Revert of Add a class representing texture swizzle.

src/gpu/GrSwizzle.h

-/*
- * Copyright 2016 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef GrSwizzle_DEFINED
-#define GrSwizzle_DEFINED
-
-#include "GrTypes.h"
-
-/** Represents a rgba swizzle. It can be converted either into a string or a eight bit int.
-    Currently there is no way to specify an arbitrary swizzle, just some static swizzles and an
-    assignment operator. That could be relaxed. */
-class GrSwizzle {
-public:
-    GrSwizzle() { *this = RGBA(); }
-
-    GrSwizzle& operator=(const GrSwizzle& that) {
-        memcpy(this, &that, sizeof(GrSwizzle));
-        return *this;
-    }
-
-    bool operator==(const GrSwizzle& that) const { return this->asUInt() == that.asUInt(); }
-
-    bool operator!=(const GrSwizzle& that) const { return !(*this == that); }
-
-    /** Compact representation of the swizzle suitable for a key. */
-    uint8_t asKey() const { return fKey; }
-
-    /** 4 char null terminated string consisting only of chars 'r', 'g', 'b', 'a'. */
-    const char* c_str() const { return fSwiz; }
-
-    static const GrSwizzle& RGBA() {
-        static GrSwizzle gRGBA("rgba");
-        return gRGBA;
-    }
-
-    static const GrSwizzle& AAAA() {
-        static GrSwizzle gAAAA("aaaa");
-        return gAAAA;
-    }
-
-    static const GrSwizzle& RRRR() {
-        static GrSwizzle gRRRR("rrrr");
-        return gRRRR;
-    }
-
-    static const GrSwizzle& BGRA() {
-        static GrSwizzle gBGRA("bgra");
-        return gBGRA;
-    }
-
-private:
-    char fSwiz[5];
-    uint8_t fKey;
-
-    static int CharToIdx(char c) {
-        switch (c) {
-            case 'r':
-                return 0;
-            case 'g':
-                return 1;
-            case 'b':
-                return 2;
-            case 'a':
-                return 3;
-            default:
-                SkFAIL("Invalid swizzle char");
-                return 0;
-        }
-    }
-
-    explicit GrSwizzle(const char* str) {
-        SkASSERT(strlen(str) == 4);
-        fSwiz[0] = str[0];
-        fSwiz[1] = str[1];
-        fSwiz[2] = str[2];
-        fSwiz[3] = str[3];
-        fSwiz[4] = 0;
-        fKey = SkToU8(CharToIdx(fSwiz[0]) | (CharToIdx(fSwiz[1]) << 2) |
-                      (CharToIdx(fSwiz[2]) << 4) | (CharToIdx(fSwiz[3]) << 6));
-    }
-
-    uint32_t* asUIntPtr() { return SkTCast<uint32_t*>(fSwiz); }
-    uint32_t asUInt() const { return *SkTCast<const uint32_t*>(fSwiz); }
-
-    GR_STATIC_ASSERT(sizeof(char[4]) == sizeof(uint32_t));
-};
-
-#endif