224 lines
6.4 KiB
C++
224 lines
6.4 KiB
C++
/*
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* Copyright © 2018 Adobe Inc.
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*
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* This is part of HarfBuzz, a text shaping library.
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*
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* Permission is hereby granted, without written agreement and without
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* license or royalty fees, to use, copy, modify, and distribute this
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* software and its documentation for any purpose, provided that the
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* above copyright notice and the following two paragraphs appear in
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* all copies of this software.
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*
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* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
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* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
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* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
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* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
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* DAMAGE.
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*
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* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
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* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
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* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
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* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
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*
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* Adobe Author(s): Michiharu Ariza
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*/
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#include "hb.hh"
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#ifndef HB_NO_SUBSET_CFF
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#include "hb-ot-cff-common.hh"
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#include "hb-ot-cff2-table.hh"
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#include "hb-subset-cff-common.hh"
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/* Disable FDSelect format 0 for compatibility with fonttools which doesn't seem choose it.
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* Rarely any/much smaller than format 3 anyway. */
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#define CFF_SERIALIZE_FDSELECT_0 0
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using namespace CFF;
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/* Determine an optimal FDSelect format according to a provided plan.
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*
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* Return value: FDSelect format, size, and ranges for the most compact subset FDSelect
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* along with a font index remapping table
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*/
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bool
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hb_plan_subset_cff_fdselect (const hb_subset_plan_t *plan,
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unsigned int fdCount,
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const FDSelect &src, /* IN */
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unsigned int &subset_fd_count /* OUT */,
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unsigned int &subset_fdselect_size /* OUT */,
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unsigned int &subset_fdselect_format /* OUT */,
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hb_vector_t<code_pair_t> &fdselect_ranges /* OUT */,
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hb_inc_bimap_t &fdmap /* OUT */)
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{
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subset_fd_count = 0;
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subset_fdselect_size = 0;
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subset_fdselect_format = 0;
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unsigned int num_ranges = 0;
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unsigned int subset_num_glyphs = plan->num_output_glyphs ();
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if (subset_num_glyphs == 0)
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return true;
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{
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/* use hb_set to determine the subset of font dicts */
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hb_set_t *set = hb_set_create ();
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if (unlikely (set == &Null (hb_set_t))) return false;
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hb_codepoint_t prev_fd = CFF_UNDEF_CODE;
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for (hb_codepoint_t i = 0; i < subset_num_glyphs; i++)
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{
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hb_codepoint_t glyph;
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hb_codepoint_t fd;
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if (!plan->old_gid_for_new_gid (i, &glyph))
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{
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/* fonttools retains FDSelect & font dicts for missing glyphs. do the same */
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glyph = i;
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}
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fd = src.get_fd (glyph);
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set->add (fd);
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if (fd != prev_fd)
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{
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num_ranges++;
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prev_fd = fd;
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code_pair_t pair = { fd, i };
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fdselect_ranges.push (pair);
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}
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}
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subset_fd_count = set->get_population ();
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if (subset_fd_count == fdCount)
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{
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/* all font dicts belong to the subset. no need to subset FDSelect & FDArray */
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fdmap.identity (fdCount);
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hb_set_destroy (set);
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}
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else
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{
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/* create a fdmap */
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fdmap.reset ();
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hb_codepoint_t fd = CFF_UNDEF_CODE;
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while (set->next (&fd))
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fdmap.add (fd);
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hb_set_destroy (set);
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if (unlikely (fdmap.get_population () != subset_fd_count))
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return false;
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}
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/* update each font dict index stored as "code" in fdselect_ranges */
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for (unsigned int i = 0; i < fdselect_ranges.length; i++)
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fdselect_ranges[i].code = fdmap[fdselect_ranges[i].code];
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}
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/* determine which FDSelect format is most compact */
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if (subset_fd_count > 0xFF)
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{
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if (unlikely (src.format != 4))
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return false;
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subset_fdselect_format = 4;
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subset_fdselect_size = FDSelect::min_size + FDSelect4::min_size + FDSelect4_Range::static_size * num_ranges + HBUINT32::static_size;
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}
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else
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{
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#if CFF_SERIALIZE_FDSELECT_0
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unsigned int format0_size = FDSelect::min_size + FDSelect0::min_size + HBUINT8::static_size * subset_num_glyphs;
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#endif
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unsigned int format3_size = FDSelect::min_size + FDSelect3::min_size + FDSelect3_Range::static_size * num_ranges + HBUINT16::static_size;
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#if CFF_SERIALIZE_FDSELECT_0
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if (format0_size <= format3_size)
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{
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// subset_fdselect_format = 0;
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subset_fdselect_size = format0_size;
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}
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else
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#endif
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{
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subset_fdselect_format = 3;
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subset_fdselect_size = format3_size;
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}
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}
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return true;
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}
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template <typename FDSELECT3_4>
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static inline bool
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serialize_fdselect_3_4 (hb_serialize_context_t *c,
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const unsigned int num_glyphs,
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const FDSelect &src,
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unsigned int size,
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const hb_vector_t<code_pair_t> &fdselect_ranges)
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{
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TRACE_SERIALIZE (this);
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FDSELECT3_4 *p = c->allocate_size<FDSELECT3_4> (size);
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if (unlikely (!p)) return_trace (false);
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p->nRanges () = fdselect_ranges.length;
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for (unsigned int i = 0; i < fdselect_ranges.length; i++)
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{
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p->ranges[i].first = fdselect_ranges[i].glyph;
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p->ranges[i].fd = fdselect_ranges[i].code;
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}
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p->sentinel () = num_glyphs;
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return_trace (true);
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}
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/* Serialize a subset FDSelect format planned above. */
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bool
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hb_serialize_cff_fdselect (hb_serialize_context_t *c,
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const unsigned int num_glyphs,
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const FDSelect &src,
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unsigned int fd_count,
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unsigned int fdselect_format,
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unsigned int size,
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const hb_vector_t<code_pair_t> &fdselect_ranges)
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{
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TRACE_SERIALIZE (this);
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FDSelect *p = c->allocate_min<FDSelect> ();
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if (unlikely (!p)) return_trace (false);
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p->format = fdselect_format;
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size -= FDSelect::min_size;
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switch (fdselect_format)
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{
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#if CFF_SERIALIZE_FDSELECT_0
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case 0:
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{
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FDSelect0 *p = c->allocate_size<FDSelect0> (size);
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if (unlikely (!p)) return_trace (false);
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unsigned int range_index = 0;
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unsigned int fd = fdselect_ranges[range_index++].code;
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for (unsigned int i = 0; i < num_glyphs; i++)
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{
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if ((range_index < fdselect_ranges.len) &&
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(i >= fdselect_ranges[range_index].glyph))
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{
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fd = fdselect_ranges[range_index++].code;
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}
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p->fds[i] = fd;
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}
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return_trace (true);
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}
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#endif /* CFF_SERIALIZE_FDSELECT_0 */
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case 3:
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return serialize_fdselect_3_4<FDSelect3> (c, num_glyphs, src,
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size, fdselect_ranges);
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case 4:
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return serialize_fdselect_3_4<FDSelect4> (c, num_glyphs, src,
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size, fdselect_ranges);
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default:
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return_trace (false);
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}
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}
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#endif
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