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Implemented quaternion_rotate_vector properly.

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git-svn-id: http://svn.berlios.de/svnroot/repos/oolite-linux/trunk@1182 127b21dd-08f5-0310-b4b7-95ae10353056
This commit is contained in:
Jens Ayton 2007-09-23 10:44:34 +00:00
parent 7d99e403a5
commit ce2080f402
2 changed files with 48 additions and 3 deletions
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18
src/Core/OOQuaternion.h
View File

@ -52,6 +52,12 @@ OOINLINE GLboolean quaternion_equal(Quaternion a, Quaternion b) INLINE_CONST_FUN
/* Multiply quaternions */
Quaternion quaternion_multiply(Quaternion q1, Quaternion q2) CONST_FUNC;
/* Negation, or additive inverse -- negate all components */
OOINLINE Quaternion quaternion_negate(Quaternion q) INLINE_CONST_FUNC;
/* Conjugate, or spacial inverse -- negate x, y, z components */
OOINLINE Quaternion quaternion_conjugate(Quaternion q) INLINE_CONST_FUNC;
/* Obsolete function equivalent to *quat = kIdentityQuaternion */
OOINLINE void quaternion_set_identity(Quaternion *quat) ALWAYS_INLINE_FUNC NONNULL_FUNC DEPRECATED_FUNC;
@ -120,6 +126,18 @@ OOINLINE GLboolean quaternion_equal(Quaternion a, Quaternion b)
}
OOINLINE Quaternion quaternion_negate(Quaternion q)
{
return make_quaternion(-q.w, -q.x, -q.y, -q.z);
}
OOINLINE Quaternion quaternion_conjugate(Quaternion q)
{
return make_quaternion(q.w, -q.x, -q.y, -q.z);
}
OOINLINE void quaternion_set_identity(Quaternion *quat)
{
*quat = kIdentityQuaternion;

33
src/Core/OOQuaternion.m
View File

@ -377,10 +377,37 @@ NSString *QuaternionDescription(Quaternion quaternion)
}
#if 0
Vector quaternion_rotate_vector(Quaternion q, Vector vector)
{
Vector u, v, w;
Quaternion v, cq, qv;
basis_vectors_from_quaternion(q, &u, &v, &w);
return make_vector(dot_product(u, vector), dot_product(v, vector), dot_product(w, vector));
/*
Quaternion rotation formula:
r(q, v) = q * v * q^-1, where q^-1 is the spacial inverse of q.
*/
v = make_quaternion(0, vector.x, vector.y, vector.z);
cq = quaternion_conjugate(q);
qv = quaternion_multiply(q, v);
v = quaternion_multiply(qv, cq);
return make_vector(v.x, v.y, v.z); // w will be zero
}
#else
Vector quaternion_rotate_vector(Quaternion q, Vector v)
{
Quaternion qv;
qv.w = 0 - q.x * v.x - q.y * v.y - q.z * v.z;
qv.x = q.w * v.x + q.y * v.z - q.z * v.y;
qv.y = q.w * v.y + q.z * v.x - q.x * v.z;
qv.z = q.w * v.z + q.x * v.y - q.y * v.x;
// w is ignored.
v.x = qv.w * -q.x + qv.x * q.w + qv.y * -q.z - qv.z * -q.y;
v.y = qv.w * -q.y + qv.y * q.w + qv.z * -q.x - qv.x * -q.z;
v.z = qv.w * -q.z + qv.z * q.w + qv.x * -q.y - qv.y * -q.x;
return v;
}
#endif