diff --git a/src/hb-subset-glyf.cc b/src/hb-subset-glyf.cc index e92228571..7b4344bbb 100644 --- a/src/hb-subset-glyf.cc +++ b/src/hb-subset-glyf.cc @@ -29,32 +29,103 @@ #include "hb-set.h" #include "hb-subset-glyf.hh" +struct loca_data_t +{ + bool is_short; + void *data; + unsigned int size; + + inline bool + _write_loca_entry (unsigned int id, + unsigned int offset) + { + unsigned int entry_size = is_short ? sizeof (OT::HBUINT16) : sizeof (OT::HBUINT32); + if ((id + 1) * entry_size <= size) + { + if (is_short) { + ((OT::HBUINT16*) data) [id].set (offset / 2); + } else { + ((OT::HBUINT32*) data) [id].set (offset); + } + return true; + } + + // Offset was not written because the write is out of bounds. + DEBUG_MSG(SUBSET, + nullptr, + "WARNING: Attempted to write an out of bounds loca entry at index %d. Loca size is %d.", + id, + size); + return false; + } + + inline bool + _add_empty_glyphs_to_loca (hb_codepoint_t from_gid, + hb_codepoint_t to_gid, + unsigned int offset) + { + bool success = true; + while (from_gid < to_gid) + { + success = success && _write_loca_entry (from_gid, + offset); + from_gid++; + } + return success; + } +}; + +/** + * If hints are being dropped find the range which in glyf at which + * the hinting instructions are located. Add them to the instruction_ranges + * vector. + */ +static bool +_add_instructions_range (const OT::glyf::accelerator_t &glyf, + hb_codepoint_t glyph_id, + unsigned int glyph_start_offset, + unsigned int glyph_end_offset, + bool drop_hints, + hb_vector_t *instruction_ranges /* OUT */) +{ + if (!instruction_ranges->resize (instruction_ranges->length + 2)) + { + DEBUG_MSG(SUBSET, nullptr, "Failed to resize instruction_ranges."); + return false; + } + unsigned int *instruction_start = &(*instruction_ranges)[instruction_ranges->length - 2]; + *instruction_start = 0; + unsigned int *instruction_end = &(*instruction_ranges)[instruction_ranges->length - 1]; + *instruction_end = 0; + + if (drop_hints) + { + if (unlikely (!glyf.get_instruction_offsets (glyph_start_offset, glyph_end_offset, + instruction_start, instruction_end))) + { + DEBUG_MSG(SUBSET, nullptr, "Unable to get instruction offsets for %d", glyph_id); + return false; + } + } + + return true; +} + static bool _calculate_glyf_and_loca_prime_size (const OT::glyf::accelerator_t &glyf, - hb_vector_t &glyph_ids, - const hb_map_t *glyph_map, - hb_bool_t drop_hints, - bool *use_short_loca /* OUT */, - unsigned int *glyf_size /* OUT */, - unsigned int *loca_size /* OUT */, - hb_vector_t *instruction_ranges /* OUT */) + const hb_subset_plan_t *plan, + loca_data_t *loca_data, /* OUT */ + unsigned int *glyf_size /* OUT */, + hb_vector_t *instruction_ranges /* OUT */) { unsigned int total = 0; hb_codepoint_t max_new_gid = 0; - for (unsigned int i = 0; i < glyph_ids.length; i++) + for (unsigned int i = 0; i < plan->glyphs.length; i++) { - hb_codepoint_t next_glyph = glyph_ids[i]; - hb_codepoint_t next_glyph_new_gid = glyph_map->get (next_glyph); - max_new_gid = MAX (max_new_gid, next_glyph_new_gid); - if (!instruction_ranges->resize (instruction_ranges->length + 2)) - { - DEBUG_MSG(SUBSET, nullptr, "Failed to resize instruction_ranges."); - return false; - } - unsigned int *instruction_start = &(*instruction_ranges)[instruction_ranges->length - 2]; - *instruction_start = 0; - unsigned int *instruction_end = &(*instruction_ranges)[instruction_ranges->length - 1]; - *instruction_end = 0; + hb_codepoint_t next_glyph = plan->glyphs[i]; + hb_codepoint_t new_gid_for_next_glyph; + if (plan->new_gid_for_old_gid (next_glyph, &new_gid_for_next_glyph)) + max_new_gid = MAX (max_new_gid, new_gid_for_next_glyph); unsigned int start_offset, end_offset; if (unlikely (!(glyf.get_offsets (next_glyph, &start_offset, &end_offset) && @@ -63,63 +134,38 @@ _calculate_glyf_and_loca_prime_size (const OT::glyf::accelerator_t &glyf, DEBUG_MSG(SUBSET, nullptr, "Invalid gid %d", next_glyph); continue; } - if (end_offset - start_offset < OT::glyf::GlyphHeader::static_size) + + bool is_zero_length = end_offset - start_offset < OT::glyf::GlyphHeader::static_size; + if (!_add_instructions_range (glyf, + next_glyph, + start_offset, + end_offset, + plan->drop_hints && !is_zero_length, + instruction_ranges)) + return false; + + if (is_zero_length) continue; /* 0-length glyph */ - if (drop_hints) - { - if (unlikely (!glyf.get_instruction_offsets (start_offset, end_offset, - instruction_start, instruction_end))) - { - DEBUG_MSG(SUBSET, nullptr, "Unable to get instruction offsets for %d", next_glyph); - return false; - } - } - - total += end_offset - start_offset - (*instruction_end - *instruction_start); + total += end_offset - start_offset + - ((*instruction_ranges)[instruction_ranges->length - 1] + - (*instruction_ranges)[instruction_ranges->length - 2]); /* round2 so short loca will work */ total += total % 2; } *glyf_size = total; - *use_short_loca = (total <= 131070); - *loca_size = (max_new_gid + 2) - * (*use_short_loca ? sizeof (OT::HBUINT16) : sizeof (OT::HBUINT32)); + loca_data->is_short = (total <= 131070); + loca_data->size = (max_new_gid + 2) + * (loca_data->is_short ? sizeof (OT::HBUINT16) : sizeof (OT::HBUINT32)); DEBUG_MSG(SUBSET, nullptr, "preparing to subset glyf: final size %d, loca size %d, using %s loca", total, - *loca_size, - *use_short_loca ? "short" : "long"); + loca_data->size, + loca_data->is_short ? "short" : "long"); return true; } -static bool -_write_loca_entry (unsigned int id, - unsigned int offset, - bool is_short, - void *loca_prime, - unsigned int loca_size) -{ - unsigned int entry_size = is_short ? sizeof (OT::HBUINT16) : sizeof (OT::HBUINT32); - if ((id + 1) * entry_size <= loca_size) - { - if (is_short) { - ((OT::HBUINT16*) loca_prime) [id].set (offset / 2); - } else { - ((OT::HBUINT32*) loca_prime) [id].set (offset); - } - return true; - } - - // Offset was not written because the write is out of bounds. - DEBUG_MSG(SUBSET, - nullptr, - "WARNING: Attempted to write an out of bounds loca entry at index %d. Loca size is %d.", - id, - loca_size); - return false; -} - static void _update_components (const hb_subset_plan_t *plan, char *glyph_start, @@ -160,33 +206,28 @@ static bool _write_glyf_and_loca_prime (const hb_subset_plan_t *plan, const OT::glyf::accelerator_t &glyf, const char *glyf_data, - bool use_short_loca, hb_vector_t &instruction_ranges, unsigned int glyf_prime_size, char *glyf_prime_data /* OUT */, - unsigned int loca_prime_size, - char *loca_prime_data /* OUT */) + loca_data_t *loca_prime /* OUT */) { const hb_vector_t &glyph_ids = plan->glyphs; - const hb_map_t *glyph_map = plan->glyph_map; char *glyf_prime_data_next = glyf_prime_data; bool success = true; - hb_codepoint_t gid = 0; + unsigned int current_gid = 0; for (unsigned int i = 0; i < glyph_ids.length; i++) { - while (gid < glyph_map->get (glyph_ids[i])) - { - // If we are retaining existing gids then there will potentially be gaps - // in the loca table between glyphs. Fill in this gap with glyphs that have - // no outlines. - success = success && _write_loca_entry (gid, - glyf_prime_data_next - glyf_prime_data, - use_short_loca, - loca_prime_data, - loca_prime_size); - gid++; - } + hb_codepoint_t next_gid = current_gid; + success = success && plan->new_gid_for_old_gid (glyph_ids[i], &next_gid); + + // If we are retaining existing gids then there will potentially be gaps + // in the loca table between glyphs. Fill in this gap with glyphs that have + // no outlines. + success = success && loca_prime->_add_empty_glyphs_to_loca (current_gid, + next_gid, + glyf_prime_data_next - glyf_prime_data); + current_gid = next_gid; unsigned int start_offset, end_offset; if (unlikely (!(glyf.get_offsets (glyph_ids[i], &start_offset, &end_offset) && @@ -223,23 +264,19 @@ _write_glyf_and_loca_prime (const hb_subset_plan_t *plan, memset (glyf_prime_data_next + instruction_start - start_offset - 2, 0, 2); } - success = success && _write_loca_entry (gid, - glyf_prime_data_next - glyf_prime_data, - use_short_loca, - loca_prime_data, - loca_prime_size); + success = success && loca_prime->_write_loca_entry (current_gid, + glyf_prime_data_next - glyf_prime_data); _update_components (plan, glyf_prime_data_next, length); // TODO: don't align to two bytes if using long loca. glyf_prime_data_next += length + (length % 2); // Align to 2 bytes for short loca. - gid++; + current_gid++; } - success = success && _write_loca_entry (gid, - glyf_prime_data_next - glyf_prime_data, - use_short_loca, - loca_prime_data, - loca_prime_size); + // loca table has n+1 entries where the last entry signifies the end location of the last + // glyph. + success = success && loca_prime->_write_loca_entry (current_gid, + glyf_prime_data_next - glyf_prime_data); return success; } @@ -248,53 +285,48 @@ _hb_subset_glyf_and_loca (const OT::glyf::accelerator_t &glyf, const char *glyf_data, hb_subset_plan_t *plan, bool *use_short_loca, - hb_blob_t **glyf_prime /* OUT */, - hb_blob_t **loca_prime /* OUT */) + hb_blob_t **glyf_prime_blob /* OUT */, + hb_blob_t **loca_prime_blob /* OUT */) { // TODO(grieger): Sanity check allocation size for the new table. - hb_vector_t &glyphs_to_retain = plan->glyphs; - + loca_data_t loca_prime; unsigned int glyf_prime_size; - unsigned int loca_prime_size; hb_vector_t instruction_ranges; instruction_ranges.init (); if (unlikely (!_calculate_glyf_and_loca_prime_size (glyf, - glyphs_to_retain, - plan->glyph_map, - plan->drop_hints, - use_short_loca, + plan, + &loca_prime, &glyf_prime_size, - &loca_prime_size, &instruction_ranges))) { instruction_ranges.fini (); return false; } + *use_short_loca = loca_prime.is_short; char *glyf_prime_data = (char *) calloc (1, glyf_prime_size); - char *loca_prime_data = (char *) calloc (1, loca_prime_size); + loca_prime.data = (void *) calloc (1, loca_prime.size); if (unlikely (!_write_glyf_and_loca_prime (plan, glyf, glyf_data, - *use_short_loca, instruction_ranges, glyf_prime_size, glyf_prime_data, - loca_prime_size, loca_prime_data))) { + &loca_prime))) { free (glyf_prime_data); - free (loca_prime_data); + free (loca_prime.data); instruction_ranges.fini (); return false; } instruction_ranges.fini (); - *glyf_prime = hb_blob_create (glyf_prime_data, - glyf_prime_size, - HB_MEMORY_MODE_READONLY, - glyf_prime_data, - free); - *loca_prime = hb_blob_create (loca_prime_data, - loca_prime_size, - HB_MEMORY_MODE_READONLY, - loca_prime_data, - free); + *glyf_prime_blob = hb_blob_create (glyf_prime_data, + glyf_prime_size, + HB_MEMORY_MODE_READONLY, + glyf_prime_data, + free); + *loca_prime_blob = hb_blob_create ((char *) loca_prime.data, + loca_prime.size, + HB_MEMORY_MODE_READONLY, + loca_prime.data, + free); return true; }