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   TO_SRGB_COLORSPACE = 2 << 1,
  24 };
  25 MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(SurfaceFlags)
  26
  27 /**
  28  * @return the default set of surface flags.
  29  */
  30 inline SurfaceFlags DefaultSurfaceFlags() { return SurfaceFlags(); }
  31
  32 /**
  33  * Given a set of imgIContainer FLAG_* flags, returns a set of SurfaceFlags with
  34  * the corresponding flags set.
  35  */
  36 inline SurfaceFlags ToSurfaceFlags(uint32_t aFlags) {
  37   SurfaceFlags flags = DefaultSurfaceFlags();
  38   if (aFlags & imgIContainer::FLAG_DECODE_NO_PREMULTIPLY_ALPHA) {
  39     flags |= SurfaceFlags::NO_PREMULTIPLY_ALPHA;
  40   }
  41   if (aFlags & imgIContainer::FLAG_DECODE_NO_COLORSPACE_CONVERSION) {
  42     flags |= SurfaceFlags::NO_COLORSPACE_CONVERSION;
  43   }
  44   if (aFlags & imgIContainer::FLAG_DECODE_TO_SRGB_COLORSPACE) {
  45     flags |= SurfaceFlags::TO_SRGB_COLORSPACE;
  46   }
  47   return flags;
  48 }
  49
  50 /**
  51  * Given a set of SurfaceFlags, returns a set of imgIContainer FLAG_* flags with
  52  * the corresponding flags set.
  53  */
  54 inline uint32_t FromSurfaceFlags(SurfaceFlags aFlags) {
  55   uint32_t flags = imgIContainer::DECODE_FLAGS_DEFAULT;
  56   if (aFlags & SurfaceFlags::NO_PREMULTIPLY_ALPHA) {
  57     flags |= imgIContainer::FLAG_DECODE_NO_PREMULTIPLY_ALPHA;
  58   }
  59   if (aFlags & SurfaceFlags::NO_COLORSPACE_CONVERSION) {
  60     flags |= imgIContainer::FLAG_DECODE_NO_COLORSPACE_CONVERSION;
  61   }
  62   if (aFlags & SurfaceFlags::TO_SRGB_COLORSPACE) {
  63     flags |= imgIContainer::FLAG_DECODE_TO_SRGB_COLORSPACE;
  64   }
  65   return flags;
  66 }
  67
  68 }  // namespace image
  69 }  // namespace mozilla
  70
  71 #endif  // mozilla_image_SurfaceFlags_h