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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_ */