External/cglm
1
0
Fork 0
mirror of https://github.com/recp/cglm.git synced 2025-10-04 01:00:46 +00:00
Code Issues Packages Projects Releases Wiki Activity

quat: quaternion for look rotation ( from source point to dest point )

Browse Source
This commit is contained in:
Recep Aslantas
2018-04-10 16:52:52 +03:00
parent 9466182c10
commit 18ef0d7af1
1 changed files with 48 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

48
include/cglm/quat.h
View File

@@ -605,4 +605,52 @@ glm_quat_look(vec3 eye, versor ori, mat4 dest) {
glm_vec_flipsign_to(t, dest[3]);
}
/*!
* @brief creates look rotation quaternion
*
* @param[in] fwd forward vector
* @param[in] up up vector
* @param[out] dest destination quaternion
*/
CGLM_INLINE
void
glm_quat_for(vec3 dir, vec3 fwd, vec3 up, versor dest) {
vec3 axis;
float dot, angle;
dot = glm_vec_dot(dir, fwd);
if (fabsf(dot + 1.0f) < 0.000001f) {
glm_quat_init(dest, up[0], up[1], up[2], CGLM_PI);
return;
}
if (fabsf(dot - 1.0f) < 0.000001f) {
glm_quat_identity(dest);
return;
}
angle = acosf(dot);
glm_cross(fwd, dir, axis);
glm_normalize(axis);
glm_quatv(dest, angle, axis);
}
/*!
* @brief creates look rotation quaternion using source and
* destination positions p suffix stands for position
*
* @param[in] from source point
* @param[in] to destination point
* @param[in] up up vector
* @param[out] dest destination quaternion
*/
CGLM_INLINE
void
glm_quat_forp(vec3 from, vec3 to, vec3 fwd, vec3 up, versor dest) {
vec3 dir;
glm_vec_sub(to, from, dir);
glm_quat_for(dir, fwd, up, dest);
}
#endif /* cglm_quat_h */