gecko-dev/image/Orientation.h

73 lines
2.0 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_image_Orientation_h
#define mozilla_image_Orientation_h
#include <stdint.h>
namespace mozilla {
namespace image {
enum class Angle : uint8_t { D0, D90, D180, D270 };
enum class Flip : uint8_t { Unflipped, Horizontal };
/**
* A struct that describes an image's orientation as a rotation optionally
* followed by a reflection. This may be used to be indicate an image's inherent
* orientation or a desired orientation for the image.
*
* When flipFirst = true, this indicates that the reflection is applied before
* the rotation. (This is used by OrientedImage to represent the inverse of an
* underlying image's Orientation.)
*/
struct Orientation {
explicit Orientation(Angle aRotation = Angle::D0,
Flip aFlip = Flip::Unflipped, bool aFlipFirst = false)
: rotation(aRotation), flip(aFlip), flipFirst(aFlipFirst) {}
Orientation Reversed() const {
return Orientation(InvertAngle(rotation), flip, !flipFirst);
}
bool IsIdentity() const {
return (rotation == Angle::D0) && (flip == Flip::Unflipped);
}
bool SwapsWidthAndHeight() const {
return (rotation == Angle::D90) || (rotation == Angle::D270);
}
bool operator==(const Orientation& aOther) const {
return rotation == aOther.rotation && flip == aOther.flip &&
flipFirst == aOther.flipFirst;
}
bool operator!=(const Orientation& aOther) const {
return !(*this == aOther);
}
static Angle InvertAngle(Angle aAngle) {
switch (aAngle) {
case Angle::D90:
return Angle::D270;
case Angle::D270:
return Angle::D90;
default:
return aAngle;
}
}
Angle rotation;
Flip flip;
bool flipFirst;
};
} // namespace image
} // namespace mozilla
#endif // mozilla_image_Orientation_h