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[subset] fix subsetting of faces created via hb_face_create_for_tables. 

Fixes #3609.
This commit is contained in:
Garret Rieger 2022-05-25 21:16:37 +00:00
parent 6010feeeb5
commit 9564d98739
2 changed files with 117 additions and 2 deletions
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83
src/hb-subset.cc
View File

@ -78,6 +78,85 @@ using OT::Layout::GSUB::GSUB;
* retain glyph ids option and configure the subset to pass through the layout tables untouched.
*/
/*
* The list of tables that the subsetter can perform subsetting for.
*/
static hb_tag_t handled_tables[] {
HB_OT_TAG_glyf,
HB_OT_TAG_hdmx,
HB_OT_TAG_name,
HB_OT_TAG_head,
HB_OT_TAG_hhea,
HB_OT_TAG_hmtx,
HB_OT_TAG_vhea,
HB_OT_TAG_vmtx,
HB_OT_TAG_maxp,
HB_OT_TAG_sbix,
HB_OT_TAG_loca,
HB_OT_TAG_cmap,
HB_OT_TAG_OS2,
HB_OT_TAG_post,
HB_OT_TAG_COLR,
HB_OT_TAG_CPAL,
HB_OT_TAG_CBLC,
HB_OT_TAG_CBDT,
HB_OT_TAG_MATH,
HB_OT_TAG_cff1,
HB_OT_TAG_cff2,
HB_OT_TAG_VORG,
HB_OT_TAG_GDEF,
HB_OT_TAG_GSUB,
HB_OT_TAG_GPOS,
HB_OT_TAG_gvar,
HB_OT_TAG_HVAR,
HB_OT_TAG_VVAR
};
static bool _table_is_empty (const hb_face_t *face, hb_tag_t tag)
{
hb_blob_t* blob = hb_face_reference_table (face, tag);
bool result = (blob == hb_blob_get_empty ());
hb_blob_destroy (blob);
return result;
}
static unsigned int
_get_table_tags (const hb_face_t *face,
unsigned int start_offset,
unsigned int *table_count, /* IN/OUT */
hb_tag_t *table_tags /* OUT */)
{
unsigned num_tables = hb_face_get_table_tags (face, 0, nullptr, nullptr);
if (num_tables)
return hb_face_get_table_tags (face, start_offset, table_count, table_tags);
// If face has 0 tables associated with it, assume that it has built from
// hb_face_create_tables and thus is unable to list its tables. Fallback to
// checking each table type we can handle for existence instead.
auto it = hb_array_t<hb_tag_t> (handled_tables);
while (bool (it) && start_offset > 0)
{
if (!_table_is_empty (face, *it))
start_offset--;
it++;
}
unsigned num_written = 0;
while (bool (it) && num_written < *table_count)
{
if (!_table_is_empty (face, *it))
table_tags[num_written++] = *it;
it++;
}
*table_count = num_written;
return 0;
}
static unsigned
_plan_estimate_subset_table_size (hb_subset_plan_t *plan,
unsigned table_len,
@ -226,7 +305,7 @@ _is_table_present (hb_face_t *source, hb_tag_t tag)
{
hb_tag_t table_tags[32];
unsigned offset = 0, num_tables = ARRAY_LENGTH (table_tags);
while ((hb_face_get_table_tags (source, offset, &num_tables, table_tags), num_tables))
while ((_get_table_tags (source, offset, &num_tables, table_tags), num_tables))
{
for (unsigned i = 0; i < num_tables; ++i)
if (table_tags[i] == tag)
@ -388,7 +467,7 @@ hb_subset_plan_execute_or_fail (hb_subset_plan_t *plan)
unsigned offset = 0, num_tables = ARRAY_LENGTH (table_tags);
hb_vector_t<char> buf;
buf.alloc (4096 - 16);
while ((hb_face_get_table_tags (plan->source, offset, &num_tables, table_tags), num_tables))
while ((_get_table_tags (plan->source, offset, &num_tables, table_tags), num_tables))
{
for (unsigned i = 0; i < num_tables; ++i)
{

36
test/api/test-subset.c
View File

@ -193,6 +193,41 @@ test_subset_plan (void)
hb_face_destroy (face_ac);
}
static hb_blob_t*
_ref_table (hb_face_t *face, hb_tag_t tag, void *user_data)
{
return hb_face_reference_table ((hb_face_t*) user_data, tag);
}
static void
test_subset_create_for_tables_face (void)
{
hb_face_t *face_abc = hb_test_open_font_file ("fonts/Roboto-Regular.abc.ttf");
hb_face_t *face_ac = hb_test_open_font_file ("fonts/Roboto-Regular.ac.ttf");
hb_face_t *face_create_for_tables = hb_face_create_for_tables (
_ref_table,
face_abc,
NULL);
hb_set_t *codepoints = hb_set_create();
hb_set_add (codepoints, 97);
hb_set_add (codepoints, 99);
hb_subset_input_t* input = hb_subset_test_create_input (codepoints);
hb_set_destroy (codepoints);
hb_face_t* face_abc_subset = hb_subset_or_fail (face_create_for_tables, input);
hb_subset_test_check (face_ac, face_abc_subset, HB_TAG ('l','o','c', 'a'));
hb_subset_test_check (face_ac, face_abc_subset, HB_TAG ('g','l','y','f'));
hb_subset_input_destroy (input);
hb_face_destroy (face_abc_subset);
hb_face_destroy (face_create_for_tables);
hb_face_destroy (face_abc);
hb_face_destroy (face_ac);
}
int
main (int argc, char **argv)
{
@ -204,6 +239,7 @@ main (int argc, char **argv)
hb_test_add (test_subset_set_flags);
hb_test_add (test_subset_sets);
hb_test_add (test_subset_plan);
hb_test_add (test_subset_create_for_tables_face);
return hb_test_run();
}