Roll HarfBuzz to 1.1.3

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 17 matching lines @@
 
 #include "hb-ot.h"
 
 #include "hb-font-private.hh"
 
 #include "hb-ot-cmap-table.hh"
 #include "hb-ot-glyf-table.hh"
 #include "hb-ot-head-table.hh"
 #include "hb-ot-hhea-table.hh"
 #include "hb-ot-hmtx-table.hh"
+#include "hb-ot-os2-table.hh"
 
 
 struct hb_ot_face_metrics_accelerator_t
 {
   unsigned int num_metrics;
   unsigned int num_advances;
   unsigned int default_advance;
+  unsigned short ascender;
+  unsigned short descender;
+  unsigned short line_gap;
+
   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)
+                    hb_tag_t _hea_tag,
+                    hb_tag_t _mtx_tag,
+                    hb_tag_t os2_tag)
   {
     this->default_advance = face->get_upem ();
 
+    bool got_font_extents = false;
+    if (os2_tag)
+    {
+      hb_blob_t *os2_blob = OT::Sanitizer<OT::os2>::sanitize (face->reference_table (os2_tag));
+      const OT::os2 *os2 = OT::Sanitizer<OT::os2>::lock_instance (os2_blob);
+#define USE_TYPO_METRICS (1u<<7)
+      if (0 != (os2->fsSelection & USE_TYPO_METRICS))
+      {
+        this->ascender = os2->sTypoAscender;
+        this->descender = os2->sTypoDescender;
+        this->line_gap = os2->sTypoLineGap;
+        got_font_extents = (this->ascender | this->descender) != 0;
+      }
+      hb_blob_destroy (os2_blob);
+    }
+
     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;
+    if (!got_font_extents)
+    {
+      this->ascender = _hea->ascender;
+      this->descender = _hea->descender;
+      this->line_gap = _hea->lineGap;
+    }
     hb_blob_destroy (_hea_blob);
 
     this->blob = OT::Sanitizer<OT::_mtx>::sanitize (face->reference_table (_mtx_tag));
 
     /* 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;
 
@@ skipping 179 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;
 
   ot_font->cmap.init (face);
-  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->h_metrics.init (face, HB_OT_TAG_hhea, HB_OT_TAG_hmtx, HB_OT_TAG_os2);
+  ot_font->v_metrics.init (face, HB_OT_TAG_vhea, HB_OT_TAG_vmtx, HB_TAG_NONE); /* 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 46 matching lines @@
 {
   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_font_h_extents (hb_font_t *font HB_UNUSED,
+                          void *font_data,
+                          hb_font_extents_t *metrics,
+                          void *user_data HB_UNUSED)
+{
+  const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
+  metrics->ascender = font->em_scale_y (ot_font->h_metrics.ascender);
+  metrics->descender = font->em_scale_y (ot_font->h_metrics.descender);
+  metrics->line_gap = font->em_scale_y (ot_font->h_metrics.line_gap);
+  return true;
+}
+
+static hb_bool_t
+hb_ot_get_font_v_extents (hb_font_t *font HB_UNUSED,
+                          void *font_data,
+                          hb_font_extents_t *metrics,
+                          void *user_data HB_UNUSED)
+{
+  const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
+  metrics->ascender = font->em_scale_x (ot_font->v_metrics.ascender);
+  metrics->descender = font->em_scale_x (ot_font->v_metrics.descender);
+  metrics->line_gap = font->em_scale_x (ot_font->v_metrics.line_gap);
+  return true;
+}
 
 static hb_font_funcs_t *static_ot_funcs = NULL;
 
 #ifdef HB_USE_ATEXIT
 static
 void free_static_ot_funcs (void)
 {
   hb_font_funcs_destroy (static_ot_funcs);
 }
 #endif
 
 static hb_font_funcs_t *
 _hb_ot_get_font_funcs (void)
 {
 retry:
   hb_font_funcs_t *funcs = (hb_font_funcs_t *) hb_atomic_ptr_get (&static_ot_funcs);
 
   if (unlikely (!funcs))
   {
     funcs = hb_font_funcs_create ();
 
+    hb_font_funcs_set_font_h_extents_func (funcs, hb_ot_get_font_h_extents, NULL, NULL);
+    hb_font_funcs_set_font_v_extents_func (funcs, hb_ot_get_font_v_extents, NULL, NULL);
     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 funcs;
 }
 
 
 /**
+ * hb_ot_font_set_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);
 }