vec3 and vec4 sign helper

include/cglm/vec3-ext.h

@@ -26,6 +26,7 @@
 #define cglm_vec3_ext_h
 
 #include "common.h"
+#include "util.h"
 #include <stdbool.h>
 #include <math.h>
 #include <float.h>
@@ -196,4 +197,19 @@ glm_vec_isvalid(vec3 v) {
   return !glm_vec_isnan(v) && !glm_vec_isinf(v);
 }
 
+/*!
+ * @brief get sign of 32 bit float as +1, -1, 0
+ *
+ * Important: It returns 0 for zero/NaN input
+ *
+ * @param v vector
+ */
+CGLM_INLINE
+void
+glm_vec_sign(vec3 v, vec3 dest) {
+  dest[0] = glm_signf(v[0]);
+  dest[1] = glm_signf(v[1]);
+  dest[2] = glm_signf(v[2]);
+}
+
 #endif /* cglm_vec3_ext_h */