gfx/2d/Scale.cpp

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #include "Scale.h"
   6
   7 #ifdef USE_SKIA
   8 #include "HelpersSkia.h"
   9 #include "skia/SkBitmap.h"
  10 #include "image_operations.h"
  11 #endif
  12
  13 namespace mozilla {
  14 namespace gfx {
  15
  16 bool Scale(uint8_t* srcData, int32_t srcWidth, int32_t srcHeight, int32_t srcStride,
  17            uint8_t* dstData, int32_t dstWidth, int32_t dstHeight, int32_t dstStride,
  18            SurfaceFormat format)
  19 {
  20 #ifdef USE_SKIA
  21   SkAlphaType alphaType;
  22   if (format == SurfaceFormat::B8G8R8A8) {
  23     alphaType = kPremul_SkAlphaType;
  24   } else {
  25     alphaType = kOpaque_SkAlphaType;
  26   }
  27
  28   SkImageInfo info = SkImageInfo::Make(srcWidth,
  29                                        srcHeight,
  30                                        GfxFormatToSkiaColorType(format),
  31                                        alphaType);
  32
  33   SkBitmap imgSrc;
  34   imgSrc.installPixels(info, srcData, srcStride);
  35
  36   // Rescaler is compatible with 32 bpp only. Convert to RGB32 if needed.
  37   if (format != SurfaceFormat::B8G8R8A8) {
  38     imgSrc.copyTo(&imgSrc, kBGRA_8888_SkColorType);
  39   }
  40
  41   // This returns an SkBitmap backed by dstData; since it also wrote to dstData,
  42   // we don't need to look at that SkBitmap.
  43   SkBitmap result = skia::ImageOperations::Resize(imgSrc,
  44                                                   skia::ImageOperations::RESIZE_BEST,
  45                                                   dstWidth, dstHeight,
  46                                                   dstData);
  47
  48   return !result.isNull();
  49 #else
  50   return false;
  51 #endif
  52 }
  53
  54 }
  55 }