git clone https://git.lucas.co/go_mono.git
font/plan9font/example_test.go (2.4K)
1 // Copyright 2015 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4
5 package plan9font_test
6
7 import (
8 "image"
9 "image/draw"
10 "io/ioutil"
11 "log"
12 "os"
13 "path"
14 "path/filepath"
15
16 "golang.org/x/image/font"
17 "golang.org/x/image/font/plan9font"
18 "golang.org/x/image/math/fixed"
19 )
20
21 func ExampleParseFont() {
22 readFile := func(name string) ([]byte, error) {
23 return ioutil.ReadFile(filepath.FromSlash(path.Join("../testdata/fixed", name)))
24 }
25 fontData, err := readFile("unicode.7x13.font")
26 if err != nil {
27 log.Fatal(err)
28 }
29 face, err := plan9font.ParseFont(fontData, readFile)
30 if err != nil {
31 log.Fatal(err)
32 }
33 ascent := face.Metrics().Ascent.Ceil()
34
35 dst := image.NewRGBA(image.Rect(0, 0, 4*7, 13))
36 draw.Draw(dst, dst.Bounds(), image.Black, image.Point{}, draw.Src)
37 d := &font.Drawer{
38 Dst: dst,
39 Src: image.White,
40 Face: face,
41 Dot: fixed.P(0, ascent),
42 }
43 // Draw:
44 // - U+0053 LATIN CAPITAL LETTER S
45 // - U+03A3 GREEK CAPITAL LETTER SIGMA
46 // - U+222B INTEGRAL
47 // - U+3055 HIRAGANA LETTER SA
48 // The testdata does not contain the CJK subfont files, so U+3055 HIRAGANA
49 // LETTER SA (さ) should be rendered as U+FFFD REPLACEMENT CHARACTER (�).
50 //
51 // The missing subfont file will trigger an "open
52 // ../testdata/shinonome/k12.3000: no such file or directory" log message.
53 // This is expected and can be ignored.
54 d.DrawString("SΣ∫さ")
55
56 // Convert the dst image to ASCII art.
57 var out []byte
58 b := dst.Bounds()
59 for y := b.Min.Y; y < b.Max.Y; y++ {
60 out = append(out, '0'+byte(y%10), ' ')
61 for x := b.Min.X; x < b.Max.X; x++ {
62 if dst.RGBAAt(x, y).R > 0 {
63 out = append(out, 'X')
64 } else {
65 out = append(out, '.')
66 }
67 }
68 // Highlight the last row before the baseline. Glyphs like 'S' without
69 // descenders should not affect any pixels whose Y coordinate is >= the
70 // baseline.
71 if y == ascent-1 {
72 out = append(out, '_')
73 }
74 out = append(out, '\n')
75 }
76 os.Stdout.Write(out)
77
78 // Output:
79 // 0 ..................X.........
80 // 1 .................X.X........
81 // 2 .XXXX..XXXXXX....X.....XXX..
82 // 3 X....X.X.........X....XX.XX.
83 // 4 X.......X........X....X.X.X.
84 // 5 X........X.......X....XXX.X.
85 // 6 .XXXX.....X......X....XX.XX.
86 // 7 .....X...X.......X....XX.XX.
87 // 8 .....X..X........X....XXXXX.
88 // 9 X....X.X.........X....XX.XX.
89 // 0 .XXXX..XXXXXX....X.....XXX.._
90 // 1 ...............X.X..........
91 // 2 ................X...........
92 }