| /* |
| * Copyright 2012 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef GrConfigConversionEffect_DEFINED |
| #define GrConfigConversionEffect_DEFINED |
| |
| #include "GrSingleTextureEffect.h" |
| #include "GrSwizzle.h" |
| |
| class GrInvariantOutput; |
| |
| /** |
| * This class is used to perform config conversions. Clients may want to read/write data that is |
| * unpremultiplied. Additionally, the channels may also be swizzled for optimal readback/upload |
| * performance. |
| */ |
| class GrConfigConversionEffect : public GrSingleTextureEffect { |
| public: |
| /** |
| * The PM->UPM or UPM->PM conversions to apply. |
| */ |
| enum PMConversion { |
| kNone_PMConversion = 0, |
| kMulByAlpha_RoundUp_PMConversion, |
| kMulByAlpha_RoundDown_PMConversion, |
| kDivByAlpha_RoundUp_PMConversion, |
| kDivByAlpha_RoundDown_PMConversion, |
| |
| kPMConversionCnt |
| }; |
| |
| static sk_sp<GrFragmentProcessor> Make(GrTexture*, const GrSwizzle&, PMConversion, |
| const SkMatrix&); |
| |
| const char* name() const override { return "Config Conversion"; } |
| |
| const GrSwizzle& swizzle() const { return fSwizzle; } |
| PMConversion pmConversion() const { return fPMConversion; } |
| |
| // This function determines whether it is possible to choose PM->UPM and UPM->PM conversions |
| // for which in any PM->UPM->PM->UPM sequence the two UPM values are the same. This means that |
| // if pixels are read back to a UPM buffer, written back to PM to the GPU, and read back again |
| // both reads will produce the same result. This test is quite expensive and should not be run |
| // multiple times for a given context. |
| static void TestForPreservingPMConversions(GrContext* context, |
| PMConversion* PMToUPMRule, |
| PMConversion* UPMToPMRule); |
| |
| private: |
| GrConfigConversionEffect(GrTexture*, |
| const GrSwizzle&, |
| PMConversion pmConversion, |
| const SkMatrix& matrix); |
| |
| GrGLSLFragmentProcessor* onCreateGLSLInstance() const override; |
| |
| void onGetGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder*) const override; |
| |
| bool onIsEqual(const GrFragmentProcessor&) const override; |
| |
| void onComputeInvariantOutput(GrInvariantOutput* inout) const override; |
| |
| GrSwizzle fSwizzle; |
| PMConversion fPMConversion; |
| |
| GR_DECLARE_FRAGMENT_PROCESSOR_TEST; |
| |
| typedef GrSingleTextureEffect INHERITED; |
| }; |
| |
| #endif |