perspective projection in vecmat3 and tX test program

vecmat3.h

@@ -190,6 +190,9 @@ void euler2rotmat(const T *eul, Mat3<T> &a, const char *type, bool transpose=0,
 template<typename T>
 void rotmat2euler(T *eul, const Mat3<T> &a, const char *type, bool transpose=0, bool direction=0, bool reverse=0);
 
+template<typename T>
+void perspective(T *proj_xy, const Vec3<T> &point, const Mat3<T> &camera_angle, const Vec3<T> &camera,  const Vec3<T> &plane_to_camera);
+
 
 }//namespace
 #endif /* _VECMAT3_H_ */