func main() {
// nGlyphs is the number of glyphs to generate: 95 characters in the range
// [0x20, 0x7e], plus the replacement character.
const nGlyphs = 95 + 1
// The particular font (unicode.7x13.font) leaves the right-most column
// empty in its ASCII glyphs. We don't have to include that column in the
// generated glyphs, so we subtract one off the effective width.
const width, height, ascent = 7 - 1, 13, 11
readFile := func(name string) ([]byte, error) {
return ioutil.ReadFile(filepath.FromSlash(path.Join("../testdata/fixed", name)))
}
fontData, err := readFile("unicode.7x13.font")
if err != nil {
log.Fatalf("readFile: %v", err)
}
face, err := plan9font.ParseFont(fontData, readFile)
if err != nil {
log.Fatalf("plan9font.ParseFont: %v", err)
}
dst := image.NewRGBA(image.Rect(0, 0, width, nGlyphs*height))
draw.Draw(dst, dst.Bounds(), image.Black, image.Point{}, draw.Src)
d := &font.Drawer{
Dst: dst,
Src: image.White,
Face: face,
}
for i := 0; i < nGlyphs; i++ {
r := '\ufffd'
if i < nGlyphs-1 {
r = 0x20 + rune(i)
}
d.Dot = fixed.P(0, height*i+ascent)
d.DrawString(string(r))
}
w := bytes.NewBuffer(nil)
w.WriteString(preamble)
fmt.Fprintf(w, "// mask7x13 contains %d %d×%d glyphs in %d Pix bytes.\n", nGlyphs, width, height, nGlyphs*width*height)
fmt.Fprintf(w, "var mask7x13 = &image.Alpha{\n")
fmt.Fprintf(w, " Stride: %d,\n", width)
fmt.Fprintf(w, " Rect: image.Rectangle{Max: image.Point{%d, %d*%d}},\n", width, nGlyphs, height)
fmt.Fprintf(w, " Pix: []byte{\n")
b := dst.Bounds()
for y := b.Min.Y; y < b.Max.Y; y++ {
if y%height == 0 {
if y != 0 {
w.WriteByte('\n')
}
i := y / height
if i < nGlyphs-1 {
i += 0x20
fmt.Fprintf(w, "// %#2x %q\n", i, rune(i))
} else {
fmt.Fprintf(w, "// U+FFFD REPLACEMENT CHARACTER\n")
}
}
for x := b.Min.X; x < b.Max.X; x++ {
if dst.RGBAAt(x, y).R > 0 {
w.WriteString("0xff,")
} else {
w.WriteString("0x00,")
}
}
w.WriteByte('\n')
}
w.WriteString("},\n}\n")
fmted, err := format.Source(w.Bytes())
if err != nil {
log.Fatalf("format.Source: %v", err)
}
if err := ioutil.WriteFile("data.go", fmted, 0644); err != nil {
log.Fatalf("ioutil.WriteFile: %v", err)
}
}
func ExampleParseFont() {
readFile := func(name string) ([]byte, error) {
return ioutil.ReadFile(filepath.FromSlash(path.Join("../testdata/fixed", name)))
}
fontData, err := readFile("unicode.7x13.font")
if err != nil {
log.Fatal(err)
}
face, err := plan9font.ParseFont(fontData, readFile)
if err != nil {
log.Fatal(err)
}
// TODO: derive the ascent from the face's metrics.
const ascent = 11
dst := image.NewRGBA(image.Rect(0, 0, 4*7, 13))
draw.Draw(dst, dst.Bounds(), image.Black, image.Point{}, draw.Src)
d := &font.Drawer{
Dst: dst,
Src: image.White,
Face: face,
Dot: fixed.P(0, ascent),
}
// Draw:
// - U+0053 LATIN CAPITAL LETTER S
// - U+03A3 GREEK CAPITAL LETTER SIGMA
// - U+222B INTEGRAL
// - U+3055 HIRAGANA LETTER SA
// The testdata does not contain the CJK subfont files, so U+3055 HIRAGANA
// LETTER SA (さ) should be rendered as U+FFFD REPLACEMENT CHARACTER (�).
//
// The missing subfont file will trigger an "open
// ../testdata/shinonome/k12.3000: no such file or directory" log message.
// This is expected and can be ignored.
d.DrawString("SΣ∫さ")
// Convert the dst image to ASCII art.
var out []byte
b := dst.Bounds()
for y := b.Min.Y; y < b.Max.Y; y++ {
out = append(out, '0'+byte(y%10), ' ')
for x := b.Min.X; x < b.Max.X; x++ {
if dst.RGBAAt(x, y).R > 0 {
out = append(out, 'X')
} else {
out = append(out, '.')
}
}
// Highlight the last row before the baseline. Glyphs like 'S' without
// descenders should not affect any pixels whose Y coordinate is >= the
// baseline.
if y == ascent-1 {
out = append(out, '_')
}
out = append(out, '\n')
}
os.Stdout.Write(out)
// Output:
// 0 ..................X.........
// 1 .................X.X........
// 2 .XXXX..XXXXXX....X.....XXX..
// 3 X....X.X.........X....XX.XX.
// 4 X.......X........X....X.X.X.
// 5 X........X.......X....XXX.X.
// 6 .XXXX.....X......X....XX.XX.
// 7 .....X...X.......X....XX.XX.
// 8 .....X..X........X....XXXXX.
// 9 X....X.X.........X....XX.XX.
// 0 .XXXX..XXXXXX....X.....XXX.._
// 1 ...............X.X..........
// 2 ................X...........
}