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| author | Matthias Clasen <mclasen@redhat.com> | 2021-08-27 10:29:13 -0400 |
|---|---|---|
| committer | Matthias Clasen <mclasen@redhat.com> | 2021-08-27 12:18:26 -0400 |
| commit | c9f3cc464c4f06cc31c2b42e5c305a7fd7ae5879 (patch) | |
| tree | 231ae9d2302a22dae157d49acfe98a6ebe7bdb6a | |
| parent | 0fe6d50dea9ae15086d292cc8af9770606f68b21 (diff) | |
| download | pango-c9f3cc464c4f06cc31c2b42e5c305a7fd7ae5879.tar.gz | |
Try harder to find positions in clusters
Try to find a single non-mark glyph in a multi-glyph
cluster to use its ligature caret information. This
fixes situations in Arabic where you can have marks
on top of ligatures, e.g. ﻉﻭ.
| -rw-r--r-- | pango/glyphstring.c | 35 |
1 files changed, 32 insertions, 3 deletions
diff --git a/pango/glyphstring.c b/pango/glyphstring.c index cda4cf40..30d68220 100644 --- a/pango/glyphstring.c +++ b/pango/glyphstring.c @@ -520,17 +520,46 @@ pango_glyph_string_index_to_x (PangoGlyphString *glyphs, * with an m-n situation, where LigatureCaretList is * not going to help. Just give up and do the simple thing. */ - if (cluster_offset > 0 && cluster_offset < cluster_chars && - start_glyph_pos == end_glyph_pos) + if (cluster_offset > 0 && cluster_offset < cluster_chars) { hb_font_t *hb_font; hb_position_t caret; unsigned int caret_count = 1; + int glyph_pos; hb_font = pango_font_get_hb_font (analysis->font); + + if (start_glyph_pos == end_glyph_pos) + glyph_pos = start_glyph_pos; + else + { + hb_face_t *hb_face; + + hb_face = hb_font_get_face (hb_font); + + glyph_pos = -1; + for (i = start_glyph_pos; i <= end_glyph_pos; i++) + { + if (hb_ot_layout_get_glyph_class (hb_face, glyphs->glyphs[i].glyph) != HB_OT_LAYOUT_GLYPH_CLASS_MARK) + { + if (glyph_pos != -1) + { + /* multiple non-mark glyphs in cluster, giving up */ + goto fallback; + } + glyph_pos = i; + } + } + if (glyph_pos == -1) + { + /* no non-mark glyph in a multi-glyph cluster, giving up */ + goto fallback; + } + } + hb_ot_layout_get_ligature_carets (hb_font, (analysis->level % 2) ? HB_DIRECTION_RTL : HB_DIRECTION_LTR, - glyphs->glyphs[start_glyph_pos].glyph, + glyphs->glyphs[glyph_pos].glyph, cluster_offset - 1, &caret_count, &caret); if (caret_count > 0) { |