Check that coverage FPs are compatible with alpha as coverage

Change-Id: Ic3b6a02248d571e82f6729827c199d358fb75114
Reviewed-on: https://skia-review.googlesource.com/8508
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/gpu/GrRenderTargetOpList.cpp b/src/gpu/GrRenderTargetOpList.cpp
index 69ba279434..b7dd37a922 100644
--- a/src/gpu/GrRenderTargetOpList.cpp
+++ b/src/gpu/GrRenderTargetOpList.cpp
@@ -315,6 +315,14 @@ void GrRenderTargetOpList::addDrawOp(const GrPipelineBuilder& pipelineBuilder,
     if (const GrFragmentProcessor* clipFP = appliedClip.clipCoverageFragmentProcessor()) {
         args.fAnalysis.fCoveragePOI.analyzeProcessors(&clipFP, 1);
     }
+#ifdef SK_DEBUG
+    // Other than tests that exercise atypical behavior we expect all coverage FPs to be compatible
+    // with the coverage-as-alpha optimization.
+    if (!args.fAnalysis.fCoveragePOI.allProcessorsCompatibleWithCoverageAsAlpha() &&
+        !args.fAnalysis.fCoveragePOI.isLCDCoverage()) {
+        GrCapsDebugf(this->caps(), "Coverage FP is not compatible with coverage as alpha.\n");
+    }
+#endif
 
     if (!renderTargetContext->accessRenderTarget()) {
         return;