[PATCH 3/5] dwrite: Implement contextual subsitution (GSUB lookup 5).
Nikolay Sivov
nsivov at codeweavers.com
Mon Jun 1 04:23:35 CDT 2020
Signed-off-by: Nikolay Sivov <nsivov at codeweavers.com>
---
dlls/dwrite/opentype.c | 165 +++++++++++++++++++++++++++++++++++++++--
1 file changed, 158 insertions(+), 7 deletions(-)
diff --git a/dlls/dwrite/opentype.c b/dlls/dwrite/opentype.c
index c724327c507..f1b9fb4e474 100644
--- a/dlls/dwrite/opentype.c
+++ b/dlls/dwrite/opentype.c
@@ -610,7 +610,7 @@ struct ot_gsub_lig
UINT16 components[1];
};
-struct ot_gsub_chaincontext_subst_format1
+struct ot_gsub_context_subst_format1
{
UINT16 format;
UINT16 coverage;
@@ -5205,6 +5205,157 @@ static BOOL opentype_layout_apply_chain_rule_set(const struct match_context *mc,
return FALSE;
}
+static BOOL opentype_layout_apply_gsub_context_lookup(unsigned int input_count, const UINT16 *input, unsigned int lookup_count,
+ const UINT16 *lookup_records, const struct match_context *mc)
+{
+ unsigned int match_positions[GLYPH_CONTEXT_MAX_LENGTH];
+ unsigned int match_length = 0;
+
+ return opentype_layout_context_match_input(mc, input_count, input, &match_length, match_positions) &&
+ opentype_layout_context_gsub_apply_lookup(mc->context, input_count, match_positions, lookup_count,
+ lookup_records, match_length);
+}
+
+static BOOL opentype_layout_apply_rule_set(const struct match_context *mc, unsigned int offset)
+{
+ unsigned int input_count, lookup_count;
+ const struct dwrite_fonttable *table = &mc->context->table->table;
+ const UINT16 *input, *lookup_records;
+ const struct ot_gsub_ruleset *ruleset;
+ unsigned int i, count;
+
+ count = table_read_be_word(table, offset);
+ ruleset = table_read_ensure(table, offset, count * sizeof(ruleset->offsets));
+
+ for (i = 0; i < count; ++i)
+ {
+ unsigned int rule_offset = offset + GET_BE_WORD(ruleset->offsets[i]);
+
+ if (!(input_count = table_read_be_word(table, rule_offset)))
+ continue;
+ rule_offset += 2;
+
+ if (!(lookup_count = table_read_be_word(table, rule_offset)))
+ continue;
+ rule_offset += 2;
+
+ if (!(input = table_read_ensure(table, rule_offset, (input_count - 1) * sizeof(*input))))
+ continue;
+ rule_offset += (input_count - 1) * sizeof(*input);
+
+ if (!(lookup_records = table_read_ensure(table, rule_offset, lookup_count * 2 * sizeof(*lookup_records))))
+ continue;
+
+ /* First applicable rule is used. */
+ if (opentype_layout_apply_gsub_context_lookup(input_count, input, lookup_count, lookup_records, mc))
+ return TRUE;
+ }
+
+ return FALSE;
+}
+
+static BOOL opentype_layout_apply_gsub_context_substitution(struct scriptshaping_context *context, const struct lookup *lookup,
+ unsigned int subtable_offset)
+{
+ struct match_context mc = { .context = context, .mask = lookup->mask };
+ const struct dwrite_fonttable *table = &context->table->table;
+ unsigned int coverage_index = GLYPH_NOT_COVERED, count, offset;
+ UINT16 glyph, format, coverage;
+ BOOL ret = FALSE;
+
+ glyph = context->u.subst.glyphs[context->cur];
+
+ format = table_read_be_word(table, subtable_offset);
+
+ if (format == 1)
+ {
+ coverage = table_read_be_word(table, subtable_offset + FIELD_OFFSET(struct ot_gsub_context_subst_format1, coverage));
+
+ coverage_index = opentype_layout_is_glyph_covered(table, subtable_offset + coverage, glyph);
+ if (coverage_index == GLYPH_NOT_COVERED)
+ return FALSE;
+
+ count = table_read_be_word(table, subtable_offset + FIELD_OFFSET(struct ot_gsub_context_subst_format1,
+ ruleset_count));
+ if (coverage_index >= count)
+ return FALSE;
+
+ offset = table_read_be_word(table, subtable_offset + FIELD_OFFSET(struct ot_gsub_context_subst_format1,
+ rulesets[coverage_index]));
+ offset += subtable_offset;
+
+ mc.match_func = opentype_match_glyph_func;
+
+ ret = opentype_layout_apply_rule_set(&mc, offset);
+ }
+ else if (format == 2)
+ {
+ unsigned int input_classdef, rule_set_idx;
+
+ offset = subtable_offset + 2 /* format */;
+
+ coverage = table_read_be_word(table, offset);
+ offset += 2;
+
+ coverage_index = opentype_layout_is_glyph_covered(table, subtable_offset + coverage, glyph);
+ if (coverage_index == GLYPH_NOT_COVERED)
+ return FALSE;
+
+ input_classdef = table_read_be_word(table, offset) + subtable_offset;
+ offset += 2;
+
+ count = table_read_be_word(table, offset);
+ offset+= 2;
+
+ rule_set_idx = opentype_layout_get_glyph_class(table, input_classdef, glyph);
+ if (rule_set_idx >= count)
+ return FALSE;
+
+ offset = table_read_be_word(table, offset + rule_set_idx * 2);
+ offset += subtable_offset;
+
+ mc.input_offset = input_classdef;
+ mc.match_func = opentype_match_class_func;
+
+ ret = opentype_layout_apply_rule_set(&mc, offset);
+ }
+ else if (format == 3)
+ {
+ unsigned int input_count, lookup_count;
+ const UINT16 *input, *lookup_records;
+
+ offset = subtable_offset + 2 /* format */;
+
+ input_count = table_read_be_word(table, offset);
+ offset += 2;
+
+ if (!input_count)
+ return FALSE;
+
+ lookup_count = table_read_be_word(table, offset);
+ offset += 2;
+
+ if (!(input = table_read_ensure(table, offset, sizeof(*input) * input_count)))
+ return FALSE;
+ offset += sizeof(*input) * input_count;
+
+ coverage_index = opentype_layout_is_glyph_covered(table, subtable_offset + GET_BE_WORD(input[0]), glyph);
+ if (coverage_index == GLYPH_NOT_COVERED)
+ return FALSE;
+
+ lookup_records = table_read_ensure(table, offset, lookup_count * 2 * sizeof(*lookup_records));
+
+ mc.input_offset = subtable_offset;
+ mc.match_func = opentype_match_coverage_func;
+
+ ret = opentype_layout_apply_gsub_context_lookup(input_count, input + 1, lookup_count, lookup_records, &mc);
+ }
+ else
+ WARN("Unknown contextual substitution format %u.\n", format);
+
+ return ret;
+}
+
static BOOL opentype_layout_apply_gsub_chain_context_substitution(struct scriptshaping_context *context,
const struct lookup *lookup, unsigned int subtable_offset)
{
@@ -5220,19 +5371,17 @@ static BOOL opentype_layout_apply_gsub_chain_context_substitution(struct scripts
if (format == 1)
{
- coverage = table_read_be_word(table, subtable_offset +
- FIELD_OFFSET(struct ot_gsub_chaincontext_subst_format1, coverage));
+ coverage = table_read_be_word(table, subtable_offset + FIELD_OFFSET(struct ot_gsub_context_subst_format1, coverage));
coverage_index = opentype_layout_is_glyph_covered(table, subtable_offset + coverage, glyph);
if (coverage_index == GLYPH_NOT_COVERED)
return FALSE;
- count = table_read_be_word(table, subtable_offset + FIELD_OFFSET(struct ot_gsub_chaincontext_subst_format1,
- ruleset_count));
+ count = table_read_be_word(table, subtable_offset + FIELD_OFFSET(struct ot_gsub_context_subst_format1, ruleset_count));
if (coverage_index >= count)
return FALSE;
- offset = table_read_be_word(table, subtable_offset + FIELD_OFFSET(struct ot_gsub_chaincontext_subst_format1,
+ offset = table_read_be_word(table, subtable_offset + FIELD_OFFSET(struct ot_gsub_context_subst_format1,
rulesets[coverage_index]));
offset += subtable_offset;
@@ -5357,10 +5506,12 @@ static BOOL opentype_layout_apply_gsub_lookup(struct scriptshaping_context *cont
case GSUB_LOOKUP_LIGATURE_SUBST:
ret = opentype_layout_apply_gsub_lig_substitution(context, lookup, subtable_offset);
break;
+ case GSUB_LOOKUP_CONTEXTUAL_SUBST:
+ ret = opentype_layout_apply_gsub_context_substitution(context, lookup, subtable_offset);
+ break;
case GSUB_LOOKUP_CHAINING_CONTEXTUAL_SUBST:
ret = opentype_layout_apply_gsub_chain_context_substitution(context, lookup, subtable_offset);
break;
- case GSUB_LOOKUP_CONTEXTUAL_SUBST:
case GSUB_LOOKUP_REVERSE_CHAINING_CONTEXTUAL_SUBST:
WARN("Unimplemented lookup %d.\n", lookup->type);
break;
--
2.26.2
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