ComposeShader GPU implementations

Bug: skia:
Change-Id: I007b46ead1900a8f5cce82dec33b6d662fc63d8e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/206918
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
diff --git a/src/gpu/effects/GrComposeLerpEffect.cpp b/src/gpu/effects/GrComposeLerpEffect.cpp
new file mode 100644
index 0000000..a768b5c
--- /dev/null
+++ b/src/gpu/effects/GrComposeLerpEffect.cpp
@@ -0,0 +1,81 @@
+/*
+ * Copyright 2019 Google LLC.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/**************************************************************************************************
+ *** This file was autogenerated from GrComposeLerpEffect.fp; do not modify.
+ **************************************************************************************************/
+#include "GrComposeLerpEffect.h"
+#include "glsl/GrGLSLFragmentProcessor.h"
+#include "glsl/GrGLSLFragmentShaderBuilder.h"
+#include "glsl/GrGLSLProgramBuilder.h"
+#include "GrTexture.h"
+#include "SkSLCPP.h"
+#include "SkSLUtil.h"
+class GrGLSLComposeLerpEffect : public GrGLSLFragmentProcessor {
+public:
+    GrGLSLComposeLerpEffect() {}
+    void emitCode(EmitArgs& args) override {
+        GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
+        const GrComposeLerpEffect& _outer = args.fFp.cast<GrComposeLerpEffect>();
+        (void)_outer;
+        auto weight = _outer.weight;
+        (void)weight;
+        weightVar =
+                args.fUniformHandler->addUniform(kFragment_GrShaderFlag, kFloat_GrSLType, "weight");
+        SkString _child0("_child0");
+        if (_outer.child1_index >= 0) {
+            this->emitChild(_outer.child1_index, &_child0, args);
+        } else {
+            fragBuilder->codeAppendf("half4 %s;", _child0.c_str());
+        }
+        SkString _child1("_child1");
+        if (_outer.child2_index >= 0) {
+            this->emitChild(_outer.child2_index, &_child1, args);
+        } else {
+            fragBuilder->codeAppendf("half4 %s;", _child1.c_str());
+        }
+        fragBuilder->codeAppendf("%s = mix(%s ? %s : %s, %s ? %s : %s, half(%s));\n",
+                                 args.fOutputColor, _outer.child1_index >= 0 ? "true" : "false",
+                                 _child0.c_str(), args.fInputColor,
+                                 _outer.child2_index >= 0 ? "true" : "false", _child1.c_str(),
+                                 args.fInputColor, args.fUniformHandler->getUniformCStr(weightVar));
+    }
+
+private:
+    void onSetData(const GrGLSLProgramDataManager& pdman,
+                   const GrFragmentProcessor& _proc) override {
+        const GrComposeLerpEffect& _outer = _proc.cast<GrComposeLerpEffect>();
+        { pdman.set1f(weightVar, (_outer.weight)); }
+    }
+    UniformHandle weightVar;
+};
+GrGLSLFragmentProcessor* GrComposeLerpEffect::onCreateGLSLInstance() const {
+    return new GrGLSLComposeLerpEffect();
+}
+void GrComposeLerpEffect::onGetGLSLProcessorKey(const GrShaderCaps& caps,
+                                                GrProcessorKeyBuilder* b) const {}
+bool GrComposeLerpEffect::onIsEqual(const GrFragmentProcessor& other) const {
+    const GrComposeLerpEffect& that = other.cast<GrComposeLerpEffect>();
+    (void)that;
+    if (weight != that.weight) return false;
+    return true;
+}
+GrComposeLerpEffect::GrComposeLerpEffect(const GrComposeLerpEffect& src)
+        : INHERITED(kGrComposeLerpEffect_ClassID, src.optimizationFlags())
+        , child1_index(src.child1_index)
+        , child2_index(src.child2_index)
+        , weight(src.weight) {
+    if (child1_index >= 0) {
+        this->registerChildProcessor(src.childProcessor(child1_index).clone());
+    }
+    if (child2_index >= 0) {
+        this->registerChildProcessor(src.childProcessor(child2_index).clone());
+    }
+}
+std::unique_ptr<GrFragmentProcessor> GrComposeLerpEffect::clone() const {
+    return std::unique_ptr<GrFragmentProcessor>(new GrComposeLerpEffect(*this));
+}