors. |
| std::unique_ptr<GrFragmentProcessor> src(GrProcessorUnitTest::MakeOptionalChildFP(d)); |
| std::unique_ptr<GrFragmentProcessor> dst(GrProcessorUnitTest::MakeChildFP(d)); |
| if (d->fRandom->nextBool()) { |
| std::swap(src, dst); |
| } |
| |
| SkBlendMode mode; |
| BlendBehavior behavior; |
| do { |
| mode = static_cast<SkBlendMode>(d->fRandom->nextRangeU(0, (int)SkBlendMode::kLastMode)); |
| behavior = static_cast<BlendBehavior>( |
| d->fRandom->nextRangeU(0, (int)BlendBehavior::kLastBlendBehavior)); |
| } while (SkBlendMode::kClear == mode || SkBlendMode::kSrc == mode || SkBlendMode::kDst == mode); |
| return std::unique_ptr<GrFragmentProcessor>( |
| new BlendFragmentProcessor(std::move(src), std::move(dst), mode, behavior)); |
| } |
| #endif |
| |
| std::unique_ptr<GrFragmentProcessor> BlendFragmentProcessor::clone() const { |
| return std::unique_ptr<GrFragmentProcessor>(new BlendFragmentProcessor(*this)); |
| } |
| |
| std::unique_ptr<GrGLSLFragmentProcessor> BlendFragmentProcessor::onMakeProgramImpl() const { |
| return std::make_unique<GLBlendFragmentProcessor>(); |
| } |
| |
| ///////////////////////////////////////////////////////////////////// |
| |
| void GLBlendFragmentProcessor::emitCode(EmitArgs& args) { |
| GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder; |
| const BlendFragmentProcessor& cs = args.fFp.cast<BlendFragmentProcessor>(); |
| SkBlendMode mode = cs.getMode(); |
| BlendBehavior behavior = cs.blendBehavior(); |
| |
| // Load the input color and make an opaque copy if needed. |
| fragBuilder->codeAppendf("// Blend mode: %s (%s behavior)\n", |
| SkBlendMode_Name(mode), BlendBehavior_Name(behavior)); |
| |
| SkString srcColor, dstColor; |
| switch (behavior) { |
| case BlendBehavior::kComposeOneBehavior: |
| // Compose-one operations historically leave the alpha on the input color. |
| srcColor = cs.childProcessor(0) ? this->invokeChild(0, "half4(1)", args) |
| : SkString(args.fInputColor); |
| dstColor = cs.childProcessor(1) ? this->invokeChild(1, "half4(1)", args) |
| : SkString(args.fInputColor); |
| break; |
| |
| case BlendBehavior::kComposeTwoBehavior: |
| // Compose-two operations historically have forced the input color to opaque. |
| // We're going to re-apply the input color's alpha below, so feed the *unpremul* RGB |
| // to the children, to avoid double-applying alpha. |
| fragBuilder->codeAppendf("half4 inputOpaque = unpremul(%s).rgb1;\n", args.fInputColor); |
| srcColor = this->invokeChild(0, "inputOpaque", args); |
| dstColor = this->invokeChild(1, "inputOpaque", args); |
| break; |
| |
| case BlendBehavior::kSkModeBehavior: |
| // SkModeColorFilter operations act like ComposeOne, but pass the input color to dst. |
| srcColor = cs.childProcessor(0) ? this->invokeChild(0, "half4(1)", args) |
| : SkString(args.fInputColor); |
| dstColor = cs.childProcessor(1) ? this->invokeChild(1, args.fInputColor, args) |
| : SkString(args.fInputColor); |
| break; |
| |
| default: |
| SK_ABORT("unrecognized blend behavior"); |
| break; |
| } |
| |
| // Blend src and dst colors together. |
| fragBuilder->codeAppendf("return %s(%s, %s)", GrGLSLBlend::BlendFuncName(mode), |
| srcColor.c_str(), dstColor.c_str()); |
| |
| // Reapply alpha from input color if we are doing a compose-two. |
| if (behavior == BlendBehavior::kComposeTwoBehavior) { |
| fragBuilder->codeAppendf(" * %s.a", args.fInputColor); |
| } |
| |
| fragBuilder->codeAppendf(";\n"); |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| |
| std::unique_ptr<GrFragmentProcessor> GrBlendFragmentProcessor::Make( |
| std::unique_ptr<GrFragmentProcessor> src, |
| std::unique_ptr<GrFragmentProcessor> dst, |
| SkBlendMode mode, BlendBehavior behavior) { |
| switch (mode) { |
| case SkBlendMode::kClear: |
| return GrFragmentProcessor::MakeColor(SK_PMColor4fTRANSPARENT); |
| case SkBlendMode::kSrc: |
| return GrFragmentProcessor::OverrideInput(std::move(src), SK_PMColor4fWHITE, |
| /*useUniform=*/false); |
| case SkBlendMode::kDst: |
| return GrFragmentProcessor::OverrideInput(std::move(dst), SK_PMColor4fWHITE, |
| /*useUniform=*/false); |
| default: |
| return BlendFragmentProcessor::Make(std::move(src), std::move(dst), mode, behavior); |
| } |
| } |