cairo/canvas.go
func (v *Context) CurveTo(x1, y1, x2, y2, x3, y3 float64) {
	C.cairo_curve_to(v.native(), C.double(x1), C.double(y1), C.double(x2), C.double(y2), C.double(x3), C.double(y3))
}
func (v *Context) CurveTo(x1, y1, x2, y2, x3, y3 float64) {
	C.cairo_curve_to(v.native(), C.double(x1), C.double(y1), C.double(x2), C.double(y2), C.double(x3), C.double(y3))
}
// CurveTo is a wrapper around cairo_curve_to().