--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/harfbuzz/src/hb-ot-kern-table.hh	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,359 @@
+/*
+ * Copyright © 2017  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): Behdad Esfahbod
+ */
+
+#ifndef HB_OT_KERN_TABLE_HH
+#define HB_OT_KERN_TABLE_HH
+
+#include "hb-aat-layout-kerx-table.hh"
+
+
+/*
+ * kern -- Kerning
+ * https://docs.microsoft.com/en-us/typography/opentype/spec/kern
+ * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6kern.html
+ */
+#define HB_OT_TAG_kern HB_TAG('k','e','r','n')
+
+
+namespace OT {
+
+
+template <typename KernSubTableHeader>
+struct KernSubTableFormat3
+{
+  int get_kerning (hb_codepoint_t left, hb_codepoint_t right) const
+  {
+    hb_array_t<const FWORD> kernValue = kernValueZ.as_array (kernValueCount);
+    hb_array_t<const HBUINT8> leftClass = StructAfter<const UnsizedArrayOf<HBUINT8>> (kernValue).as_array (glyphCount);
+    hb_array_t<const HBUINT8> rightClass = StructAfter<const UnsizedArrayOf<HBUINT8>> (leftClass).as_array (glyphCount);
+    hb_array_t<const HBUINT8> kernIndex = StructAfter<const UnsizedArrayOf<HBUINT8>> (rightClass).as_array (leftClassCount * rightClassCount);
+
+    unsigned int leftC = leftClass[left];
+    unsigned int rightC = rightClass[right];
+    if (unlikely (leftC >= leftClassCount || rightC >= rightClassCount))
+      return 0;
+    unsigned int i = leftC * rightClassCount + rightC;
+    return kernValue[kernIndex[i]];
+  }
+
+  bool apply (AAT::hb_aat_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+
+    if (!c->plan->requested_kerning)
+      return false;
+
+    if (header.coverage & header.Backwards)
+      return false;
+
+    hb_kern_machine_t<KernSubTableFormat3> machine (*this, header.coverage & header.CrossStream);
+    machine.kern (c->font, c->buffer, c->plan->kern_mask);
+
+    return_trace (true);
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) &&
+		  c->check_range (kernValueZ,
+				  kernValueCount * sizeof (FWORD) +
+				  glyphCount * 2 +
+				  leftClassCount * rightClassCount));
+  }
+
+  protected:
+  KernSubTableHeader
+		header;
+  HBUINT16	glyphCount;	/* The number of glyphs in this font. */
+  HBUINT8	kernValueCount;	/* The number of kerning values. */
+  HBUINT8	leftClassCount;	/* The number of left-hand classes. */
+  HBUINT8	rightClassCount;/* The number of right-hand classes. */
+  HBUINT8	flags;		/* Set to zero (reserved for future use). */
+  UnsizedArrayOf<FWORD>
+		kernValueZ;	/* The kerning values.
+				 * Length kernValueCount. */
+#if 0
+  UnsizedArrayOf<HBUINT8>
+		leftClass;	/* The left-hand classes.
+				 * Length glyphCount. */
+  UnsizedArrayOf<HBUINT8>
+		rightClass;	/* The right-hand classes.
+				 * Length glyphCount. */
+  UnsizedArrayOf<HBUINT8>kernIndex;
+				/* The indices into the kernValue array.
+				 * Length leftClassCount * rightClassCount */
+#endif
+  public:
+  DEFINE_SIZE_ARRAY (KernSubTableHeader::static_size + 6, kernValueZ);
+};
+
+template <typename KernSubTableHeader>
+struct KernSubTable
+{
+  unsigned int get_size () const { return u.header.length; }
+  unsigned int get_type () const { return u.header.format; }
+
+  int get_kerning (hb_codepoint_t left, hb_codepoint_t right) const
+  {
+    switch (get_type ()) {
+    /* This method hooks up to hb_font_t's get_h_kerning.  Only support Format0. */
+    case 0: return u.format0.get_kerning (left, right);
+    default:return 0;
+    }
+  }
+
+  template <typename context_t, typename ...Ts>
+  typename context_t::return_t dispatch (context_t *c, Ts&&... ds) const
+  {
+    unsigned int subtable_type = get_type ();
+    TRACE_DISPATCH (this, subtable_type);
+    switch (subtable_type) {
+    case 0:	return_trace (c->dispatch (u.format0));
+#ifndef HB_NO_AAT_SHAPE
+    case 1:	return_trace (u.header.apple ? c->dispatch (u.format1, std::forward<Ts> (ds)...) : c->default_return_value ());
+#endif
+    case 2:	return_trace (c->dispatch (u.format2));
+#ifndef HB_NO_AAT_SHAPE
+    case 3:	return_trace (u.header.apple ? c->dispatch (u.format3, std::forward<Ts> (ds)...) : c->default_return_value ());
+#endif
+    default:	return_trace (c->default_return_value ());
+    }
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    if (unlikely (!u.header.sanitize (c) ||
+		  u.header.length < u.header.min_size ||
+		  !c->check_range (this, u.header.length))) return_trace (false);
+
+    return_trace (dispatch (c));
+  }
+
+  public:
+  union {
+  KernSubTableHeader				header;
+  AAT::KerxSubTableFormat0<KernSubTableHeader>	format0;
+  AAT::KerxSubTableFormat1<KernSubTableHeader>	format1;
+  AAT::KerxSubTableFormat2<KernSubTableHeader>	format2;
+  KernSubTableFormat3<KernSubTableHeader>	format3;
+  } u;
+  public:
+  DEFINE_SIZE_MIN (KernSubTableHeader::static_size);
+};
+
+
+struct KernOTSubTableHeader
+{
+  static constexpr bool apple = false;
+  typedef AAT::ObsoleteTypes Types;
+
+  unsigned   tuple_count () const { return 0; }
+  bool     is_horizontal () const { return (coverage & Horizontal); }
+
+  enum Coverage
+  {
+    Horizontal	= 0x01u,
+    Minimum	= 0x02u,
+    CrossStream	= 0x04u,
+    Override	= 0x08u,
+
+    /* Not supported: */
+    Backwards	= 0x00u,
+    Variation	= 0x00u,
+  };
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this));
+  }
+
+  public:
+  HBUINT16	versionZ;	/* Unused. */
+  HBUINT16	length;		/* Length of the subtable (including this header). */
+  HBUINT8	format;		/* Subtable format. */
+  HBUINT8	coverage;	/* Coverage bits. */
+  public:
+  DEFINE_SIZE_STATIC (6);
+};
+
+struct KernOT : AAT::KerxTable<KernOT>
+{
+  friend struct AAT::KerxTable<KernOT>;
+
+  static constexpr hb_tag_t tableTag = HB_OT_TAG_kern;
+  static constexpr unsigned minVersion = 0u;
+
+  typedef KernOTSubTableHeader SubTableHeader;
+  typedef SubTableHeader::Types Types;
+  typedef KernSubTable<SubTableHeader> SubTable;
+
+  protected:
+  HBUINT16	version;	/* Version--0x0000u */
+  HBUINT16	tableCount;	/* Number of subtables in the kerning table. */
+  SubTable	firstSubTable;	/* Subtables. */
+  public:
+  DEFINE_SIZE_MIN (4);
+};
+
+
+struct KernAATSubTableHeader
+{
+  static constexpr bool apple = true;
+  typedef AAT::ObsoleteTypes Types;
+
+  unsigned   tuple_count () const { return 0; }
+  bool     is_horizontal () const { return !(coverage & Vertical); }
+
+  enum Coverage
+  {
+    Vertical	= 0x80u,
+    CrossStream	= 0x40u,
+    Variation	= 0x20u,
+
+    /* Not supported: */
+    Backwards	= 0x00u,
+  };
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this));
+  }
+
+  public:
+  HBUINT32	length;		/* Length of the subtable (including this header). */
+  HBUINT8	coverage;	/* Coverage bits. */
+  HBUINT8	format;		/* Subtable format. */
+  HBUINT16	tupleIndex;	/* The tuple index (used for variations fonts).
+				 * This value specifies which tuple this subtable covers.
+				 * Note: We don't implement. */
+  public:
+  DEFINE_SIZE_STATIC (8);
+};
+
+struct KernAAT : AAT::KerxTable<KernAAT>
+{
+  friend struct AAT::KerxTable<KernAAT>;
+
+  static constexpr hb_tag_t tableTag = HB_OT_TAG_kern;
+  static constexpr unsigned minVersion = 0x00010000u;
+
+  typedef KernAATSubTableHeader SubTableHeader;
+  typedef SubTableHeader::Types Types;
+  typedef KernSubTable<SubTableHeader> SubTable;
+
+  protected:
+  HBUINT32	version;	/* Version--0x00010000u */
+  HBUINT32	tableCount;	/* Number of subtables in the kerning table. */
+  SubTable	firstSubTable;	/* Subtables. */
+  public:
+  DEFINE_SIZE_MIN (8);
+};
+
+struct kern
+{
+  static constexpr hb_tag_t tableTag = HB_OT_TAG_kern;
+
+  bool     has_data () const { return u.version32; }
+  unsigned get_type () const { return u.major; }
+
+  bool has_state_machine () const
+  {
+    switch (get_type ()) {
+    case 0: return u.ot.has_state_machine ();
+#ifndef HB_NO_AAT_SHAPE
+    case 1: return u.aat.has_state_machine ();
+#endif
+    default:return false;
+    }
+  }
+
+  bool has_cross_stream () const
+  {
+    switch (get_type ()) {
+    case 0: return u.ot.has_cross_stream ();
+#ifndef HB_NO_AAT_SHAPE
+    case 1: return u.aat.has_cross_stream ();
+#endif
+    default:return false;
+    }
+  }
+
+  int get_h_kerning (hb_codepoint_t left, hb_codepoint_t right) const
+  {
+    switch (get_type ()) {
+    case 0: return u.ot.get_h_kerning (left, right);
+#ifndef HB_NO_AAT_SHAPE
+    case 1: return u.aat.get_h_kerning (left, right);
+#endif
+    default:return 0;
+    }
+  }
+
+  bool apply (AAT::hb_aat_apply_context_t *c) const
+  { return dispatch (c); }
+
+  template <typename context_t, typename ...Ts>
+  typename context_t::return_t dispatch (context_t *c, Ts&&... ds) const
+  {
+    unsigned int subtable_type = get_type ();
+    TRACE_DISPATCH (this, subtable_type);
+    switch (subtable_type) {
+    case 0:	return_trace (c->dispatch (u.ot, std::forward<Ts> (ds)...));
+#ifndef HB_NO_AAT_SHAPE
+    case 1:	return_trace (c->dispatch (u.aat, std::forward<Ts> (ds)...));
+#endif
+    default:	return_trace (c->default_return_value ());
+    }
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    if (!u.version32.sanitize (c)) return_trace (false);
+    return_trace (dispatch (c));
+  }
+
+  protected:
+  union {
+  HBUINT32		version32;
+  HBUINT16		major;
+  KernOT		ot;
+#ifndef HB_NO_AAT_SHAPE
+  KernAAT		aat;
+#endif
+  } u;
+  public:
+  DEFINE_SIZE_UNION (4, version32);
+};
+
+} /* namespace OT */
+
+
+#endif /* HB_OT_KERN_TABLE_HH */