| /* |
| * Copyright 2014 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/GrPipeline.h" |
| #include "src/gpu/GrProcessor.h" |
| #include "src/gpu/GrShaderCaps.h" |
| #include "src/gpu/effects/GrDisableColorXP.h" |
| #include "src/gpu/glsl/GrGLSLFragmentShaderBuilder.h" |
| #include "src/gpu/glsl/GrGLSLProgramDataManager.h" |
| #include "src/gpu/glsl/GrGLSLXferProcessor.h" |
| |
| /** |
| * This xfer processor disables color writing. Thus color and coverage and ignored and no blending |
| * occurs. This XP is usful for things like stenciling. |
| */ |
| class DisableColorXP : public GrXferProcessor { |
| public: |
| DisableColorXP() : INHERITED(kDisableColorXP_ClassID) {} |
| |
| private: |
| const char* name() const override { return "Disable Color"; } |
| bool onIsEqual(const GrXferProcessor& xpBase) const override { return true; } |
| void onGetGLSLProcessorKey(const GrShaderCaps& caps, GrProcessorKeyBuilder* b) const override { |
| return; // No key. |
| } |
| void onGetBlendInfo(GrXferProcessor::BlendInfo* blendInfo) const override { |
| blendInfo->fWriteColor = false; |
| } |
| GrGLSLXferProcessor* createGLSLInstance() const override; |
| |
| using INHERITED = GrXferProcessor; |
| }; |
| |
| class GLDisableColorXP : public GrGLSLXferProcessor { |
| private: |
| void emitOutputsForBlendState(const EmitArgs& args) override { |
| if (args.fShaderCaps->mustWriteToFragColor()) { |
| // This emit code should be empty. However, on the nexus 6 there is a driver bug where |
| // if you do not give gl_FragColor a value, the gl context is lost and we end up drawing |
| // nothing. So this fix just sets the gl_FragColor arbitrarily to 0. |
| // https://bugs.chromium.org/p/chromium/issues/detail?id=445377 |
| GrGLSLXPFragmentBuilder* fragBuilder = args.fXPFragBuilder; |
| fragBuilder->codeAppendf("%s = half4(0);", args.fOutputPrimary); |
| } |
| } |
| |
| void emitWriteSwizzle(GrGLSLXPFragmentBuilder*, |
| const GrSwizzle&, |
| const char*, |
| const char*) const override { |
| // Don't write any swizzling. This makes sure the final shader does not output a color. |
| return; |
| } |
| |
| void onSetData(const GrGLSLProgramDataManager&, const GrXferProcessor&) override {} |
| |
| using INHERITED = GrGLSLXferProcessor; |
| }; |
| |
| GrGLSLXferProcessor* DisableColorXP::createGLSLInstance() const { |
| return new GLDisableColorXP(); |
| } |
| |
| sk_sp<const GrXferProcessor> GrDisableColorXPFactory::MakeXferProcessor() { |
| return sk_make_sp<DisableColorXP>(); |
| } |
| |
| GR_DEFINE_XP_FACTORY_TEST(GrDisableColorXPFactory); |
| |
| #if GR_TEST_UTILS |
| const GrXPFactory* GrDisableColorXPFactory::TestGet(GrProcessorTestData*) { |
| return GrDisableColorXPFactory::Get(); |
| } |
| #endif |