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/* -*- 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_BASEPOINT_H_
#define MOZILLA_GFX_BASEPOINT_H_
#include <cmath>
#include <ostream>
#include "mozilla/Attributes.h"
#include "mozilla/FloatingPoint.h"
#include "mozilla/TypeTraits.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, class Coord = T>
struct BasePoint {
union {
struct {
T x, y;
};
T components[2];
};
// Constructors
constexpr BasePoint() : x(0), y(0) {}
constexpr BasePoint(Coord aX, Coord aY) : x(aX), y(aY) {}
void MoveTo(T aX, T aY) { x = aX; y = aY; }
void MoveBy(T aDx, T aDy) { x += aDx; y += aDy; }
// Note that '=' isn't defined so we'll get the
// compiler generated default assignment operator
bool operator==(const Sub& aPoint) const {
return x == aPoint.x && y == aPoint.y;
}
bool operator!=(const Sub& aPoint) const {
return x != aPoint.x || y != aPoint.y;
}
Sub operator+(const Sub& aPoint) const {
return Sub(x + aPoint.x, y + aPoint.y);
}
Sub operator-(const Sub& aPoint) const {
return Sub(x - aPoint.x, y - aPoint.y);
}
Sub& operator+=(const Sub& aPoint) {
x += aPoint.x;
y += aPoint.y;
return *static_cast<Sub*>(this);
}
Sub& operator-=(const Sub& aPoint) {
x -= aPoint.x;
y -= aPoint.y;
return *static_cast<Sub*>(this);
}
Sub operator*(T aScale) const {
return Sub(x * aScale, y * aScale);
}
Sub operator/(T aScale) const {
return Sub(x / aScale, y / aScale);
}
Sub operator-() const {
return Sub(-x, -y);
}
T DotProduct(const Sub& aPoint) const {
return x * aPoint.x + y * aPoint.y;
}
Coord Length() const {
return hypot(x, y);
}
T LengthSquare() const {
return x * x + y * y;
}
// Round() is *not* rounding to nearest integer if the values are negative.
// They are always rounding as floor(n + 0.5).
// See https://bugzilla.mozilla.org/show_bug.cgi?id=410748#c14
Sub& Round() {
x = Coord(floor(T(x) + T(0.5)));
y = Coord(floor(T(y) + T(0.5)));
return *static_cast<Sub*>(this);
}
// "Finite" means not inf and not NaN
bool IsFinite() const
{
typedef typename mozilla::Conditional<mozilla::IsSame<T, float>::value, float, double>::Type FloatType;
return (mozilla::IsFinite(FloatType(x)) && mozilla::IsFinite(FloatType(y)));
return true;
}
void Clamp(T aMaxAbsValue)
{
x = std::max(std::min(x, aMaxAbsValue), -aMaxAbsValue);
y = std::max(std::min(y, aMaxAbsValue), -aMaxAbsValue);
}
friend std::ostream& operator<<(std::ostream& stream, const BasePoint<T, Sub, Coord>& aPoint) {
return stream << '(' << aPoint.x << ',' << aPoint.y << ')';
}
};
} // namespace gfx
} // namespace mozilla
#endif /* MOZILLA_GFX_BASEPOINT_H_ */
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