Introduce GrColorSpaceXform, for gamut conversion on textures

src/gpu/effects/GrBicubicEffect.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrBicubicTextureEffect_DEFINED
 #define GrBicubicTextureEffect_DEFINED
 
@@ skipping 11 matching lines @@
                              // surrounding texels are needed by the kernel in x and y.
     };
     virtual ~GrBicubicEffect();
 
     const float* coefficients() const { return fCoefficients; }
 
     const char* name() const override { return "Bicubic"; }
 
     const GrTextureDomain& domain() const { return fDomain; }
 
+    GrColorSpaceXform* colorSpaceXform() const { return fColorSpaceXform.get(); }
+
     /**
      * Create a simple filter effect with custom bicubic coefficients and optional domain.
      */
-    static sk_sp<GrFragmentProcessor> Make(GrTexture* tex, const SkScalar coefficients[16],
+    static sk_sp<GrFragmentProcessor> Make(GrTexture* tex,
+                                           sk_sp<GrColorSpaceXform> colorSpaceXform,
+                                           const SkScalar coefficients[16],
                                            const SkRect* domain = nullptr) {
         if (nullptr == domain) {
             static const SkShader::TileMode kTileModes[] = { SkShader::kClamp_TileMode,
                                                              SkShader::kClamp_TileMode };
-            return Make(tex, coefficients, GrCoordTransform::MakeDivByTextureWHMatrix(tex),
-                        kTileModes);
+            return Make(tex, std::move(colorSpaceXform), coefficients,
+                        GrCoordTransform::MakeDivByTextureWHMatrix(tex), kTileModes);
         } else {
             return sk_sp<GrFragmentProcessor>(
-                new GrBicubicEffect(tex, coefficients,
+                new GrBicubicEffect(tex, std::move(colorSpaceXform), coefficients,
                                     GrCoordTransform::MakeDivByTextureWHMatrix(tex), *domain));
         }
     }
 
     /**
      * Create a Mitchell filter effect with specified texture matrix and x/y tile modes.
      */
-    static sk_sp<GrFragmentProcessor> Make(GrTexture* tex, const SkMatrix& matrix,
+    static sk_sp<GrFragmentProcessor> Make(GrTexture* tex,
+                                           sk_sp<GrColorSpaceXform> colorSpaceXform,
+                                           const SkMatrix& matrix,
                                            const SkShader::TileMode tileModes[2]) {
-        return Make(tex, gMitchellCoefficients, matrix, tileModes);
+        return Make(tex, std::move(colorSpaceXform), gMitchellCoefficients, matrix, tileModes);
     }
 
     /**
      * Create a filter effect with custom bicubic coefficients, the texture matrix, and the x/y
      * tilemodes.
      */
-    static sk_sp<GrFragmentProcessor> Make(GrTexture* tex, const SkScalar coefficients[16],
+    static sk_sp<GrFragmentProcessor> Make(GrTexture* tex,
+                                           sk_sp<GrColorSpaceXform> colorSpaceXform, 
+                                           const SkScalar coefficients[16],
                                            const SkMatrix& matrix,
                                            const SkShader::TileMode tileModes[2]) {
-        return sk_sp<GrFragmentProcessor>(new GrBicubicEffect(tex, coefficients, matrix,
-                                                              tileModes));
+        return sk_sp<GrFragmentProcessor>(new GrBicubicEffect(tex, std::move(colorSpaceXform),
+                                                              coefficients, matrix, tileModes));
     }
 
     /**
      * Create a Mitchell filter effect with a texture matrix and a domain.
      */
-    static sk_sp<GrFragmentProcessor> Make(GrTexture* tex, const SkMatrix& matrix,
+    static sk_sp<GrFragmentProcessor> Make(GrTexture* tex,
+                                           sk_sp<GrColorSpaceXform> colorSpaceXform,
+                                           const SkMatrix& matrix,
                                            const SkRect& domain) {
-        return sk_sp<GrFragmentProcessor>(new GrBicubicEffect(tex, gMitchellCoefficients, matrix,
+        return sk_sp<GrFragmentProcessor>(new GrBicubicEffect(tex, std::move(colorSpaceXform),
+                                                              gMitchellCoefficients, matrix,
                                                               domain));
     }
 
     /**
      * Determines whether the bicubic effect should be used based on the transformation from the
      * local coords to the device. Returns true if the bicubic effect should be used. filterMode
      * is set to appropriate filtering mode to use regardless of the return result (e.g. when this
      * returns false it may indicate that the best fallback is to use kMipMap, kBilerp, or
      * kNearest).
      */
     static bool ShouldUseBicubic(const SkMatrix& localCoordsToDevice,
                                  GrTextureParams::FilterMode* filterMode);
 
 private:
-    GrBicubicEffect(GrTexture*, const SkScalar coefficients[16], const SkMatrix &matrix,
-                    const SkShader::TileMode tileModes[2]);
-    GrBicubicEffect(GrTexture*, const SkScalar coefficients[16], const SkMatrix &matrix,
-                    const SkRect& domain);
+    GrBicubicEffect(GrTexture*, sk_sp<GrColorSpaceXform>, const SkScalar coefficients[16],
+                    const SkMatrix &matrix, const SkShader::TileMode tileModes[2]);
+    GrBicubicEffect(GrTexture*, sk_sp<GrColorSpaceXform>, const SkScalar coefficients[16],
+                    const SkMatrix &matrix, const SkRect& domain);
 
     GrGLSLFragmentProcessor* onCreateGLSLInstance() const override;
 
     void onGetGLSLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder*) const override;
 
     bool onIsEqual(const GrFragmentProcessor&) const override;
 
     void onComputeInvariantOutput(GrInvariantOutput* inout) const override;
 
     float           fCoefficients[16];
     GrTextureDomain fDomain;
+    sk_sp<GrColorSpaceXform> fColorSpaceXform;
 
     GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
 
     static const SkScalar gMitchellCoefficients[16];
 
     typedef GrSingleTextureEffect INHERITED;
 };
 
 #endif