gecko-dev/gfx/2d/BasePoint4D.h
Kearwood (Kip) Gilbert b25f2d6a84 Bug 1276066 - Add Union with "components" member to math classes to enable array access to members. r=bas
- Adding an array member to access the components of vector, size,
  and matrix classes reduces the code needed when passing all of the
  members to functions.

MozReview-Commit-ID: A6XL7y3zwsV

--HG--
extra : rebase_source : 77fb1b9784ae1213530cff7f42563e0afc8859e3
2016-04-18 12:12:36 -07:00

132 lines
3.3 KiB
C++

/* -*- 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_BASEPOINT4D_H_
#define MOZILLA_BASEPOINT4D_H_
#include "mozilla/Assertions.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>
struct BasePoint4D {
union {
struct {
T x, y, z, w;
};
T components[4];
};
// Constructors
BasePoint4D() : x(0), y(0), z(0), w(0) {}
BasePoint4D(T aX, T aY, T aZ, T aW) : x(aX), y(aY), z(aZ), w(aW) {}
void MoveTo(T aX, T aY, T aZ, T aW) { x = aX; y = aY; z = aZ; w = aW; }
void MoveBy(T aDx, T aDy, T aDz, T aDw) { x += aDx; y += aDy; z += aDz; w += aDw; }
// 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 &&
z == aPoint.z && w == aPoint.w;
}
bool operator!=(const Sub& aPoint) const {
return x != aPoint.x || y != aPoint.y ||
z != aPoint.z || w != aPoint.w;
}
Sub operator+(const Sub& aPoint) const {
return Sub(x + aPoint.x, y + aPoint.y, z + aPoint.z, w + aPoint.w);
}
Sub operator-(const Sub& aPoint) const {
return Sub(x - aPoint.x, y - aPoint.y, z - aPoint.z, w - aPoint.w);
}
Sub& operator+=(const Sub& aPoint) {
x += aPoint.x;
y += aPoint.y;
z += aPoint.z;
w += aPoint.w;
return *static_cast<Sub*>(this);
}
Sub& operator-=(const Sub& aPoint) {
x -= aPoint.x;
y -= aPoint.y;
z -= aPoint.z;
w -= aPoint.w;
return *static_cast<Sub*>(this);
}
Sub operator*(T aScale) const {
return Sub(x * aScale, y * aScale, z * aScale, w * aScale);
}
Sub operator/(T aScale) const {
return Sub(x / aScale, y / aScale, z / aScale, w / aScale);
}
Sub& operator*=(T aScale) {
x *= aScale;
y *= aScale;
z *= aScale;
w *= aScale;
return *static_cast<Sub*>(this);
}
Sub& operator/=(T aScale) {
x /= aScale;
y /= aScale;
z /= aScale;
w /= aScale;
return *static_cast<Sub*>(this);
}
Sub operator-() const {
return Sub(-x, -y, -z, -w);
}
T& operator[](int aIndex) {
MOZ_ASSERT(aIndex >= 0 && aIndex <= 3, "Invalid array index");
return *((&x)+aIndex);
}
const T& operator[](int aIndex) const {
MOZ_ASSERT(aIndex >= 0 && aIndex <= 3, "Invalid array index");
return *((&x)+aIndex);
}
T DotProduct(const Sub& aPoint) const {
return x * aPoint.x + y * aPoint.y + z * aPoint.z + w * aPoint.w;
}
// Ignores the 4th component!
Sub CrossProduct(const Sub& aPoint) const {
return Sub(y * aPoint.z - aPoint.y * z,
z * aPoint.x - aPoint.z * x,
x * aPoint.y - aPoint.x * y,
0);
}
T Length() const {
return sqrt(x*x + y*y + z*z + w*w);
}
void Normalize() {
*this /= Length();
}
bool HasPositiveWCoord() { return w > 0; }
};
} // namespace gfx
} // namespace mozilla
#endif /* MOZILLA_BASEPOINT4D_H_ */