func Frustum(left float64, right float64, bottom float64, top float64, zNear float64, zFar float64) {
	C.glowFrustum(gpFrustum, (C.GLdouble)(left), (C.GLdouble)(right), (C.GLdouble)(bottom), (C.GLdouble)(top), (C.GLdouble)(zNear), (C.GLdouble)(zFar))
}
func Frustum(left float64, right float64, bottom float64, top float64, zNear float64, zFar float64) {
	C.glowFrustum(gpFrustum, (C.GLdouble)(left), (C.GLdouble)(right), (C.GLdouble)(bottom), (C.GLdouble)(top), (C.GLdouble)(zNear), (C.GLdouble)(zFar))
}
func Frustum ( left float64 , right float64 , bottom float64 , top float64 , zNear float64 , zFar float64 ) { C . glowFrustum ( gpFrustum , ( C . GLdouble ) ( left ) , ( C . GLdouble ) ( right ) , ( C . GLdouble ) ( bottom ) , ( C . GLdouble ) ( top ) , ( C . GLdouble ) ( zNear ) , ( C . GLdouble ) ( zFar ) ) }
// multiply the current matrix by a perspective matrix
multiply the current matrix by a perspective matrix