diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/include/gpu/GrTextureAccess.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/include/gpu/GrTextureAccess.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,188 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrTextureAccess_DEFINED
+#define GrTextureAccess_DEFINED
+
+#include "SkRefCnt.h"
+#include "SkShader.h"
+#include "SkTypes.h"
+
+class GrTexture;
+
+/**
+ * Represents the filtering and tile modes used to access a texture. It is mostly used with
+ * GrTextureAccess (defined below). Also, some of the texture cache methods require knowledge about
+ * filtering and tiling to perform a cache lookup. If it wasn't for this latter usage this would
+ * be folded into GrTextureAccess. The default is clamp tile modes and no filtering.
+ */
+class GrTextureParams {
+public:
+    GrTextureParams() {
+        this->reset();
+    }
+
+    enum FilterMode {
+        kNone_FilterMode,
+        kBilerp_FilterMode,
+        kMipMap_FilterMode
+    };
+
+    GrTextureParams(SkShader::TileMode tileXAndY, FilterMode filterMode) {
+        this->reset(tileXAndY, filterMode);
+    }
+
+    GrTextureParams(const SkShader::TileMode tileModes[2], FilterMode filterMode) {
+        this->reset(tileModes, filterMode);
+    }
+
+    GrTextureParams(const GrTextureParams& params) {
+        *this = params;
+    }
+
+    GrTextureParams& operator= (const GrTextureParams& params) {
+        fTileModes[0] = params.fTileModes[0];
+        fTileModes[1] = params.fTileModes[1];
+        fFilterMode = params.fFilterMode;
+        return *this;
+    }
+
+    void reset() {
+        this->reset(SkShader::kClamp_TileMode, kNone_FilterMode);
+    }
+
+    void reset(SkShader::TileMode tileXAndY, FilterMode filterMode) {
+        fTileModes[0] = fTileModes[1] = tileXAndY;
+        fFilterMode = filterMode;
+    }
+
+    void reset(const SkShader::TileMode tileModes[2], FilterMode filterMode) {
+        fTileModes[0] = tileModes[0];
+        fTileModes[1] = tileModes[1];
+        fFilterMode = filterMode;
+    }
+
+    void setClampNoFilter() {
+        fTileModes[0] = fTileModes[1] = SkShader::kClamp_TileMode;
+        fFilterMode = kNone_FilterMode;
+    }
+
+    void setClamp() {
+        fTileModes[0] = fTileModes[1] = SkShader::kClamp_TileMode;
+    }
+
+    void setFilterMode(FilterMode filterMode) { fFilterMode = filterMode; }
+
+    void setTileModeX(const SkShader::TileMode tm) { fTileModes[0] = tm; }
+    void setTileModeY(const SkShader::TileMode tm) { fTileModes[1] = tm; }
+    void setTileModeXAndY(const SkShader::TileMode tm) { fTileModes[0] = fTileModes[1] = tm; }
+
+    SkShader::TileMode getTileModeX() const { return fTileModes[0]; }
+
+    SkShader::TileMode getTileModeY() const { return fTileModes[1]; }
+
+    bool isTiled() const {
+        return SkShader::kClamp_TileMode != fTileModes[0] ||
+               SkShader::kClamp_TileMode != fTileModes[1];
+    }
+
+    FilterMode filterMode() const { return fFilterMode; }
+
+    bool operator== (const GrTextureParams& other) const {
+        return fTileModes[0] == other.fTileModes[0] &&
+               fTileModes[1] == other.fTileModes[1] &&
+               fFilterMode == other.fFilterMode;
+    }
+
+    bool operator!= (const GrTextureParams& other) const { return !(*this == other); }
+
+private:
+
+    SkShader::TileMode fTileModes[2];
+    FilterMode         fFilterMode;
+};
+
+/** A class representing the swizzle access pattern for a texture. Note that if the texture is
+ *  an alpha-only texture then the alpha channel is substituted for other components. Any mangling
+ *  to handle the r,g,b->a conversions for alpha textures is automatically included in the stage
+ *  key. However, if a GrEffect uses different swizzles based on its input then it must
+ *  consider that variation in its key-generation.
+ */
+class GrTextureAccess : public SkNoncopyable {
+public:
+    /**
+     * A default GrTextureAccess must have reset() called on it in a GrEffect subclass's
+     * constructor if it will be accessible via GrEffect::textureAccess().
+     */
+    GrTextureAccess();
+
+    /**
+     * Uses the default swizzle, "rgba".
+     */
+    GrTextureAccess(GrTexture*, const GrTextureParams&);
+    explicit GrTextureAccess(GrTexture*,
+                             GrTextureParams::FilterMode = GrTextureParams::kNone_FilterMode,
+                             SkShader::TileMode tileXAndY = SkShader::kClamp_TileMode);
+
+    /**
+     * swizzle must be a string between one and four (inclusive) characters containing only 'r',
+     * 'g', 'b',  and/or 'a'.
+     */
+    GrTextureAccess(GrTexture*, const char* swizzle, const GrTextureParams&);
+    GrTextureAccess(GrTexture*,
+                    const char* swizzle,
+                    GrTextureParams::FilterMode = GrTextureParams::kNone_FilterMode,
+                    SkShader::TileMode tileXAndY = SkShader::kClamp_TileMode);
+
+    void reset(GrTexture*, const GrTextureParams&);
+    void reset(GrTexture*,
+               GrTextureParams::FilterMode = GrTextureParams::kNone_FilterMode,
+               SkShader::TileMode tileXAndY = SkShader::kClamp_TileMode);
+    void reset(GrTexture*, const char* swizzle, const GrTextureParams&);
+    void reset(GrTexture*,
+               const char* swizzle,
+               GrTextureParams::FilterMode = GrTextureParams::kNone_FilterMode,
+               SkShader::TileMode tileXAndY = SkShader::kClamp_TileMode);
+
+    bool operator== (const GrTextureAccess& other) const {
+#ifdef SK_DEBUG
+        // below assumes all chars in fSwizzle are initialized even if string is < 4 chars long.
+        SkASSERT(memcmp(fSwizzle, other.fSwizzle, sizeof(fSwizzle)-1) ==
+                 strcmp(fSwizzle, other.fSwizzle));
+#endif
+        return fParams == other.fParams &&
+               (fTexture.get() == other.fTexture.get()) &&
+               (0 == memcmp(fSwizzle, other.fSwizzle, sizeof(fSwizzle)-1));
+    }
+
+    bool operator!= (const GrTextureAccess& other) const { return !(*this == other); }
+
+    GrTexture* getTexture() const { return fTexture.get(); }
+
+    /**
+     * Returns a string representing the swizzle. The string is is null-terminated.
+     */
+    const char* getSwizzle() const { return fSwizzle; }
+
+    /** Returns a mask indicating which components are referenced in the swizzle. The return
+        is a bitfield of GrColorComponentFlags. */
+    uint32_t swizzleMask() const { return fSwizzleMask; }
+
+    const GrTextureParams& getParams() const { return fParams; }
+
+private:
+    void setSwizzle(const char*);
+
+    GrTextureParams         fParams;
+    SkAutoTUnref<GrTexture> fTexture;
+    uint32_t                fSwizzleMask;
+    char                    fSwizzle[5];
+
+    typedef SkNoncopyable INHERITED;
+};
+
+#endif