cairo/canvas.go
func (v *Context) LineTo(x, y float64) {
	C.cairo_line_to(v.native(), C.double(x), C.double(y))
}
func (v *Context) LineTo(x, y float64) {
	C.cairo_line_to(v.native(), C.double(x), C.double(y))
}
// LineTo is a wrapper around cairo_line_to().