int w_BezierCurve_getDerivative(lua_State *L)
{
	BezierCurve *curve = luax_checkbeziercurve(L, 1);
	BezierCurve *deriv = new BezierCurve(curve->getDerivative());
	luax_pushtype(L, MATH_BEZIER_CURVE_ID, deriv);
	deriv->release();
	return 1;
}