gecko-dev/image/Resolution.h

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1.9 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_Resolution_h
#define mozilla_image_Resolution_h
#include "mozilla/Assertions.h"
#include <cmath>
namespace mozilla {
namespace image {
/**
* The resolution of an image, in dppx.
*/
struct Resolution {
Resolution() = default;
Resolution(float aX, float aY) : mX(aX), mY(aY) {
MOZ_ASSERT(mX != 0.0f);
MOZ_ASSERT(mY != 0.0f);
}
bool operator==(const Resolution& aOther) const {
return mX == aOther.mX && mY == aOther.mY;
}
bool operator!=(const Resolution& aOther) const { return !(*this == aOther); }
float mX = 1.0f;
float mY = 1.0f;
void ScaleBy(float aScale) {
if (MOZ_LIKELY(aScale != 0.0f)) {
mX *= aScale;
mY *= aScale;
}
}
void ApplyXTo(int32_t& aWidth) const {
if (mX != 1.0f) {
aWidth = std::round(float(aWidth) / mX);
}
}
void ApplyXTo(float& aWidth) const {
if (mX != 1.0f) {
aWidth /= mX;
}
}
void ApplyYTo(int32_t& aHeight) const {
if (mY != 1.0f) {
aHeight = std::round(float(aHeight) / mY);
}
}
void ApplyYTo(float& aHeight) const {
if (mY != 1.0f) {
aHeight /= mY;
}
}
void ApplyTo(int32_t& aWidth, int32_t& aHeight) const {
ApplyXTo(aWidth);
ApplyYTo(aHeight);
}
void ApplyTo(float& aWidth, float& aHeight) const {
ApplyXTo(aWidth);
ApplyYTo(aHeight);
}
void ApplyInverseTo(int32_t& aWidth, int32_t& aHeight) {
if (mX != 1.0f) {
aWidth = std::round(float(aWidth) * mX);
}
if (mY != 1.0f) {
aHeight = std::round(float(aHeight) * mY);
}
}
};
} // namespace image
using ImageResolution = image::Resolution;
} // namespace mozilla
#endif