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-rw-r--r--gfx/harfbuzz/src/hb-subset.cc269
1 files changed, 269 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-subset.cc b/gfx/harfbuzz/src/hb-subset.cc
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+++ b/gfx/harfbuzz/src/hb-subset.cc
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+/*
+ * 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 "hb-ot-color-sbix-table.hh"
+#include "hb-ot-color-colr-table.hh"
+#include "hb-ot-os2-table.hh"
+#include "hb-ot-post-table.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-gsub-table.hh"
+#include "hb-ot-layout-gpos-table.hh"
+#include "hb-ot-var-gvar-table.hh"
+#include "hb-ot-var-hvar-table.hh"
+
+
+static unsigned
+_plan_estimate_subset_table_size (hb_subset_plan_t *plan, unsigned table_len)
+{
+ unsigned src_glyphs = plan->source->get_num_glyphs ();
+ unsigned dst_glyphs = plan->glyphset ()->get_population ();
+
+ if (unlikely (!src_glyphs))
+ return 512 + table_len;
+
+ return 512 + (unsigned) (table_len * sqrt ((double) dst_glyphs / src_glyphs));
+}
+
+template<typename TableType>
+static bool
+_subset (hb_subset_plan_t *plan)
+{
+ bool result = false;
+ hb_blob_t *source_blob = hb_sanitize_context_t ().reference_table<TableType> (plan->source);
+ const TableType *table = source_blob->as<TableType> ();
+
+ hb_tag_t tag = TableType::tableTag;
+ if (source_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 ();
+
+ result = !serializer.in_error ();
+
+ 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));
+ }
+ }
+ }
+ 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!");
+ return result;
+}
+
+static bool
+_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))
+ {
+ 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 */
+ 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;
+
+#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
+
+ default:
+ return false;
+ }
+}
+
+static bool
+_subset_table (hb_subset_plan_t *plan, hb_tag_t 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_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);
+ 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_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_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_CBDT: return true; /* skip CBDT, handled by CBLC */
+
+#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);
+#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);
+#endif
+
+ 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;
+ }
+}
+
+/**
+ * hb_subset:
+ * @source: font face data to be subset.
+ * @input: input to use for the subsetting.
+ *
+ * Subsets a font according to provided input.
+ **/
+hb_face_t *
+hb_subset (hb_face_t *source, 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_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))
+ {
+ 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;
+ }
+ offset += num_tables;
+ }
+end:
+
+ hb_face_t *result = success ? hb_face_reference (plan->dest) : hb_face_get_empty ();
+
+ hb_subset_plan_destroy (plan);
+ return result;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-02 14:32:28 +0000