Add a GrCustomCoordsTextureEffect class

src/gpu/effects/GrCustomCoordsTextureEffect.cpp

+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrCustomCoordsTextureEffect.h"
+#include "gl/GrGLEffect.h"
+#include "gl/GrGLEffectMatrix.h"
+#include "gl/GrGLSL.h"
+#include "gl/GrGLTexture.h"
+#include "GrTBackendEffectFactory.h"
+#include "GrTexture.h"
+
+class GrGLCustomCoordsTextureEffect : public GrGLEffect {
+public:
+    GrGLCustomCoordsTextureEffect(const GrBackendEffectFactory& factory, const GrDrawEffect& drawEffect)
+        : INHERITED (factory) {}
+
+    virtual void emitCode(GrGLShaderBuilder* builder,
+                          const GrDrawEffect& drawEffect,
+                          EffectKey key,
+                          const char* outputColor,
+                          const char* inputColor,
+                          const TextureSamplerArray& samplers) SK_OVERRIDE {
+        GrGLShaderBuilder::VertexBuilder* vertexBuilder = builder->getVertexBuilder();
+        SkASSERT(NULL != vertexBuilder);
+        SkASSERT(1 == drawEffect.castEffect<GrCustomCoordsTextureEffect>().numVertexAttribs());
+
+        SkString fsCoordName;
+        const char* vsVaryingName;
+        const char* fsVaryingNamePtr;
+        vertexBuilder->addVarying(kVec2f_GrSLType, "textureCoords", &vsVaryingName, &fsVaryingNamePtr);
+        fsCoordName = fsVaryingNamePtr;
+
+        const char* attrName =
+            vertexBuilder->getEffectAttributeName(drawEffect.getVertexAttribIndices()[0])->c_str();
+        vertexBuilder->vsCodeAppendf("\t%s = %s;\n", vsVaryingName, attrName);
+
+        builder->fsCodeAppendf("\t%s = ", outputColor);
+        builder->fsAppendTextureLookupAndModulate(inputColor,
+                                                  samplers[0],
+                                                  fsCoordName.c_str(),
+                                                  kVec2f_GrSLType);
+        builder->fsCodeAppend(";\n");
+    }
+
+    static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
+        return 1 << GrGLEffectMatrix::kKeyBits;
+    }
+
+    virtual void setData(const GrGLUniformManager& uman,
+                         const GrDrawEffect& drawEffect) SK_OVERRIDE {}
+
+private:
+    typedef GrGLEffect INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+GrCustomCoordsTextureEffect::GrCustomCoordsTextureEffect(GrTexture* texture,
+                                                         const GrTextureParams& params)
+    : fTextureAccess(texture, params) {
+    this->addTextureAccess(&fTextureAccess);
+    this->addVertexAttrib(kVec2f_GrSLType);
+}
+
+bool GrCustomCoordsTextureEffect::onIsEqual(const GrEffect& other) const {
+    const GrCustomCoordsTextureEffect& cte = CastEffect<GrCustomCoordsTextureEffect>(other);
+    return fTextureAccess == cte.fTextureAccess;
+}
+
+void GrCustomCoordsTextureEffect::getConstantColorComponents(GrColor* color,
+                                                             uint32_t* validFlags) const {
+    if ((*validFlags & kA_GrColorComponentFlag) && 0xFF == GrColorUnpackA(*color) &&
+        GrPixelConfigIsOpaque(this->texture(0)->config())) {
+        *validFlags = kA_GrColorComponentFlag;
+    } else {
+        *validFlags = 0;
+    }
+}
+
+const GrBackendEffectFactory& GrCustomCoordsTextureEffect::getFactory() const {
+    return GrTBackendEffectFactory<GrCustomCoordsTextureEffect>::getInstance();
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+GR_DEFINE_EFFECT_TEST(GrCustomCoordsTextureEffect);
+
+GrEffectRef* GrCustomCoordsTextureEffect::TestCreate(SkRandom* random,
+                                                     GrContext*,
+                                                     const GrDrawTargetCaps&,
+                                                     GrTexture* textures[]) {
+    int texIdx = random->nextBool() ? GrEffectUnitTest::kSkiaPMTextureIdx :
+                                      GrEffectUnitTest::kAlphaTextureIdx;
+    static const SkShader::TileMode kTileModes[] = {
+        SkShader::kClamp_TileMode,
+        SkShader::kRepeat_TileMode,
+        SkShader::kMirror_TileMode,
+    };
+    SkShader::TileMode tileModes[] = {
+        kTileModes[random->nextULessThan(SK_ARRAY_COUNT(kTileModes))],
+        kTileModes[random->nextULessThan(SK_ARRAY_COUNT(kTileModes))],
+    };
+    GrTextureParams params(tileModes, random->nextBool() ? GrTextureParams::kBilerp_FilterMode :
+                                                           GrTextureParams::kNone_FilterMode);
+
+    return GrCustomCoordsTextureEffect::Create(textures[texIdx], params);
+}