# kb-text-shape
Haskell wrapper for the [kb_text_shape.h] unicode segmentation and shaping library (v2.06).
[kb_text_shape.h]: https://github.com/JimmyLefevre/kb/blob/main/kb_text_shape.h
> ```
> 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.
```haskell
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.
```haskell
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
```