diff options
Diffstat (limited to 'crates/typst-layout')
| -rw-r--r-- | crates/typst-layout/src/inline/shaping.rs | 40 |
1 files changed, 35 insertions, 5 deletions
diff --git a/crates/typst-layout/src/inline/shaping.rs b/crates/typst-layout/src/inline/shaping.rs index 159619eb..8236d1e3 100644 --- a/crates/typst-layout/src/inline/shaping.rs +++ b/crates/typst-layout/src/inline/shaping.rs @@ -824,12 +824,42 @@ fn shape_segment<'a>( // Add the glyph to the shaped output. if info.glyph_id != 0 && is_covered(cluster) { - // Determine the text range of the glyph. + // Assume we have the following sequence of (glyph_id, cluster): + // [(120, 0), (80, 0), (3, 3), (755, 4), (69, 4), (424, 13), + // (63, 13), (193, 25), (80, 25), (3, 31) + // + // We then want the sequence of (glyph_id, text_range) to look as follows: + // [(120, 0..3), (80, 0..3), (3, 3..4), (755, 4..13), (69, 4..13), + // (424, 13..25), (63, 13..25), (193, 25..31), (80, 25..31), (3, 31..x)] + // + // Each glyph in the same cluster should be assigned the full text + // range. This is necessary because only this way krilla can + // properly assign `ActualText` attributes in complex shaping + // scenarios. + + // The start of the glyph's text range. let start = base + cluster; - let end = base - + if ltr { i.checked_add(1) } else { i.checked_sub(1) } - .and_then(|last| infos.get(last)) - .map_or(text.len(), |info| info.cluster as usize); + + // Determine the end of the glyph's text range. + let mut k = i; + let step: isize = if ltr { 1 } else { -1 }; + let end = loop { + // If we've reached the end of the glyphs, the `end` of the + // range should be the end of the full text. + let Some((next, next_info)) = k + .checked_add_signed(step) + .and_then(|n| infos.get(n).map(|info| (n, info))) + else { + break base + text.len(); + }; + + // If the cluster doesn't match anymore, we've reached the end. + if next_info.cluster != info.cluster { + break base + next_info.cluster as usize; + } + + k = next; + }; let c = text[cluster..].chars().next().unwrap(); let script = c.script(); |