From 292dff589ee26e69a028cb27feabe2a3ca8345d1 Mon Sep 17 00:00:00 2001 From: Nikolay Sivov Date: Thu, 11 Jun 2020 15:08:59 +0300 Subject: [PATCH] dwrite: Implement ligature substitution. Signed-off-by: Nikolay Sivov Signed-off-by: Alexandre Julliard --- dlls/dwrite/dwrite_private.h | 2 +- dlls/dwrite/opentype.c | 134 +++++++++++++++++++++++++---------- 2 files changed, 97 insertions(+), 39 deletions(-) diff --git a/dlls/dwrite/dwrite_private.h b/dlls/dwrite/dwrite_private.h index 4cb35a44e49..661e01123c9 100644 --- a/dlls/dwrite/dwrite_private.h +++ b/dlls/dwrite/dwrite_private.h @@ -529,7 +529,7 @@ struct shaping_glyph_properties UINT16 isZeroWidthSpace : 1; UINT16 reserved : 1; UINT16 components : 4; - UINT16 reserved2 : 4; + UINT16 lig_component : 4; }; struct scriptshaping_context; diff --git a/dlls/dwrite/opentype.c b/dlls/dwrite/opentype.c index 63b35155b31..a6e2663ab16 100644 --- a/dlls/dwrite/opentype.c +++ b/dlls/dwrite/opentype.c @@ -5104,11 +5104,71 @@ static BOOL opentype_layout_apply_gsub_alt_substitution(struct scriptshaping_con return TRUE; } -static BOOL opentype_layout_apply_ligature(struct scriptshaping_context *context, unsigned int offset) +static BOOL opentype_layout_context_match_input(const struct match_context *mc, unsigned int count, const UINT16 *input, + unsigned int *end_offset, unsigned int *match_positions) { + struct match_data match_data = { .mc = mc, .subtable_offset = mc->input_offset }; + struct scriptshaping_context *context = mc->context; + struct glyph_iterator iter; + unsigned int i; + + if (count > GLYPH_CONTEXT_MAX_LENGTH) + return FALSE; + + match_positions[0] = context->cur; + + glyph_iterator_init(context, mc->lookup->flags, context->cur, count - 1, &iter); + iter.mask = mc->lookup->mask; + iter.match_func = mc->match_func; + iter.match_data = &match_data; + iter.glyph_data = input; + + for (i = 1; i < count; ++i) + { + if (!glyph_iterator_next(&iter)) + return FALSE; + + match_positions[i] = iter.pos; + } + + *end_offset = iter.pos - context->cur + 1; + + return TRUE; +} + +static void opentype_layout_unsafe_to_break(struct scriptshaping_context *context, unsigned int idx) +{ + if (context->u.buffer.glyph_props[idx].isClusterStart) + context->u.buffer.text_props[context->glyph_infos[idx].start_text_idx].canBreakShapingAfter = 0; +} + +static void opentype_layout_delete_glyph(struct scriptshaping_context *context, unsigned int idx) +{ + unsigned int shift_len; + + shift_len = context->glyph_count - context->cur - 1; + + if (shift_len) + { + memmove(&context->u.buffer.glyphs[idx], &context->u.buffer.glyphs[idx + 1], + shift_len * sizeof(*context->u.buffer.glyphs)); + memmove(&context->u.buffer.glyph_props[idx], &context->u.buffer.glyph_props[idx + 1], + shift_len * sizeof(*context->u.buffer.glyph_props)); + memmove(&context->glyph_infos[idx], &context->glyph_infos[idx + 1], shift_len * sizeof(*context->glyph_infos)); + } + + context->glyph_count--; +} + +static BOOL opentype_layout_apply_ligature(struct scriptshaping_context *context, unsigned int offset, + const struct lookup *lookup) +{ + struct match_context mc = { .context = context, .lookup = lookup, .match_func = opentype_match_glyph_func }; const struct dwrite_fonttable *gsub = &context->table->table; + unsigned int match_positions[GLYPH_CONTEXT_MAX_LENGTH]; + unsigned int i, j, comp_count, match_length = 0; const struct ot_gsub_lig *lig; - unsigned int comp_count; + UINT16 lig_glyph; comp_count = table_read_be_word(gsub, offset + FIELD_OFFSET(struct ot_gsub_lig, comp_count)); @@ -5119,16 +5179,46 @@ static BOOL opentype_layout_apply_ligature(struct scriptshaping_context *context if (!lig) return FALSE; + lig_glyph = GET_BE_WORD(lig->lig_glyph); + if (comp_count == 1) { - opentype_layout_replace_glyph(context, GET_BE_WORD(lig->lig_glyph)); + opentype_layout_replace_glyph(context, lig_glyph); context->cur++; return TRUE; } - /* TODO: actually apply ligature */ + if (!opentype_layout_context_match_input(&mc, comp_count, lig->components, &match_length, match_positions)) + return FALSE; - return FALSE; + opentype_layout_replace_glyph(context, lig_glyph); + context->u.buffer.glyph_props[context->cur].components = comp_count; + + /* Positioning against a ligature implies keeping track of ligature component + glyph should be attached to. Update per-glyph property for interleaving glyphs, + 0 means attaching to last component, n - attaching to n-th glyph before last. */ + for (i = 1; i < comp_count; ++i) + { + j = match_positions[i - 1] + 1; + while (j < match_positions[i]) + { + context->u.buffer.glyph_props[j++].lig_component = comp_count - i; + } + opentype_layout_unsafe_to_break(context, i); + context->u.buffer.glyph_props[i].isClusterStart = 0; + context->glyph_infos[i].start_text_idx = 0; + } + + /* Delete ligated glyphs, backwards to preserve index. */ + for (i = 1; i < comp_count; ++i) + { + opentype_layout_delete_glyph(context, match_positions[comp_count - i]); + } + + /* Skip whole matched sequence, accounting for deleted glyphs. */ + context->cur += match_length - (comp_count - 1); + + return TRUE; } static BOOL opentype_layout_apply_gsub_lig_substitution(struct scriptshaping_context *context, const struct lookup *lookup, @@ -5173,7 +5263,7 @@ static BOOL opentype_layout_apply_gsub_lig_substitution(struct scriptshaping_con /* First applicable ligature is used. */ for (i = 0; i < lig_count; ++i) { - if (opentype_layout_apply_ligature(context, offset + GET_BE_WORD(lig_set->offsets[i]))) + if (opentype_layout_apply_ligature(context, offset + GET_BE_WORD(lig_set->offsets[i]), lookup)) return TRUE; } } @@ -5183,38 +5273,6 @@ static BOOL opentype_layout_apply_gsub_lig_substitution(struct scriptshaping_con return FALSE; } -static BOOL opentype_layout_context_match_input(const struct match_context *mc, unsigned int count, const UINT16 *input, - unsigned int *end_offset, unsigned int *match_positions) -{ - struct match_data match_data = { .mc = mc, .subtable_offset = mc->input_offset }; - struct scriptshaping_context *context = mc->context; - struct glyph_iterator iter; - unsigned int i; - - if (count > GLYPH_CONTEXT_MAX_LENGTH) - return FALSE; - - match_positions[0] = context->cur; - - glyph_iterator_init(context, mc->lookup->flags, context->cur, count - 1, &iter); - iter.mask = mc->lookup->mask; - iter.match_func = mc->match_func; - iter.match_data = &match_data; - iter.glyph_data = input; - - for (i = 1; i < count; ++i) - { - if (!glyph_iterator_next(&iter)) - return FALSE; - - match_positions[i] = iter.pos; - } - - *end_offset = iter.pos - context->cur + 1; - - return TRUE; -} - static BOOL opentype_layout_context_match_backtrack(const struct match_context *mc, unsigned int count, const UINT16 *backtrack, unsigned int *match_start) {