image/SurfaceFlags.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef mozilla_image_SurfaceFlags_h
   7 #define mozilla_image_SurfaceFlags_h
   8
   9 #include "imgIContainer.h"
  10 #include "mozilla/TypedEnumBits.h"
  11
  12 namespace mozilla {
  13 namespace image {
  14
  15 /**
  16  * Flags that change the output a decoder generates. Because different
  17  * combinations of these flags result in logically different surfaces, these
  18  * flags must be taken into account in SurfaceCache lookups.
  19  */
  20 enum class SurfaceFlags : uint8_t {
  21   NO_PREMULTIPLY_ALPHA = 1 << 0,
  22   NO_COLORSPACE_CONVERSION = 1 << 1
  23 };
  24 MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(SurfaceFlags)
  25
  26 /**
  27  * @return the default set of surface flags.
  28  */
  29 inline SurfaceFlags DefaultSurfaceFlags() { return SurfaceFlags(); }
  30
  31 /**
  32  * Given a set of imgIContainer FLAG_* flags, returns a set of SurfaceFlags with
  33  * the corresponding flags set.
  34  */
  35 inline SurfaceFlags ToSurfaceFlags(uint32_t aFlags) {
  36   SurfaceFlags flags = DefaultSurfaceFlags();
  37   if (aFlags & imgIContainer::FLAG_DECODE_NO_PREMULTIPLY_ALPHA) {
  38     flags |= SurfaceFlags::NO_PREMULTIPLY_ALPHA;
  39   }
  40   if (aFlags & imgIContainer::FLAG_DECODE_NO_COLORSPACE_CONVERSION) {
  41     flags |= SurfaceFlags::NO_COLORSPACE_CONVERSION;
  42   }
  43   return flags;
  44 }
  45
  46 /**
  47  * Given a set of SurfaceFlags, returns a set of imgIContainer FLAG_* flags with
  48  * the corresponding flags set.
  49  */
  50 inline uint32_t FromSurfaceFlags(SurfaceFlags aFlags) {
  51   uint32_t flags = imgIContainer::DECODE_FLAGS_DEFAULT;
  52   if (aFlags & SurfaceFlags::NO_PREMULTIPLY_ALPHA) {
  53     flags |= imgIContainer::FLAG_DECODE_NO_PREMULTIPLY_ALPHA;
  54   }
  55   if (aFlags & SurfaceFlags::NO_COLORSPACE_CONVERSION) {
  56     flags |= imgIContainer::FLAG_DECODE_NO_COLORSPACE_CONVERSION;
  57   }
  58   return flags;
  59 }
  60
  61 }  // namespace image
  62 }  // namespace mozilla
  63
  64 #endif  // mozilla_image_SurfaceFlags_h