--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/harfbuzz/src/OT/Layout/GSUB/SubstLookup.hh	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,220 @@
+#ifndef OT_LAYOUT_GSUB_SUBSTLOOKUP_HH
+#define OT_LAYOUT_GSUB_SUBSTLOOKUP_HH
+
+#include "Common.hh"
+#include "SubstLookupSubTable.hh"
+
+namespace OT {
+namespace Layout {
+namespace GSUB_impl {
+
+struct SubstLookup : Lookup
+{
+  using SubTable = SubstLookupSubTable;
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  { return Lookup::sanitize<SubTable> (c); }
+
+  const SubTable& get_subtable (unsigned int i) const
+  { return Lookup::get_subtable<SubTable> (i); }
+
+  static inline bool lookup_type_is_reverse (unsigned int lookup_type)
+  { return lookup_type == SubTable::ReverseChainSingle; }
+
+  bool is_reverse () const
+  {
+    unsigned int type = get_type ();
+    if (unlikely (type == SubTable::Extension))
+      return get_subtable (0).u.extension.is_reverse ();
+    return lookup_type_is_reverse (type);
+  }
+
+  bool may_have_non_1to1 () const
+  {
+    hb_have_non_1to1_context_t c;
+    return dispatch (&c);
+  }
+
+  bool apply (hb_ot_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+    return_trace (dispatch (c));
+  }
+
+  bool intersects (const hb_set_t *glyphs) const
+  {
+    hb_intersects_context_t c (glyphs);
+    return dispatch (&c);
+  }
+
+  hb_closure_context_t::return_t closure (hb_closure_context_t *c, unsigned int this_index) const
+  {
+    if (!c->should_visit_lookup (this_index))
+      return hb_closure_context_t::default_return_value ();
+
+    c->set_recurse_func (dispatch_closure_recurse_func);
+
+    hb_closure_context_t::return_t ret = dispatch (c);
+
+    c->flush ();
+
+    return ret;
+  }
+
+  hb_closure_lookups_context_t::return_t closure_lookups (hb_closure_lookups_context_t *c, unsigned this_index) const
+  {
+    if (c->is_lookup_visited (this_index))
+      return hb_closure_lookups_context_t::default_return_value ();
+
+    c->set_lookup_visited (this_index);
+    if (!intersects (c->glyphs))
+    {
+      c->set_lookup_inactive (this_index);
+      return hb_closure_lookups_context_t::default_return_value ();
+    }
+
+    hb_closure_lookups_context_t::return_t ret = dispatch (c);
+    return ret;
+  }
+
+  hb_collect_glyphs_context_t::return_t collect_glyphs (hb_collect_glyphs_context_t *c) const
+  {
+    c->set_recurse_func (dispatch_recurse_func<hb_collect_glyphs_context_t>);
+    return dispatch (c);
+  }
+
+  template <typename set_t>
+  void collect_coverage (set_t *glyphs) const
+  {
+    hb_collect_coverage_context_t<set_t> c (glyphs);
+    dispatch (&c);
+  }
+
+  bool would_apply (hb_would_apply_context_t *c,
+                    const hb_ot_layout_lookup_accelerator_t *accel) const
+  {
+    if (unlikely (!c->len)) return false;
+    if (!accel->may_have (c->glyphs[0])) return false;
+      return dispatch (c);
+  }
+
+  template<typename Glyphs, typename Substitutes,
+	   hb_requires (hb_is_sorted_source_of (Glyphs,
+						const hb_codepoint_t) &&
+			hb_is_source_of (Substitutes,
+					 const hb_codepoint_t))>
+  bool serialize_single (hb_serialize_context_t *c,
+                         uint32_t lookup_props,
+                         Glyphs glyphs,
+                         Substitutes substitutes)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!Lookup::serialize (c, SubTable::Single, lookup_props, 1))) return_trace (false);
+    if (c->push<SubTable> ()->u.single.serialize (c, hb_zip (glyphs, substitutes)))
+    {
+      c->add_link (get_subtables<SubTable> ()[0], c->pop_pack ());
+      return_trace (true);
+    }
+    c->pop_discard ();
+    return_trace (false);
+  }
+
+  template<typename Iterator,
+           hb_requires (hb_is_sorted_iterator (Iterator))>
+  bool serialize (hb_serialize_context_t *c,
+		  uint32_t lookup_props,
+		  Iterator it)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!Lookup::serialize (c, SubTable::Multiple, lookup_props, 1))) return_trace (false);
+    if (c->push<SubTable> ()->u.multiple.
+        serialize (c, it))
+    {
+      c->add_link (get_subtables<SubTable> ()[0], c->pop_pack ());
+      return_trace (true);
+    }
+    c->pop_discard ();
+    return_trace (false);
+  }
+
+  bool serialize_alternate (hb_serialize_context_t *c,
+                            uint32_t lookup_props,
+                            hb_sorted_array_t<const HBGlyphID16> glyphs,
+                            hb_array_t<const unsigned int> alternate_len_list,
+                            hb_array_t<const HBGlyphID16> alternate_glyphs_list)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!Lookup::serialize (c, SubTable::Alternate, lookup_props, 1))) return_trace (false);
+
+    if (c->push<SubTable> ()->u.alternate.
+        serialize (c,
+                   glyphs,
+                   alternate_len_list,
+                   alternate_glyphs_list))
+    {
+      c->add_link (get_subtables<SubTable> ()[0], c->pop_pack ());
+      return_trace (true);
+    }
+    c->pop_discard ();
+    return_trace (false);
+  }
+
+  bool serialize_ligature (hb_serialize_context_t *c,
+                           uint32_t lookup_props,
+                           hb_sorted_array_t<const HBGlyphID16> first_glyphs,
+                           hb_array_t<const unsigned int> ligature_per_first_glyph_count_list,
+                           hb_array_t<const HBGlyphID16> ligatures_list,
+                           hb_array_t<const unsigned int> component_count_list,
+                           hb_array_t<const HBGlyphID16> component_list /* Starting from second for each ligature */)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!Lookup::serialize (c, SubTable::Ligature, lookup_props, 1))) return_trace (false);
+    if (c->push<SubTable> ()->u.ligature.
+        serialize (c,
+                   first_glyphs,
+                   ligature_per_first_glyph_count_list,
+                   ligatures_list,
+                   component_count_list,
+                   component_list))
+    {
+      c->add_link (get_subtables<SubTable> ()[0], c->pop_pack ());
+      return_trace (true);
+    }
+    c->pop_discard ();
+    return_trace (false);
+  }
+
+  template <typename context_t>
+  static inline typename context_t::return_t dispatch_recurse_func (context_t *c, unsigned int lookup_index);
+
+  static inline typename hb_closure_context_t::return_t closure_glyphs_recurse_func (hb_closure_context_t *c, unsigned lookup_index, hb_set_t *covered_seq_indices, unsigned seq_index, unsigned end_index);
+
+  static inline hb_closure_context_t::return_t dispatch_closure_recurse_func (hb_closure_context_t *c, unsigned lookup_index, hb_set_t *covered_seq_indices, unsigned seq_index, unsigned end_index)
+  {
+    if (!c->should_visit_lookup (lookup_index))
+      return hb_empty_t ();
+
+    hb_closure_context_t::return_t ret = closure_glyphs_recurse_func (c, lookup_index, covered_seq_indices, seq_index, end_index);
+
+    /* While in theory we should flush here, it will cause timeouts because a recursive
+     * lookup can keep growing the glyph set.  Skip, and outer loop will retry up to
+     * HB_CLOSURE_MAX_STAGES time, which should be enough for every realistic font. */
+    //c->flush ();
+
+    return ret;
+  }
+
+  template <typename context_t, typename ...Ts>
+  typename context_t::return_t dispatch (context_t *c, Ts&&... ds) const
+  { return Lookup::dispatch<SubTable> (c, std::forward<Ts> (ds)...); }
+
+  bool subset (hb_subset_context_t *c) const
+  { return Lookup::subset<SubTable> (c); }
+};
+
+
+}
+}
+}
+
+#endif  /* OT_LAYOUT_GSUB_SUBSTLOOKUP_HH */