| /* |
| * 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.hh" |
| #include "hb-open-type.hh" |
| |
| #include "hb-subset.hh" |
| |
| #include "hb-open-file.hh" |
| #include "hb-ot-cmap-table.hh" |
| #include "hb-ot-glyf-table.hh" |
| #include "hb-ot-hdmx-table.hh" |
| #include "hb-ot-head-table.hh" |
| #include "hb-ot-hhea-table.hh" |
| #include "hb-ot-hmtx-table.hh" |
| #include "hb-ot-maxp-table.hh" |
| #include "OT/Color/CBDT/CBDT.hh" |
| #include "OT/Color/COLR/COLR.hh" |
| #include "OT/Color/CPAL/CPAL.hh" |
| #include "OT/Color/sbix/sbix.hh" |
| #include "hb-ot-os2-table.hh" |
| #include "hb-ot-post-table.hh" |
| #include "hb-ot-post-table-v2subset.hh" |
| #include "hb-ot-cff1-table.hh" |
| #include "hb-ot-cff2-table.hh" |
| #include "hb-ot-vorg-table.hh" |
| #include "hb-ot-name-table.hh" |
| #include "hb-ot-layout-gsub-table.hh" |
| #include "hb-ot-layout-gpos-table.hh" |
| #include "hb-ot-var-avar-table.hh" |
| #include "hb-ot-var-cvar-table.hh" |
| #include "hb-ot-var-fvar-table.hh" |
| #include "hb-ot-var-gvar-table.hh" |
| #include "hb-ot-var-hvar-table.hh" |
| #include "hb-ot-var-mvar-table.hh" |
| #include "hb-ot-math-table.hh" |
| #include "hb-ot-stat-table.hh" |
| #include "hb-repacker.hh" |
| #include "hb-subset-accelerator.hh" |
| |
| using OT::Layout::GSUB; |
| using OT::Layout::GPOS; |
| |
| |
| #ifndef HB_NO_SUBSET_CFF |
| template<> |
| struct hb_subset_plan_t::source_table_loader<const OT::cff1> |
| { |
| auto operator () (hb_subset_plan_t *plan) |
| HB_AUTO_RETURN (plan->accelerator ? plan->accelerator->cff1_accel : |
| plan->inprogress_accelerator ? plan->inprogress_accelerator->cff1_accel : |
| plan->cff1_accel) |
| }; |
| template<> |
| struct hb_subset_plan_t::source_table_loader<const OT::cff2> |
| { |
| auto operator () (hb_subset_plan_t *plan) |
| HB_AUTO_RETURN (plan->accelerator ? plan->accelerator->cff2_accel : |
| plan->inprogress_accelerator ? plan->inprogress_accelerator->cff2_accel : |
| plan->cff2_accel) |
| }; |
| #endif |
| |
| |
| /** |
| * SECTION:hb-subset |
| * @title: hb-subset |
| * @short_description: Subsets font files. |
| * @include: hb-subset.h |
| * |
| * Subsetting reduces the codepoint coverage of font files and removes all data |
| * that is no longer needed. A subset input describes the desired subset. The input is |
| * provided along with a font to the subsetting operation. Output is a new font file |
| * containing only the data specified in the input. |
| * |
| * Currently most outline and bitmap tables are supported: glyf, CFF, CFF2, sbix, |
| * COLR, and CBDT/CBLC. This also includes fonts with variable outlines via OpenType |
| * variations. Notably EBDT/EBLC and SVG are not supported. Layout subsetting is supported |
| * only for OpenType Layout tables (GSUB, GPOS, GDEF). Notably subsetting of graphite or AAT tables |
| * is not yet supported. |
| * |
| * Fonts with graphite or AAT tables may still be subsetted but will likely need to use the |
| * retain glyph ids option and configure the subset to pass through the layout tables untouched. |
| */ |
| |
| |
| hb_user_data_key_t _hb_subset_accelerator_user_data_key = {}; |
| |
| |
| /* |
| * The list of tables in the open type spec. Used to check for tables that may need handling |
| * if we are unable to list the tables in a face. |
| */ |
| static hb_tag_t known_tables[] { |
| HB_TAG ('a', 'v', 'a', 'r'), |
| HB_OT_TAG_BASE, |
| HB_OT_TAG_CBDT, |
| HB_OT_TAG_CBLC, |
| HB_OT_TAG_CFF1, |
| HB_OT_TAG_CFF2, |
| HB_OT_TAG_cmap, |
| HB_OT_TAG_COLR, |
| HB_OT_TAG_CPAL, |
| HB_TAG ('c', 'v', 'a', 'r'), |
| HB_TAG ('c', 'v', 't', ' '), |
| HB_TAG ('D', 'S', 'I', 'G'), |
| HB_TAG ('E', 'B', 'D', 'T'), |
| HB_TAG ('E', 'B', 'L', 'C'), |
| HB_TAG ('E', 'B', 'S', 'C'), |
| HB_TAG ('f', 'p', 'g', 'm'), |
| HB_TAG ('f', 'v', 'a', 'r'), |
| HB_TAG ('g', 'a', 's', 'p'), |
| HB_OT_TAG_GDEF, |
| HB_OT_TAG_glyf, |
| HB_OT_TAG_GPOS, |
| HB_OT_TAG_GSUB, |
| HB_OT_TAG_gvar, |
| HB_OT_TAG_hdmx, |
| HB_OT_TAG_head, |
| HB_OT_TAG_hhea, |
| HB_OT_TAG_hmtx, |
| HB_OT_TAG_HVAR, |
| HB_OT_TAG_JSTF, |
| HB_TAG ('k', 'e', 'r', 'n'), |
| HB_OT_TAG_loca, |
| HB_TAG ('L', 'T', 'S', 'H'), |
| HB_OT_TAG_MATH, |
| HB_OT_TAG_maxp, |
| HB_TAG ('M', 'E', 'R', 'G'), |
| HB_TAG ('m', 'e', 't', 'a'), |
| HB_TAG ('M', 'V', 'A', 'R'), |
| HB_TAG ('P', 'C', 'L', 'T'), |
| HB_OT_TAG_post, |
| HB_TAG ('p', 'r', 'e', 'p'), |
| HB_OT_TAG_sbix, |
| HB_TAG ('S', 'T', 'A', 'T'), |
| HB_TAG ('S', 'V', 'G', ' '), |
| HB_TAG ('V', 'D', 'M', 'X'), |
| HB_OT_TAG_vhea, |
| HB_OT_TAG_vmtx, |
| HB_OT_TAG_VORG, |
| HB_OT_TAG_VVAR, |
| HB_OT_TAG_name, |
| HB_OT_TAG_OS2 |
| }; |
| |
| 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_subset_plan_t* plan, |
| unsigned int start_offset, |
| unsigned int *table_count, /* IN/OUT */ |
| hb_tag_t *table_tags /* OUT */) |
| { |
| unsigned num_tables = hb_face_get_table_tags (plan->source, 0, nullptr, nullptr); |
| if (num_tables) |
| return hb_face_get_table_tags (plan->source, start_offset, table_count, table_tags); |
| |
| // If face has 0 tables associated with it, assume that it was 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_concat ( |
| + hb_array (known_tables) |
| | hb_filter ([&] (hb_tag_t tag) { |
| return !_table_is_empty (plan->source, tag) && !plan->no_subset_tables.has (tag); |
| }) |
| | hb_map ([] (hb_tag_t tag) -> hb_tag_t { return tag; }), |
| |
| plan->no_subset_tables.iter () |
| | hb_filter([&] (hb_tag_t tag) { |
| return !_table_is_empty (plan->source, tag); |
| })); |
| |
| it += start_offset; |
| |
| unsigned num_written = 0; |
| while (bool (it) && num_written < *table_count) |
| table_tags[num_written++] = *it++; |
| |
| *table_count = num_written; |
| return num_written; |
| } |
| |
| |
| static unsigned |
| _plan_estimate_subset_table_size (hb_subset_plan_t *plan, |
| unsigned table_len, |
| hb_tag_t table_tag) |
| { |
| unsigned src_glyphs = plan->source->get_num_glyphs (); |
| unsigned dst_glyphs = plan->glyphset ()->get_population (); |
| |
| unsigned bulk = 8192; |
| /* Tables that we want to allocate same space as the source table. For GSUB/GPOS it's |
| * because those are expensive to subset, so giving them more room is fine. */ |
| bool same_size = table_tag == HB_OT_TAG_GSUB || |
| table_tag == HB_OT_TAG_GPOS || |
| table_tag == HB_OT_TAG_name; |
| |
| if (plan->flags & HB_SUBSET_FLAGS_RETAIN_GIDS) |
| { |
| if (table_tag == HB_OT_TAG_CFF1) |
| { |
| /* Add some extra room for the CFF charset. */ |
| bulk += src_glyphs * 16; |
| } |
| else if (table_tag == HB_OT_TAG_CFF2) |
| { |
| /* Just extra CharString offsets. */ |
| bulk += src_glyphs * 4; |
| } |
| } |
| |
| if (unlikely (!src_glyphs) || same_size) |
| return bulk + table_len; |
| |
| return bulk + (unsigned) (table_len * sqrt ((double) dst_glyphs / src_glyphs)); |
| } |
| |
| /* |
| * Repack the serialization buffer if any offset overflows exist. |
| */ |
| static hb_blob_t* |
| _repack (hb_tag_t tag, const hb_serialize_context_t& c) |
| { |
| if (!c.offset_overflow ()) |
| return c.copy_blob (); |
| |
| hb_blob_t* result = hb_resolve_overflows (c.object_graph (), tag); |
| |
| if (unlikely (!result)) |
| { |
| DEBUG_MSG (SUBSET, nullptr, "OT::%c%c%c%c offset overflow resolution failed.", |
| HB_UNTAG (tag)); |
| return nullptr; |
| } |
| |
| return result; |
| } |
| |
| template<typename TableType> |
| static |
| bool |
| _try_subset (const TableType *table, |
| hb_vector_t<char>* buf, |
| hb_subset_context_t* c /* OUT */) |
| { |
| c->serializer->start_serialize (); |
| if (c->serializer->in_error ()) return false; |
| |
| bool needed = table->subset (c); |
| if (!c->serializer->ran_out_of_room ()) |
| { |
| c->serializer->end_serialize (); |
| return needed; |
| } |
| |
| unsigned buf_size = buf->allocated; |
| buf_size = buf_size * 2 + 16; |
| |
| |
| |
| |
| DEBUG_MSG (SUBSET, nullptr, "OT::%c%c%c%c ran out of room; reallocating to %u bytes.", |
| HB_UNTAG (c->table_tag), buf_size); |
| |
| if (unlikely (buf_size > c->source_blob->length * 16 || |
| !buf->alloc (buf_size, true))) |
| { |
| DEBUG_MSG (SUBSET, nullptr, "OT::%c%c%c%c failed to reallocate %u bytes.", |
| HB_UNTAG (c->table_tag), buf_size); |
| return needed; |
| } |
| |
| c->serializer->reset (buf->arrayZ, buf->allocated); |
| return _try_subset (table, buf, c); |
| } |
| |
| template <typename T> |
| static auto _do_destroy (T &t, hb_priority<1>) HB_RETURN (void, t.destroy ()) |
| |
| template <typename T> |
| static void _do_destroy (T &t, hb_priority<0>) {} |
| |
| template<typename TableType> |
| static bool |
| _subset (hb_subset_plan_t *plan, hb_vector_t<char> &buf) |
| { |
| auto &&source_blob = plan->source_table<TableType> (); |
| auto *table = source_blob.get (); |
| |
| hb_tag_t tag = TableType::tableTag; |
| hb_blob_t *blob = source_blob.get_blob(); |
| if (unlikely (!blob || !blob->data)) |
| { |
| DEBUG_MSG (SUBSET, nullptr, |
| "OT::%c%c%c%c::subset sanitize failed on source table.", HB_UNTAG (tag)); |
| _do_destroy (source_blob, hb_prioritize); |
| return false; |
| } |
| |
| unsigned buf_size = _plan_estimate_subset_table_size (plan, blob->length, TableType::tableTag); |
| DEBUG_MSG (SUBSET, nullptr, |
| "OT::%c%c%c%c initial estimated table size: %u bytes.", HB_UNTAG (tag), buf_size); |
| if (unlikely (!buf.alloc (buf_size))) |
| { |
| DEBUG_MSG (SUBSET, nullptr, "OT::%c%c%c%c failed to allocate %u bytes.", HB_UNTAG (tag), buf_size); |
| _do_destroy (source_blob, hb_prioritize); |
| return false; |
| } |
| |
| bool needed = false; |
| hb_serialize_context_t serializer (buf.arrayZ, buf.allocated); |
| { |
| hb_subset_context_t c (blob, plan, &serializer, tag); |
| needed = _try_subset (table, &buf, &c); |
| } |
| _do_destroy (source_blob, hb_prioritize); |
| |
| if (serializer.in_error () && !serializer.only_offset_overflow ()) |
| { |
| DEBUG_MSG (SUBSET, nullptr, "OT::%c%c%c%c::subset FAILED!", HB_UNTAG (tag)); |
| return false; |
| } |
| |
| if (!needed) |
| { |
| DEBUG_MSG (SUBSET, nullptr, "OT::%c%c%c%c::subset table subsetted to empty.", HB_UNTAG (tag)); |
| return true; |
| } |
| |
| bool result = false; |
| hb_blob_t *dest_blob = _repack (tag, serializer); |
| if (dest_blob) |
| { |
| DEBUG_MSG (SUBSET, nullptr, |
| "OT::%c%c%c%c final subset table size: %u bytes.", |
| HB_UNTAG (tag), dest_blob->length); |
| result = plan->add_table (tag, dest_blob); |
| hb_blob_destroy (dest_blob); |
| } |
| |
| DEBUG_MSG (SUBSET, nullptr, "OT::%c%c%c%c::subset %s", |
| HB_UNTAG (tag), result ? "success" : "FAILED!"); |
| return result; |
| } |
| |
| static bool |
| _is_table_present (hb_face_t *source, hb_tag_t tag) |
| { |
| |
| if (!hb_face_get_table_tags (source, 0, nullptr, nullptr)) { |
| // If face has 0 tables associated with it, assume that it was built from |
| // hb_face_create_tables and thus is unable to list its tables. Fallback to |
| // checking if the blob associated with tag is empty. |
| return !_table_is_empty (source, tag); |
| } |
| |
| hb_tag_t table_tags[32]; |
| unsigned offset = 0, num_tables = ARRAY_LENGTH (table_tags); |
| while (((void) hb_face_get_table_tags (source, offset, &num_tables, table_tags), num_tables)) |
| { |
| for (unsigned i = 0; i < num_tables; ++i) |
| if (table_tags[i] == tag) |
| return true; |
| offset += num_tables; |
| } |
| return false; |
| } |
| |
| static bool |
| _should_drop_table (hb_subset_plan_t *plan, hb_tag_t tag) |
| { |
| if (plan->drop_tables.has (tag)) |
| return true; |
| |
| switch (tag) |
| { |
| case HB_TAG ('c','v','a','r'): /* hint table, fallthrough */ |
| return plan->all_axes_pinned || (plan->flags & HB_SUBSET_FLAGS_NO_HINTING); |
| |
| case HB_TAG ('c','v','t',' '): /* hint table, fallthrough */ |
| case HB_TAG ('f','p','g','m'): /* hint table, fallthrough */ |
| case HB_TAG ('p','r','e','p'): /* hint table, fallthrough */ |
| case HB_TAG ('h','d','m','x'): /* hint table, fallthrough */ |
| case HB_TAG ('V','D','M','X'): /* hint table, fallthrough */ |
| return plan->flags & HB_SUBSET_FLAGS_NO_HINTING; |
| |
| #ifdef HB_NO_SUBSET_LAYOUT |
| // Drop Layout Tables if requested. |
| case HB_OT_TAG_GDEF: |
| case HB_OT_TAG_GPOS: |
| case HB_OT_TAG_GSUB: |
| case HB_TAG ('m','o','r','x'): |
| case HB_TAG ('m','o','r','t'): |
| case HB_TAG ('k','e','r','x'): |
| case HB_TAG ('k','e','r','n'): |
| return true; |
| #endif |
| |
| case HB_TAG ('a','v','a','r'): |
| case HB_TAG ('f','v','a','r'): |
| case HB_TAG ('g','v','a','r'): |
| case HB_OT_TAG_HVAR: |
| case HB_OT_TAG_VVAR: |
| case HB_TAG ('M','V','A','R'): |
| return plan->all_axes_pinned; |
| |
| default: |
| return false; |
| } |
| } |
| |
| static bool |
| _passthrough (hb_subset_plan_t *plan, hb_tag_t tag) |
| { |
| hb_blob_t *source_table = hb_face_reference_table (plan->source, tag); |
| bool result = plan->add_table (tag, source_table); |
| hb_blob_destroy (source_table); |
| return result; |
| } |
| |
| static bool |
| _dependencies_satisfied (hb_subset_plan_t *plan, hb_tag_t tag, |
| const hb_set_t &subsetted_tags, |
| const hb_set_t &pending_subset_tags) |
| { |
| switch (tag) |
| { |
| case HB_OT_TAG_hmtx: |
| case HB_OT_TAG_vmtx: |
| case HB_OT_TAG_maxp: |
| return !plan->normalized_coords || !pending_subset_tags.has (HB_OT_TAG_glyf); |
| default: |
| return true; |
| } |
| } |
| |
| static bool |
| _subset_table (hb_subset_plan_t *plan, |
| hb_vector_t<char> &buf, |
| hb_tag_t tag) |
| { |
| if (plan->no_subset_tables.has (tag)) { |
| return _passthrough (plan, tag); |
| } |
| |
| DEBUG_MSG (SUBSET, nullptr, "subset %c%c%c%c", HB_UNTAG (tag)); |
| switch (tag) |
| { |
| case HB_OT_TAG_glyf: return _subset<const OT::glyf> (plan, buf); |
| case HB_OT_TAG_hdmx: return _subset<const OT::hdmx> (plan, buf); |
| case HB_OT_TAG_name: return _subset<const OT::name> (plan, buf); |
| case HB_OT_TAG_head: |
| if (_is_table_present (plan->source, HB_OT_TAG_glyf) && !_should_drop_table (plan, HB_OT_TAG_glyf)) |
| return true; /* skip head, handled by glyf */ |
| return _subset<const OT::head> (plan, buf); |
| case HB_OT_TAG_hhea: return true; /* skip hhea, handled by hmtx */ |
| case HB_OT_TAG_hmtx: return _subset<const OT::hmtx> (plan, buf); |
| case HB_OT_TAG_vhea: return true; /* skip vhea, handled by vmtx */ |
| case HB_OT_TAG_vmtx: return _subset<const OT::vmtx> (plan, buf); |
| case HB_OT_TAG_maxp: return _subset<const OT::maxp> (plan, buf); |
| case HB_OT_TAG_sbix: return _subset<const OT::sbix> (plan, buf); |
| case HB_OT_TAG_loca: return true; /* skip loca, handled by glyf */ |
| case HB_OT_TAG_cmap: return _subset<const OT::cmap> (plan, buf); |
| case HB_OT_TAG_OS2 : return _subset<const OT::OS2 > (plan, buf); |
| case HB_OT_TAG_post: return _subset<const OT::post> (plan, buf); |
| case HB_OT_TAG_COLR: return _subset<const OT::COLR> (plan, buf); |
| case HB_OT_TAG_CPAL: return _subset<const OT::CPAL> (plan, buf); |
| case HB_OT_TAG_CBLC: return _subset<const OT::CBLC> (plan, buf); |
| case HB_OT_TAG_CBDT: return true; /* skip CBDT, handled by CBLC */ |
| case HB_OT_TAG_MATH: return _subset<const OT::MATH> (plan, buf); |
| |
| #ifndef HB_NO_SUBSET_CFF |
| case HB_OT_TAG_CFF1: return _subset<const OT::cff1> (plan, buf); |
| case HB_OT_TAG_CFF2: return _subset<const OT::cff2> (plan, buf); |
| case HB_OT_TAG_VORG: return _subset<const OT::VORG> (plan, buf); |
| #endif |
| |
| #ifndef HB_NO_SUBSET_LAYOUT |
| case HB_OT_TAG_GDEF: return _subset<const OT::GDEF> (plan, buf); |
| case HB_OT_TAG_GSUB: return _subset<const GSUB> (plan, buf); |
| case HB_OT_TAG_GPOS: return _subset<const GPOS> (plan, buf); |
| case HB_OT_TAG_gvar: return _subset<const OT::gvar> (plan, buf); |
| case HB_OT_TAG_HVAR: return _subset<const OT::HVAR> (plan, buf); |
| case HB_OT_TAG_VVAR: return _subset<const OT::VVAR> (plan, buf); |
| #endif |
| |
| #ifndef HB_NO_VAR |
| case HB_OT_TAG_fvar: |
| if (plan->user_axes_location.is_empty ()) return _passthrough (plan, tag); |
| return _subset<const OT::fvar> (plan, buf); |
| case HB_OT_TAG_avar: |
| if (plan->user_axes_location.is_empty ()) return _passthrough (plan, tag); |
| return _subset<const OT::avar> (plan, buf); |
| case HB_OT_TAG_cvar: |
| if (plan->user_axes_location.is_empty ()) return _passthrough (plan, tag); |
| return _subset<const OT::cvar> (plan, buf); |
| case HB_OT_TAG_MVAR: |
| if (plan->user_axes_location.is_empty ()) return _passthrough (plan, tag); |
| return _subset<const OT::MVAR> (plan, buf); |
| #endif |
| |
| case HB_OT_TAG_STAT: |
| if (!plan->user_axes_location.is_empty ()) return _subset<const OT::STAT> (plan, buf); |
| else return _passthrough (plan, tag); |
| |
| case HB_TAG ('c', 'v', 't', ' '): |
| #ifndef HB_NO_VAR |
| if (_is_table_present (plan->source, HB_OT_TAG_cvar) && |
| plan->normalized_coords && !plan->pinned_at_default) |
| { |
| auto &cvar = *plan->source->table.cvar; |
| return OT::cvar::add_cvt_and_apply_deltas (plan, cvar.get_tuple_var_data (), &cvar); |
| } |
| #endif |
| return _passthrough (plan, tag); |
| default: |
| if (plan->flags & HB_SUBSET_FLAGS_PASSTHROUGH_UNRECOGNIZED) |
| return _passthrough (plan, tag); |
| |
| // Drop table |
| return true; |
| } |
| } |
| |
| static void _attach_accelerator_data (hb_subset_plan_t* plan, |
| hb_face_t* face /* IN/OUT */) |
| { |
| if (!plan->inprogress_accelerator) return; |
| |
| // Transfer the accelerator from the plan to us. |
| hb_subset_accelerator_t* accel = plan->inprogress_accelerator; |
| plan->inprogress_accelerator = nullptr; |
| |
| if (accel->in_error ()) |
| { |
| hb_subset_accelerator_t::destroy (accel); |
| return; |
| } |
| |
| // Populate caches that need access to the final tables. |
| hb_blob_ptr_t<OT::cmap> cmap_ptr (hb_sanitize_context_t ().reference_table<OT::cmap> (face)); |
| accel->cmap_cache = OT::cmap::create_filled_cache (cmap_ptr); |
| accel->destroy_cmap_cache = OT::SubtableUnicodesCache::destroy; |
| |
| if (!hb_face_set_user_data(face, |
| hb_subset_accelerator_t::user_data_key(), |
| accel, |
| hb_subset_accelerator_t::destroy, |
| true)) |
| hb_subset_accelerator_t::destroy (accel); |
| } |
| |
| /** |
| * hb_subset_or_fail: |
| * @source: font face data to be subset. |
| * @input: input to use for the subsetting. |
| * |
| * Subsets a font according to provided input. Returns nullptr |
| * if the subset operation fails. |
| * |
| * Since: 2.9.0 |
| **/ |
| hb_face_t * |
| hb_subset_or_fail (hb_face_t *source, const hb_subset_input_t *input) |
| { |
| if (unlikely (!input || !source)) return hb_face_get_empty (); |
| |
| hb_subset_plan_t *plan = hb_subset_plan_create_or_fail (source, input); |
| if (unlikely (!plan)) { |
| return nullptr; |
| } |
| |
| hb_face_t * result = hb_subset_plan_execute_or_fail (plan); |
| hb_subset_plan_destroy (plan); |
| return result; |
| } |
| |
| |
| /** |
| * hb_subset_plan_execute_or_fail: |
| * @plan: a subsetting plan. |
| * |
| * Executes the provided subsetting @plan. |
| * |
| * Return value: |
| * on success returns a reference to generated font subset. If the subsetting operation fails |
| * returns nullptr. |
| * |
| * Since: 4.0.0 |
| **/ |
| hb_face_t * |
| hb_subset_plan_execute_or_fail (hb_subset_plan_t *plan) |
| { |
| if (unlikely (!plan || plan->in_error ())) { |
| return nullptr; |
| } |
| |
| hb_tag_t table_tags[32]; |
| unsigned offset = 0, num_tables = ARRAY_LENGTH (table_tags); |
| |
| hb_set_t subsetted_tags, pending_subset_tags; |
| while (((void) _get_table_tags (plan, offset, &num_tables, table_tags), num_tables)) |
| { |
| for (unsigned i = 0; i < num_tables; ++i) |
| { |
| hb_tag_t tag = table_tags[i]; |
| if (_should_drop_table (plan, tag)) continue; |
| pending_subset_tags.add (tag); |
| } |
| |
| offset += num_tables; |
| } |
| |
| bool success = true; |
| |
| { |
| // Grouping to deallocate buf before calling hb_face_reference (plan->dest). |
| |
| hb_vector_t<char> buf; |
| buf.alloc (8192 - 16); |
| |
| while (!pending_subset_tags.is_empty ()) |
| { |
| if (subsetted_tags.in_error () |
| || pending_subset_tags.in_error ()) { |
| success = false; |
| goto end; |
| } |
| |
| bool made_changes = false; |
| for (hb_tag_t tag : pending_subset_tags) |
| { |
| if (!_dependencies_satisfied (plan, tag, |
| subsetted_tags, |
| pending_subset_tags)) |
| { |
| // delayed subsetting for some tables since they might have dependency on other tables |
| // in some cases: e.g: during instantiating glyf tables, hmetrics/vmetrics are updated |
| // and saved in subset plan, hmtx/vmtx subsetting need to use these updated metrics values |
| continue; |
| } |
| |
| pending_subset_tags.del (tag); |
| subsetted_tags.add (tag); |
| made_changes = true; |
| |
| success = _subset_table (plan, buf, tag); |
| if (unlikely (!success)) goto end; |
| } |
| |
| if (!made_changes) |
| { |
| DEBUG_MSG (SUBSET, nullptr, "Table dependencies unable to be satisfied. Subset failed."); |
| success = false; |
| goto end; |
| } |
| } |
| } |
| |
| if (success && plan->attach_accelerator_data) { |
| _attach_accelerator_data (plan, plan->dest); |
| } |
| |
| end: |
| return success ? hb_face_reference (plan->dest) : nullptr; |
| } |