Draft change to start pulling uniform color into GP

src/gpu/effects/GrPorterDuffXferProcessor.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "effects/GrPorterDuffXferProcessor.h"
 
 #include "GrBlend.h"
@@ skipping 48 matching lines @@
                 case GrPorterDuffXferProcessor::kCoverageISC_SecondaryOutputType:
                     fsBuilder->codeAppendf("%s = (vec4(1.0) - %s) * %s;",
                                            args.fOutputSecondary, args.fInputColor,
                                            args.fInputCoverage);
                     break;
                 default:
                     SkFAIL("Unexpected Secondary Output");
             }
         }
         
-        fsBuilder->codeAppendf("%s = %s * %s;", args.fOutputPrimary, args.fInputColor,
-                               args.fInputCoverage);
-        if (GrPorterDuffXferProcessor::kCombineWithDst_PrimaryOutputType == xp.primaryOutputType()){
-            fsBuilder->codeAppendf("%s += (vec4(1.0) - %s) * %s;", args.fOutputPrimary,
-                                   args.fInputCoverage, fsBuilder->dstColor());
+        switch (xp.primaryOutputType()) {
+            case GrPorterDuffXferProcessor::kNone_PrimaryOutputType:
+                fsBuilder->codeAppendf("%s = vec4(0);", args.fOutputPrimary);
+                break;
+            case GrPorterDuffXferProcessor::kColor_PrimaryOutputType:
+                fsBuilder->codeAppendf("%s = %s;", args.fOutputPrimary, args.fInputColor);
+                break;
+            case GrPorterDuffXferProcessor::kCoverage_PrimaryOutputType:
+                fsBuilder->codeAppendf("%s = %s;", args.fOutputPrimary, args.fInputCoverage);
+                break;
+            case GrPorterDuffXferProcessor::kModulate_PrimaryOutputType:
+            case GrPorterDuffXferProcessor::kCombineWithDst_PrimaryOutputType:
+                fsBuilder->codeAppendf("%s = %s * %s;", args.fOutputPrimary, args.fInputColor,
+                                       args.fInputCoverage);
+                if (GrPorterDuffXferProcessor::kCombineWithDst_PrimaryOutputType ==
+                    xp.primaryOutputType()){
+                    fsBuilder->codeAppendf("%s += (vec4(1.0) - %s) * %s;", args.fOutputPrimary,
+                                           args.fInputCoverage, fsBuilder->dstColor());
+                }
+                break;
+            default:
+                SkFAIL("Unexpected Primary Output");
         }
     }
 
     virtual void setData(const GrGLProgramDataManager&, const GrXferProcessor&) SK_OVERRIDE {};
 
     static void GenKey(const GrProcessor& processor, const GrGLCaps& caps,
                        GrProcessorKeyBuilder* b) {
         const GrPorterDuffXferProcessor& xp = processor.cast<GrPorterDuffXferProcessor>();
         b->add32(xp.primaryOutputType());
         b->add32(xp.secondaryOutputType());
@@ skipping 48 matching lines @@
                                                                         coverage);
 
     this->calcOutputTypes(optFlags, caps, isCoverageDrawing || coveragePOI.isSolidWhite(),
                           colorPOI.readsDst() || coveragePOI.readsDst());
     return optFlags;
 }
 
 void GrPorterDuffXferProcessor::calcOutputTypes(GrXferProcessor::OptFlags optFlags,
                                                 const GrDrawTargetCaps& caps,
                                                 bool hasSolidCoverage, bool readsDst) {
+    if (optFlags & kClearColorStages_OptFlag) {
+        if (optFlags & kClearCoverageStages_OptFlag) {
+            fPrimaryOutputType = kNone_PrimaryOutputType;
+            return;
+        } else {
+            fPrimaryOutputType = kCoverage_PrimaryOutputType;
+            return;
+        }
+    } else if (optFlags & kClearCoverageStages_OptFlag) {
+        fPrimaryOutputType = kColor_PrimaryOutputType;
+        return;
+    }
+
     // If we do have coverage determine whether it matters.  Dual source blending is expensive so
     // we don't do it if we are doing coverage drawing.  If we aren't then We always do dual source
     // blending if we have any effective coverage stages OR the geometry processor doesn't emits
     // solid coverage.
     if (!(optFlags & kSetCoverageDrawing_OptFlag) && !hasSolidCoverage) {
         if (caps.dualSourceBlendingSupport()) {
             if (kZero_GrBlendCoeff == fDstBlend) {
                 // write the coverage value to second color
                 fSecondaryOutputType = kCoverage_SecondaryOutputType;
                 fDstBlend = (GrBlendCoeff)GrGpu::kIS2C_GrBlendCoeff;
@@ skipping 397 matching lines @@
     } while (GrBlendCoeffRefsSrc(src));
 
     GrBlendCoeff dst;
     do {
         dst = GrBlendCoeff(random->nextRangeU(kFirstPublicGrBlendCoeff, kLastPublicGrBlendCoeff));
     } while (GrBlendCoeffRefsDst(dst));
 
     return GrPorterDuffXPFactory::Create(src, dst);
 }