goat3d

view libs/vmath/quat.inl @ 34:8471225a460c

merged
author John Tsiombikas <nuclear@member.fsf.org>
date Sat, 05 Oct 2013 03:08:22 +0300
parents 4deb0b12fe14
children
line source
1 /*
2 libvmath - a vector math library
3 Copyright (C) 2004-2011 John Tsiombikas <nuclear@member.fsf.org>
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as published
7 by the Free Software Foundation, either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
17 */
19 #include "vector.h"
20 #include "matrix.h"
22 #ifdef __cplusplus
23 extern "C" {
24 #endif /* __cplusplus */
26 static VMATH_INLINE quat_t quat_mul(quat_t q1, quat_t q2)
27 {
28 quat_t res;
29 vec3_t v1 = quat_vec(q1);
30 vec3_t v2 = quat_vec(q2);
32 res.w = q1.w * q2.w - v3_dot(v1, v2);
33 /* resvec = v2 * q1 + v1 * q2 + cross(v1, v2) */
34 res.x = v2.x * q1.w + v1.x * q2.w + (v1.y * v2.z - v1.z * v2.y);
35 res.y = v2.y * q1.w + v1.y * q2.w + (v1.z * v2.x - v1.x * v2.z);
36 res.z = v2.z * q1.w + v1.z * q2.w + (v1.x * v2.y - v1.y * v2.x);
37 return res;
38 }
40 static VMATH_INLINE quat_t quat_conjugate(quat_t q)
41 {
42 q.x = -q.x;
43 q.y = -q.y;
44 q.z = -q.z;
45 return q;
46 }
48 static VMATH_INLINE quat_t quat_inverse(quat_t q)
49 {
50 scalar_t lensq = quat_length_sq(q);
51 q = quat_conjugate(q);
52 q.x /= lensq;
53 q.y /= lensq;
54 q.z /= lensq;
55 q.w /= lensq;
56 return q;
57 }
59 static VMATH_INLINE void quat_to_mat3(mat3_t res, quat_t q)
60 {
61 m3_cons(res, 1.0 - 2.0 * q.y*q.y - 2.0 * q.z*q.z, 2.0 * q.x * q.y - 2.0 * q.w * q.z, 2.0 * q.z * q.x + 2.0 * q.w * q.y,
62 2.0 * q.x * q.y + 2.0 * q.w * q.z, 1.0 - 2.0 * q.x*q.x - 2.0 * q.z*q.z, 2.0 * q.y * q.z - 2.0 * q.w * q.x,
63 2.0 * q.z * q.x - 2.0 * q.w * q.y, 2.0 * q.y * q.z + 2.0 * q.w * q.x, 1.0 - 2.0 * q.x*q.x - 2.0 * q.y*q.y);
64 }
66 static VMATH_INLINE void quat_to_mat4(mat4_t res, quat_t q)
67 {
68 m4_cons(res, 1.0 - 2.0 * q.y*q.y - 2.0 * q.z*q.z, 2.0 * q.x * q.y - 2.0 * q.w * q.z, 2.0 * q.z * q.x + 2.0 * q.w * q.y, 0,
69 2.0 * q.x * q.y + 2.0 * q.w * q.z, 1.0 - 2.0 * q.x*q.x - 2.0 * q.z*q.z, 2.0 * q.y * q.z - 2.0 * q.w * q.x, 0,
70 2.0 * q.z * q.x - 2.0 * q.w * q.y, 2.0 * q.y * q.z + 2.0 * q.w * q.x, 1.0 - 2.0 * q.x*q.x - 2.0 * q.y*q.y, 0,
71 0, 0, 0, 1);
72 }
74 #ifdef __cplusplus
75 } /* extern "C" */
77 VMATH_INLINE Quaternion lerp(const Quaternion &a, const Quaternion &b, scalar_t t)
78 {
79 return slerp(a, b, t);
80 }
81 #endif /* __cplusplus */