STOP COMMITS TO SVN REPO -- WORK IN PROGRESS

git-svn-id: https://serveur-svn.lri.fr/svn/modhel/luatex/trunk@7545 0b2b3880-5936-4365-a048-eb17d2e5a6bf

Author: luigiScarso

source/libs/harfbuzz/harfbuzz-src/src/graph/classdef-graph.hh

@@ -0,0 +1,216 @@
+/*
+ * Copyright © 2022  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
+ */
+
+#include "graph.hh"
+#include "../hb-ot-layout-common.hh"
+
+#ifndef GRAPH_CLASSDEF_GRAPH_HH
+#define GRAPH_CLASSDEF_GRAPH_HH
+
+namespace graph {
+
+struct ClassDefFormat1 : public OT::ClassDefFormat1_3<SmallTypes>
+{
+  bool sanitize (graph_t::vertex_t& vertex) const
+  {
+    int64_t vertex_len = vertex.obj.tail - vertex.obj.head;
+    constexpr unsigned min_size = OT::ClassDefFormat1_3<SmallTypes>::min_size;
+    if (vertex_len < min_size) return false;
+    return vertex_len >= min_size + classValue.get_size () - classValue.len.get_size ();
+  }
+};
+
+struct ClassDefFormat2 : public OT::ClassDefFormat2_4<SmallTypes>
+{
+  bool sanitize (graph_t::vertex_t& vertex) const
+  {
+    int64_t vertex_len = vertex.obj.tail - vertex.obj.head;
+    constexpr unsigned min_size = OT::ClassDefFormat2_4<SmallTypes>::min_size;
+    if (vertex_len < min_size) return false;
+    return vertex_len >= min_size + rangeRecord.get_size () - rangeRecord.len.get_size ();
+  }
+};
+
+struct ClassDef : public OT::ClassDef
+{
+  template<typename It>
+  static bool add_class_def (gsubgpos_graph_context_t& c,
+                             unsigned parent_id,
+                             unsigned link_position,
+                             It glyph_and_class,
+                             unsigned max_size)
+  {
+    unsigned class_def_prime_id = c.graph.new_node (nullptr, nullptr);
+    auto& class_def_prime_vertex = c.graph.vertices_[class_def_prime_id];
+    if (!make_class_def (c, glyph_and_class, class_def_prime_id, max_size))
+      return false;
+
+    auto* class_def_link = c.graph.vertices_[parent_id].obj.real_links.push ();
+    class_def_link->width = SmallTypes::size;
+    class_def_link->objidx = class_def_prime_id;
+    class_def_link->position = link_position;
+    class_def_prime_vertex.parents.push (parent_id);
+
+    return true;
+  }
+
+  template<typename It>
+  static bool make_class_def (gsubgpos_graph_context_t& c,
+                              It glyph_and_class,
+                              unsigned dest_obj,
+                              unsigned max_size)
+  {
+    char* buffer = (char*) hb_calloc (1, max_size);
+    hb_serialize_context_t serializer (buffer, max_size);
+    OT::ClassDef_serialize (&serializer, glyph_and_class);
+    serializer.end_serialize ();
+    if (serializer.in_error ())
+    {
+      hb_free (buffer);
+      return false;
+    }
+
+    hb_bytes_t class_def_copy = serializer.copy_bytes ();
+    c.add_buffer ((char *) class_def_copy.arrayZ); // Give ownership to the context, it will cleanup the buffer.
+
+    auto& obj = c.graph.vertices_[dest_obj].obj;
+    obj.head = (char *) class_def_copy.arrayZ;
+    obj.tail = obj.head + class_def_copy.length;
+
+    hb_free (buffer);
+    return true;
+  }
+
+  bool sanitize (graph_t::vertex_t& vertex) const
+  {
+    int64_t vertex_len = vertex.obj.tail - vertex.obj.head;
+    if (vertex_len < OT::ClassDef::min_size) return false;
+    switch (u.format)
+    {
+    case 1: return ((ClassDefFormat1*)this)->sanitize (vertex);
+    case 2: return ((ClassDefFormat2*)this)->sanitize (vertex);
+#ifndef HB_NO_BORING_EXPANSION
+    // Not currently supported
+    case 3:
+    case 4:
+#endif
+    default: return false;
+    }
+  }
+};
+
+
+struct class_def_size_estimator_t
+{
+  template<typename It>
+  class_def_size_estimator_t (It glyph_and_class)
+      : gids_consecutive (true), num_ranges_per_class (), glyphs_per_class ()
+  {
+    unsigned last_gid = (unsigned) -1;
+    for (auto p : + glyph_and_class)
+    {
+      unsigned gid = p.first;
+      unsigned klass = p.second;
+
+      if (last_gid != (unsigned) -1 && gid != last_gid + 1)
+        gids_consecutive = false;
+      last_gid = gid;
+
+      hb_set_t* glyphs;
+      if (glyphs_per_class.has (klass, &glyphs) && glyphs) {
+        glyphs->add (gid);
+        continue;
+      }
+
+      hb_set_t new_glyphs;
+      new_glyphs.add (gid);
+      glyphs_per_class.set (klass, std::move (new_glyphs));
+    }
+
+    if (in_error ()) return;
+
+    for (unsigned klass : glyphs_per_class.keys ())
+    {
+      if (!klass) continue; // class 0 doesn't get encoded.
+
+      const hb_set_t& glyphs = glyphs_per_class.get (klass);
+      hb_codepoint_t start = HB_SET_VALUE_INVALID;
+      hb_codepoint_t end = HB_SET_VALUE_INVALID;
+
+      unsigned count = 0;
+      while (glyphs.next_range (&start, &end))
+        count++;
+
+      num_ranges_per_class.set (klass, count);
+    }
+  }
+
+  // Incremental increase in the Coverage and ClassDef table size
+  // (worst case) if all glyphs associated with 'klass' were added.
+  unsigned incremental_coverage_size (unsigned klass) const
+  {
+    // Coverage takes 2 bytes per glyph worst case,
+    return 2 * glyphs_per_class.get (klass).get_population ();
+  }
+
+  // Incremental increase in the Coverage and ClassDef table size
+  // (worst case) if all glyphs associated with 'klass' were added.
+  unsigned incremental_class_def_size (unsigned klass) const
+  {
+    // ClassDef takes 6 bytes per range
+    unsigned class_def_2_size = 6 * num_ranges_per_class.get (klass);
+    if (gids_consecutive)
+    {
+      // ClassDef1 takes 2 bytes per glyph, but only can be used
+      // when gids are consecutive.
+      return hb_min (2 * glyphs_per_class.get (klass).get_population (), class_def_2_size);
+    }
+
+    return class_def_2_size;
+  }
+
+  bool in_error ()
+  {
+    if (num_ranges_per_class.in_error ()) return true;
+    if (glyphs_per_class.in_error ()) return true;
+
+    for (const hb_set_t& s : glyphs_per_class.values ())
+    {
+      if (s.in_error ()) return true;
+    }
+    return false;
+  }
+
+ private:
+  bool gids_consecutive;
+  hb_hashmap_t<unsigned, unsigned> num_ranges_per_class;
+  hb_hashmap_t<unsigned, hb_set_t> glyphs_per_class;
+};
+
+
+}
+
+#endif  // GRAPH_CLASSDEF_GRAPH_HH