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; }