gfx/2d/Scale.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "Scale.h"
   8
   9 #include "HelpersSkia.h"
  10 #include "skia/src/core/SkBitmapScaler.h"
  11
  12 namespace mozilla {
  13 namespace gfx {
  14
  15 bool Scale(uint8_t* srcData, int32_t srcWidth, int32_t srcHeight,
  16            int32_t srcStride, uint8_t* dstData, int32_t dstWidth,
  17            int32_t dstHeight, int32_t dstStride, SurfaceFormat format) {
  18   SkPixmap srcPixmap(MakeSkiaImageInfo(IntSize(srcWidth, srcHeight), format),
  19                      srcData, srcStride);
  20
  21   // Rescaler is compatible with N32 only. Convert to N32 if needed.
  22   SkBitmap tmpBitmap;
  23   if (srcPixmap.colorType() != kN32_SkColorType) {
  24     if (!tmpBitmap.tryAllocPixels(
  25             SkImageInfo::MakeN32Premul(srcWidth, srcHeight)) ||
  26         !tmpBitmap.writePixels(srcPixmap) ||
  27         !tmpBitmap.peekPixels(&srcPixmap)) {
  28       return false;
  29     }
  30   }
  31
  32   SkPixmap dstPixmap(SkImageInfo::MakeN32Premul(dstWidth, dstHeight), dstData,
  33                      dstStride);
  34   return SkBitmapScaler::Resize(dstPixmap, srcPixmap,
  35                                 SkBitmapScaler::RESIZE_LANCZOS3);
  36 }
  37
  38 }  // namespace gfx
  39 }  // namespace mozilla