submodule/skia/src/gpu/Swizzle.cpp

   1 /*
   2  * Copyright 2019 Google LLC
   3  *
   4  * Use of this source code is governed by a BSD-style license that can be
   5  * found in the LICENSE file.
   6  */
   7
   8 #include "src/gpu/Swizzle.h"
   9
  10 #include "src/core/SkRasterPipeline.h"
  11
  12 namespace skgpu {
  13
  14 void Swizzle::apply(SkRasterPipeline* pipeline) const {
  15     SkASSERT(pipeline);
  16     switch (fKey) {
  17         case Swizzle("rgba").asKey():
  18             return;
  19         case Swizzle("bgra").asKey():
  20             pipeline->append(SkRasterPipeline::swap_rb);
  21             return;
  22         case Swizzle("aaa1").asKey():
  23             pipeline->append(SkRasterPipeline::alpha_to_gray);
  24             return;
  25         case Swizzle("rgb1").asKey():
  26             pipeline->append(SkRasterPipeline::force_opaque);
  27             return;
  28         case Swizzle("a001").asKey():
  29             pipeline->append(SkRasterPipeline::alpha_to_red);
  30             return;
  31         default: {
  32             static_assert(sizeof(uintptr_t) >= 4 * sizeof(char));
  33             // Rather than allocate the 4 control bytes on the heap somewhere, just jam them right
  34             // into a uintptr_t context.
  35             uintptr_t ctx;
  36             memcpy(&ctx, this->asString().c_str(), 4 * sizeof(char));
  37             pipeline->append(SkRasterPipeline::swizzle, ctx);
  38             return;
  39         }
  40     }
  41 }
  42
  43 SkString Swizzle::asString() const {
  44     char swiz[5];
  45     uint16_t key = fKey;
  46     for (int i = 0; i < 4; ++i) {
  47         swiz[i] = IToC(key & 0xfU);
  48         key >>= 4;
  49     }
  50     swiz[4] = '\0';
  51     return SkString(swiz);
  52 }
  53
  54 } // namespace skgpu