diff options
Diffstat (limited to 'src/3rdparty/harfbuzz-ng/src/hb-subset.cc')
-rw-r--r-- | src/3rdparty/harfbuzz-ng/src/hb-subset.cc | 649 |
1 files changed, 542 insertions, 107 deletions
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-subset.cc b/src/3rdparty/harfbuzz-ng/src/hb-subset.cc index 8b77ecd45a..f10ef54dbd 100644 --- a/src/3rdparty/harfbuzz-ng/src/hb-subset.cc +++ b/src/3rdparty/harfbuzz-ng/src/hb-subset.cc @@ -37,105 +37,359 @@ #include "hb-ot-hhea-table.hh" #include "hb-ot-hmtx-table.hh" #include "hb-ot-maxp-table.hh" -#include "hb-ot-color-sbix-table.hh" -#include "hb-ot-color-colr-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-color-cbdt-table.hh" +#include "hb-ot-layout-base-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) +_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 (); - if (unlikely (!src_glyphs)) - return 512 + table_len; + 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 512 + (unsigned) (table_len * sqrt ((double) dst_glyphs / src_glyphs)); + 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) +_subset (hb_subset_plan_t *plan, hb_vector_t<char> &buf) { - bool result = false; - hb_blob_t *source_blob = hb_sanitize_context_t ().reference_table<TableType> (plan->source); - const TableType *table = source_blob->as<TableType> (); + auto &&source_blob = plan->source_table<TableType> (); + auto *table = source_blob.get (); hb_tag_t tag = TableType::tableTag; - if (source_blob->data) + hb_blob_t *blob = source_blob.get_blob(); + if (unlikely (!blob || !blob->data)) { - hb_vector_t<char> buf; - /* TODO Not all tables are glyph-related. 'name' table size for example should not be - * affected by number of glyphs. Accommodate that. */ - unsigned buf_size = _plan_estimate_subset_table_size (plan, source_blob->length); - 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); - hb_blob_destroy (source_blob); - return false; - } - retry: - hb_serialize_context_t serializer ((void *) buf, buf_size); - serializer.start_serialize<TableType> (); - hb_subset_context_t c (source_blob, plan, &serializer, tag); - bool needed = table->subset (&c); - if (serializer.ran_out_of_room) - { - buf_size += (buf_size >> 1) + 32; - DEBUG_MSG (SUBSET, nullptr, "OT::%c%c%c%c ran out of room; reallocating to %u bytes.", HB_UNTAG (tag), buf_size); - if (unlikely (!buf.alloc (buf_size))) - { - DEBUG_MSG (SUBSET, nullptr, "OT::%c%c%c%c failed to reallocate %u bytes.", HB_UNTAG (tag), buf_size); - hb_blob_destroy (source_blob); - return false; - } - goto retry; - } - serializer.end_serialize (); + 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; + } - result = !serializer.in_error (); + 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; + } - if (result) - { - if (needed) - { - hb_blob_t *dest_blob = serializer.copy_blob (); - DEBUG_MSG (SUBSET, nullptr, "OT::%c%c%c%c final subset table size: %u bytes.", HB_UNTAG (tag), dest_blob->length); - result = c.plan->add_table (tag, dest_blob); - hb_blob_destroy (dest_blob); - } - else - { - DEBUG_MSG (SUBSET, nullptr, "OT::%c%c%c%c::subset table subsetted to empty.", HB_UNTAG (tag)); - } - } + 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); } - else - DEBUG_MSG (SUBSET, nullptr, "OT::%c%c%c%c::subset sanitize failed on source table.", HB_UNTAG (tag)); - hb_blob_destroy (source_blob); - DEBUG_MSG (SUBSET, nullptr, "OT::%c%c%c%c::subset %s", HB_UNTAG (tag), result ? "success" : "FAILED!"); + 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 ((hb_face_get_table_tags (source, offset, &num_tables, table_tags), num_tables)) + 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) @@ -148,18 +402,20 @@ _is_table_present (hb_face_t *source, hb_tag_t tag) static bool _should_drop_table (hb_subset_plan_t *plan, hb_tag_t tag) { - if (plan->drop_tables->has (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->drop_hints; + return plan->flags & HB_SUBSET_FLAGS_NO_HINTING; #ifdef HB_NO_SUBSET_LAYOUT // Drop Layout Tables if requested. @@ -173,97 +429,276 @@ _should_drop_table (hb_subset_plan_t *plan, hb_tag_t tag) 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 -_subset_table (hb_subset_plan_t *plan, hb_tag_t tag) +_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: + case HB_OT_TAG_OS2: + return !plan->normalized_coords || !pending_subset_tags.has (HB_OT_TAG_glyf); + case HB_OT_TAG_GPOS: + return plan->all_axes_pinned || !pending_subset_tags.has (HB_OT_TAG_GDEF); + 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); - case HB_OT_TAG_hdmx: return _subset<const OT::hdmx> (plan); - case HB_OT_TAG_name: return _subset<const OT::name> (plan); + 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); + 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); + 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); - case HB_OT_TAG_maxp: return _subset<const OT::maxp> (plan); - case HB_OT_TAG_sbix: return _subset<const OT::sbix> (plan); + 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); - case HB_OT_TAG_OS2 : return _subset<const OT::OS2 > (plan); - case HB_OT_TAG_post: return _subset<const OT::post> (plan); - case HB_OT_TAG_COLR: return _subset<const OT::COLR> (plan); - case HB_OT_TAG_CBLC: return _subset<const OT::CBLC> (plan); + 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); + case HB_OT_TAG_BASE: return _subset<const OT::BASE> (plan, buf); #ifndef HB_NO_SUBSET_CFF - case HB_OT_TAG_cff1: return _subset<const OT::cff1> (plan); - case HB_OT_TAG_cff2: return _subset<const OT::cff2> (plan); - case HB_OT_TAG_VORG: return _subset<const OT::VORG> (plan); + 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); - case HB_OT_TAG_GSUB: return _subset<const OT::GSUB> (plan); - case HB_OT_TAG_GPOS: return _subset<const OT::GPOS> (plan); - case HB_OT_TAG_gvar: return _subset<const OT::gvar> (plan); - case HB_OT_TAG_HVAR: return _subset<const OT::HVAR> (plan); - case HB_OT_TAG_VVAR: return _subset<const OT::VVAR> (plan); + 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: - 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; + 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: + * 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. + * Subsets a font according to provided input. Returns nullptr + * if the subset operation fails. + * + * Since: 2.9.0 **/ hb_face_t * -hb_subset (hb_face_t *source, hb_subset_input_t *input) +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 (source, input); - if (unlikely (plan->in_error ())) - 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_set_t tags_set; - bool success = true; 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)) + + 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) && !tags_set.has (tag)) continue; - tags_set.add (tag); - success = _subset_table (plan, tag); - if (unlikely (!success)) goto end; + if (_should_drop_table (plan, tag)) continue; + pending_subset_tags.add (tag); } + offset += num_tables; } -end: - hb_face_t *result = success ? hb_face_reference (plan->dest) : hb_face_get_empty (); + bool success = true; - hb_subset_plan_destroy (plan); - return result; + { + // 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; } |