//go:build ignore // fontgen.go is the source of truth for CaptureStudio's embedded bitmap font. // // It holds one hand-drawn 5x8 glyph per printable ASCII code point as plain // ASCII art ('#' = ink, '.' = paper) and packs each row into the low five bits // of a byte, most significant bit = leftmost pixel. The packed table is written // to font.go, which is what actually ships and compiles in. Nothing is loaded // at run time and there is no font file anywhere. // // Rows 0-6 are cap height with the baseline on row 6. Row 7 is the descender // row, used only by g j p q y , ; and _ , which is why glyph() takes seven // rows and pads, while glyph8() takes all eight. // // go run fontgen.go > font.go && gofmt -w font.go package main import ( "fmt" "os" "strings" ) // g records one glyph. The strings are the pixel rows, top first. type g struct { r rune rows [8]string } func glyph(r rune, r0, r1, r2, r3, r4, r5, r6 string) g { return g{r, [8]string{r0, r1, r2, r3, r4, r5, r6, "....."}} } func glyph8(r rune, r0, r1, r2, r3, r4, r5, r6, r7 string) g { return g{r, [8]string{r0, r1, r2, r3, r4, r5, r6, r7}} } var glyphs = []g{ glyph(' ', ".....", ".....", ".....", ".....", ".....", ".....", "....."), glyph('!', "..#..", "..#..", "..#..", "..#..", "..#..", ".....", "..#.."), glyph('"', ".#.#.", ".#.#.", ".....", ".....", ".....", ".....", "....."), glyph('#', ".#.#.", ".#.#.", "#####", ".#.#.", "#####", ".#.#.", ".#.#."), glyph('$', "..#..", ".####", "#.#..", ".###.", "..#.#", "####.", "..#.."), glyph('%', "##..#", "##..#", "...#.", "..#..", ".#...", "#..##", "#..##"), glyph('&', ".##..", "#..#.", "#.#..", ".#...", "#.#.#", "#..#.", ".##.#"), glyph('\'', "..#..", "..#..", ".....", ".....", ".....", ".....", "....."), glyph('(', "...#.", "..#..", ".#...", ".#...", ".#...", "..#..", "...#."), glyph(')', ".#...", "..#..", "...#.", "...#.", "...#.", "..#..", ".#..."), glyph('*', ".....", "#.#.#", ".###.", "#####", ".###.", "#.#.#", "....."), glyph('+', ".....", "..#..", "..#..", "#####", "..#..", "..#..", "....."), glyph8(',', ".....", ".....", ".....", ".....", ".....", "..##.", "..#..", ".#..."), glyph('-', ".....", ".....", ".....", "#####", ".....", ".....", "....."), glyph('.', ".....", ".....", ".....", ".....", ".....", ".##..", ".##.."), glyph('/', "....#", "...#.", "...#.", "..#..", ".#...", ".#...", "#...."), glyph('0', ".###.", "#...#", "#..##", "#.#.#", "##..#", "#...#", ".###."), glyph('1', "..#..", ".##..", "..#..", "..#..", "..#..", "..#..", ".###."), glyph('2', ".###.", "#...#", "....#", "...#.", "..#..", ".#...", "#####"), glyph('3', "#####", "...#.", "..#..", "...#.", "....#", "#...#", ".###."), glyph('4', "...#.", "..##.", ".#.#.", "#..#.", "#####", "...#.", "...#."), glyph('5', "#####", "#....", "####.", "....#", "....#", "#...#", ".###."), glyph('6', "..##.", ".#...", "#....", "####.", "#...#", "#...#", ".###."), glyph('7', "#####", "....#", "...#.", "..#..", ".#...", ".#...", ".#..."), glyph('8', ".###.", "#...#", "#...#", ".###.", "#...#", "#...#", ".###."), glyph('9', ".###.", "#...#", "#...#", ".####", "....#", "...#.", ".##.."), glyph(':', ".....", ".##..", ".##..", ".....", ".##..", ".##..", "....."), glyph8(';', ".....", ".##..", ".##..", ".....", ".##..", ".##..", "..#..", ".#..."), glyph('<', "...#.", "..#..", ".#...", "#....", ".#...", "..#..", "...#."), glyph('=', ".....", ".....", "#####", ".....", "#####", ".....", "....."), glyph('>', ".#...", "..#..", "...#.", "....#", "...#.", "..#..", ".#..."), glyph('?', ".###.", "#...#", "....#", "...#.", "..#..", ".....", "..#.."), glyph('@', ".###.", "#...#", "....#", "#.###", "#.#.#", "#.###", ".###."), glyph('A', "..#..", ".#.#.", "#...#", "#...#", "#####", "#...#", "#...#"), glyph('B', "####.", "#...#", "#...#", "####.", "#...#", "#...#", "####."), glyph('C', ".###.", "#...#", "#....", "#....", "#....", "#...#", ".###."), glyph('D', "###..", "#..#.", "#...#", "#...#", "#...#", "#..#.", "###.."), glyph('E', "#####", "#....", "#....", "####.", "#....", "#....", "#####"), glyph('F', "#####", "#....", "#....", "####.", "#....", "#....", "#...."), glyph('G', ".###.", "#...#", "#....", "#..##", "#...#", "#...#", ".####"), glyph('H', "#...#", "#...#", "#...#", "#####", "#...#", "#...#", "#...#"), glyph('I', ".###.", "..#..", "..#..", "..#..", "..#..", "..#..", ".###."), glyph('J', "..###", "...#.", "...#.", "...#.", "...#.", "#..#.", ".##.."), glyph('K', "#...#", "#..#.", "#.#..", "##...", "#.#..", "#..#.", "#...#"), glyph('L', "#....", "#....", "#....", "#....", "#....", "#....", "#####"), glyph('M', "#...#", "##.##", "#.#.#", "#.#.#", "#...#", "#...#", "#...#"), glyph('N', "#...#", "#...#", "##..#", "#.#.#", "#..##", "#...#", "#...#"), glyph('O', ".###.", "#...#", "#...#", "#...#", "#...#", "#...#", ".###."), glyph('P', "####.", "#...#", "#...#", "####.", "#....", "#....", "#...."), glyph('Q', ".###.", "#...#", "#...#", "#...#", "#.#.#", "#..#.", ".##.#"), glyph('R', "####.", "#...#", "#...#", "####.", "#.#..", "#..#.", "#...#"), glyph('S', ".####", "#....", "#....", ".###.", "....#", "....#", "####."), glyph('T', "#####", "..#..", "..#..", "..#..", "..#..", "..#..", "..#.."), glyph('U', "#...#", "#...#", "#...#", "#...#", "#...#", "#...#", ".###."), glyph('V', "#...#", "#...#", "#...#", "#...#", "#...#", ".#.#.", "..#.."), glyph('W', "#...#", "#...#", "#...#", "#.#.#", "#.#.#", "##.##", "#...#"), glyph('X', "#...#", "#...#", ".#.#.", "..#..", ".#.#.", "#...#", "#...#"), glyph('Y', "#...#", "#...#", ".#.#.", "..#..", "..#..", "..#..", "..#.."), glyph('Z', "#####", "....#", "...#.", "..#..", ".#...", "#....", "#####"), glyph('[', ".###.", ".#...", ".#...", ".#...", ".#...", ".#...", ".###."), glyph('\\', "#....", ".#...", ".#...", "..#..", "...#.", "...#.", "....#"), glyph(']', ".###.", "...#.", "...#.", "...#.", "...#.", "...#.", ".###."), glyph('^', "..#..", ".#.#.", "#...#", ".....", ".....", ".....", "....."), glyph8('_', ".....", ".....", ".....", ".....", ".....", ".....", ".....", "#####"), glyph('`', ".#...", "..#..", ".....", ".....", ".....", ".....", "....."), glyph('a', ".....", ".....", ".###.", "....#", ".####", "#...#", ".####"), glyph('b', "#....", "#....", "####.", "#...#", "#...#", "#...#", "####."), glyph('c', ".....", ".....", ".###.", "#....", "#....", "#....", ".###."), glyph('d', "....#", "....#", ".####", "#...#", "#...#", "#...#", ".####"), glyph('e', ".....", ".....", ".###.", "#...#", "#####", "#....", ".###."), glyph('f', "..##.", ".#..#", ".#...", "####.", ".#...", ".#...", ".#..."), glyph8('g', ".....", ".....", ".####", "#...#", "#...#", ".####", "....#", ".###."), glyph('h', "#....", "#....", "####.", "#...#", "#...#", "#...#", "#...#"), glyph('i', "..#..", ".....", ".##..", "..#..", "..#..", "..#..", ".###."), glyph8('j', "...#.", ".....", "..##.", "...#.", "...#.", "...#.", "#..#.", ".##.."), glyph('k', "#....", "#....", "#..#.", "#.#..", "##...", "#.#..", "#..#."), glyph('l', ".##..", "..#..", "..#..", "..#..", "..#..", "..#..", ".###."), glyph('m', ".....", ".....", "##.#.", "#.#.#", "#.#.#", "#...#", "#...#"), glyph('n', ".....", ".....", "####.", "#...#", "#...#", "#...#", "#...#"), glyph('o', ".....", ".....", ".###.", "#...#", "#...#", "#...#", ".###."), glyph8('p', ".....", ".....", "####.", "#...#", "#...#", "####.", "#....", "#...."), glyph8('q', ".....", ".....", ".####", "#...#", "#...#", ".####", "....#", "....#"), glyph('r', ".....", ".....", "#.##.", "##..#", "#....", "#....", "#...."), glyph('s', ".....", ".....", ".####", "#....", ".###.", "....#", "####."), glyph('t', ".#...", ".#...", "####.", ".#...", ".#...", ".#..#", "..##."), glyph('u', ".....", ".....", "#...#", "#...#", "#...#", "#..##", ".##.#"), glyph('v', ".....", ".....", "#...#", "#...#", "#...#", ".#.#.", "..#.."), glyph('w', ".....", ".....", "#...#", "#...#", "#.#.#", "#.#.#", ".#.#."), glyph('x', ".....", ".....", "#...#", ".#.#.", "..#..", ".#.#.", "#...#"), glyph8('y', ".....", ".....", "#...#", "#...#", "#...#", ".####", "....#", ".###."), glyph('z', ".....", ".....", "#####", "...#.", "..#..", ".#...", "#####"), glyph('{', "...##", "..#..", "..#..", ".##..", "..#..", "..#..", "...##"), glyph('|', "..#..", "..#..", "..#..", "..#..", "..#..", "..#..", "..#.."), glyph('}', "##...", "..#..", "..#..", "..##.", "..#..", "..#..", "##..."), glyph('~', ".....", ".#...", "#.#.#", "...#.", ".....", ".....", "....."), } // fallback is drawn for any rune the font does not cover (everything outside // printable ASCII). A hollow box is the conventional "missing glyph". var fallback = [8]string{ ".....", ".....", "####.", "#..#.", "#..#.", "#..#.", "####.", ".....", } func pack(rows [8]string) [8]uint8 { var out [8]uint8 for y, row := range rows { if len(row) != 5 { fmt.Fprintf(os.Stderr, "row %q is not 5 columns wide\n", row) os.Exit(1) } var b uint8 for x := 0; x < 5; x++ { if row[x] == '#' { b |= 1 << uint(4-x) } else if row[x] != '.' { fmt.Fprintf(os.Stderr, "row %q has a character that is neither # nor .\n", row) os.Exit(1) } } out[y] = b } return out } func main() { if len(glyphs) != 95 { fmt.Fprintf(os.Stderr, "expected 95 glyphs, have %d\n", len(glyphs)) os.Exit(1) } for i, gl := range glyphs { if want := rune(0x20 + i); gl.r != want { fmt.Fprintf(os.Stderr, "glyph %d is %q, expected %q\n", i, gl.r, want) os.Exit(1) } } var b strings.Builder b.WriteString("// Code generated by \"go run fontgen.go\"; DO NOT EDIT.\n") b.WriteString("// The glyph artwork lives in fontgen.go.\n\n") b.WriteString("package main\n\n") b.WriteString("// Bitmap font geometry. Each glyph is glyphW x glyphH pixels, drawn into a\n") b.WriteString("// cellW x cellH character cell with the glyph offset by (glyphX, glyphY).\n") b.WriteString("const (\n") b.WriteString("\tglyphW = 5\n") b.WriteString("\tglyphH = 8\n") b.WriteString("\tcellW = 6\n") b.WriteString("\tcellH = 11\n") b.WriteString("\tglyphX = 0\n") b.WriteString("\tglyphY = 1\n") b.WriteString(")\n\n") b.WriteString("// fontBits holds one packed row per scan line for U+0020..U+007E in order.\n") b.WriteString("// Bit 4 is the leftmost pixel, bit 0 the rightmost; bits 5-7 are always zero.\n") b.WriteString("var fontBits = [95][8]uint8{\n") for _, gl := range glyphs { p := pack(gl.rows) name := string(gl.r) if gl.r == '\\' { name = "\\\\" } fmt.Fprintf(&b, "\t{0x%02x, 0x%02x, 0x%02x, 0x%02x, 0x%02x, 0x%02x, 0x%02x, 0x%02x}, // %q\n", p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], name) } b.WriteString("}\n\n") b.WriteString("// fontFallback is drawn for every rune outside printable ASCII.\n") p := pack(fallback) fmt.Fprintf(&b, "var fontFallback = [8]uint8{0x%02x, 0x%02x, 0x%02x, 0x%02x, 0x%02x, 0x%02x, 0x%02x, 0x%02x}\n", p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]) fmt.Print(b.String()) }