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      1 /*
      2  * Copyright 2016 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #ifndef SkColorSpaceXform_Base_DEFINED
      9 #define SkColorSpaceXform_Base_DEFINED
     10 
     11 #include "SkColorSpace.h"
     12 #include "SkColorSpaceXform.h"
     13 #include "SkResourceCache.h"
     14 
     15 class SkColorSpace_XYZ;
     16 
     17 class SkColorSpaceXform_Base : public SkColorSpaceXform {
     18 public:
     19     // A somewhat more powerful SkColorSpaceXform::New() that allows tweaking premulBehavior.
     20     static std::unique_ptr<SkColorSpaceXform> New(SkColorSpace* srcSpace,
     21                                                   SkColorSpace* dstSpace,
     22                                                   SkTransferFunctionBehavior premulBehavior);
     23 
     24     static constexpr int kDstGammaTableSize = 1024;
     25     static void BuildDstGammaTables(const uint8_t* outGammaTables[3],
     26                                     uint8_t* gammaTableStorage,
     27                                     const SkColorSpace_XYZ* space,
     28                                     bool gammasAreMatching);
     29 
     30     virtual bool onApply(ColorFormat dstFormat, void* dst, ColorFormat srcFormat, const void* src,
     31                          int count, SkAlphaType alphaType) const = 0;
     32 };
     33 
     34 enum SrcGamma {
     35     kLinear_SrcGamma,
     36     kTable_SrcGamma,
     37     kSRGB_SrcGamma,
     38 };
     39 
     40 enum DstGamma {
     41     kLinear_DstGamma,
     42     kSRGB_DstGamma,
     43     k2Dot2_DstGamma,
     44     kTable_DstGamma,
     45 };
     46 
     47 class SkColorSpaceXform_XYZ : public SkColorSpaceXform_Base {
     48 public:
     49     SkColorSpaceXform_XYZ(SkColorSpace_XYZ* src, SkColorSpace_XYZ* dst, SkTransferFunctionBehavior);
     50 
     51     bool onApply(ColorFormat dstFormat, void* dst,
     52                  ColorFormat srcFormat, const void* src,
     53                  int count, SkAlphaType alphaType) const override;
     54 
     55     void pretendNotToBeIdentityForTesting() {
     56         fSrcToDstIsIdentity = false;
     57     }
     58 
     59 private:
     60     // These tables pointers may point into fSrcStorage/fDstStorage or into pre-baked tables.
     61     const float*               fSrcGammaTables[3];
     62     const uint8_t*             fDstGammaTables[3];
     63     SkAutoTMalloc<float>       fSrcStorage;
     64     sk_sp<SkData>              fDstStorage;
     65 
     66     float                      fSrcToDst[12];
     67     bool                       fSrcToDstIsIdentity;
     68     bool                       fColorSpacesAreIdentical;
     69     SrcGamma                   fSrcGamma;
     70     DstGamma                   fDstGamma;
     71     SkTransferFunctionBehavior fPremulBehavior;
     72 };
     73 
     74 struct LoadTablesContext {
     75     const void*  fSrc;
     76     const float* fR;
     77     const float* fG;
     78     const float* fB;
     79 };
     80 
     81 // Must be kept in sync with "Tables" struct in RasterPipeline_opts byte_tables_rgb.
     82 struct TablesContext {
     83     const uint8_t* fR;
     84     const uint8_t* fG;
     85     const uint8_t* fB;
     86     int            fCount;
     87 };
     88 
     89 // For testing.  Bypasses opts for when src and dst color spaces are equal.
     90 std::unique_ptr<SkColorSpaceXform> SlowIdentityXform(SkColorSpace_XYZ* space);
     91 
     92 #endif
     93