gecko-dev/gfx/thebes/gfxQuaternion.h

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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 GFX_QUATERNION_H
#define GFX_QUATERNION_H
#include "mozilla/gfx/BasePoint4D.h"
#include "gfx3DMatrix.h"
#include "nsAlgorithm.h"
struct THEBES_API gfxQuaternion : public mozilla::gfx::BasePoint4D<gfxFloat, gfxQuaternion> {
typedef mozilla::gfx::BasePoint4D<gfxFloat, gfxQuaternion> Super;
gfxQuaternion() : Super() {}
gfxQuaternion(gfxFloat aX, gfxFloat aY, gfxFloat aZ, gfxFloat aW) : Super(aX, aY, aZ, aW) {}
gfxQuaternion(const gfx3DMatrix& aMatrix) {
w = 0.5 * sqrt(NS_MAX(1 + aMatrix[0][0] + aMatrix[1][1] + aMatrix[2][2], 0.0f));
x = 0.5 * sqrt(NS_MAX(1 + aMatrix[0][0] - aMatrix[1][1] - aMatrix[2][2], 0.0f));
y = 0.5 * sqrt(NS_MAX(1 - aMatrix[0][0] + aMatrix[1][1] - aMatrix[2][2], 0.0f));
z = 0.5 * sqrt(NS_MAX(1 - aMatrix[0][0] - aMatrix[1][1] + aMatrix[2][2], 0.0f));
if(aMatrix[2][1] > aMatrix[1][2])
x = -x;
if(aMatrix[0][2] > aMatrix[2][0])
y = -y;
if(aMatrix[1][0] > aMatrix[0][1])
z = -z;
}
gfxQuaternion Slerp(const gfxQuaternion &aOther, gfxFloat aCoeff) {
gfxFloat dot = mozilla::clamped(DotProduct(aOther), -1.0, 1.0);
if (dot == 1.0) {
return *this;
}
gfxFloat theta = acos(dot);
gfxFloat rsintheta = 1/sqrt(1 - dot*dot);
gfxFloat w = sin(aCoeff*theta)*rsintheta;
gfxQuaternion left = *this;
gfxQuaternion right = aOther;
left *= cos(aCoeff*theta) - dot*w;
right *= w;
return left + right;
}
gfx3DMatrix ToMatrix() {
gfx3DMatrix temp;
temp[0][0] = 1 - 2 * (y * y + z * z);
temp[0][1] = 2 * (x * y + w * z);
temp[0][2] = 2 * (x * z - w * y);
temp[1][0] = 2 * (x * y - w * z);
temp[1][1] = 1 - 2 * (x * x + z * z);
temp[1][2] = 2 * (y * z + w * x);
temp[2][0] = 2 * (x * z + w * y);
temp[2][1] = 2 * (y * z - w * x);
temp[2][2] = 1 - 2 * (x * x + y * y);
return temp;
}
};
#endif /* GFX_QUATERNION_H */