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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_BASEPOINT_H_
#define MOZILLA_GFX_BASEPOINT_H_
#include <cmath>
#include <ostream>
#include <type_traits>
#include "mozilla/Attributes.h"
#include "mozilla/FloatingPoint.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 {
Coord x, y;
};
Coord components[2];
};
// Constructors
constexpr BasePoint() : x(0), y(0) {}
constexpr BasePoint(Coord aX, Coord aY) : x(aX), y(aY) {}
MOZ_ALWAYS_INLINE Coord X() const { return x; }
MOZ_ALWAYS_INLINE Coord Y() const { return y; }
void MoveTo(Coord aX, Coord aY) {
x = aX;
y = aY;
}
void MoveBy(Coord aDx, Coord 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.value * aPoint.x.value + y.value * aPoint.y.value;
}
// FIXME: Maybe Length() should return a float Coord event for integer Points?
Coord Length() const {
return static_cast<decltype(x.value)>(hypot(x.value, y.value));
}
T LengthSquare() const { return x.value * x.value + y.value * y.value; }
// 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(std::floor(T(x) + T(0.5f)));
y = Coord(std::floor(T(y) + T(0.5f)));
return *static_cast<Sub*>(this);
}
// "Finite" means not inf and not NaN
bool IsFinite() const {
using FloatType =
std::conditional_t<std::is_same_v<T, float>, float, double>;
return (std::isfinite(FloatType(x)) && std::isfinite(FloatType(y)));
}
void Clamp(Coord 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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