Index8 GPU and CPU raster support.

src/gpu/effects/GrIndex8toRGBEffect.cpp

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrIndex8toRGBEffect.h"
+
+#include "GrCoordTransform.h"
+#include "GrInvariantOutput.h"
+#include "GrProcessor.h"
+#include "gl/GrGLFragmentProcessor.h"
+#include "gl/builders/GrGLProgramBuilder.h"
+#include "glsl/GrGLSLProgramDataManager.h"
+
+namespace {
+
+    class Index8toRGBEffect : public GrSingleTextureEffect {
+    public:
+        static GrFragmentProcessor* Create(GrTexture* tex, GrTexture* colorMapTexture,
+                                           const SkMatrix& matrix, GrCoordSet coordSet = kLocal_GrCoordSet) {
+            return new Index8toRGBEffect(tex, colorMapTexture, matrix, coordSet);
+        }
+
+        const char* name() const override { return "Index8 to RGB"; }
+
+        class GLProcessor : public GrGLFragmentProcessor {
+        public:
+            // this class always generates the same code.
+            static void GenKey(const GrProcessor&, const GrGLSLCaps&, GrProcessorKeyBuilder*) {}
+
+            GLProcessor(const GrProcessor&) {}
+
+            virtual void emitCode(EmitArgs& args) override {
+                GrGLSLFragmentBuilder* fsBuilder = args.fBuilder->getFragmentShaderBuilder();
+                // float a = texture2D(sampler, texC).a;
+                // gl_FragColor = texture2D(paletteSampler, vec2(a, .5));
+                fsBuilder->codeAppend("\tfloat a = ");
+                fsBuilder->appendTextureLookup(args.fSamplers[0], args.fCoords[0].c_str());
+                fsBuilder->codeAppend(".a;\n");
+
+                fsBuilder->codeAppendf("\t%s = ", args.fOutputColor);
+                fsBuilder->appendTextureLookup(args.fSamplers[1], "vec2(a, .5)");
+                fsBuilder->codeAppend(";\n");
+            }
+
+        private:
+            typedef GrGLFragmentProcessor INHERITED;
+        };
+
+    private:
+        Index8toRGBEffect(GrTexture* tex, GrTexture* colorMapTexture,
+                          const SkMatrix& matrix, GrCoordSet coordSet)
+            : GrSingleTextureEffect(tex, matrix, GrTextureParams::kNone_FilterMode, coordSet)
+            , fColorMapTextureAccess(colorMapTexture) {
+            this->initClassID<Index8toRGBEffect>();
+            this->addTextureAccess(&fColorMapTextureAccess);
+        }
+
+        GrGLFragmentProcessor* onCreateGLInstance() const override { return new GLProcessor(*this); }
+
+        virtual void onGetGLProcessorKey(const GrGLSLCaps& caps,
+            GrProcessorKeyBuilder* b) const override {
+            GLProcessor::GenKey(*this, caps, b);
+        }
+
+        void onComputeInvariantOutput(GrInvariantOutput* inout) const override {
+            updateInvariantOutputForModulation(inout);
+        }
+
+        bool onIsEqual(const GrFragmentProcessor& other) const override { return true; }
+
+        GrTextureAccess  fColorMapTextureAccess;
+
+        typedef GrFragmentProcessor INHERITED;
+    };
+}
+//////////////////////////////////////////////////////////////////////////////
+
+GrFragmentProcessor* GrIndex8toRGBEffect::Create(GrTexture* tex, GrTexture* colorMapTexture,
+                                                 const SkMatrix& matrix, GrCoordSet coordSet) {
+    SkASSERT(tex && colorMapTexture);
+    return Index8toRGBEffect::Create(tex, colorMapTexture, matrix, coordSet);
+}