Potentially optimize some GrGLEffects for known input color values

src/gpu/GrAAConvexPathRenderer.cpp

 
 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrAAConvexPathRenderer.h"
 
@@ skipping 513 matching lines @@
 
     class GLEffect : public GrGLVertexEffect {
     public:
         GLEffect(const GrBackendEffectFactory& factory, const GrDrawEffect&)
             : INHERITED (factory) {}
 
         virtual void emitCode(GrGLFullShaderBuilder* builder,
                               const GrDrawEffect& drawEffect,
                               EffectKey key,
                               const char* outputColor,
-                              const char* inputColor,
+                              const GrGLSLExpr4& inputColor,
                               const TransformedCoordsArray&,
                               const TextureSamplerArray& samplers) SK_OVERRIDE {
             const char *vsName, *fsName;
             const SkString* attrName =
                 builder->getEffectAttributeName(drawEffect.getVertexAttribIndices()[0]);
             builder->fsCodeAppendf("\t\tfloat edgeAlpha;\n");
 
             SkAssertResult(builder->enableFeature(
                                               GrGLShaderBuilder::kStandardDerivatives_GLSLFeature));
             builder->addVarying(kVec4f_GrSLType, "QuadEdge", &vsName, &fsName);
 
             // keep the derivative instructions outside the conditional
             builder->fsCodeAppendf("\t\tvec2 duvdx = dFdx(%s.xy);\n", fsName);
             builder->fsCodeAppendf("\t\tvec2 duvdy = dFdy(%s.xy);\n", fsName);
             builder->fsCodeAppendf("\t\tif (%s.z > 0.0 && %s.w > 0.0) {\n", fsName, fsName);
             // today we know z and w are in device space. We could use derivatives
             builder->fsCodeAppendf("\t\t\tedgeAlpha = min(min(%s.z, %s.w) + 0.5, 1.0);\n", fsName,
                                     fsName);
             builder->fsCodeAppendf ("\t\t} else {\n");
             builder->fsCodeAppendf("\t\t\tvec2 gF = vec2(2.0*%s.x*duvdx.x - duvdx.y,\n"
                                    "\t\t\t               2.0*%s.x*duvdy.x - duvdy.y);\n",
                                    fsName, fsName);
             builder->fsCodeAppendf("\t\t\tedgeAlpha = (%s.x*%s.x - %s.y);\n", fsName, fsName,
                                     fsName);
             builder->fsCodeAppendf("\t\t\tedgeAlpha = "
                                    "clamp(0.5 - edgeAlpha / length(gF), 0.0, 1.0);\n\t\t}\n");
 
 
             builder->fsCodeAppendf("\t%s = %s;\n", outputColor,
-                                   (GrGLSLExpr4(inputColor) * GrGLSLExpr1("edgeAlpha")).c_str());
+                                   (inputColor * GrGLSLExpr1("edgeAlpha")).c_str());
 
             builder->vsCodeAppendf("\t%s = %s;\n", vsName, attrName->c_str());
         }
 
         static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
             return 0x0;
         }
 
         virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE {}
 
@@ skipping 130 matching lines @@
                             vOffset,  // start vertex
                             0,        // start index
                             draw.fVertexCnt,
                             draw.fIndexCnt,
                             &devBounds);
         vOffset += draw.fVertexCnt;
     }
 
     return true;
 }