vector common funcs

include/cglm-vec.h

@@ -8,6 +8,50 @@
 #ifndef cglm_vec_h
 #define cglm_vec_h
 
+#include "cglm.h"
 
+CGLM_INLINE
+float
+glm_vec_dot(vec3 a, vec3 b) {
+  return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
+}
+
+CGLM_INLINE
+float
+glm_vec_dot4(vec4 a, vec4 b) {
+  return a[0] * b[0] + a[1] * b[1] + a[2] * b[2] + a[3] * b[3];
+}
+
+CGLM_INLINE
+void
+glm_vec_cross(vec3 a, vec3 b, vec3 d) {
+  /* (u2.v3 - u3.v2, u3.v1 - u1.v3, u1.v2 - u2.v1) */
+  d[0] = a[1] * b[2] - a[2] * b[1];
+  d[1] = a[2] * b[0] - a[0] * b[2];
+  d[2] = a[0] * b[1] - a[1] * b[0];
+}
+
+CGLM_INLINE
+float
+glm_vec_norm(vec3 vec) {
+  return sqrt(vec[0] * vec[0] + vec[1] * vec[1] + vec[2] * vec[2]);
+}
+
+CGLM_INLINE
+void
+glm_vec_normalize(vec3 vec, vec3 dest) {
+  float norm;
+
+  norm = glm_vec_norm(vec);
+
+  if (norm == 0.0f) {
+    dest[0] = dest[1] = dest[2] = 0.0f;
+    return;
+  }
+
+  dest[0] = vec[0] / norm;
+  dest[1] = vec[1] / norm;
+  dest[2] = vec[2] / norm;
+}
 
 #endif /* cglm_vec_h */