| /* |
| * Copyright 2017 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef GrNonlinearColorSpaceXformEffect_DEFINED |
| #define GrNonlinearColorSpaceXformEffect_DEFINED |
| |
| #include "GrFragmentProcessor.h" |
| #include "SkColorSpace.h" |
| #include "SkMatrix44.h" |
| |
| /** |
| * The output of this effect is the input, transformed into a different color space. |
| * This effect is used for nonlinear blending color space support - it does not assume HW sRGB |
| * capabilities, and performs both the source and destination transfer functions numerically in |
| * the shader. Any parametric transfer function is supported. Because of the nonlinear blending, |
| * premultiplication is also nonlinear - source pixels are unpremultiplied before the source |
| * transfer function, and then premultiplied after the destination transfer function. |
| */ |
| class GrNonlinearColorSpaceXformEffect : public GrFragmentProcessor { |
| public: |
| /** |
| * The conversion effect is only well defined with a valid source and destination color space. |
| * This will return nullptr if either space is nullptr, if both spaces are equal, or if either |
| * space has a non-parametric transfer funcion (e.g. lookup table or A2B). |
| */ |
| static std::unique_ptr<GrFragmentProcessor> Make(const SkColorSpace* src, |
| const SkColorSpace* dst); |
| |
| const char* name() const override { return "NonlinearColorSpaceXform"; } |
| |
| std::unique_ptr<GrFragmentProcessor> clone() const override; |
| |
| static const int kNumTransferFnCoeffs = 7; |
| |
| /** |
| * Flags that specify which operations are performed for one particular conversion. |
| * Some color space pairs may not need all operations, if one or both transfer functions |
| * is linear, or if the gamuts are the same. |
| */ |
| enum Ops { |
| kSrcTransfer_Op = 0x1, |
| kGamutXform_Op = 0x2, |
| kDstTransfer_Op = 0x4, |
| }; |
| |
| uint32_t ops() const { return fOps; } |
| const float* srcTransferFnCoeffs() const { return fSrcTransferFnCoeffs; } |
| const float* dstTransferFnCoeffs() const { return fDstTransferFnCoeffs; } |
| const SkMatrix44& gamutXform() const { return fGamutXform; } |
| |
| private: |
| GrNonlinearColorSpaceXformEffect(uint32_t ops, |
| const SkColorSpaceTransferFn& srcTransferFn, |
| const SkColorSpaceTransferFn& dstTransferFn, |
| const SkMatrix44& gamutXform); |
| GrNonlinearColorSpaceXformEffect(const GrNonlinearColorSpaceXformEffect&); |
| |
| GrGLSLFragmentProcessor* onCreateGLSLInstance() const override; |
| void onGetGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder*) const override; |
| bool onIsEqual(const GrFragmentProcessor&) const override; |
| |
| float fSrcTransferFnCoeffs[kNumTransferFnCoeffs]; |
| float fDstTransferFnCoeffs[kNumTransferFnCoeffs]; |
| SkMatrix44 fGamutXform; |
| uint32_t fOps; |
| |
| GR_DECLARE_FRAGMENT_PROCESSOR_TEST |
| |
| typedef GrFragmentProcessor INHERITED; |
| }; |
| |
| #endif |