move extracting planes to camera header

* since it related to view frustum / camera it should be in thie header or separate header called frustum.h
* update LICENSE to add authors of algorithm

LICENSE

@@ -52,3 +52,9 @@ LICENSE:
 
   Computing Euler angles from a rotation matrix (euler.pdf)
   Gregory G. Slabaugh
+
+4. Extracting Planes
+Fast Extraction of Viewing Frustum Planes from the World-View-Projection Matrix
+Authors:
+  Gil Gribb (ggribb@ravensoft.com)
+  Klaus Hartmann (k_hartmann@osnabrueck.netsurf.de)

include/cglm/call/cam.h

@@ -48,6 +48,10 @@ glmc_lookat(vec3 eye,
             vec3 up,
             mat4 dest);
 
+CGLM_EXPORT
+void
+glmc_extract_planes(mat4 m, vec4 dest[6]);
+
 #ifdef __cplusplus
 }
 #endif

include/cglm/call/plane.h

@@ -17,10 +17,6 @@ CGLM_EXPORT
 void
 glmc_plane_normalize(vec4 plane);
 
-CGLM_EXPORT
-void
-glmc_plane_extract(mat4 projView, vec4 dest[6]);
-
 #ifdef __cplusplus
 }
 #endif

include/cglm/cam.h

@@ -50,12 +50,14 @@
                                        float * __restrict farVal);
    CGLM_INLINE void glm_persp_decomp_far(mat4 proj, float * __restrict farVal);
    CGLM_INLINE void glm_persp_decomp_near(mat4 proj, float *__restrict nearVal);
+   CGLM_INLINE void glm_extract_planes(mat4 m, vec4 dest[6]);
  */
 
 #ifndef cglm_vcam_h
 #define cglm_vcam_h
 
 #include "common.h"
+#include "plane.h"
 
 /*!
  * @brief set up perspective peprojection matrix
@@ -422,4 +424,45 @@ void
 glm_persp_decomp_near(mat4 proj, float * __restrict nearVal) {
   *nearVal = proj[3][2] / (proj[2][2] - 1);
 }
+
+
+/*!
+ * @brief extracts view frustum planes
+ *
+ * planes' space:
+ *  1- if m = proj:     View Space
+ *  2- if m = projView: World Space
+ *  3- if m = MVP:      Object Space
+ *
+ * You probably want to extract planes in world space so use projView as m
+ * Computing projView:
+ *   glm_mat4_mul(proj, view, projView);
+ *
+ * Exracted planes order: [left, right, bottom, top, near, far]
+ *
+ * @param[in]  m    matrix (see brief)
+ * @param[out] dest exracted view frustum planes (see brief)
+ */
+CGLM_INLINE
+void
+glm_extract_planes(mat4 m, vec4 dest[6]) {
+  mat4 t;
+
+  glm_mat4_transpose_to(m, t);
+
+  glm_vec4_add(t[3], t[0], dest[0]); /* left   */
+  glm_vec4_sub(t[3], t[0], dest[1]); /* right  */
+  glm_vec4_add(t[3], t[1], dest[2]); /* bottom */
+  glm_vec4_sub(t[3], t[1], dest[3]); /* top    */
+  glm_vec4_add(t[3], t[2], dest[4]); /* near   */
+  glm_vec4_sub(t[3], t[2], dest[5]); /* far    */
+
+  glm_plane_normalize(dest[0]);
+  glm_plane_normalize(dest[1]);
+  glm_plane_normalize(dest[2]);
+  glm_plane_normalize(dest[3]);
+  glm_plane_normalize(dest[4]);
+  glm_plane_normalize(dest[5]);
+}
+
 #endif /* cglm_vcam_h */

include/cglm/plane.h

@@ -11,6 +11,7 @@
 #include "common.h"
 #include "mat4.h"
 #include "vec4.h"
+#include "vec3.h"
 
 /*
  Plane equation:  Ax + By + Cz + D = 0;
@@ -21,7 +22,6 @@
 /*
  Functions:
    CGLM_INLINE void  glm_plane_normalize(vec4 plane);
-   CGLM_INLINE void  glm_plane_extract(mat4 projView, vec4 dest[6]);
  */
 
 /*!
@@ -35,36 +35,4 @@ glm_plane_normalize(vec4 plane) {
   glm_vec4_scale(plane, 1.0f / glm_vec_norm(plane), plane);
 }
 
-/*!
- * @brief extracts view frustum planes
- *
- * computing projView: glm_mat4_mul(proj, view, projView);
- *
- * exracted planes order: [left, right, bottom, top, near, far]
- *
- * @param[in]  projView source
- * @param[out] dest     exracted view frustum planes (see brief)
- */
-CGLM_INLINE
-void
-glm_plane_extract(mat4 projView, vec4 dest[6]) {
-  mat4 m;
-
-  glm_mat4_transpose_to(projView, m);
-
-  glm_vec4_add(m[3], m[0], dest[0]);
-  glm_vec4_sub(m[3], m[0], dest[1]);
-  glm_vec4_add(m[3], m[1], dest[2]);
-  glm_vec4_sub(m[3], m[1], dest[3]);
-  glm_vec4_add(m[3], m[2], dest[4]);
-  glm_vec4_sub(m[3], m[2], dest[5]);
-
-  glm_plane_normalize(dest[0]);
-  glm_plane_normalize(dest[1]);
-  glm_plane_normalize(dest[2]);
-  glm_plane_normalize(dest[3]);
-  glm_plane_normalize(dest[4]);
-  glm_plane_normalize(dest[5]);
-}
-
 #endif /* cglm_plane_h */

src/cam.c

@@ -66,3 +66,9 @@ glmc_lookat(vec3 eye,
             mat4 dest) {
   glm_lookat(eye, center, up, dest);
 }
+
+CGLM_EXPORT
+void
+glmc_extract_planes(mat4 m, vec4 dest[6]) {
+  glm_extract_planes(m, dest);
+}

src/plane.c

@@ -13,9 +13,3 @@ void
 glmc_plane_normalize(vec4 plane) {
   glm_plane_normalize(plane);
 }
-
-CGLM_EXPORT
-void
-glmc_plane_extract(mat4 projView, vec4 dest[6]) {
-  glm_plane_extract(projView, dest);
-}