gecko-dev/gfx/2d/Quaternion.h

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2.4 KiB
C++

/* -*- Mode: C++; tab-width: 20; 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_QUATERNION_H_
#define MOZILLA_GFX_QUATERNION_H_
#include "Types.h"
#include <math.h>
#include "mozilla/Attributes.h"
#include "mozilla/DebugOnly.h"
namespace mozilla {
namespace gfx {
class Matrix4x4;
class Quaternion
{
public:
Quaternion()
: x(0.0f), y(0.0f), z(0.0f), w(1.0f)
{}
Quaternion(Float aX, Float aY, Float aZ, Float aW)
: x(aX), y(aY), z(aZ), w(aW)
{}
Quaternion(const Quaternion& aOther)
{
memcpy(this, &aOther, sizeof(*this));
}
Float x, y, z, w;
friend std::ostream& operator<<(std::ostream& aStream, const Quaternion& aQuat);
void Set(Float aX, Float aY, Float aZ, Float aW)
{
x = aX; y = aY; z = aZ; w = aW;
}
// Assumes upper 3x3 of aMatrix is a pure rotation matrix (no scaling)
void SetFromRotationMatrix(const Matrix4x4& aMatrix);
// result = this * aQuat
Quaternion operator*(const Quaternion &aQuat) const
{
Quaternion o;
const Float bx = aQuat.x, by = aQuat.y, bz = aQuat.z, bw = aQuat.w;
o.x = x*bw + w*bx + y*bz - z*by;
o.y = y*bw + w*by + z*bx - x*bz;
o.z = z*bw + w*bz + x*by - y*bx;
o.w = w*bw - x*bx - y*by - z*bz;
return o;
}
Quaternion& operator*=(const Quaternion &aQuat)
{
*this = *this * aQuat;
return *this;
}
Float Length() const
{
return sqrt(x*x + y*y + z*z + w*w);
}
Quaternion& Conjugate()
{
x *= -1.f; y *= -1.f; z *= -1.f;
return *this;
}
Quaternion& Normalize()
{
Float l = Length();
if (l) {
l = 1.0f / l;
x *= l; y *= l; z *= l; w *= l;
} else {
x = y = z = 0.f;
w = 1.f;
}
return *this;
}
Quaternion& Invert()
{
return Conjugate().Normalize();
}
Point3D RotatePoint(const Point3D& aPoint) {
Float uvx = Float(2.0) * (y*aPoint.z - z*aPoint.y);
Float uvy = Float(2.0) * (z*aPoint.x - x*aPoint.z);
Float uvz = Float(2.0) * (x*aPoint.y - y*aPoint.x);
return Point3D(aPoint.x + w*uvx + y*uvz - z*uvy,
aPoint.y + w*uvy + z*uvx - x*uvz,
aPoint.z + w*uvz + x*uvy - y*uvx);
}
};
} // namespace gfx
} // namespace mozilla
#endif