From 8f8f5ad0a284d341c3d4dfa24f7af8106e4feba8 Mon Sep 17 00:00:00 2001
From: hasufell <hasufell@hasufell.de>
Date: Sat, 10 May 2014 18:35:22 +0200
Subject: [PATCH] Add normalize_vector() function

---
 src/vec_math.c | 34 ++++++++++++++++++++++++++++++++++
 src/vec_math.h |  1 +
 2 files changed, 35 insertions(+)

diff --git a/src/vec_math.c b/src/vec_math.c
index b66f707..7444a52 100644
--- a/src/vec_math.c
+++ b/src/vec_math.c
@@ -20,6 +20,9 @@
 #include "types.h"
 #include "vec_math.h"
 
+#include <errno.h>
+#include <fenv.h>
+#include <math.h>
 #include <stdbool.h>
 #include <stdlib.h>
 
@@ -51,6 +54,37 @@ bool vector_product(vector *a, vector *b, vector *c)
 	return true;
 }
 
+/**
+ * Normalize a vector into a unit vector
+ * of length 1. This function is aliasing safe.
+ *
+ * @param a vector
+ * @param b vector
+ * @return true/false for success/failure
+ */
+bool normalize_vector(vector *a, vector *b)
+{
+	if (!a || !b)
+		return false;
+
+	vector a_tmp;
+	float vector_length;
+
+	copy_vector(a, &a_tmp);
+
+	vector_length = sqrt((a_tmp.x * a_tmp.x) +
+			(a_tmp.y * a_tmp.y) + (a_tmp.z * a_tmp.z));
+
+	if (errno == EDOM)
+		return false;
+
+	b->x = a_tmp.x / vector_length;
+	b->y = a_tmp.y / vector_length;
+	b->z = a_tmp.z / vector_length;
+
+	return true;
+}
+
 /**
  * Copy coordinates from vector a to vector b.
  *
diff --git a/src/vec_math.h b/src/vec_math.h
index 77923ec..ba3bbed 100644
--- a/src/vec_math.h
+++ b/src/vec_math.h
@@ -26,6 +26,7 @@
 
 
 bool vector_product(vector *a, vector *b, vector *c);
+bool normalize_vector(vector *a, vector *b);
 bool copy_vector(vector *a, vector *b);