Implement support for mixed sampled render targets

src/gpu/GrPipeline.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrPipeline.h"
 
 #include "GrBatch.h"
@@ skipping 11 matching lines @@
                        const GrDeviceCoordTexture* dstCopy) {
     // Create XferProcessor from DS's XPFactory
     SkAutoTUnref<GrXferProcessor> xferProcessor(
         pipelineBuilder.getXPFactory()->createXferProcessor(colorPOI, coveragePOI, dstCopy, caps));
 
     GrColor overrideColor = GrColor_ILLEGAL;
     if (colorPOI.firstEffectiveStageIndex() != 0) {
         overrideColor = colorPOI.inputColorToEffectiveStage();
     }
 
+    fRenderTarget.reset(pipelineBuilder.fRenderTarget.get());
+    SkASSERT(fRenderTarget);
+
     GrXferProcessor::OptFlags optFlags;
     if (xferProcessor) {
         fXferProcessor.reset(xferProcessor.get());
 
-        optFlags = xferProcessor->getOptimizations(colorPOI,
+        GrProcOptInfo localColorPOI = colorPOI;
+        // Optimizations will try to turn off blending which is required by mixed
+        // sampled modes.
+        bool isMixedSampledTarget =
+            (this->getRenderTarget()->sampleConfig() == kStencil_GrSampleConfig);
+        localColorPOI.setNeedsCoverageModulation(isMixedSampledTarget);

[Chris Dalton, 2015/03/14 02:51:30]

No need to force blending unless we're actually using the mixed samples: (after
https://codereview.chromium.org/1002013006/)

 localColorPOI.setNeedsCoverageModulation(pipelineBuilder.isHWAntialias() &&
isMixedSampledTarget);

(Or we may want to move the block that sets fFlags to before this line, then
say:

  localColorPOI.setNeedsCoverageModulation(this->isHWAntialiasState() &&
isMixedSampledTarget);

)

+
+        optFlags = xferProcessor->getOptimizations(localColorPOI,
                                                    coveragePOI,
                                                    pipelineBuilder.getStencil().doesWrite(),
                                                    &overrideColor,
                                                    caps);
     }
 
     // When path rendering the stencil settings are not always set on the GrPipelineBuilder
     // so we must check the draw type. In cases where we will skip drawing we simply return a
     // null GrPipeline.
     if (!xferProcessor || (GrXferProcessor::kSkipDraw_OptFlag & optFlags)) {
         // Set the fields that don't default init and return. The lack of a render target will
         // indicate that this can be skipped.
         fFlags = 0;
         fDrawFace = GrPipelineBuilder::kInvalid_DrawFace;
         return;
     }
 
-    fRenderTarget.reset(pipelineBuilder.fRenderTarget.get());
-    SkASSERT(fRenderTarget);
     fScissorState = scissorState;
     fStencilSettings = pipelineBuilder.getStencil();
     fDrawFace = pipelineBuilder.getDrawFace();
 
     fFlags = 0;
     if (pipelineBuilder.isHWAntialias()) {
         fFlags |= kHWAA_Flag;
     }
     if (pipelineBuilder.isDither()) {
         fFlags |= kDither_Flag;
@@ skipping 85 matching lines @@
     SkASSERT(this->numFragmentStages() == that.numFragmentStages());
     for (int i = 0; i < this->numFragmentStages(); i++) {
 
         if (this->getFragmentStage(i) != that.getFragmentStage(i)) {
             return false;
         }
     }
     return true;
 }