func Measure(r io.RuneReader, f font.Face) (size fixed.Point26_6, err error) {
var char rune
var prev rune
w := fixed.Int26_6(0)
m := f.Metrics()
size.Y = m.Height + m.Descent
for {
if char, _, err = r.ReadRune(); err != nil {
if err == io.EOF {
err = nil
}
size.X = maxInt26_6(size.X, w)
return
}
if char == '\n' {
size.X = maxInt26_6(size.X, w)
size.Y += m.Height
w, prev = 0, 0
continue
}
if prev != 0 {
w += f.Kern(prev, char)
}
w += advance(f, char)
prev = char
}
}
func (self rightToLeft) Advance(face font.Face, origin fixed.Point26_6, dot fixed.Point26_6, prev rune, char rune) (begin fixed.Point26_6, end fixed.Point26_6) {
if char == '\n' {
dot.X = origin.X
dot.Y += face.Metrics().Height
return dot, dot
}
if prev != 0 {
dot.X -= face.Kern(prev, char)
}
dot.X -= advance(face, char)
return dot, dot
}