зеркало из https://github.com/mozilla/gecko-dev.git
86 строки
2.9 KiB
C++
86 строки
2.9 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
|
|
/* 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_BASECOORD_H_
|
|
#define MOZILLA_GFX_BASECOORD_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 BaseCoord {
|
|
T value;
|
|
|
|
// Constructors
|
|
constexpr BaseCoord() : value(0) {}
|
|
explicit constexpr BaseCoord(T aValue) : value(aValue) {}
|
|
|
|
// Note that '=' isn't defined so we'll get the
|
|
// compiler generated default assignment operator
|
|
|
|
operator T() const { return value; }
|
|
|
|
friend bool operator==(Sub aA, Sub aB) { return aA.value == aB.value; }
|
|
friend bool operator!=(Sub aA, Sub aB) { return aA.value != aB.value; }
|
|
|
|
friend Sub operator+(Sub aA, Sub aB) { return Sub(aA.value + aB.value); }
|
|
friend Sub operator-(Sub aA, Sub aB) { return Sub(aA.value - aB.value); }
|
|
friend Sub operator*(Sub aCoord, T aScale) {
|
|
return Sub(aCoord.value * aScale);
|
|
}
|
|
friend Sub operator*(T aScale, Sub aCoord) {
|
|
return Sub(aScale * aCoord.value);
|
|
}
|
|
friend Sub operator/(Sub aCoord, T aScale) {
|
|
return Sub(aCoord.value / aScale);
|
|
}
|
|
// 'scale / coord' is intentionally omitted because it doesn't make sense.
|
|
|
|
Sub& operator+=(Sub aCoord) {
|
|
value += aCoord.value;
|
|
return *static_cast<Sub*>(this);
|
|
}
|
|
Sub& operator-=(Sub aCoord) {
|
|
value -= aCoord.value;
|
|
return *static_cast<Sub*>(this);
|
|
}
|
|
Sub& operator*=(T aScale) {
|
|
value *= aScale;
|
|
return *static_cast<Sub*>(this);
|
|
}
|
|
Sub& operator/=(T aScale) {
|
|
value /= aScale;
|
|
return *static_cast<Sub*>(this);
|
|
}
|
|
|
|
// Since BaseCoord is implicitly convertible to its value type T, we need
|
|
// mixed-type operator overloads to avoid ambiguities at mixed-type call
|
|
// sites. As we transition more of our code to strongly-typed classes, we
|
|
// may be able to remove some or all of these overloads.
|
|
friend bool operator==(Sub aA, T aB) { return aA.value == aB; }
|
|
friend bool operator==(T aA, Sub aB) { return aA == aB.value; }
|
|
friend bool operator!=(Sub aA, T aB) { return aA.value != aB; }
|
|
friend bool operator!=(T aA, Sub aB) { return aA != aB.value; }
|
|
friend T operator+(Sub aA, T aB) { return aA.value + aB; }
|
|
friend T operator+(T aA, Sub aB) { return aA + aB.value; }
|
|
friend T operator-(Sub aA, T aB) { return aA.value - aB; }
|
|
friend T operator-(T aA, Sub aB) { return aA - aB.value; }
|
|
|
|
Sub operator-() const { return Sub(-value); }
|
|
};
|
|
|
|
} // namespace gfx
|
|
} // namespace mozilla
|
|
|
|
#endif /* MOZILLA_GFX_BASECOORD_H_ */
|