func New(w, h vg.Length) *Canvas {
buf := new(bytes.Buffer)
c := &Canvas{
svg: svgo.New(buf),
w: w,
h: h,
buf: buf,
ht: w.Points(),
stk: []context{context{}},
}
// This is like svg.Start, except it uses floats
// and specifies the units.
fmt.Fprintf(buf, `<?xml version="1.0"?>
<!-- Generated by SVGo and Plotinum VG -->
<svg width="%.*gin" height="%.*gin"
xmlns="http://www.w3.org/2000/svg"
xmlns:xlink="http://www.w3.org/1999/xlink">`+"\n",
pr, w/vg.Inch,
pr, h/vg.Inch,
)
// Swap the origin to the bottom left.
// This must be matched with a </g> when saving,
// before the closing </svg>.
c.svg.Gtransform(fmt.Sprintf("scale(1, -1) translate(0, -%.*g)", pr, h.Dots(c)))
vg.Initialize(c)
return c
}
// unit returns a pdf.Unit, converted from a vg.Length.
func unit(l vg.Length) pdf.Unit {
return pdf.Unit(l.Points()) * pdf.Pt
}