nuclear@2: /*
nuclear@2: libvmath - a vector math library
nuclear@2: Copyright (C) 2004-2011 John Tsiombikas <nuclear@member.fsf.org>
nuclear@2: 
nuclear@2: This program is free software: you can redistribute it and/or modify
nuclear@2: it under the terms of the GNU Lesser General Public License as published
nuclear@2: by the Free Software Foundation, either version 3 of the License, or
nuclear@2: (at your option) any later version.
nuclear@2: 
nuclear@2: This program is distributed in the hope that it will be useful,
nuclear@2: but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@2: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nuclear@2: GNU Lesser General Public License for more details.
nuclear@2: 
nuclear@2: You should have received a copy of the GNU Lesser General Public License
nuclear@2: along with this program.  If not, see <http://www.gnu.org/licenses/>.
nuclear@2: */
nuclear@2: 
nuclear@2: #include "vector.h"
nuclear@2: #include "matrix.h"
nuclear@2: 
nuclear@2: #ifdef __cplusplus
nuclear@2: extern "C" {
nuclear@2: #endif	/* __cplusplus */
nuclear@2: 
nuclear@2: static inline quat_t quat_mul(quat_t q1, quat_t q2)
nuclear@2: {
nuclear@2: 	quat_t res;
nuclear@2: 	vec3_t v1 = quat_vec(q1);
nuclear@2: 	vec3_t v2 = quat_vec(q2);
nuclear@2: 
nuclear@2: 	res.w = q1.w * q2.w - v3_dot(v1, v2);
nuclear@2: 	/* resvec = v2 * q1 + v1 * q2 + cross(v1, v2) */
nuclear@2: 	res.x = v2.x * q1.w + v1.x * q2.w + (v1.y * v2.z - v1.z * v2.y);
nuclear@2: 	res.y = v2.y * q1.w + v1.y * q2.w + (v1.z * v2.x - v1.x * v2.z);
nuclear@2: 	res.z = v2.z * q1.w + v1.z * q2.w + (v1.x * v2.y - v1.y * v2.x);
nuclear@2: 	return res;
nuclear@2: }
nuclear@2: 
nuclear@2: static inline quat_t quat_conjugate(quat_t q)
nuclear@2: {
nuclear@2: 	q.x = -q.x;
nuclear@2: 	q.y = -q.y;
nuclear@2: 	q.z = -q.z;
nuclear@2: 	return q;
nuclear@2: }
nuclear@2: 
nuclear@2: static inline quat_t quat_inverse(quat_t q)
nuclear@2: {
nuclear@2: 	scalar_t lensq = quat_length_sq(q);
nuclear@2: 	q = quat_conjugate(q);
nuclear@2: 	q.x /= lensq;
nuclear@2: 	q.y /= lensq;
nuclear@2: 	q.z /= lensq;
nuclear@2: 	q.w /= lensq;
nuclear@2: 	return q;
nuclear@2: }
nuclear@2: 
nuclear@2: static inline void quat_to_mat3(mat3_t res, quat_t q)
nuclear@2: {
nuclear@2: 	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,
nuclear@2: 				 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,
nuclear@2: 				 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);
nuclear@2: }
nuclear@2: 
nuclear@2: static inline void quat_to_mat4(mat4_t res, quat_t q)
nuclear@2: {
nuclear@2: 	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,
nuclear@2: 				 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,
nuclear@2: 				 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,
nuclear@2: 				 0, 0, 0, 1);
nuclear@2: }
nuclear@2: 
nuclear@2: #ifdef __cplusplus
nuclear@2: }	/* extern "C" */
nuclear@2: 
nuclear@2: inline Quaternion lerp(const Quaternion &a, const Quaternion &b, scalar_t t)
nuclear@2: {
nuclear@2: 	return slerp(a, b, t);
nuclear@2: }
nuclear@2: #endif	/* __cplusplus */