Roll HarfBuzz to 1.1.1

third_party/harfbuzz-ng/src/hb-ot-font.cc

 /*
  * Copyright © 2011,2014  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.
@@ skipping 28 matching lines @@
 
 struct hb_ot_face_metrics_accelerator_t
 {
   unsigned int num_metrics;
   unsigned int num_advances;
   unsigned int default_advance;
   const OT::_mtx *table;
   hb_blob_t *blob;
 
   inline void init (hb_face_t *face,
-                    hb_tag_t _hea_tag, hb_tag_t _mtx_tag,
-                    unsigned int default_advance_)
+                    hb_tag_t _hea_tag, hb_tag_t _mtx_tag)
   {
-    this->default_advance = default_advance_;
-    this->num_metrics = face->get_num_glyphs ();
+    this->default_advance = face->get_upem ();
 
     hb_blob_t *_hea_blob = OT::Sanitizer<OT::_hea>::sanitize (face->reference_table (_hea_tag));
     const OT::_hea *_hea = OT::Sanitizer<OT::_hea>::lock_instance (_hea_blob);
     this->num_advances = _hea->numberOfLongMetrics;
     hb_blob_destroy (_hea_blob);
 
     this->blob = OT::Sanitizer<OT::_mtx>::sanitize (face->reference_table (_mtx_tag));
-    if (unlikely (!this->num_advances ||
-                  2 * (this->num_advances + this->num_metrics) > hb_blob_get_length (this->blob)))
+
+    /* Cap num_metrics() and num_advances() based on table length. */
+    unsigned int len = hb_blob_get_length (this->blob);
+    if (unlikely (this->num_advances * 4 > len))
+      this->num_advances = len / 4;
+    this->num_metrics = this->num_advances + (len - 4 * this->num_advances) / 2;
+
+    /* We MUST set num_metrics to zero if num_advances is zero.
+     * Our get_advance() depends on that. */
+    if (unlikely (!this->num_advances))
     {
       this->num_metrics = this->num_advances = 0;
       hb_blob_destroy (this->blob);
       this->blob = hb_blob_get_empty ();
     }
     this->table = OT::Sanitizer<OT::_mtx>::lock_instance (this->blob);
   }
 
   inline void fini (void)
   {
@@ skipping 165 matching lines @@
 
 
 static hb_ot_font_t *
 _hb_ot_font_create (hb_face_t *face)
 {
   hb_ot_font_t *ot_font = (hb_ot_font_t *) calloc (1, sizeof (hb_ot_font_t));
 
   if (unlikely (!ot_font))
     return NULL;
 
-  unsigned int upem = face->get_upem ();
-
   ot_font->cmap.init (face);
-  ot_font->h_metrics.init (face, HB_OT_TAG_hhea, HB_OT_TAG_hmtx, upem>>1);
-  ot_font->v_metrics.init (face, HB_OT_TAG_vhea, HB_OT_TAG_vmtx, upem); /* TODO Can we do this lazily? */
+  ot_font->h_metrics.init (face, HB_OT_TAG_hhea, HB_OT_TAG_hmtx);
+  ot_font->v_metrics.init (face, HB_OT_TAG_vhea, HB_OT_TAG_vmtx); /* TODO Can we do this lazily? */
   ot_font->glyf.init (face);
 
   return ot_font;
 }
 
 static void
 _hb_ot_font_destroy (hb_ot_font_t *ot_font)
 {
   ot_font->cmap.fini ();
   ot_font->h_metrics.fini ();
@@ skipping 31 matching lines @@
 hb_ot_get_glyph_v_advance (hb_font_t *font HB_UNUSED,
                            void *font_data,
                            hb_codepoint_t glyph,
                            void *user_data HB_UNUSED)
 {
   const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
   return font->em_scale_y (-(int) ot_font->v_metrics.get_advance (glyph));
 }
 
 static hb_bool_t
-hb_ot_get_glyph_h_origin (hb_font_t *font HB_UNUSED,
-                          void *font_data HB_UNUSED,
-                          hb_codepoint_t glyph HB_UNUSED,
-                          hb_position_t *x HB_UNUSED,
-                          hb_position_t *y HB_UNUSED,
-                          void *user_data HB_UNUSED)
-{
-  /* We always work in the horizontal coordinates. */
-  return true;
-}
-
-static hb_bool_t
-hb_ot_get_glyph_v_origin (hb_font_t *font HB_UNUSED,
-                          void *font_data,
-                          hb_codepoint_t glyph,
-                          hb_position_t *x,
-                          hb_position_t *y,
-                          void *user_data HB_UNUSED)
-{
-  /* TODO */
-  return false;
-}
-
-static hb_position_t
-hb_ot_get_glyph_h_kerning (hb_font_t *font,
-                           void *font_data,
-                           hb_codepoint_t left_glyph,
-                           hb_codepoint_t right_glyph,
-                           void *user_data HB_UNUSED)
-{
-  /* TODO */
-  return 0;
-}
-
-static hb_position_t
-hb_ot_get_glyph_v_kerning (hb_font_t *font HB_UNUSED,
-                           void *font_data HB_UNUSED,
-                           hb_codepoint_t top_glyph HB_UNUSED,
-                           hb_codepoint_t bottom_glyph HB_UNUSED,
-                           void *user_data HB_UNUSED)
-{
-  /* OpenType doesn't have vertical-kerning other than GPOS. */
-  return 0;
-}
-
-static hb_bool_t
 hb_ot_get_glyph_extents (hb_font_t *font HB_UNUSED,
                          void *font_data,
                          hb_codepoint_t glyph,
                          hb_glyph_extents_t *extents,
                          void *user_data HB_UNUSED)
 {
   const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
   bool ret = ot_font->glyf.get_extents (glyph, extents);
   extents->x_bearing = font->em_scale_x (extents->x_bearing);
   extents->y_bearing = font->em_scale_y (extents->y_bearing);
   extents->width     = font->em_scale_x (extents->width);
   extents->height    = font->em_scale_y (extents->height);
   return ret;
 }
 
-static hb_bool_t
-hb_ot_get_glyph_contour_point (hb_font_t *font HB_UNUSED,
-                               void *font_data,
-                               hb_codepoint_t glyph,
-                               unsigned int point_index,
-                               hb_position_t *x,
-                               hb_position_t *y,
-                               void *user_data HB_UNUSED)
+
+static hb_font_funcs_t *static_ot_funcs = NULL;
+
+#ifdef HB_USE_ATEXIT
+static
+void free_static_ot_funcs (void)
 {
-  /* TODO */
-  return false;
+  hb_font_funcs_destroy (static_ot_funcs);
 }
-
-static hb_bool_t
-hb_ot_get_glyph_name (hb_font_t *font HB_UNUSED,
-                      void *font_data,
-                      hb_codepoint_t glyph,
-                      char *name, unsigned int size,
-                      void *user_data HB_UNUSED)
-{
-  /* TODO */
-  return false;
-}
-
-static hb_bool_t
-hb_ot_get_glyph_from_name (hb_font_t *font HB_UNUSED,
-                           void *font_data,
-                           const char *name, int len, /* -1 means nul-terminated */
-                           hb_codepoint_t *glyph,
-                           void *user_data HB_UNUSED)
-{
-  /* TODO */
-  return false;
-}
-
+#endif
 
 static hb_font_funcs_t *
 _hb_ot_get_font_funcs (void)
 {
-  static const hb_font_funcs_t ot_ffuncs = {
-    HB_OBJECT_HEADER_STATIC,
+retry:
+  hb_font_funcs_t *funcs = (hb_font_funcs_t *) hb_atomic_ptr_get (&static_ot_funcs);
 
-    true, /* immutable */
+  if (unlikely (!funcs))
+  {
+    funcs = hb_font_funcs_create ();
 
-    {
-#define HB_FONT_FUNC_IMPLEMENT(name) hb_ot_get_##name,
-      HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
-#undef HB_FONT_FUNC_IMPLEMENT
+    hb_font_funcs_set_glyph_func (funcs, hb_ot_get_glyph, NULL, NULL);
+    hb_font_funcs_set_glyph_h_advance_func (funcs, hb_ot_get_glyph_h_advance, NULL, NULL);
+    hb_font_funcs_set_glyph_v_advance_func (funcs, hb_ot_get_glyph_v_advance, NULL, NULL);
+    //hb_font_funcs_set_glyph_h_origin_func (funcs, hb_ot_get_glyph_h_origin, NULL, NULL);
+    //hb_font_funcs_set_glyph_v_origin_func (funcs, hb_ot_get_glyph_v_origin, NULL, NULL);
+    //hb_font_funcs_set_glyph_h_kerning_func (funcs, hb_ot_get_glyph_h_kerning, NULL, NULL); TODO
+    //hb_font_funcs_set_glyph_v_kerning_func (funcs, hb_ot_get_glyph_v_kerning, NULL, NULL);
+    hb_font_funcs_set_glyph_extents_func (funcs, hb_ot_get_glyph_extents, NULL, NULL);
+    //hb_font_funcs_set_glyph_contour_point_func (funcs, hb_ot_get_glyph_contour_point, NULL, NULL); TODO
+    //hb_font_funcs_set_glyph_name_func (funcs, hb_ot_get_glyph_name, NULL, NULL); TODO
+    //hb_font_funcs_set_glyph_from_name_func (funcs, hb_ot_get_glyph_from_name, NULL, NULL); TODO
+
+    hb_font_funcs_make_immutable (funcs);
+
+    if (!hb_atomic_ptr_cmpexch (&static_ot_funcs, NULL, funcs)) {
+      hb_font_funcs_destroy (funcs);
+      goto retry;
     }
+
+#ifdef HB_USE_ATEXIT
+    atexit (free_static_ot_funcs); /* First person registers atexit() callback. */
+#endif
   };
 
-  return const_cast<hb_font_funcs_t *> (&ot_ffuncs);
+  return funcs;
 }
 
 
 /**
  * Since: 0.9.28
  **/
 void
 hb_ot_font_set_funcs (hb_font_t *font)
 {
   hb_ot_font_t *ot_font = _hb_ot_font_create (font->face);
   if (unlikely (!ot_font))
     return;
 
   hb_font_set_funcs (font,
                      _hb_ot_get_font_funcs (),
                      ot_font,
                      (hb_destroy_func_t) _hb_ot_font_destroy);
 }