1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/2d/BasePoint.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,83 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef MOZILLA_GFX_BASEPOINT_H_
1.10 +#define MOZILLA_GFX_BASEPOINT_H_
1.11 +
1.12 +#include <cmath>
1.13 +#include "mozilla/Attributes.h"
1.14 +
1.15 +namespace mozilla {
1.16 +namespace gfx {
1.17 +
1.18 +/**
1.19 + * Do not use this class directly. Subclass it, pass that subclass as the
1.20 + * Sub parameter, and only use that subclass. This allows methods to safely
1.21 + * cast 'this' to 'Sub*'.
1.22 + */
1.23 +template <class T, class Sub>
1.24 +struct BasePoint {
1.25 + T x, y;
1.26 +
1.27 + // Constructors
1.28 + MOZ_CONSTEXPR BasePoint() : x(0), y(0) {}
1.29 + MOZ_CONSTEXPR BasePoint(T aX, T aY) : x(aX), y(aY) {}
1.30 +
1.31 + void MoveTo(T aX, T aY) { x = aX; y = aY; }
1.32 + void MoveBy(T aDx, T aDy) { x += aDx; y += aDy; }
1.33 +
1.34 + // Note that '=' isn't defined so we'll get the
1.35 + // compiler generated default assignment operator
1.36 +
1.37 + bool operator==(const Sub& aPoint) const {
1.38 + return x == aPoint.x && y == aPoint.y;
1.39 + }
1.40 + bool operator!=(const Sub& aPoint) const {
1.41 + return x != aPoint.x || y != aPoint.y;
1.42 + }
1.43 +
1.44 + Sub operator+(const Sub& aPoint) const {
1.45 + return Sub(x + aPoint.x, y + aPoint.y);
1.46 + }
1.47 + Sub operator-(const Sub& aPoint) const {
1.48 + return Sub(x - aPoint.x, y - aPoint.y);
1.49 + }
1.50 + Sub& operator+=(const Sub& aPoint) {
1.51 + x += aPoint.x;
1.52 + y += aPoint.y;
1.53 + return *static_cast<Sub*>(this);
1.54 + }
1.55 + Sub& operator-=(const Sub& aPoint) {
1.56 + x -= aPoint.x;
1.57 + y -= aPoint.y;
1.58 + return *static_cast<Sub*>(this);
1.59 + }
1.60 +
1.61 + Sub operator*(T aScale) const {
1.62 + return Sub(x * aScale, y * aScale);
1.63 + }
1.64 + Sub operator/(T aScale) const {
1.65 + return Sub(x / aScale, y / aScale);
1.66 + }
1.67 +
1.68 + Sub operator-() const {
1.69 + return Sub(-x, -y);
1.70 + }
1.71 +
1.72 + // Round() is *not* rounding to nearest integer if the values are negative.
1.73 + // They are always rounding as floor(n + 0.5).
1.74 + // See https://bugzilla.mozilla.org/show_bug.cgi?id=410748#c14
1.75 + Sub& Round() {
1.76 + x = static_cast<T>(floor(x + 0.5));
1.77 + y = static_cast<T>(floor(y + 0.5));
1.78 + return *static_cast<Sub*>(this);
1.79 + }
1.80 +
1.81 +};
1.82 +
1.83 +}
1.84 +}
1.85 +
1.86 +#endif /* MOZILLA_GFX_BASEPOINT_H_ */
