exracting planes

README.md

@@ -50,6 +50,7 @@ https://github.com/g-truc/glm
 - euler angles / yaw-pitch-roll to matrix
 - extract euler angles
 - inline or pre-compiled function call
+- extract view frustum planes
 
 <hr />
 

include/cglm/call.h

@@ -20,6 +20,7 @@ extern "C" {
 #include "call/cam.h"
 #include "call/quat.h"
 #include "call/euler.h"
+#include "call/plane.h"
 #include "call/io.h"
 
 #ifdef __cplusplus

include/cglm/call/plane.h

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c), Recep Aslantas.
+ *
+ * MIT License (MIT), http://opensource.org/licenses/MIT
+ * Full license can be found in the LICENSE file
+ */
+
+#ifndef cglmc_plane_h
+#define cglmc_plane_h
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "../cglm.h"
+
+CGLM_EXPORT
+void
+glmc_plane_normalize(vec4 plane);
+
+CGLM_EXPORT
+void
+glmc_plane_extract(mat4 projView, vec4 dest[6]);
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* cglmc_plane_h */

include/cglm/cglm.h

@@ -17,6 +17,7 @@
 #include "cam.h"
 #include "quat.h"
 #include "euler.h"
+#include "plane.h"
 #include "util.h"
 #include "io.h"
 

include/cglm/plane.h

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c), Recep Aslantas.
+ *
+ * MIT License (MIT), http://opensource.org/licenses/MIT
+ * Full license can be found in the LICENSE file
+ */
+
+#ifndef cglm_plane_h
+#define cglm_plane_h
+
+#include "common.h"
+#include "mat4.h"
+#include "vec4.h"
+
+/*
+ Plane equation:  Ax + By + Cz + D = 0;
+
+ It stored in vec4 as [A, B, C, D]. (A, B, C) is normal and D is distance
+*/
+
+/*
+ Functions:
+   CGLM_INLINE void  glm_plane_normalize(vec4 plane);
+   CGLM_INLINE void  glm_plane_extract(mat4 projView, vec4 dest[6]);
+ */
+
+/*!
+ * @brief normalizes a plane
+ *
+ * @param[in, out] plane pnale to normalize
+ */
+CGLM_INLINE
+void
+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/plane.c

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c), Recep Aslantas.
+ *
+ * MIT License (MIT), http://opensource.org/licenses/MIT
+ * Full license can be found in the LICENSE file
+ */
+
+#include "../include/cglm/cglm.h"
+#include "../include/cglm/call.h"
+
+CGLM_EXPORT
+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);
+}