Introduce GrColorSpaceXform, for gamut conversion on textures

src/gpu/effects/GrBicubicEffect.cpp

Index: src/gpu/effects/GrBicubicEffect.cpp
diff --git a/src/gpu/effects/GrBicubicEffect.cpp b/src/gpu/effects/GrBicubicEffect.cpp
index 5e6967ce4bbaebf6776c07e15f742b2d2474f896..427e375084ac1d5f63f8ee83e4fae12cba338574 100644
--- a/src/gpu/effects/GrBicubicEffect.cpp
+++ b/src/gpu/effects/GrBicubicEffect.cpp
@@ -134,20 +134,23 @@ static inline void convert_row_major_scalar_coeffs_to_column_major_floats(float
 }
 
 GrBicubicEffect::GrBicubicEffect(GrTexture* texture,
+                                 sk_sp<GrColorSpaceXform> colorSpaceXform,
                                  const SkScalar coefficients[16],
                                  const SkMatrix &matrix,
                                  const SkShader::TileMode tileModes[2])
-  : INHERITED(texture, matrix, GrTextureParams(tileModes, GrTextureParams::kNone_FilterMode))
+  : INHERITED(texture, std::move(colorSpaceXform), matrix,

[bsalomon, 2016/07/15 15:09:24]

Should this effect forward on the xform to the access or should it filter and
then apply the xform itself?

[Brian Osman, 2016/07/15 15:29:02]

Ah, that's a good point. The math should come out the same, and converting after
filtering will be a big perf win. I'll look into fixing that.

+              GrTextureParams(tileModes, GrTextureParams::kNone_FilterMode))
   , fDomain(GrTextureDomain::IgnoredDomain()) {
     this->initClassID<GrBicubicEffect>();
     convert_row_major_scalar_coeffs_to_column_major_floats(fCoefficients, coefficients);
 }
 
 GrBicubicEffect::GrBicubicEffect(GrTexture* texture,
+                                 sk_sp<GrColorSpaceXform> colorSpaceXform,
                                  const SkScalar coefficients[16],
                                  const SkMatrix &matrix,
                                  const SkRect& domain)
-  : INHERITED(texture, matrix,
+  : INHERITED(texture, std::move(colorSpaceXform), matrix,
               GrTextureParams(SkShader::kClamp_TileMode, GrTextureParams::kNone_FilterMode))
   , fDomain(domain, GrTextureDomain::kClamp_Mode) {
     this->initClassID<GrBicubicEffect>();
@@ -186,7 +189,7 @@ sk_sp<GrFragmentProcessor> GrBicubicEffect::TestCreate(GrProcessorTestData* d) {
     for (int i = 0; i < 16; i++) {
         coefficients[i] = d->fRandom->nextSScalar1();
     }
-    return GrBicubicEffect::Make(d->fTextures[texIdx], coefficients);
+    return GrBicubicEffect::Make(d->fTextures[texIdx], nullptr, coefficients);
 }
 
 //////////////////////////////////////////////////////////////////////////////