frillrun/include/cglm/project.h

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2024-08-24 04:47:58 +00:00
/*
* Copyright (c), Recep Aslantas.
*
* MIT License (MIT), http://opensource.org/licenses/MIT
* Full license can be found in the LICENSE file
*/
#ifndef cglm_project_h
#define cglm_project_h
#include "common.h"
#include "vec3.h"
#include "vec4.h"
#include "mat4.h"
#ifndef CGLM_CLIPSPACE_INCLUDE_ALL
# if CGLM_CONFIG_CLIP_CONTROL & CGLM_CLIP_CONTROL_ZO_BIT
# include "clipspace/project_zo.h"
# elif CGLM_CONFIG_CLIP_CONTROL & CGLM_CLIP_CONTROL_NO_BIT
# include "clipspace/project_no.h"
# endif
#else
# include "clipspace/project_zo.h"
# include "clipspace/project_no.h"
#endif
/*!
* @brief maps the specified viewport coordinates into specified space [1]
* the matrix should contain projection matrix.
*
* if you don't have ( and don't want to have ) an inverse matrix then use
* glm_unproject version. You may use existing inverse of matrix in somewhere
* else, this is why glm_unprojecti exists to save save inversion cost
*
* [1] space:
* 1- if m = invProj: View Space
* 2- if m = invViewProj: World Space
* 3- if m = invMVP: Object Space
*
* You probably want to map the coordinates into object space
* so use invMVP as m
*
* Computing viewProj:
* glm_mat4_mul(proj, view, viewProj);
* glm_mat4_mul(viewProj, model, MVP);
* glm_mat4_inv(viewProj, invMVP);
*
* @param[in] pos point/position in viewport coordinates
* @param[in] invMat matrix (see brief)
* @param[in] vp viewport as [x, y, width, height]
* @param[out] dest unprojected coordinates
*/
CGLM_INLINE
void
glm_unprojecti(vec3 pos, mat4 invMat, vec4 vp, vec3 dest) {
#if CGLM_CONFIG_CLIP_CONTROL & CGLM_CLIP_CONTROL_ZO_BIT
glm_unprojecti_zo(pos, invMat, vp, dest);
#elif CGLM_CONFIG_CLIP_CONTROL & CGLM_CLIP_CONTROL_NO_BIT
glm_unprojecti_no(pos, invMat, vp, dest);
#endif
}
/*!
* @brief maps the specified viewport coordinates into specified space [1]
* the matrix should contain projection matrix.
*
* this is same as glm_unprojecti except this function get inverse matrix for
* you.
*
* [1] space:
* 1- if m = proj: View Space
* 2- if m = viewProj: World Space
* 3- if m = MVP: Object Space
*
* You probably want to map the coordinates into object space
* so use MVP as m
*
* Computing viewProj and MVP:
* glm_mat4_mul(proj, view, viewProj);
* glm_mat4_mul(viewProj, model, MVP);
*
* @param[in] pos point/position in viewport coordinates
* @param[in] m matrix (see brief)
* @param[in] vp viewport as [x, y, width, height]
* @param[out] dest unprojected coordinates
*/
CGLM_INLINE
void
glm_unproject(vec3 pos, mat4 m, vec4 vp, vec3 dest) {
mat4 inv;
glm_mat4_inv(m, inv);
glm_unprojecti(pos, inv, vp, dest);
}
/*!
* @brief map object coordinates to window coordinates
*
* Computing MVP:
* glm_mat4_mul(proj, view, viewProj);
* glm_mat4_mul(viewProj, model, MVP);
*
* @param[in] pos object coordinates
* @param[in] m MVP matrix
* @param[in] vp viewport as [x, y, width, height]
* @param[out] dest projected coordinates
*/
CGLM_INLINE
void
glm_project(vec3 pos, mat4 m, vec4 vp, vec3 dest) {
#if CGLM_CONFIG_CLIP_CONTROL & CGLM_CLIP_CONTROL_ZO_BIT
glm_project_zo(pos, m, vp, dest);
#elif CGLM_CONFIG_CLIP_CONTROL & CGLM_CLIP_CONTROL_NO_BIT
glm_project_no(pos, m, vp, dest);
#endif
}
/*!
* @brief map object's z coordinate to window coordinates
*
* Computing MVP:
* glm_mat4_mul(proj, view, viewProj);
* glm_mat4_mul(viewProj, model, MVP);
*
* @param[in] v object coordinates
* @param[in] m MVP matrix
*
* @returns projected z coordinate
*/
CGLM_INLINE
float
glm_project_z(vec3 v, mat4 m) {
#if CGLM_CONFIG_CLIP_CONTROL & CGLM_CLIP_CONTROL_ZO_BIT
return glm_project_z_zo(v, m);
#elif CGLM_CONFIG_CLIP_CONTROL & CGLM_CLIP_CONTROL_NO_BIT
return glm_project_z_no(v, m);
#endif
}
/*!
* @brief define a picking region
*
* @param[in] center center [x, y] of a picking region in window coordinates
* @param[in] size size [width, height] of the picking region in window coordinates
* @param[in] vp viewport as [x, y, width, height]
* @param[out] dest projected coordinates
*/
CGLM_INLINE
void
glm_pickmatrix(vec2 center, vec2 size, vec4 vp, mat4 dest) {
mat4 res;
vec3 v;
if (size[0] <= 0.0f || size[1] <= 0.0f)
return;
/* Translate and scale the picked region to the entire window */
v[0] = (vp[2] - 2.0f * (center[0] - vp[0])) / size[0];
v[1] = (vp[3] - 2.0f * (center[1] - vp[1])) / size[1];
v[2] = 0.0f;
glm_translate_make(res, v);
v[0] = vp[2] / size[0];
v[1] = vp[3] / size[1];
v[2] = 1.0f;
glm_scale(res, v);
glm_mat4_copy(res, dest);
}
#endif /* cglm_project_h */