gecko-dev/gfx/2d/BaseSize.h

101 lines
2.7 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_GFX_BASESIZE_H_
#define MOZILLA_GFX_BASESIZE_H_
#include "mozilla/Attributes.h"
namespace mozilla {
namespace gfx {
/**
* Do not use this class directly. Subclass it, pass that subclass as the
* Sub parameter, and only use that subclass. This allows methods to safely
* cast 'this' to 'Sub*'.
*/
template <class T, class Sub>
struct BaseSize {
union {
struct {
T width, height;
};
T components[2];
};
// Constructors
constexpr BaseSize() : width(0), height(0) {}
constexpr BaseSize(T aWidth, T aHeight) : width(aWidth), height(aHeight) {}
void SizeTo(T aWidth, T aHeight) { width = aWidth; height = aHeight; }
bool IsEmpty() const {
return width <= 0 || height <= 0;
}
bool IsSquare() const {
return width == height;
}
// Note that '=' isn't defined so we'll get the
// compiler generated default assignment operator
bool operator==(const Sub& aSize) const {
return width == aSize.width && height == aSize.height;
}
bool operator!=(const Sub& aSize) const {
return width != aSize.width || height != aSize.height;
}
bool operator<=(const Sub& aSize) const {
return width <= aSize.width && height <= aSize.height;
}
bool operator<(const Sub& aSize) const {
return *this <= aSize && *this != aSize;
}
Sub operator+(const Sub& aSize) const {
return Sub(width + aSize.width, height + aSize.height);
}
Sub operator-(const Sub& aSize) const {
return Sub(width - aSize.width, height - aSize.height);
}
Sub& operator+=(const Sub& aSize) {
width += aSize.width;
height += aSize.height;
return *static_cast<Sub*>(this);
}
Sub& operator-=(const Sub& aSize) {
width -= aSize.width;
height -= aSize.height;
return *static_cast<Sub*>(this);
}
Sub operator*(T aScale) const {
return Sub(width * aScale, height * aScale);
}
Sub operator/(T aScale) const {
return Sub(width / aScale, height / aScale);
}
friend Sub operator*(T aScale, const Sub& aSize) {
return Sub(aScale * aSize.width, aScale * aSize.height);
}
void Scale(T aXScale, T aYScale) {
width *= aXScale;
height *= aYScale;
}
Sub operator*(const Sub& aSize) const {
return Sub(width * aSize.width, height * aSize.height);
}
Sub operator/(const Sub& aSize) const {
return Sub(width / aSize.width, height / aSize.height);
}
};
} // namespace gfx
} // namespace mozilla
#endif /* MOZILLA_GFX_BASESIZE_H_ */