add gpu impl for shadermaskfilter

adds MulChildAlphaByInput
renames MulOutputByInputAlpha --> MulChildByInputAlpha

Bug: skia:7500
Change-Id: Ic0615d4d23a887fbee510901ed77a36f98a1b11d
Reviewed-on: https://skia-review.googlesource.com/102440
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Mike Reed <reed@google.com>

1 files changed, 20 insertions, 1 deletions

diff --git a/src/effects/SkShaderMaskFilter.cpp b/src/effects/SkShaderMaskFilter.cpp
index f2088fce72..74352acb65 100644
--- a/src/effects/SkShaderMaskFilter.cpp
+++ b/src/effects/SkShaderMaskFilter.cpp
@@ -9,7 +9,7 @@
 #include "SkMaskFilterBase.h"
 #include "SkReadBuffer.h"
 #include "SkShaderMaskFilter.h"
-#include "SkShader.h"
+#include "SkShaderBase.h"
 #include "SkString.h"
 
 class SkShaderMF : public SkMaskFilterBase {
@@ -30,6 +30,12 @@ public:
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkShaderMF)
 
+protected:
+#if SK_SUPPORT_GPU
+    std::unique_ptr<GrFragmentProcessor> onAsFragmentProcessor(const GrFPArgs&) const override;
+    bool onHasFragmentProcessor() const override;
+#endif
+
 private:
     sk_sp<SkShader> fShader;
 
@@ -108,6 +114,19 @@ bool SkShaderMF::filterMask(SkMask* dst, const SkMask& src, const SkMatrix& ctm,
 }
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
+#if SK_SUPPORT_GPU
+#include "GrFragmentProcessor.h"
+
+std::unique_ptr<GrFragmentProcessor> SkShaderMF::onAsFragmentProcessor(const GrFPArgs& args) const {
+    return GrFragmentProcessor::MulInputByChildAlpha(as_SB(fShader)->asFragmentProcessor(args));
+}
+
+bool SkShaderMF::onHasFragmentProcessor() const {
+    return true;
+}
+
+#endif
+///////////////////////////////////////////////////////////////////////////////////////////////////
 
 sk_sp<SkMaskFilter> SkShaderMaskFilter::Make(sk_sp<SkShader> shader) {
     return shader ? sk_sp<SkMaskFilter>(new SkShaderMF(std::move(shader))) : nullptr;