func PixelZoom(xfactor float32, yfactor float32) {
	syscall.Syscall(gpPixelZoom, 2, uintptr(math.Float32bits(xfactor)), uintptr(math.Float32bits(yfactor)), 0)
}
func PixelZoom(xfactor float32, yfactor float32) {
	syscall.Syscall(gpPixelZoom, 2, uintptr(math.Float32bits(xfactor)), uintptr(math.Float32bits(yfactor)), 0)
}
func PixelZoom ( xfactor float32 , yfactor float32 ) { syscall . Syscall ( gpPixelZoom , 2 , uintptr ( math . Float32bits ( xfactor ) ) , uintptr ( math . Float32bits ( yfactor ) ) , 0 ) }
// specify the pixel zoom factors
specify the pixel zoom factors