Implement color filter as GrGLEffect

src/gpu/gl/GrGLProgramDesc.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrGLProgramDesc.h"
 #include "GrBackendEffectFactory.h"
 #include "GrDrawEffect.h"
@@ skipping 48 matching lines @@
     // to a canonical value to avoid duplicate programs with different keys.
 
     bool requiresColorAttrib = !skipColor && drawState.hasColorVertexAttribute();
     bool requiresCoverageAttrib = !skipCoverage && drawState.hasCoverageVertexAttribute();
     // we only need the local coords if we're actually going to generate effect code
     bool requiresLocalCoordAttrib = !(skipCoverage  && skipColor) &&
                                     drawState.hasLocalCoordAttribute();
 
     bool colorIsTransBlack = SkToBool(blendOpts & GrDrawState::kEmitTransBlack_BlendOptFlag);
     bool colorIsSolidWhite = (blendOpts & GrDrawState::kEmitCoverage_BlendOptFlag) ||
-                             (!requiresColorAttrib && 0xffffffff == drawState.getColor());
+                             (!requiresColorAttrib && 0xffffffff == drawState.getColor()) ||
+                             drawState.numColorStages() > 0 && !(*drawState.getColorStage(0)->getEffect())->getWillUseInputColor();
 
     int numEffects = (skipColor ? 0 : drawState.numColorStages()) +
                      (skipCoverage ? 0 : drawState.numCoverageStages());
 
     size_t newKeyLength = KeyLength(numEffects);
     bool allocChanged;
     desc->fKey.reset(newKeyLength, SkAutoMalloc::kAlloc_OnShrink, &allocChanged);
     if (allocChanged || !desc->fInitialized) {
         // make sure any padding in the header is zero if we we haven't used this allocation before.
         memset(desc->header(), 0, kHeaderSize);
@@ skipping 16 matching lines @@
     }
     if (!skipCoverage) {
         for (int s = 0; s < drawState.numCoverageStages(); ++s) {
             effectKeys[currEffectKey++] =
                 get_key_and_update_stats(drawState.getCoverageStage(s), gpu->glCaps(),
                                          requiresLocalCoordAttrib, &readsDst, &readFragPosition);
         }
     }
 
     header->fEmitsPointSize = isPoints;
-    header->fColorFilterXfermode = skipColor ? SkXfermode::kDst_Mode : drawState.getColorFilterMode();
 
     // Currently the experimental GS will only work with triangle prims (and it doesn't do anything
     // other than pass through values from the VS to the FS anyway).
 #if GR_GL_EXPERIMENTAL_GS
 #if 0
     header->fExperimentalGS = gpu->caps().geometryShaderSupport();
 #else
     header->fExperimentalGS = false;
 #endif
 #endif
@@ skipping 67 matching lines @@
 
     // Set these defaults and then possibly change our mind if there is coverage.
     header->fDiscardIfZeroCoverage = false;
     header->fCoverageOutput = kModulate_CoverageOutput;
 
     // If we do have coverage determine whether it matters.
     bool separateCoverageFromColor = false;
     if (!drawState.isCoverageDrawing() && !skipCoverage &&
         (drawState.numCoverageStages() > 0 || requiresCoverageAttrib)) {
         // color filter is applied between color/coverage computation
-        if (SkXfermode::kDst_Mode != header->fColorFilterXfermode) {
+        // TODO:
+        //if (SkXfermode::kDst_Mode != header->fColorFilterXfermode) {
             separateCoverageFromColor = true;
-        }
+            //}
 
         // If we're stenciling then we want to discard samples that have zero coverage
         if (drawState.getStencil().doesWrite()) {
             header->fDiscardIfZeroCoverage = true;
             separateCoverageFromColor = true;
         }
 
         if (gpu->caps()->dualSourceBlendingSupport() &&
             !(blendOpts & (GrDrawState::kEmitCoverage_BlendOptFlag |
                            GrDrawState::kCoverageAsAlpha_BlendOptFlag))) {
@@ skipping 45 matching lines @@
 
 GrGLProgramDesc& GrGLProgramDesc::operator= (const GrGLProgramDesc& other) {
     fInitialized = other.fInitialized;
     if (fInitialized) {
         size_t keyLength = other.keyLength();
         fKey.reset(keyLength);
         memcpy(fKey.get(), other.fKey.get(), keyLength);
     }
     return *this;
 }