commit 097a2c11ca7adfc74e876b78992c95f3a5700f67
author John Stiles <johnstiles@google.com> Wed Apr 12 19:10:17 2023 -0400
committer SkCQ <skcq-be@skia-corp.google.com.iam.gserviceaccount.com> Thu Apr 13 18:53:56 2023 +0000
tree 64ed15c3efd23f9d873697dff03ce895eb6a1ca2
parent 809449e83aea9cff604d866b8321a1f507138c3a

Migrate color filter flag into SkRuntimeEffect.

The alpha-unchanged flag previously lived in SkFilterColorProgram,
but in SkRP we won't use SkFilterColorProgram. There wasn't any
benefit to keeping the flag in the helper class, so it's now a flag
in SkRuntimeEffect proper.

Change-Id: I84b2ba6dd9ab896ccdcd737d236f7159c98dbb47
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/670343
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>

include/effects/SkRuntimeEffect.h

diff --git a/include/effects/SkRuntimeEffect.h b/include/effects/SkRuntimeEffect.h
index ef4fa11..4d3450e 100644
--- a/include/effects/SkRuntimeEffect.h
+++ b/include/effects/SkRuntimeEffect.h
@@ -283,6 +283,7 @@
         kSamplesOutsideMain_Flag = 0x10,
         kUsesColorTransform_Flag = 0x20,
         kAlwaysOpaque_Flag       = 0x40,
+        kAlphaUnchanged_Flag     = 0x80,
     };
 
     SkRuntimeEffect(std::unique_ptr<SkSL::Program> baseProgram,
@@ -308,6 +309,7 @@
     bool samplesOutsideMain() const { return (fFlags & kSamplesOutsideMain_Flag); }
     bool usesColorTransform() const { return (fFlags & kUsesColorTransform_Flag); }
     bool alwaysOpaque()       const { return (fFlags & kAlwaysOpaque_Flag);       }
+    bool isAlphaUnchanged()   const { return (fFlags & kAlphaUnchanged_Flag);     }
 
     const SkFilterColorProgram* getFilterColorProgram() const;
     const SkSL::RP::Program* getRPProgram(SkSL::DebugTracePriv* debugTrace) const;

src/core/SkRuntimeEffect.cpp

diff --git a/src/core/SkRuntimeEffect.cpp b/src/core/SkRuntimeEffect.cpp
index eca0f07..829c3d3 100644
--- a/src/core/SkRuntimeEffect.cpp
+++ b/src/core/SkRuntimeEffect.cpp
@@ -549,6 +549,15 @@
         flags |= kSamplesOutsideMain_Flag;
     }
 
+    // Look for color filters that preserve the input alpha. This analysis is very conservative, and
+    // only returns true when the input alpha is returned as-is from main() with no intervening
+    // copies or arithmetic.
+    if (flags & kAllowColorFilter_Flag) {
+        if (SkSL::Analysis::ReturnsInputAlpha(*main->definition(), *program->usage())) {
+            flags |= kAlphaUnchanged_Flag;
+        }
+    }
+
     // Determine if this effect uses of the color transform intrinsics. Effects need to know this
     // so they can allocate color transform objects, etc.
     if (SkSL::Analysis::CallsColorTransformIntrinsics(*program)) {
@@ -978,24 +987,16 @@
         return nullptr;
     }
 
-    // This is very conservative, and only returns true when the input alpha is returned as-is
-    // from main() with no intervening copies or arithmetic.
-    bool alphaUnchanged = SkSL::Analysis::ReturnsInputAlpha(effect->fMain,
-                                                            *effect->fBaseProgram->usage());
-
     // We'll use this program to filter one color at a time, don't bother with jit
     return std::unique_ptr<SkFilterColorProgram>(
             new SkFilterColorProgram(p.done(/*debug_name=*/nullptr, /*allow_jit=*/false),
-                                     std::move(sampleCalls),
-                                     alphaUnchanged));
+                                     std::move(sampleCalls)));
 }
 
 SkFilterColorProgram::SkFilterColorProgram(skvm::Program program,
-                                           std::vector<SampleCall> sampleCalls,
-                                           bool alphaUnchanged)
+                                           std::vector<SampleCall> sampleCalls)
         : fProgram(std::move(program))
-        , fSampleCalls(std::move(sampleCalls))
-        , fAlphaUnchanged(alphaUnchanged) {}
+        , fSampleCalls(std::move(sampleCalls)) {}
 
 SkPMColor4f SkFilterColorProgram::eval(
         const SkPMColor4f& inColor,
@@ -1347,7 +1348,7 @@
 
     bool onIsAlphaUnchanged() const override {
         return fEffect->getFilterColorProgram() &&
-               fEffect->getFilterColorProgram()->isAlphaUnchanged();
+               fEffect->isAlphaUnchanged();
     }
 
     void flatten(SkWriteBuffer& buffer) const override {

src/core/SkRuntimeEffectPriv.h

diff --git a/src/core/SkRuntimeEffectPriv.h b/src/core/SkRuntimeEffectPriv.h
index 46264ad..557c526 100644
--- a/src/core/SkRuntimeEffectPriv.h
+++ b/src/core/SkRuntimeEffectPriv.h
@@ -142,8 +142,6 @@
                      const void* uniformData,
                      std::function<SkPMColor4f(int, SkPMColor4f)> evalChild) const;
 
-    bool isAlphaUnchanged() const { return fAlphaUnchanged; }
-
 private:
     struct SampleCall {
         enum class Kind {
@@ -162,13 +160,10 @@
         };
     };
 
-    SkFilterColorProgram(skvm::Program program,
-                         std::vector<SampleCall> sampleCalls,
-                         bool alphaUnchanged);
+    SkFilterColorProgram(skvm::Program program, std::vector<SampleCall> sampleCalls);
 
     skvm::Program           fProgram;
     std::vector<SampleCall> fSampleCalls;
-    bool                    fAlphaUnchanged;
 };
 
 #endif  // SK_ENABLE_SKSL