Enable local coordinates in runtime effects.

At present, we calculate the coordinates, but we don't yet use them
anywhere, because the runtime effect code isn't being included in the
finished program.

Change-Id: I6eb6b1b43ce78da31884b7a8b1bac2aa9ba5407b
Bug: skia:13405
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/549101
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>

src/core/SkKeyHelpers.cpp

@@ -570,8 +570,10 @@ RuntimeShaderBlock::ShaderData::ShaderData(sk_sp<const SkRuntimeEffect> effect)
         : fEffect(std::move(effect)) {}
 
 RuntimeShaderBlock::ShaderData::ShaderData(sk_sp<const SkRuntimeEffect> effect,
+                                           const SkMatrix& localMatrix,
                                            sk_sp<const SkData> uniforms)
         : fEffect(std::move(effect))
+        , fLocalMatrix(localMatrix)
         , fUniforms(std::move(uniforms)) {}
 
 static bool skdata_matches(const SkData* a, const SkData* b) {
@@ -582,6 +584,7 @@ static bool skdata_matches(const SkData* a, const SkData* b) {
 
 bool RuntimeShaderBlock::ShaderData::operator==(const ShaderData& rhs) const {
     return fEffect == rhs.fEffect &&
+           fLocalMatrix == rhs.fLocalMatrix &&
            skdata_matches(fUniforms.get(), rhs.fUniforms.get());
 }
 
@@ -600,6 +603,13 @@ void RuntimeShaderBlock::BeginBlock(const SkKeyContext& keyContext,
                 [[maybe_unused]] const SkShaderCodeDictionary* dict = keyContext.dict();
                 VALIDATE_UNIFORMS(gatherer, dict, kCodeSnippetID)
                 gatherer->addFlags(dict->getSnippetRequirementFlags(kCodeSnippetID));
+
+                // Pass the local matrix inverse so we can use local coordinates.
+                SkMatrix inverseLocalMatrix;
+                if (!shaderData.fLocalMatrix.invert(&inverseLocalMatrix)) {
+                    inverseLocalMatrix.setIdentity();
+                }
+                gatherer->write(SkM44(inverseLocalMatrix));
             }
             // Use the combination of {SkSL program hash, uniform size} as our key.
             // In the unfortunate event of a hash collision, at least we'll have the right amount of
@@ -717,7 +727,7 @@ SkUniquePaintParamsID CreateKey(const SkKeyContext& keyContext,
             {
                 sk_sp<SkRuntimeEffect> effect = TestingOnly_GetCommonRuntimeEffect();
                 RuntimeShaderBlock::BeginBlock(keyContext, builder, nullptr,
-                                               {effect, /*uniforms=*/nullptr});
+                                               {effect, SkMatrix::I(), /*uniforms=*/nullptr});
                 builder->endBlock();
             }
             break;

src/core/SkKeyHelpers.h

@@ -176,13 +176,16 @@ struct RuntimeShaderBlock {
         ShaderData(sk_sp<const SkRuntimeEffect> effect);
 
         // This ctor is used when extracting information from PaintParams.
-        ShaderData(sk_sp<const SkRuntimeEffect> effect, sk_sp<const SkData> uniforms);
+        ShaderData(sk_sp<const SkRuntimeEffect> effect,
+                   const SkMatrix& localMatrix,
+                   sk_sp<const SkData> uniforms);
 
         bool operator==(const ShaderData& rhs) const;
         bool operator!=(const ShaderData& rhs) const { return !(*this == rhs); }
 
         // Runtime shader data.
         sk_sp<const SkRuntimeEffect> fEffect;
+        SkMatrix                     fLocalMatrix;
         sk_sp<const SkData>          fUniforms;
     };
 

src/core/SkRuntimeEffect.cpp

@@ -1156,7 +1156,8 @@ public:
     void addToKey(const SkKeyContext& keyContext,
                   SkPaintParamsKeyBuilder* builder,
                   SkPipelineDataGatherer* gatherer) const override {
-        RuntimeShaderBlock::BeginBlock(keyContext, builder, gatherer, {fEffect, fUniforms});
+        RuntimeShaderBlock::BeginBlock(keyContext, builder, gatherer,
+                                       {fEffect, this->getLocalMatrix(), fUniforms});
         builder->endBlock();
     }
 

src/core/SkShaderCodeDictionary.cpp

@@ -542,6 +542,10 @@ static constexpr char kBlendShaderName[] = "sk_blend_shader";
 //--------------------------------------------------------------------------------------------------
 static constexpr char kRuntimeShaderName[] = "sk_runtime_placeholder";
 
+static constexpr SkUniform kRuntimeShaderUniforms[] = {
+        {"localMatrix", SkSLType::kFloat4x4},
+};
+
 static constexpr DataPayloadField kRuntimeShaderDataPayload[] = {
         {"runtime effect hash", DataPayloadType::kByte, 4},
         {"uniform data size (bytes)", DataPayloadType::kByte, 4},
@@ -824,8 +828,8 @@ SkShaderCodeDictionary::SkShaderCodeDictionary() {
     };
     fBuiltInCodeSnippets[(int) SkBuiltInCodeSnippetID::kRuntimeShader] = {
             "RuntimeShader",
-            { },     // no uniforms
-            SnippetRequirementFlags::kNone,
+            SkMakeSpan(kRuntimeShaderUniforms),
+            SnippetRequirementFlags::kLocalCoords,
             { },     // no samplers
             kRuntimeShaderName,
             GenerateDefaultGlueCode,

src/sksl/sksl_graphite_frag.sksl

@@ -4,8 +4,8 @@ half4 sk_error() {
     return half4(1.0, 0.0, 1.0, 1.0);
 }
 
-half4 sk_runtime_placeholder() {
-    // TODO(skia:13405): remove me when RuntimeShader is implemented
+half4 sk_runtime_placeholder(float4x4 dev2Local) {
+    float2 pos = (dev2Local * sk_FragCoord).xy;
     return half4(0.75, 0.0, 1.0, 1.0);
 }