Fix PatchAttribs issues with explicit curve type

- PathTessellator was accidentally not updating its own attribs when
  kExplicitCurveType was needed.

- GrPathTessellationShader was asserting too broadly surrounding
  kExplicitCurveType.

Bug: skia:12524
Change-Id: Iafe543cbc65c2225a9a99f14d7172182033e92c9
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/470518
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Jorge Betancourt <jmbetancourt@google.com>
Auto-Submit: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Jorge Betancourt <jmbetancourt@google.com>

src/gpu/tessellate/PathTessellator.h

@@ -118,7 +118,7 @@ protected:
 
     PathTessellator(bool infinitySupport, PatchAttribs attribs) : fAttribs(attribs) {
         if (!infinitySupport) {
-            attribs |= PatchAttribs::kExplicitCurveType;
+            fAttribs |= PatchAttribs::kExplicitCurveType;
         }
     }
 

src/gpu/tessellate/shaders/GrPathTessellationShader.cpp

@@ -115,12 +115,6 @@ float2 eval_rational_cubic(float4x3 P, float T) {
 
 void GrPathTessellationShader::Impl::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) {
     const auto& shader = args.fGeomProc.cast<GrPathTessellationShader>();
-
-    // We should use explicit curve type when, and only when, there isn't infinity support.
-    // Otherwise the GPU can infer curve type based on infinity.
-    SkASSERT(args.fShaderCaps->infinitySupport() !=
-             (shader.fAttribs & PatchAttribs::kExplicitCurveType));
-
     args.fVaryingHandler->emitAttributes(shader);
 
     // Vertex shader.

src/gpu/tessellate/shaders/GrPathTessellationShader_Hardware.cpp

@@ -343,6 +343,7 @@ GrPathTessellationShader* GrPathTessellationShader::MakeHardwareTessellationShad
         SkArenaAlloc* arena, const SkMatrix& viewMatrix, const SkPMColor4f& color,
         PatchAttribs attribs) {
     SkASSERT(!(attribs & PatchAttribs::kColor));  // Not yet implemented.
+    SkASSERT(!(attribs & PatchAttribs::kExplicitCurveType));  // Not yet implemented.
     if (attribs & PatchAttribs::kFanPoint) {
         return arena->make<HardwareWedgeShader>(viewMatrix, color, attribs);
     } else {

src/gpu/tessellate/shaders/GrPathTessellationShader_MiddleOut.cpp

@@ -210,7 +210,13 @@ std::unique_ptr<GrGeometryProcessor::ProgramImpl> MiddleOutShader::makeProgramIm
 }  // namespace
 
 GrPathTessellationShader* GrPathTessellationShader::MakeMiddleOutFixedCountShader(
-        const GrShaderCaps& shaderCaps, SkArenaAlloc* arena, const SkMatrix& viewMatrix,
-        const SkPMColor4f& color, PatchAttribs attribs) {
+        const GrShaderCaps& shaderCaps,
+        SkArenaAlloc* arena,
+        const SkMatrix& viewMatrix,
+        const SkPMColor4f& color,
+        PatchAttribs attribs) {
+    // We should use explicit curve type when, and only when, there isn't infinity support.
+    // Otherwise the GPU can infer curve type based on infinity.
+    SkASSERT(shaderCaps.infinitySupport() != (attribs & PatchAttribs::kExplicitCurveType));
     return arena->make<MiddleOutShader>(shaderCaps, viewMatrix, color, attribs);
 }