claude
6b10c4a57c
- .font format: glyph sections with #/. grids, proportional widths, literal unicode glyph names, spacing/space-width/line-height/baseline - build (atlas white-on-transparent + JSON metrics), render (text -> PNG with \n, scale, color), info, preview (terminal half-blocks) - example tiny5 font: A-Z, ÅÄÖ, 0-9, punctuation (47 glyphs, 3x5) - go tests: parsing, errors, atlas metrics, text rendering Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MmdG9GqfSWCzts7AkDwRDh
76 lines
1.9 KiB
Markdown
76 lines
1.9 KiB
Markdown
# bitmap-font-maker (`fontc`)
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Turns `.font` text files — pixel glyph grids an agent can read and edit
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directly — into **font atlases (PNG + JSON metrics)** and renders text
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strings to PNG. Proportional widths, unicode glyph names (ÅÄÖ works).
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Go, zero dependencies, single static binary.
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## Build
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```bash
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# Arch/Garuda: sudo pacman -S go
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cd bitmap-font-maker
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go build -o build/fontc . # or the VS Code task "build bitmap-font-maker"
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go test ./...
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```
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## The `.font` format
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```
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# comment
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font: tiny5 optional name
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spacing: 1 px between glyphs (default 1)
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space-width: 3 advance of ' ' (default: width of '0')
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line-height: 7 default: glyph height + 1
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baseline: 5 default: glyph height
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glyph A:
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.#.
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#.#
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###
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#.#
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#.#
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glyph :: the char between "glyph " and ":" is literal
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.
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#
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.
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#
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.
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```
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- `#` = pixel on, `.` = off.
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- **All glyphs share one height; widths may differ** (proportional fonts —
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`M` can be 5 px wide while `.` is 1 px).
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- Max glyph size 64x64.
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## Commands
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```bash
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fontc build tiny5.font -o out/tiny5 # -> tiny5.png (atlas) + tiny5.json (metrics)
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fontc render tiny5.font 'HEJ!\nRAD 2' --scale 4 --color '#FFD700' -o title.png
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fontc info tiny5.font # validate + list glyphs
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fontc preview tiny5.font 'HELLO' # draw in the terminal
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```
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## Atlas + metrics
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The atlas draws glyphs **white on transparent** so game engines can tint
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them. The JSON carries everything a loader needs:
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```json
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{
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"name": "tiny5", "atlas": "tiny5.png",
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"height": 5, "lineHeight": 6, "baseline": 5,
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"spacing": 1, "spaceWidth": 3,
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"glyphs": { "A": {"x": 0, "y": 0, "w": 3, "h": 5, "advance": 4}, ... }
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}
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```
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Drawing text in a game: blit `glyphs[c]` from the atlas, advance the
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cursor by `advance`; spaces advance `spaceWidth + spacing`; new lines
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step `lineHeight`.
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[`examples/tiny5.font`](examples/tiny5.font) is a complete 3x5 font:
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A-Z, ÅÄÖ, 0-9 and punctuation.
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