Implement support for mixed sampled render targets

src/gpu/GrStencilAndCoverTextContext.cpp

Index: src/gpu/GrStencilAndCoverTextContext.cpp
diff --git a/src/gpu/GrStencilAndCoverTextContext.cpp b/src/gpu/GrStencilAndCoverTextContext.cpp
index 1456aa22b5802d0e860dbcf1c17d18258e6499e1..7542647d6904d3d7d4f6bc0cb95e9c32b08cc364 100644
--- a/src/gpu/GrStencilAndCoverTextContext.cpp
+++ b/src/gpu/GrStencilAndCoverTextContext.cpp
@@ -69,6 +69,21 @@ bool GrStencilAndCoverTextContext::canDraw(const GrRenderTarget* rt,
         return false;
     }
 
+    if (skPaint.isAntiAlias() &&
+        GrRenderTarget::kStencil_SampleConfig == rt->sampleConfig()) {
+        if (!paint.getXPFactory()->canTweakAlphaForCoverage()) {
+            return false;
+        }
+        // No Xfer processors that might do blending inside the shader.
+        // Coverage modulation for mixed samples is done *after* shading, so blending
+        // must occur in the ROP.
+        // TODO: Update Xfer processors to better support mixed samples.
+        if (paint.getXPFactory()->willNeedDstCopy(*fContext->getGpu()->caps(),
+                GrProcOptInfo(), GrProcOptInfo())) {
+            return false;
+        }
+    }
+
     // No color bitmap fonts.
     SkScalerContext::Rec    rec;
     SkScalerContext::MakeRec(skPaint, &fDeviceProperties, NULL, &rec);
@@ -374,6 +389,8 @@ void GrStencilAndCoverTextContext::init(GrRenderTarget* rt,
     fStateRestore.set(&fPipelineBuilder);
 
     fPipelineBuilder.setFromPaint(fPaint, fRenderTarget, fClip);
+    SkASSERT(fRenderTarget->isMultisampled(GrRenderTarget::kStencil_BufferBit));
+    fPipelineBuilder.setState(GrPipelineBuilder::kHWAntialias_StateBit, fPaint.isAntiAlias());
 
     GR_STATIC_CONST_SAME_STENCIL(kStencilPass,
                                  kZero_StencilOp,