func TextField(x, y, w, h int, corners CornerFlags, state WidgetState, label string, cstart, cend int) {
clabel := C.CString(label)
defer C.free(unsafe.Pointer(clabel))
C.bndTextField(vg, C.float(x), C.float(y), C.float(w), C.float(h),
C.int(corners), C.BNDwidgetState(state), -1, clabel,
C.int(cstart), C.int(cend))
}
func Button(x, y, w, h int, corners CornerFlags, state WidgetState, label string) {
clabel := C.CString(label)
defer C.free(unsafe.Pointer(clabel))
C.bndToolButton(vg, C.float(x), C.float(y), C.float(w), C.float(h),
C.int(corners), C.BNDwidgetState(state), -1, clabel)
}