orbit-plus/include/cglm/clipspace/view_lh.h
2023-02-11 23:18:45 -05:00

100 lines
2.5 KiB
C

/*
* Copyright (c), Recep Aslantas.
*
* MIT License (MIT), http://opensource.org/licenses/MIT
* Full license can be found in the LICENSE file
*/
/*
Functions:
CGLM_INLINE void glm_lookat_lh(vec3 eye, vec3 center, vec3 up, mat4 dest)
CGLM_INLINE void glm_look_lh(vec3 eye, vec3 dir, vec3 up, mat4 dest)
CGLM_INLINE void glm_look_anyup_lh(vec3 eye, vec3 dir, mat4 dest)
*/
#ifndef cglm_view_lh_h
#define cglm_view_lh_h
#include "../common.h"
#include "../plane.h"
/*!
* @brief set up view matrix (LH)
*
* NOTE: The UP vector must not be parallel to the line of sight from
* the eye point to the reference point
*
* @param[in] eye eye vector
* @param[in] center center vector
* @param[in] up up vector
* @param[out] dest result matrix
*/
CGLM_INLINE
void
glm_lookat_lh(vec3 eye, vec3 center, vec3 up, mat4 dest) {
CGLM_ALIGN(8) vec3 f, u, s;
glm_vec3_sub(center, eye, f);
glm_vec3_normalize(f);
glm_vec3_crossn(up, f, s);
glm_vec3_cross(f, s, u);
dest[0][0] = s[0];
dest[0][1] = u[0];
dest[0][2] = f[0];
dest[1][0] = s[1];
dest[1][1] = u[1];
dest[1][2] = f[1];
dest[2][0] = s[2];
dest[2][1] = u[2];
dest[2][2] = f[2];
dest[3][0] =-glm_vec3_dot(s, eye);
dest[3][1] =-glm_vec3_dot(u, eye);
dest[3][2] =-glm_vec3_dot(f, eye);
dest[0][3] = dest[1][3] = dest[2][3] = 0.0f;
dest[3][3] = 1.0f;
}
/*!
* @brief set up view matrix with left handed coordinate system
*
* convenient wrapper for lookat: if you only have direction not target self
* then this might be useful. Because you need to get target from direction.
*
* NOTE: The UP vector must not be parallel to the line of sight from
* the eye point to the reference point
*
* @param[in] eye eye vector
* @param[in] dir direction vector
* @param[in] up up vector
* @param[out] dest result matrix
*/
CGLM_INLINE
void
glm_look_lh(vec3 eye, vec3 dir, vec3 up, mat4 dest) {
CGLM_ALIGN(8) vec3 target;
glm_vec3_add(eye, dir, target);
glm_lookat_lh(eye, target, up, dest);
}
/*!
* @brief set up view matrix with left handed coordinate system
*
* convenient wrapper for look: if you only have direction and if you don't
* care what UP vector is then this might be useful to create view matrix
*
* @param[in] eye eye vector
* @param[in] dir direction vector
* @param[out] dest result matrix
*/
CGLM_INLINE
void
glm_look_anyup_lh(vec3 eye, vec3 dir, mat4 dest) {
CGLM_ALIGN(8) vec3 up;
glm_vec3_ortho(dir, up);
glm_look_lh(eye, dir, up, dest);
}
#endif /*cglm_view_lh_h*/