kb-text-shape: Unicode segmentation and shaping using kb_text_shape

This is a package candidate release! Here you can preview how this package release will appear once published to the main package index (which can be accomplished via the 'maintain' link below). Please note that once a package has been published to the main package index it cannot be undone! Please consult the package uploading documentation for more information.

[maintain] [Publish]

Warnings:

[no-description] No 'description' field.
[missing-upper-bounds] On library, these packages miss upper bounds: - bytestring - containers - text Please add them. There is more information at https://pvp.haskell.org/

[Skip to Readme]

Properties

Versions	0.1.0.0
Change log	CHANGELOG.md
Dependencies	base (>=4.16 && <5), bytestring, containers, text [details]
License	BSD-3-Clause
Copyright	2025 IC Rainbow
Author	IC Rainbow
Maintainer	aenor.realm@gmail.com
Category	Font
Home page	https://github.com/dpwiz/kb-text-shape#readme
Bug tracker	https://github.com/dpwiz/kb-text-shape/issues
Source repo	head: git clone https://github.com/dpwiz/kb-text-shape
Uploaded	by AlexanderBondarenko at 2025-12-26T20:19:16Z

Modules

[Index] [Quick Jump]

KB
- Text
  - KB.Text.Shape
    - FFI
    - KB.Text.Shape.Font

Flags

Manual Flags

Name	Description	Default
trace-blocks		Disabled

Use -f <flag> to enable a flag, or -f -<flag> to disable that flag. More info

Downloads

kb-text-shape-0.1.0.0.tar.gz [browse] (Cabal source package)
Package description (as included in the package)

Maintainer's Corner

Package maintainers

AlexanderBondarenko

For package maintainers and hackage trustees

edit package information

Readme for kb-text-shape-0.1.0.0

[back to package description]

kb-text-shape

Haskell wrapper for the kb_text_shape.h unicode segmentation and shaping library.

  Your text       A        Text runs with         B       Sequence of glyphs      C
  (Probably ------------> uniform direction ------------> ready to rasterize ------------> Pixels
  UTF-8)                    and script
We call arrow A text segmentation, arrow B text shaping, and arrow C rasterization. This library does A and B.

import KB.Text.Shape where qualified as TextShape

main = do
  TextShape.withContext \ctx -> do
    _fallback <- TextShape.pushFontFromFile ctx "test/NotoSans-Regular.ttf" 0
    _main <- TextShape.pushFontFromFile ctx "test/Ubuntu-R.ttf" 0
    results <- TextShape.run ctx do
      TextShape.text_ "A bunch of characters"
      TextShape.char_ '!'
    forM_ results \(run, glyphs) ->
      forM_ glyphs \glyph ->
        print (run.font, glyph.id, glyph.gpos.advanceX)

Font blobs

The library has an internal "blob" format for the pre-processed font data for leaner files and faster loading.

import KB.Text.Shape.Font qualified as Font

main = do
  ttfData <- ByteString.readFile "test/Ubuntu-R.ttf"
  putStrLn $ "Distilling " <> show (ByteString.length ttfData `div` 1024) <> "Kb of TTF"
  blobData <- Font.extractBlob ttfData 0
  putStrLn $ "Distilled into " <> show (ByteString.length blobData `div` 1024) <> "Kb blob"
  ByteString.writeFile "test/Ubuntu-R.kbts" blobData

The savings are modest, but can be improved even further with compression.

Distilling 1047Kb of TTF
Distilled into 618Kb blob