Internal call graph ▾

In the call graph viewer below, each node is a function belonging to this package and its children are the functions it calls—perhaps dynamically.

The root nodes are the entry points of the package: functions that may be called from outside the package. There may be non-exported or anonymous functions among them if they are called dynamically from another package.

Click a node to visit that function's source code. From there you can visit its callers by clicking its declaring func token.

Functions may be omitted if they were determined to be unreachable in the particular programs or tests that were analyzed.

▾ Example

Code:

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)
}
ascent := face.Metrics().Ascent.Ceil()

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...........