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/* -*- 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_SCALEFACTORS2D_H_
#define MOZILLA_GFX_SCALEFACTORS2D_H_
#include <ostream>
#include "mozilla/Attributes.h"
#include "mozilla/FloatingPoint.h"
#include "mozilla/gfx/ScaleFactor.h"
#include "gfxPoint.h"
namespace mozilla {
namespace gfx {
/*
* This class is like ScaleFactor, but allows different scales on the x and
* y axes.
*/
template <class src, class dst>
struct ScaleFactors2D {
float xScale;
float yScale;
constexpr ScaleFactors2D() : xScale(1.0), yScale(1.0) {}
constexpr ScaleFactors2D(const ScaleFactors2D<src, dst>& aCopy)
: xScale(aCopy.xScale), yScale(aCopy.yScale) {}
constexpr ScaleFactors2D(float aXScale, float aYScale)
: xScale(aXScale), yScale(aYScale) {}
// Layout code often uses gfxSize to represent a pair of x/y scales.
explicit constexpr ScaleFactors2D(const gfxSize& aSize)
: xScale(aSize.width), yScale(aSize.height) {}
// "Upgrade" from a ScaleFactor.
// This is deliberately 'explicit' so that the treatment of a single scale
// number as both the x- and y-scale in a context where they are allowed to
// be different, is more visible.
explicit constexpr ScaleFactors2D(const ScaleFactor<src, dst>& aScale)
: xScale(aScale.scale), yScale(aScale.scale) {}
bool AreScalesSame() const {
return FuzzyEqualsMultiplicative(xScale, yScale);
}
// Convert to a ScaleFactor. Asserts that the scales are, in fact, equal.
ScaleFactor<src, dst> ToScaleFactor() const {
MOZ_ASSERT(AreScalesSame());
return ScaleFactor<src, dst>(xScale);
}
ScaleFactors2D<src, dst>& operator=(const ScaleFactors2D<src, dst>&) =
default;
bool operator==(const ScaleFactors2D<src, dst>& aOther) const {
return xScale == aOther.xScale && yScale == aOther.yScale;
}
bool operator!=(const ScaleFactors2D<src, dst>& aOther) const {
return !(*this == aOther);
}
friend std::ostream& operator<<(std::ostream& aStream,
const ScaleFactors2D<src, dst>& aScale) {
if (aScale.AreScalesSame()) {
return aStream << aScale.xScale;
} else {
return aStream << '(' << aScale.xScale << ',' << aScale.yScale << ')';
}
}
template <class other>
ScaleFactors2D<other, dst> operator/(
const ScaleFactors2D<src, other>& aOther) const {
return ScaleFactors2D<other, dst>(xScale / aOther.xScale,
yScale / aOther.yScale);
}
template <class other>
ScaleFactors2D<src, other> operator/(
const ScaleFactors2D<other, dst>& aOther) const {
return ScaleFactors2D<src, other>(xScale / aOther.xScale,
yScale / aOther.yScale);
}
template <class other>
ScaleFactors2D<src, other> operator*(
const ScaleFactors2D<dst, other>& aOther) const {
return ScaleFactors2D<src, other>(xScale * aOther.xScale,
yScale * aOther.yScale);
}
template <class other>
ScaleFactors2D<other, dst> operator*(
const ScaleFactors2D<other, src>& aOther) const {
return ScaleFactors2D<other, dst>(xScale * aOther.xScale,
yScale * aOther.yScale);
}
template <class other>
ScaleFactors2D<src, other> operator*(
const ScaleFactor<dst, other>& aOther) const {
return *this * ScaleFactors2D<dst, other>(aOther);
}
template <class other>
ScaleFactors2D<other, dst> operator*(
const ScaleFactor<other, src>& aOther) const {
return *this * ScaleFactors2D<other, src>(aOther);
}
template <class other>
ScaleFactors2D<src, other> operator/(
const ScaleFactor<other, dst>& aOther) const {
return *this / ScaleFactors2D<other, dst>(aOther);
}
template <class other>
ScaleFactors2D<other, dst> operator/(
const ScaleFactor<src, other>& aOther) const {
return *this / ScaleFactors2D<src, other>(aOther);
}
template <class other>
friend ScaleFactors2D<other, dst> operator*(
const ScaleFactor<other, src>& aA, const ScaleFactors2D<src, dst>& aB) {
return ScaleFactors2D<other, src>(aA) * aB;
}
template <class other>
friend ScaleFactors2D<other, src> operator/(
const ScaleFactor<other, dst>& aA, const ScaleFactors2D<src, dst>& aB) {
return ScaleFactors2D<other, src>(aA) / aB;
}
// Divide two scales of the same units, yielding a scale with no units,
// represented as a gfxSize. This can mean e.g. the change in a particular
// scale from one frame to the next.
gfxSize operator/(const ScaleFactors2D& aOther) const {
return gfxSize(xScale / aOther.xScale, yScale / aOther.yScale);
}
};
} // namespace gfx
} // namespace mozilla
#endif /* MOZILLA_GFX_SCALEFACTORS2D_H_ */