Implement color filter as GrGLEffect

src/gpu/effects/GrBicubicEffect.cpp

 #include "GrBicubicEffect.h"
 
 #define DS(x) SkDoubleToScalar(x)
 
 const SkScalar GrBicubicEffect::gMitchellCoefficients[16] = {
     DS( 1.0 / 18.0), DS(-9.0 / 18.0), DS( 15.0 / 18.0), DS( -7.0 / 18.0),
     DS(16.0 / 18.0), DS( 0.0 / 18.0), DS(-36.0 / 18.0), DS( 21.0 / 18.0),
     DS( 1.0 / 18.0), DS( 9.0 / 18.0), DS( 27.0 / 18.0), DS(-21.0 / 18.0),
     DS( 0.0 / 18.0), DS( 0.0 / 18.0), DS( -6.0 / 18.0), DS(  7.0 / 18.0),
 };
@@ skipping 26 matching lines @@
     : INHERITED(factory) {
 }
 
 void GrGLBicubicEffect::emitCode(GrGLShaderBuilder* builder,
                                  const GrDrawEffect&,
                                  EffectKey key,
                                  const char* outputColor,
                                  const char* inputColor,
                                  const TransformedCoordsArray& coords,
                                  const TextureSamplerArray& samplers) {
+    sk_ignore_unused_variable(inputColor);
+
     SkString coords2D = builder->ensureFSCoords2D(coords, 0);
     fCoefficientsUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                            kMat44f_GrSLType, "Coefficients");
     fImageIncrementUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                              kVec2f_GrSLType, "ImageIncrement");
 
     const char* imgInc = builder->getUniformCStr(fImageIncrementUni);
     const char* coeff = builder->getUniformCStr(fCoefficientsUni);
 
     SkString cubicBlendName;
@@ skipping 42 matching lines @@
 
 GrBicubicEffect::GrBicubicEffect(GrTexture* texture,
                                  const SkScalar coefficients[16])
   : INHERITED(texture, MakeDivByTextureWHMatrix(texture)) {
     for (int y = 0; y < 4; y++) {
         for (int x = 0; x < 4; x++) {
             // Convert from row-major scalars to column-major floats.
             fCoefficients[x * 4 + y] = SkScalarToFloat(coefficients[y * 4 + x]);
         }
     }
+    this->setWillNotUseInputColor();
 }
 
 GrBicubicEffect::GrBicubicEffect(GrTexture* texture,
                                  const SkScalar coefficients[16],
                                  const SkMatrix &matrix,
                                  const GrTextureParams &params,
                                  GrCoordSet coordSet)
   : INHERITED(texture, MakeDivByTextureWHMatrix(texture), params, coordSet) {
     for (int y = 0; y < 4; y++) {
         for (int x = 0; x < 4; x++) {
             // Convert from row-major scalars to column-major floats.
             fCoefficients[x * 4 + y] = SkScalarToFloat(coefficients[y * 4 + x]);
         }
     }
+    this->setWillNotUseInputColor();
 }
 
 GrBicubicEffect::~GrBicubicEffect() {
 }
 
 const GrBackendEffectFactory& GrBicubicEffect::getFactory() const {
     return GrTBackendEffectFactory<GrBicubicEffect>::getInstance();
 }
 
 bool GrBicubicEffect::onIsEqual(const GrEffect& sBase) const {
@@ skipping 15 matching lines @@
                                          const GrDrawTargetCaps&,
                                          GrTexture* textures[]) {
     int texIdx = random->nextBool() ? GrEffectUnitTest::kSkiaPMTextureIdx :
                                       GrEffectUnitTest::kAlphaTextureIdx;
     SkScalar coefficients[16];
     for (int i = 0; i < 16; i++) {
         coefficients[i] = random->nextSScalar1();
     }
     return GrBicubicEffect::Create(textures[texIdx], coefficients);
 }