--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/harfbuzz/src/hb-subset-cff-common.cc	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,220 @@
+/*
+ * Copyright © 2018 Adobe 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.
+ *
+ * Adobe Author(s): Michiharu Ariza
+ */
+
+#include "hb.hh"
+
+#ifndef HB_NO_SUBSET_CFF
+
+#include "hb-ot-cff-common.hh"
+#include "hb-ot-cff2-table.hh"
+#include "hb-subset-cff-common.hh"
+
+/* Disable FDSelect format 0 for compatibility with fonttools which doesn't seem choose it.
+ * Rarely any/much smaller than format 3 anyway. */
+#define CFF_SERIALIZE_FDSELECT_0  0
+
+using namespace CFF;
+
+
+/* Determine an optimal FDSelect format according to a provided plan.
+ *
+ * Return value: FDSelect format, size, and ranges for the most compact subset FDSelect
+ * along with a font index remapping table
+ */
+
+bool
+hb_plan_subset_cff_fdselect (const hb_subset_plan_t *plan,
+			     unsigned int fdCount,
+			     const FDSelect &src, /* IN */
+			     unsigned int &subset_fd_count /* OUT */,
+			     unsigned int &subset_fdselect_size /* OUT */,
+			     unsigned int &subset_fdselect_format /* OUT */,
+			     hb_vector_t<code_pair_t> &fdselect_ranges /* OUT */,
+			     hb_inc_bimap_t &fdmap /* OUT */)
+{
+  subset_fd_count = 0;
+  subset_fdselect_size = 0;
+  subset_fdselect_format = 0;
+  unsigned int num_ranges = 0;
+
+  unsigned int subset_num_glyphs = plan->num_output_glyphs ();
+  if (subset_num_glyphs == 0)
+    return true;
+
+  {
+    /* use hb_set to determine the subset of font dicts */
+    hb_set_t set;
+    hb_codepoint_t prev_fd = CFF_UNDEF_CODE;
+    for (hb_codepoint_t i = 0; i < subset_num_glyphs; i++)
+    {
+      hb_codepoint_t glyph;
+      hb_codepoint_t fd;
+      if (!plan->old_gid_for_new_gid (i, &glyph))
+      {
+	/* fonttools retains FDSelect & font dicts for missing glyphs. do the same */
+	glyph = i;
+      }
+      fd = src.get_fd (glyph);
+      set.add (fd);
+
+      if (fd != prev_fd)
+      {
+	num_ranges++;
+	prev_fd = fd;
+	code_pair_t pair = { fd, i };
+	fdselect_ranges.push (pair);
+      }
+    }
+
+    subset_fd_count = set.get_population ();
+    if (subset_fd_count == fdCount)
+    {
+      /* all font dicts belong to the subset. no need to subset FDSelect & FDArray */
+      fdmap.identity (fdCount);
+    }
+    else
+    {
+      /* create a fdmap */
+      fdmap.reset ();
+
+      hb_codepoint_t fd = CFF_UNDEF_CODE;
+      while (set.next (&fd))
+	fdmap.add (fd);
+      if (unlikely (fdmap.get_population () != subset_fd_count))
+	return false;
+    }
+
+    /* update each font dict index stored as "code" in fdselect_ranges */
+    for (unsigned int i = 0; i < fdselect_ranges.length; i++)
+      fdselect_ranges[i].code = fdmap[fdselect_ranges[i].code];
+  }
+
+  /* determine which FDSelect format is most compact */
+  if (subset_fd_count > 0xFF)
+  {
+    if (unlikely (src.format != 4))
+      return false;
+    subset_fdselect_format = 4;
+    subset_fdselect_size = FDSelect::min_size + FDSelect4::min_size + FDSelect4_Range::static_size * num_ranges + HBUINT32::static_size;
+  }
+  else
+  {
+#if CFF_SERIALIZE_FDSELECT_0
+    unsigned int format0_size = FDSelect::min_size + FDSelect0::min_size + HBUINT8::static_size * subset_num_glyphs;
+#endif
+    unsigned int format3_size = FDSelect::min_size + FDSelect3::min_size + FDSelect3_Range::static_size * num_ranges + HBUINT16::static_size;
+
+#if CFF_SERIALIZE_FDSELECT_0
+    if (format0_size <= format3_size)
+    {
+      // subset_fdselect_format = 0;
+      subset_fdselect_size = format0_size;
+    }
+    else
+#endif
+    {
+      subset_fdselect_format = 3;
+      subset_fdselect_size = format3_size;
+    }
+  }
+
+  return true;
+}
+
+template <typename FDSELECT3_4>
+static inline bool
+serialize_fdselect_3_4 (hb_serialize_context_t *c,
+			const unsigned int num_glyphs,
+			const FDSelect &src,
+			unsigned int size,
+			const hb_vector_t<code_pair_t> &fdselect_ranges)
+{
+  TRACE_SERIALIZE (this);
+  FDSELECT3_4 *p = c->allocate_size<FDSELECT3_4> (size);
+  if (unlikely (!p)) return_trace (false);
+  p->nRanges () = fdselect_ranges.length;
+  for (unsigned int i = 0; i < fdselect_ranges.length; i++)
+  {
+    p->ranges[i].first = fdselect_ranges[i].glyph;
+    p->ranges[i].fd = fdselect_ranges[i].code;
+  }
+  p->sentinel () = num_glyphs;
+  return_trace (true);
+}
+
+/* Serialize a subset FDSelect format planned above. */
+bool
+hb_serialize_cff_fdselect (hb_serialize_context_t *c,
+			   const unsigned int num_glyphs,
+			   const FDSelect &src,
+			   unsigned int fd_count,
+			   unsigned int fdselect_format,
+			   unsigned int size,
+			   const hb_vector_t<code_pair_t> &fdselect_ranges)
+{
+  TRACE_SERIALIZE (this);
+  FDSelect *p = c->allocate_min<FDSelect> ();
+  if (unlikely (!p)) return_trace (false);
+  p->format = fdselect_format;
+  size -= FDSelect::min_size;
+
+  switch (fdselect_format)
+  {
+#if CFF_SERIALIZE_FDSELECT_0
+  case 0:
+  {
+    FDSelect0 *p = c->allocate_size<FDSelect0> (size);
+    if (unlikely (!p)) return_trace (false);
+    unsigned int range_index = 0;
+    unsigned int fd = fdselect_ranges[range_index++].code;
+    for (unsigned int i = 0; i < num_glyphs; i++)
+    {
+      if ((range_index < fdselect_ranges.len) &&
+	  (i >= fdselect_ranges[range_index].glyph))
+      {
+	fd = fdselect_ranges[range_index++].code;
+      }
+      p->fds[i] = fd;
+    }
+    return_trace (true);
+  }
+#endif /* CFF_SERIALIZE_FDSELECT_0 */
+
+  case 3:
+    return serialize_fdselect_3_4<FDSelect3> (c, num_glyphs, src,
+					      size, fdselect_ranges);
+
+  case 4:
+    return serialize_fdselect_3_4<FDSelect4> (c, num_glyphs, src,
+					      size, fdselect_ranges);
+
+  default:
+    return_trace (false);
+  }
+}
+
+
+#endif