code: func (f *Fpdf) CurveBezierCubic(x0, y0, cx0, cy0, cx1, cy1, x1, y1 float64, styleStr string) {
  	f.point(x0, y0)
  	f.outf("%.5f %.5f %.5f %.5f %.5f %.5f c %s", cx0*f.k, (f.h-cy0)*f.k,
  		cx1*f.k, (f.h-cy1)*f.k, x1*f.k, (f.h-y1)*f.k, fillDrawOp(styleStr))
  }
docs: // CurveBezierCubic draws a single-segment cubic Bézier curve. The curve starts at
  // the point (x0, y0) and ends at the point (x1, y1). The control points (cx0,
  // cy0) and (cx1, cy1) specify the curvature. At the start point, the curve is
  // tangent to the straight line between the start point and the control point
  // (cx0, cy0). At the end point, the curve is tangent to the straight line
  // between the end point and the control point (cx1, cy1).
  //
  // styleStr can be "F" for filled, "D" for outlined only, or "DF" or "FD" for
  // outlined and filled. An empty string will be replaced with "D". Drawing uses
  // the current draw color, line width, and cap style centered on the curve's
  // path. Filling uses the current fill color.
  //
  // This routine performs the same function as CurveCubic() but uses standard
  // argument order.
  //
  // The Circle() example demonstrates this method.