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 {
  22   NO_PREMULTIPLY_ALPHA     = 1 << 0,
  23   NO_COLORSPACE_CONVERSION = 1 << 1
  24 };
  25 MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(SurfaceFlags)
  26
  27 /**
  28  * @return the default set of surface flags.
  29  */
  30 inline SurfaceFlags
  31 DefaultSurfaceFlags()
  32 {
  33   return SurfaceFlags();
  34 }
  35
  36 /**
  37  * Given a set of imgIContainer FLAG_* flags, returns a set of SurfaceFlags with
  38  * the corresponding flags set.
  39  */
  40 inline SurfaceFlags
  41 ToSurfaceFlags(uint32_t aFlags)
  42 {
  43   SurfaceFlags flags = DefaultSurfaceFlags();
  44   if (aFlags & imgIContainer::FLAG_DECODE_NO_PREMULTIPLY_ALPHA) {
  45     flags |= SurfaceFlags::NO_PREMULTIPLY_ALPHA;
  46   }
  47   if (aFlags & imgIContainer::FLAG_DECODE_NO_COLORSPACE_CONVERSION) {
  48     flags |= SurfaceFlags::NO_COLORSPACE_CONVERSION;
  49   }
  50   return flags;
  51 }
  52
  53 /**
  54  * Given a set of SurfaceFlags, returns a set of imgIContainer FLAG_* flags with
  55  * the corresponding flags set.
  56  */
  57 inline uint32_t
  58 FromSurfaceFlags(SurfaceFlags aFlags)
  59 {
  60   uint32_t flags = imgIContainer::DECODE_FLAGS_DEFAULT;
  61   if (aFlags & SurfaceFlags::NO_PREMULTIPLY_ALPHA) {
  62     flags |= imgIContainer::FLAG_DECODE_NO_PREMULTIPLY_ALPHA;
  63   }
  64   if (aFlags & SurfaceFlags::NO_COLORSPACE_CONVERSION) {
  65     flags |= imgIContainer::FLAG_DECODE_NO_COLORSPACE_CONVERSION;
  66   }
  67   return flags;
  68 }
  69
  70 } // namespace image
  71 } // namespace mozilla
  72
  73 #endif // mozilla_image_SurfaceFlags_h