image/Orientation.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_Orientation_h
   7 #define mozilla_image_Orientation_h
   8
   9 #include <stdint.h>
  10
  11 namespace mozilla {
  12 namespace image {
  13
  14 enum class Angle : uint8_t {
  15   D0,
  16   D90,
  17   D180,
  18   D270
  19 };
  20
  21 enum class Flip : uint8_t {
  22   Unflipped,
  23   Horizontal
  24 };
  25
  26 /**
  27  * A struct that describes an image's orientation as a rotation optionally
  28  * followed by a reflection. This may be used to be indicate an image's inherent
  29  * orientation or a desired orientation for the image.
  30  */
  31 struct Orientation
  32 {
  33   explicit Orientation(Angle aRotation = Angle::D0,
  34                        Flip mFlip = Flip::Unflipped)
  35     : rotation(aRotation)
  36     , flip(mFlip)
  37   { }
  38
  39   bool IsIdentity() const {
  40     return (rotation == Angle::D0) && (flip == Flip::Unflipped);
  41   }
  42
  43   bool SwapsWidthAndHeight() const {
  44     return (rotation == Angle::D90) || (rotation == Angle::D270);
  45   }
  46
  47   bool operator==(const Orientation& aOther) const {
  48     return (rotation == aOther.rotation) && (flip == aOther.flip);
  49   }
  50
  51   bool operator!=(const Orientation& aOther) const {
  52     return !(*this == aOther);
  53   }
  54
  55   Angle rotation;
  56   Flip  flip;
  57 };
  58
  59 } // namespace image
  60 } // namespace mozilla
  61
  62 #endif // mozilla_image_Orientation_h