NAME
s3d_vector_angle - calculate angle between two vectors
SYNOPSIS
#include <s3d.h>
float s3d_vector_angle(const float vector1[], const float vector2[]);
DESCRIPTION
Calculates and returns the angle between vector1 and vector2. Please
note that the resulting angle is between 0 and PI, therefore not
covering the whole period! To convert in degrees just do
result*180/M_PI. All vectors should have the format float[3]. More info
on wikipedia. http://en.wikipedia.org/wiki/Vector_(spatial)
AUTHOR
Simon Wunderlich
Author of s3d