commit 9acf68267ae2ff808c4f33942beaa2c47a0bbc86
author Chris Dalton <csmartdalton@google.com> Tue Nov 12 11:52:40 2019 -0700
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Tue Nov 12 21:19:05 2019 +0000
tree 69cb45cc0889f8624b55354dca254ab6770a824c
parent 8c1e0effbbe1cf87e1f0d7aa8cb22e04ec6728e5

Fix detection of when we will have mixed sampled coverage

Change-Id: I32de8bdea7b7aafd202f44a2036872f25d531ae3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/253763
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>

src/gpu/GrRenderTargetContext.cpp

diff --git a/src/gpu/GrRenderTargetContext.cpp b/src/gpu/GrRenderTargetContext.cpp
index ef69bca..1e0cc19 100644
--- a/src/gpu/GrRenderTargetContext.cpp
+++ b/src/gpu/GrRenderTargetContext.cpp
@@ -2303,29 +2303,28 @@
     GrAppliedClip appliedClip;
     GrDrawOp::FixedFunctionFlags fixedFunctionFlags = op->fixedFunctionFlags();
     bool usesHWAA = fixedFunctionFlags & GrDrawOp::FixedFunctionFlags::kUsesHWAA;
-    bool usesStencil = fixedFunctionFlags & GrDrawOp::FixedFunctionFlags::kUsesStencil;
+    bool usesUserStencilBits = fixedFunctionFlags & GrDrawOp::FixedFunctionFlags::kUsesStencil;
 
-    if (usesStencil) {
+    if (usesUserStencilBits) {  // Stencil clipping will call setNeedsStencil on its own, if needed.
         this->setNeedsStencil(usesHWAA);
     }
 
-    if (!clip.apply(fContext, this, usesHWAA, usesStencil, &appliedClip, &bounds)) {
+    if (!clip.apply(fContext, this, usesHWAA, usesUserStencilBits, &appliedClip, &bounds)) {
         fContext->priv().opMemoryPool()->release(std::move(op));
         return;
     }
 
-    SkASSERT((!usesStencil && !appliedClip.hasStencilClip()) || (fNumStencilSamples > 0));
+    bool willUseStencil = usesUserStencilBits || appliedClip.hasStencilClip();
+    SkASSERT(!willUseStencil || fNumStencilSamples > 0);
+
+    // If stencil is enabled and the framebuffer is mixed sampled, then the graphics pipeline will
+    // have mixed sampled coverage, regardless of whether HWAA is enabled. (e.g., a non-aa draw
+    // that uses a stencil test when the stencil buffer is multisampled.)
+    bool hasMixedSampledCoverage = (
+            willUseStencil && fNumStencilSamples > this->numSamples());
+    SkASSERT(!hasMixedSampledCoverage || fRenderTargetProxy->canUseMixedSamples(*this->caps()));
 
     GrClampType clampType = GrColorTypeClampType(this->colorInfo().colorType());
-    // MIXED SAMPLES TODO: If we start using mixed samples for clips we will need to check the clip
-    // here as well.
-    bool hasMixedSampledCoverage = (usesHWAA && this->numSamples() <= 1);
-#ifdef SK_DEBUG
-    if (hasMixedSampledCoverage) {
-        SkASSERT(usesStencil);
-        SkASSERT(fRenderTargetProxy->canUseMixedSamples(*this->caps()));
-    }
-#endif
     GrProcessorSet::Analysis analysis = op->finalize(
             *this->caps(), &appliedClip, hasMixedSampledCoverage, clampType);