You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: svg.go
    path of file: ./repos/tegola/maths/clip/internal/draw
    
    the code of the file until where you have to start completion: package draw

import (
	"fmt"
	"io"

	"github.com/ajstarks/svgo"
	"github.com/go-spatial/tegola"
	"github.com/go-spatial/tegola/maths"
	"github.com/go-spatial/tegola/maths/clip/region"
)

type SVG struct {
	Filename string
}
    
func DrawLine(canvas *svg.SVG, l tegola.LineString, id string, style string, pointStyle string) {
	var points []maths.Pt
	pts := l.Subpoints()

	canvas.Gid(id)
	path := ""
	canvas.Gid(id + "_path")
	for i, pt := range pts {
		points = append(points, maths.Pt{X: pt.X(), Y: pt.Y()})
		if i == 0 {
			path += "M "
		} else {
			path += "L "
		}
		path += fmt.Sprintf("%v %v ", pt.X(), pt.Y())
	}
	canvas.Path(path, style)
	canvas.Gend()
	canvas.Gid(id + "_points")
	for _, pt := range points {
		x, y := int(pt.X), int(pt.Y)
		if pointStyle == "" {
			pointStyle = "fill:black"
		}
		canvas.Circle(x, y, 1, pointStyle)
		canvas.Group(fmt.Sprintf(`id="pt%v_%v" style="text-anchor:middle;font-size:8;fill:white;stroke:black;opacity:0"`, x, y))
		canvas.Text(x, y+5, fmt.Sprintf("(%v %v)", x, y))
		canvas.Gend()
	}
	canvas.Gend()
	canvas.Gend()
}