Remove clamping of kPlus with F16 configs

The most common use-case for F16 is to draw things that are explicitly
outside of [0,1]. We can't prevent out-of-range values in general, users
could just draw out-of-range content in src mode. We've decided that
it's best to avoid surprising behavior, and trust the user in these
situations.

This effectively reverts https://skia-review.googlesource.com/c/skia/+/48183

Bug: skia:
Change-Id: I71c2dd925c567e2862d96ab70c752f19245a69c4
Reviewed-on: https://skia-review.googlesource.com/140500
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

7 files changed, 20 insertions, 41 deletions

diff --git a/src/gpu/effects/GrCoverageSetOpXP.cpp b/src/gpu/effects/GrCoverageSetOpXP.cpp
index 2524c9c298..e7ac874c2b 100644
--- a/src/gpu/effects/GrCoverageSetOpXP.cpp
+++ b/src/gpu/effects/GrCoverageSetOpXP.cpp
@@ -211,8 +211,7 @@ sk_sp<const GrXferProcessor> GrCoverageSetOpXPFactory::makeXferProcessor(
         const GrProcessorAnalysisColor&,
         GrProcessorAnalysisCoverage,
         bool hasMixedSamples,
-        const GrCaps& caps,
-        GrPixelConfigIsClamped dstIsClamped) const {
+        const GrCaps& caps) const {
     // We don't support inverting coverage with mixed samples. We don't expect to ever want this in
     // the future, however we could at some point make this work using an inverted coverage
     // modulation table. Note that an inverted table still won't work if there are coverage procs.
diff --git a/src/gpu/effects/GrCoverageSetOpXP.h b/src/gpu/effects/GrCoverageSetOpXP.h
index cf91848944..e8bc5a223f 100644
--- a/src/gpu/effects/GrCoverageSetOpXP.h
+++ b/src/gpu/effects/GrCoverageSetOpXP.h
@@ -37,13 +37,11 @@ private:
     sk_sp<const GrXferProcessor> makeXferProcessor(const GrProcessorAnalysisColor&,
                                                    GrProcessorAnalysisCoverage,
                                                    bool hasMixedSamples,
-                                                   const GrCaps&,
-                                                   GrPixelConfigIsClamped) const override;
+                                                   const GrCaps&) const override;
 
     AnalysisProperties analysisProperties(const GrProcessorAnalysisColor&,
                                           const GrProcessorAnalysisCoverage&,
-                                          const GrCaps&,
-                                          GrPixelConfigIsClamped) const override {
+                                          const GrCaps&) const override {
         return AnalysisProperties::kIgnoresInputColor;
     }
 
diff --git a/src/gpu/effects/GrCustomXfermode.cpp b/src/gpu/effects/GrCustomXfermode.cpp
index bdeda9467c..5c352604c6 100644
--- a/src/gpu/effects/GrCustomXfermode.cpp
+++ b/src/gpu/effects/GrCustomXfermode.cpp
@@ -217,13 +217,11 @@ private:
     sk_sp<const GrXferProcessor> makeXferProcessor(const GrProcessorAnalysisColor&,
                                                    GrProcessorAnalysisCoverage,
                                                    bool hasMixedSamples,
-                                                   const GrCaps&,
-                                                   GrPixelConfigIsClamped) const override;
+                                                   const GrCaps&) const override;
 
     AnalysisProperties analysisProperties(const GrProcessorAnalysisColor&,
                                           const GrProcessorAnalysisCoverage&,
-                                          const GrCaps&,
-                                          GrPixelConfigIsClamped) const override;
+                                          const GrCaps&) const override;
 
     GR_DECLARE_XP_FACTORY_TEST
 
@@ -243,8 +241,7 @@ sk_sp<const GrXferProcessor> CustomXPFactory::makeXferProcessor(
         const GrProcessorAnalysisColor&,
         GrProcessorAnalysisCoverage coverage,
         bool hasMixedSamples,
-        const GrCaps& caps,
-        GrPixelConfigIsClamped dstIsClamped) const {
+        const GrCaps& caps) const {
     SkASSERT(GrCustomXfermode::IsSupportedMode(fMode));
     if (can_use_hw_blend_equation(fHWBlendEquation, coverage, caps)) {
         return sk_sp<GrXferProcessor>(new CustomXP(fMode, fHWBlendEquation));
@@ -254,7 +251,7 @@ sk_sp<const GrXferProcessor> CustomXPFactory::makeXferProcessor(
 
 GrXPFactory::AnalysisProperties CustomXPFactory::analysisProperties(
         const GrProcessorAnalysisColor&, const GrProcessorAnalysisCoverage& coverage,
-        const GrCaps& caps, GrPixelConfigIsClamped dstIsClamped) const {
+        const GrCaps& caps) const {
     /*
       The general SVG blend equation is defined in the spec as follows:
 
diff --git a/src/gpu/effects/GrDisableColorXP.cpp b/src/gpu/effects/GrDisableColorXP.cpp
index 314be6ee13..3f9f71e314 100644
--- a/src/gpu/effects/GrDisableColorXP.cpp
+++ b/src/gpu/effects/GrDisableColorXP.cpp
@@ -79,8 +79,7 @@ sk_sp<const GrXferProcessor> GrDisableColorXPFactory::makeXferProcessor(
         const GrProcessorAnalysisColor&,
         GrProcessorAnalysisCoverage,
         bool hasMixedSamples,
-        const GrCaps& caps,
-        GrPixelConfigIsClamped dstIsClamped) const {
+        const GrCaps& caps) const {
     return sk_sp<const GrXferProcessor>(new DisableColorXP);
 }
 
diff --git a/src/gpu/effects/GrDisableColorXP.h b/src/gpu/effects/GrDisableColorXP.h
index 0c4f5cf2bb..d15f9525c8 100644
--- a/src/gpu/effects/GrDisableColorXP.h
+++ b/src/gpu/effects/GrDisableColorXP.h
@@ -30,8 +30,7 @@ private:
 
     AnalysisProperties analysisProperties(const GrProcessorAnalysisColor&,
                                           const GrProcessorAnalysisCoverage&,
-                                          const GrCaps&,
-                                          GrPixelConfigIsClamped) const override {
+                                          const GrCaps&) const override {
         return AnalysisProperties::kCompatibleWithAlphaAsCoverage |
                AnalysisProperties::kIgnoresInputColor;
     }
@@ -39,8 +38,7 @@ private:
     sk_sp<const GrXferProcessor> makeXferProcessor(const GrProcessorAnalysisColor&,
                                                    GrProcessorAnalysisCoverage,
                                                    bool hasMixedSamples,
-                                                   const GrCaps&,
-                                                   GrPixelConfigIsClamped) const override;
+                                                   const GrCaps&) const override;
 
     GR_DECLARE_XP_FACTORY_TEST
 
diff --git a/src/gpu/effects/GrPorterDuffXferProcessor.cpp b/src/gpu/effects/GrPorterDuffXferProcessor.cpp
index ca082603de..89f61ecd1f 100644
--- a/src/gpu/effects/GrPorterDuffXferProcessor.cpp
+++ b/src/gpu/effects/GrPorterDuffXferProcessor.cpp
@@ -759,7 +759,7 @@ const GrXPFactory* GrPorterDuffXPFactory::Get(SkBlendMode blendMode) {
 
 sk_sp<const GrXferProcessor> GrPorterDuffXPFactory::makeXferProcessor(
         const GrProcessorAnalysisColor& color, GrProcessorAnalysisCoverage coverage,
-        bool hasMixedSamples, const GrCaps& caps, GrPixelConfigIsClamped dstIsClamped) const {
+        bool hasMixedSamples, const GrCaps& caps) const {
     BlendFormula blendFormula;
     bool isLCD = coverage == GrProcessorAnalysisCoverage::kLCD;
     if (isLCD) {
@@ -778,10 +778,8 @@ sk_sp<const GrXferProcessor> GrPorterDuffXPFactory::makeXferProcessor(
                                   hasMixedSamples, fBlendMode);
     }
 
-    bool needsClamp = SkBlendMode::kPlus == fBlendMode;
     if ((blendFormula.hasSecondaryOutput() && !caps.shaderCaps()->dualSourceBlendingSupport()) ||
-        (isLCD && (SkBlendMode::kSrcOver != fBlendMode /*|| !color.isOpaque()*/)) ||
-        (needsClamp && (GrPixelConfigIsClamped::kNo == dstIsClamped))) {
+        (isLCD && (SkBlendMode::kSrcOver != fBlendMode /*|| !color.isOpaque()*/))) {
         return sk_sp<const GrXferProcessor>(new ShaderPDXferProcessor(hasMixedSamples, fBlendMode,
                                                                       coverage));
     }
@@ -790,7 +788,7 @@ sk_sp<const GrXferProcessor> GrPorterDuffXPFactory::makeXferProcessor(
 
 static inline GrXPFactory::AnalysisProperties analysis_properties(
         const GrProcessorAnalysisColor& color, const GrProcessorAnalysisCoverage& coverage,
-        const GrCaps& caps, GrPixelConfigIsClamped dstIsClamped, SkBlendMode mode) {
+        const GrCaps& caps, SkBlendMode mode) {
     using AnalysisProperties = GrXPFactory::AnalysisProperties;
     AnalysisProperties props = AnalysisProperties::kNone;
     bool hasCoverage = GrProcessorAnalysisCoverage::kNone != coverage;
@@ -837,11 +835,6 @@ static inline GrXPFactory::AnalysisProperties analysis_properties(
         }
     }
 
-    bool needsClamp = SkBlendMode::kPlus == mode;
-    if (needsClamp && (GrPixelConfigIsClamped::kNo == dstIsClamped)) {
-        props |= AnalysisProperties::kReadsDstInShader;
-    }
-
     if (!formula.modifiesDst() || !formula.usesInputColor()) {
         props |= AnalysisProperties::kIgnoresInputColor;
     }
@@ -857,9 +850,8 @@ static inline GrXPFactory::AnalysisProperties analysis_properties(
 GrXPFactory::AnalysisProperties GrPorterDuffXPFactory::analysisProperties(
         const GrProcessorAnalysisColor& color,
         const GrProcessorAnalysisCoverage& coverage,
-        const GrCaps& caps,
-        GrPixelConfigIsClamped dstIsClamped) const {
-    return analysis_properties(color, coverage, caps, dstIsClamped, fBlendMode);
+        const GrCaps& caps) const {
+    return analysis_properties(color, coverage, caps, fBlendMode);
 }
 
 GR_DEFINE_XP_FACTORY_TEST(GrPorterDuffXPFactory);
@@ -946,7 +938,6 @@ sk_sp<const GrXferProcessor> GrPorterDuffXPFactory::MakeNoCoverageXP(SkBlendMode
 GrXPFactory::AnalysisProperties GrPorterDuffXPFactory::SrcOverAnalysisProperties(
         const GrProcessorAnalysisColor& color,
         const GrProcessorAnalysisCoverage& coverage,
-        const GrCaps& caps,
-        GrPixelConfigIsClamped dstIsClamped) {
-    return analysis_properties(color, coverage, caps, dstIsClamped, SkBlendMode::kSrcOver);
+        const GrCaps& caps) {
+    return analysis_properties(color, coverage, caps, SkBlendMode::kSrcOver);
 }
diff --git a/src/gpu/effects/GrPorterDuffXferProcessor.h b/src/gpu/effects/GrPorterDuffXferProcessor.h
index 74ae1533bf..ebe02126d2 100644
--- a/src/gpu/effects/GrPorterDuffXferProcessor.h
+++ b/src/gpu/effects/GrPorterDuffXferProcessor.h
@@ -41,8 +41,7 @@ public:
 
     static AnalysisProperties SrcOverAnalysisProperties(const GrProcessorAnalysisColor&,
                                                         const GrProcessorAnalysisCoverage&,
-                                                        const GrCaps&,
-                                                        GrPixelConfigIsClamped);
+                                                        const GrCaps&);
 
 private:
     constexpr GrPorterDuffXPFactory(SkBlendMode);
@@ -50,13 +49,11 @@ private:
     sk_sp<const GrXferProcessor> makeXferProcessor(const GrProcessorAnalysisColor&,
                                                    GrProcessorAnalysisCoverage,
                                                    bool hasMixedSamples,
-                                                   const GrCaps&,
-                                                   GrPixelConfigIsClamped) const override;
+                                                   const GrCaps&) const override;
 
     AnalysisProperties analysisProperties(const GrProcessorAnalysisColor&,
                                           const GrProcessorAnalysisCoverage&,
-                                          const GrCaps&,
-                                          GrPixelConfigIsClamped) const override;
+                                          const GrCaps&) const override;
 
     GR_DECLARE_XP_FACTORY_TEST
     static void TestGetXPOutputTypes(const GrXferProcessor*, int* outPrimary, int* outSecondary);