The module text_shaping
Text shaping as a module (docs/FONTS.md, section 12.3): each export calls one function of support/text_shaping over tables in memory of the caller. The spacing of the font is two tables of the caller: the advances of the characters 32 to 126 and the pairs, of one scale of a glyph cache (text_shaping.spacing_of gives them from a cache). The module holds no state of a program.
The tables are hostile input: the counts are checked here; each advance, each pair, each byte and each range is read once by the package, and kept in its limits there, because the caller can change them during the call.
| Fact | Value |
|---|---|
| Source | modules/text_shaping |
| Boot image | in the boot image; the image is not built, so its size is not known |
| Imports | none |
| Imported by | none |
Exports
| Export | What it does |
|---|---|
| shape_text(advances: Table(Character_Advance, Read), pairs: Table(Pair_Entry, Read), text: Bytes(Read), placed: Table(Placed_Glyph, Append)) -> Integer | appends the placed glyphs of a text: one for each byte, x from the origin of the text and the advance with the pair adjustment, in 1/64 of a pixel |
| measure_texts(advances: Table(Character_Advance, Read), pairs: Table(Pair_Entry, Read), text: Bytes(Read), ranges: Table(Text_Range, Change)) -> Integer | writes the width of each text of a table of ranges into one table of bytes, in 1/64 of a pixel: a window measures all its labels in one call |
Read from the source of the module, as the build reads it to describe the exports (tools/kerneltool/describe.odin).