/* * Copyright © 2018 Google, Inc. * * This is part of HarfBuzz, a text shaping library. * * Permission is hereby granted, without written agreement and without * license or royalty fees, to use, copy, modify, and distribute this * software and its documentation for any purpose, provided that the * above copyright notice and the following two paragraphs appear in * all copies of this software. * * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH * DAMAGE. * * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. * * Google Author(s): Garret Rieger, Rod Sheeter, Behdad Esfahbod */ #include "hb-object-private.hh" #include "hb-open-type-private.hh" #include "hb-subset-glyf.hh" #include "hb-subset-private.hh" #include "hb-subset-plan.hh" #include "hb-open-file-private.hh" #include "hb-ot-cmap-table.hh" #include "hb-ot-glyf-table.hh" #include "hb-ot-head-table.hh" #include "hb-ot-maxp-table.hh" #include "hb-ot-os2-table.hh" #ifndef HB_NO_VISIBILITY const void * const OT::_hb_NullPool[HB_NULL_POOL_SIZE / sizeof (void *)] = {}; #endif struct hb_subset_profile_t { hb_object_header_t header; ASSERT_POD (); }; /** * hb_subset_profile_create: * * Return value: New profile with default settings. * * Since: 1.8.0 **/ hb_subset_profile_t * hb_subset_profile_create () { return hb_object_create(); } /** * hb_subset_profile_destroy: * * Since: 1.8.0 **/ void hb_subset_profile_destroy (hb_subset_profile_t *profile) { if (!hb_object_destroy (profile)) return; free (profile); } template static hb_blob_t * _subset (hb_subset_plan_t *plan, hb_face_t *source) { OT::Sanitizer sanitizer; hb_blob_t *source_blob = sanitizer.sanitize (source->reference_table (TableType::tableTag)); const TableType *table = OT::Sanitizer::lock_instance (source_blob); hb_blob_t *result = table->subset(plan, source); hb_blob_destroy (source_blob); hb_tag_t tag = TableType::tableTag; DEBUG_MSG(SUBSET, nullptr, "OT::%c%c%c%c::subset %s", HB_UNTAG(tag), result ? "success" : "FAILED!"); return result; } /* * A face that has add_table(). */ struct hb_subset_face_data_t { struct table_entry_t { inline int cmp (const hb_tag_t *t) const { if (*t < tag) return -1; if (*t > tag) return -1; return 0; } hb_tag_t tag; hb_blob_t *blob; }; hb_prealloced_array_t tables; }; static hb_subset_face_data_t * _hb_subset_face_data_create (void) { hb_subset_face_data_t *data = (hb_subset_face_data_t *) calloc (1, sizeof (hb_subset_face_data_t)); if (unlikely (!data)) return nullptr; return data; } static void _hb_subset_face_data_destroy (void *user_data) { hb_subset_face_data_t *data = (hb_subset_face_data_t *) user_data; data->tables.finish (); free (data); } static hb_blob_t * _hb_subset_face_data_reference_blob (hb_subset_face_data_t *data) { unsigned int table_count = data->tables.len; unsigned int face_length = table_count * 16 + 12; for (unsigned int i = 0; i < table_count; i++) face_length += _hb_ceil_to_4 (hb_blob_get_length (data->tables.array[i].blob)); char *buf = (char *) malloc (face_length); if (unlikely (!buf)) return nullptr; OT::hb_serialize_context_t c (buf, face_length); OT::OpenTypeFontFile *f = c.start_serialize (); bool is_cff = data->tables.lsearch (HB_TAG ('C','F','F',' ')) || data->tables.lsearch (HB_TAG ('C','F','F','2')); hb_tag_t sfnt_tag = is_cff ? OT::OpenTypeFontFile::CFFTag : OT::OpenTypeFontFile::TrueTypeTag; OT::Supplier tags_supplier (&data->tables[0].tag, table_count, sizeof (data->tables[0])); OT::Supplier blobs_supplier (&data->tables[0].blob, table_count, sizeof (data->tables[0])); bool ret = f->serialize_single (&c, sfnt_tag, tags_supplier, blobs_supplier, table_count); c.end_serialize (); if (unlikely (!ret)) { free (buf); return nullptr; } return hb_blob_create (buf, face_length, HB_MEMORY_MODE_WRITABLE, buf, free); } static hb_blob_t * _hb_subset_face_reference_table (hb_face_t *face, hb_tag_t tag, void *user_data) { hb_subset_face_data_t *data = (hb_subset_face_data_t *) user_data; if (!tag) return _hb_subset_face_data_reference_blob (data); hb_subset_face_data_t::table_entry_t *entry = data->tables.lsearch (tag); if (entry) return hb_blob_reference (entry->blob); return nullptr; } static hb_face_t * hb_subset_face_create (void) { hb_subset_face_data_t *data = _hb_subset_face_data_create (); if (unlikely (!data)) return hb_face_get_empty (); return hb_face_create_for_tables (_hb_subset_face_reference_table, data, _hb_subset_face_data_destroy); } static bool hb_subset_face_add_table (hb_face_t *face, hb_tag_t tag, hb_blob_t *blob) { if (unlikely (face->destroy != _hb_subset_face_data_destroy)) return false; hb_subset_face_data_t *data = (hb_subset_face_data_t *) face->user_data; hb_subset_face_data_t::table_entry_t *entry = data->tables.push (); if (unlikely (!entry)) return false; entry->tag = tag; entry->blob = hb_blob_reference (blob); return true; } static bool _add_head_and_set_loca_version (hb_face_t *source, bool use_short_loca, hb_face_t *dest) { hb_blob_t *head_blob = OT::Sanitizer().sanitize (hb_face_reference_table (source, HB_OT_TAG_head)); const OT::head *head = OT::Sanitizer::lock_instance (head_blob); bool has_head = (head != nullptr); if (has_head) { OT::head *head_prime = (OT::head *) calloc (OT::head::static_size, 1); memcpy (head_prime, head, OT::head::static_size); head_prime->indexToLocFormat.set (use_short_loca ? 0 : 1); hb_blob_t *head_prime_blob = hb_blob_create ((const char*) head_prime, OT::head::static_size, HB_MEMORY_MODE_READONLY, head_prime, free); has_head = hb_subset_face_add_table (dest, HB_OT_TAG_head, head_prime_blob); hb_blob_destroy (head_prime_blob); } hb_blob_destroy (head_blob); return has_head; } static bool _subset_glyf (hb_subset_plan_t *plan, hb_face_t *source, hb_face_t *dest) { hb_blob_t *glyf_prime = nullptr; hb_blob_t *loca_prime = nullptr; bool success = true; bool use_short_loca = false; // TODO(grieger): Migrate to subset function on the table like cmap. if (hb_subset_glyf_and_loca (plan, source, &use_short_loca, &glyf_prime, &loca_prime)) { success = success && hb_subset_face_add_table (dest, HB_OT_TAG_glyf, glyf_prime); success = success && hb_subset_face_add_table (dest, HB_OT_TAG_loca, loca_prime); success = success && _add_head_and_set_loca_version (source, use_short_loca, dest); } else { success = false; } hb_blob_destroy (loca_prime); hb_blob_destroy (glyf_prime); return success; } static bool _subset_table (hb_subset_plan_t *plan, hb_face_t *source, hb_tag_t tag, hb_blob_t *source_blob, hb_face_t *dest) { // TODO (grieger): Handle updating the head table (loca format + num glyphs) DEBUG_MSG(SUBSET, nullptr, "begin subset %c%c%c%c", HB_UNTAG(tag)); hb_blob_t *dest_blob; switch (tag) { case HB_OT_TAG_glyf: return _subset_glyf (plan, source, dest); case HB_OT_TAG_head: // SKIP head, it's handled by glyf return true; case HB_OT_TAG_maxp: dest_blob = _subset (plan, source); break; case HB_OT_TAG_loca: // SKIP loca, it's handle by glyf return true; case HB_OT_TAG_cmap: dest_blob = _subset (plan, source); break; case HB_OT_TAG_os2: dest_blob = _subset (plan, source); break; default: dest_blob = source_blob; break; } DEBUG_MSG(SUBSET, nullptr, "subset %c%c%c%c %s", HB_UNTAG(tag), dest_blob ? "ok" : "FAILED"); if (unlikely(!dest_blob)) return false; if (unlikely(!hb_subset_face_add_table (dest, tag, dest_blob))) return false; return true; } static bool _should_drop_table(hb_tag_t tag) { switch (tag) { case HB_TAG ('G', 'D', 'E', 'F'): /* temporary */ case HB_TAG ('G', 'P', 'O', 'S'): /* temporary */ case HB_TAG ('G', 'S', 'U', 'B'): /* temporary */ case HB_TAG ('D', 'S', 'I', 'G'): return true; default: return false; } } /** * hb_subset: * @source: font face data to be subset. * @profile: profile to use for the subsetting. * @input: input to use for the subsetting. * * Subsets a font according to provided profile and input. **/ hb_face_t * hb_subset (hb_face_t *source, hb_subset_profile_t *profile, hb_subset_input_t *input) { if (unlikely (!profile || !input || !source)) return hb_face_get_empty(); hb_subset_plan_t *plan = hb_subset_plan_create (source, profile, input); hb_face_t *dest = hb_subset_face_create (); hb_tag_t table_tags[32]; unsigned int offset = 0, count; bool success = true; do { count = ARRAY_LENGTH (table_tags); hb_face_get_table_tags (source, offset, &count, table_tags); for (unsigned int i = 0; i < count; i++) { hb_tag_t tag = table_tags[i]; if (_should_drop_table(tag)) { DEBUG_MSG(SUBSET, nullptr, "drop %c%c%c%c", HB_UNTAG(tag)); continue; } hb_blob_t *blob = hb_face_reference_table (source, tag); success = success && _subset_table (plan, source, tag, blob, dest); hb_blob_destroy (blob); } } while (count == ARRAY_LENGTH (table_tags)); hb_subset_plan_destroy (plan); return success ? dest : hb_face_get_empty (); }