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

49 lines
1.1 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_persp_decomp_far(mat4 proj, float *farZ)
CGLM_INLINE float glm_persp_fovy(mat4 proj)
CGLM_INLINE float glm_persp_aspect(mat4 proj)
CGLM_INLINE void glm_persp_sizes(mat4 proj, float fovy, vec4 dest)
*/
#ifndef cglm_persp_h
#define cglm_persp_h
#include "../common.h"
#include "../plane.h"
#include "../mat4.h"
/*!
* @brief returns field of view angle along the Y-axis (in radians)
*
* if you need to degrees, use glm_deg to convert it or use this:
* fovy_deg = glm_deg(glm_persp_fovy(projMatrix))
*
* @param[in] proj perspective projection matrix
*/
CGLM_INLINE
float
glm_persp_fovy(mat4 proj) {
return 2.0f * atanf(1.0f / proj[1][1]);
}
/*!
* @brief returns aspect ratio of perspective projection
*
* @param[in] proj perspective projection matrix
*/
CGLM_INLINE
float
glm_persp_aspect(mat4 proj) {
return proj[1][1] / proj[0][0];
}
#endif /* cglm_persp_h */