Potentially optimize some GrGLEffects for known input color values

src/effects/SkTableColorFilter.cpp

 
 #include "SkBitmap.h"
 #include "SkTableColorFilter.h"
 #include "SkColorPriv.h"
 #include "SkFlattenableBuffers.h"
 #include "SkUnPreMultiply.h"
 #include "SkString.h"
 
 class SkTable_ColorFilter : public SkColorFilter {
 public:
@@ skipping 253 matching lines @@
 };
 
 class GLColorTableEffect : public GrGLEffect {
 public:
     GLColorTableEffect(const GrBackendEffectFactory&, const GrDrawEffect&);
 
     virtual void emitCode(GrGLShaderBuilder*,
                           const GrDrawEffect&,
                           EffectKey,
                           const char* outputColor,
-                          const char* inputColor,
+                          const GrGLSLExpr4& inputColor,
                           const TransformedCoordsArray&,
                           const TextureSamplerArray&) SK_OVERRIDE;
 
     virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE {}
 
     static EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&);
 
 private:
 
     typedef GrGLEffect INHERITED;
 };
 
 GLColorTableEffect::GLColorTableEffect(const GrBackendEffectFactory& factory, const GrDrawEffect&)
     : INHERITED(factory) {
  }
 
 void GLColorTableEffect::emitCode(GrGLShaderBuilder* builder,
                                   const GrDrawEffect&,
                                   EffectKey,
                                   const char* outputColor,
-                                  const char* inputColor,
+                                  const GrGLSLExpr4& inputColor,
                                   const TransformedCoordsArray&,
                                   const TextureSamplerArray& samplers) {
 
     static const float kColorScaleFactor = 255.0f / 256.0f;
     static const float kColorOffsetFactor = 1.0f / 512.0f;
-    if (NULL == inputColor) {
+    if (inputColor.isOnes()) {
         // the input color is solid white (all ones).
         static const float kMaxValue = kColorScaleFactor + kColorOffsetFactor;
         builder->fsCodeAppendf("\t\tvec4 coord = vec4(%f, %f, %f, %f);\n",
                                kMaxValue, kMaxValue, kMaxValue, kMaxValue);
 
     } else {
-        builder->fsCodeAppendf("\t\tfloat nonZeroAlpha = max(%s.a, .0001);\n", inputColor);
-        builder->fsCodeAppendf("\t\tvec4 coord = vec4(%s.rgb / nonZeroAlpha, nonZeroAlpha);\n", inputColor);
+        builder->fsCodeAppendf("\t\tfloat nonZeroAlpha = %s;\n", GrGLSL::max(inputColor.a(), 0.0001f).c_str());
+        builder->fsCodeAppendf("\t\tvec4 coord = vec4(%s.rgb / nonZeroAlpha, nonZeroAlpha);\n", inputColor.c_str());
         builder->fsCodeAppendf("\t\tcoord = coord * %f + vec4(%f, %f, %f, %f);\n",
                               kColorScaleFactor,
                               kColorOffsetFactor, kColorOffsetFactor,
                               kColorOffsetFactor, kColorOffsetFactor);
     }
 
     builder->fsCodeAppendf("\t\t%s.a = ", outputColor);
     builder->fsAppendTextureLookup(samplers[0], "vec2(coord.a, 0.125)");
     builder->fsCodeAppend(";\n");
 
@@ skipping 104 matching lines @@
 SkColorFilter* SkTableColorFilter::CreateARGB(const uint8_t tableA[256],
                                               const uint8_t tableR[256],
                                               const uint8_t tableG[256],
                                               const uint8_t tableB[256]) {
     return SkNEW_ARGS(SkTable_ColorFilter, (tableA, tableR, tableG, tableB));
 }
 
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkTableColorFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkTable_ColorFilter)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END