blender/intern/moto/include/MT_Quaternion.inl
Kester Maddock 4f2e57a541 Fix bug #2006:
Floating point imprecision made MT_Quaternion::angle return NaN, since acos(x) is NaN for |x| > 1.

Because of the way NaN's propagate through float math, the view pos would be set to [NaN, NaN, NaN] resulting in a grey screen.
2005-01-09 00:06:45 +00:00

93 lines
3.0 KiB
C++

#include "MT_Optimize.h"
GEN_INLINE MT_Quaternion& MT_Quaternion::operator*=(const MT_Quaternion& q) {
setValue(m_co[3] * q[0] + m_co[0] * q[3] + m_co[1] * q[2] - m_co[2] * q[1],
m_co[3] * q[1] + m_co[1] * q[3] + m_co[2] * q[0] - m_co[0] * q[2],
m_co[3] * q[2] + m_co[2] * q[3] + m_co[0] * q[1] - m_co[1] * q[0],
m_co[3] * q[3] - m_co[0] * q[0] - m_co[1] * q[1] - m_co[2] * q[2]);
return *this;
}
GEN_INLINE void MT_Quaternion::conjugate() {
m_co[0] = -m_co[0]; m_co[1] = -m_co[1]; m_co[2] = -m_co[2];
}
GEN_INLINE MT_Quaternion MT_Quaternion::conjugate() const {
return MT_Quaternion(-m_co[0], -m_co[1], -m_co[2], m_co[3]);
}
GEN_INLINE void MT_Quaternion::invert() {
conjugate();
*this /= length2();
}
GEN_INLINE MT_Quaternion MT_Quaternion::inverse() const {
return conjugate() / length2();
}
// From: "Uniform Random Rotations", Ken Shoemake, Graphics Gems III,
// pg. 124-132
GEN_INLINE MT_Quaternion MT_Quaternion::random() {
MT_Scalar x0 = MT_random();
MT_Scalar r1 = sqrt(MT_Scalar(1.0) - x0), r2 = sqrt(x0);
MT_Scalar t1 = MT_2_PI * MT_random(), t2 = MT_2_PI * MT_random();
MT_Scalar c1 = cos(t1), s1 = sin(t1);
MT_Scalar c2 = cos(t2), s2 = sin(t2);
return MT_Quaternion(s1 * r1, c1 * r1, s2 * r2, c2 * r2);
}
GEN_INLINE MT_Quaternion operator*(const MT_Quaternion& q1,
const MT_Quaternion& q2) {
return MT_Quaternion(q1[3] * q2[0] + q1[0] * q2[3] + q1[1] * q2[2] - q1[2] * q2[1],
q1[3] * q2[1] + q1[1] * q2[3] + q1[2] * q2[0] - q1[0] * q2[2],
q1[3] * q2[2] + q1[2] * q2[3] + q1[0] * q2[1] - q1[1] * q2[0],
q1[3] * q2[3] - q1[0] * q2[0] - q1[1] * q2[1] - q1[2] * q2[2]);
}
GEN_INLINE MT_Quaternion operator*(const MT_Quaternion& q, const MT_Vector3& w)
{
return MT_Quaternion( q[3] * w[0] + q[1] * w[2] - q[2] * w[1],
q[3] * w[1] + q[2] * w[0] - q[0] * w[2],
q[3] * w[2] + q[0] * w[1] - q[1] * w[0],
-q[0] * w[0] - q[1] * w[1] - q[2] * w[2]);
}
GEN_INLINE MT_Quaternion operator*(const MT_Vector3& w, const MT_Quaternion& q)
{
return MT_Quaternion( w[0] * q[3] + w[1] * q[2] - w[2] * q[1],
w[1] * q[3] + w[2] * q[0] - w[0] * q[2],
w[2] * q[3] + w[0] * q[1] - w[1] * q[0],
-w[0] * q[0] - w[1] * q[1] - w[2] * q[2]);
}
GEN_INLINE MT_Scalar MT_Quaternion::angle(const MT_Quaternion& q) const
{
MT_Scalar s = sqrt(length2() * q.length2());
assert(s != MT_Scalar(0.0));
s = dot(q) / s;
s = MT_clamp(s, -1.0, 1.0);
return acos(s);
}
GEN_INLINE MT_Quaternion MT_Quaternion::slerp(const MT_Quaternion& q, const MT_Scalar& t) const
{
MT_Scalar theta = angle(q);
if (!MT_fuzzyZero(theta))
{
MT_Scalar d = MT_Scalar(1.0) / sin(theta);
MT_Scalar s0 = sin((MT_Scalar(1.0) - t) * theta);
MT_Scalar s1 = sin(t * theta);
return d*(*this * s0 + q * s1);
}
else
{
return *this;
}
}