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Diffstat (limited to 'include/cglm/project.h')
| -rw-r--r-- | include/cglm/project.h | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/include/cglm/project.h b/include/cglm/project.h new file mode 100644 index 0000000..1d0a4e5 --- /dev/null +++ b/include/cglm/project.h @@ -0,0 +1,172 @@ +/* + * 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 */ |