Roll harfbuzz-ng to 1.0.5

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 13 matching lines @@
  * Google Author(s): Behdad Esfahbod, Roozbeh Pournader
  */
 
 #include "hb-private.hh"
 
 #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"
 
 
 struct hb_ot_face_metrics_accelerator_t
 {
   unsigned int num_metrics;
   unsigned int num_advances;
   unsigned int default_advance;
   const OT::_mtx *table;
@@ skipping 25 matching lines @@
   inline void fini (void)
   {
     hb_blob_destroy (this->blob);
   }
 
   inline unsigned int get_advance (hb_codepoint_t glyph) const
   {
     if (unlikely (glyph >= this->num_metrics))
     {
       /* If this->num_metrics is zero, it means we don't have the metrics table
-       * for this direction: return one EM.  Otherwise, it means that the glyph
-       * index is out of bound: return zero. */
+       * for this direction: return default advance.  Otherwise, it means that the
+       * glyph index is out of bound: return zero. */
       if (this->num_metrics)
         return 0;
       else
         return this->default_advance;
     }
 
     if (glyph >= this->num_advances)
       glyph = this->num_advances - 1;
 
     return this->table->longMetric[glyph].advance;
   }
 };
 
+struct hb_ot_face_glyf_accelerator_t
+{
+  bool short_offset;
+  unsigned int num_glyphs;
+  const OT::loca *loca;
+  const OT::glyf *glyf;
+  hb_blob_t *loca_blob;
+  hb_blob_t *glyf_blob;
+  unsigned int glyf_len;
+
+  inline void init (hb_face_t *face)
+  {
+    hb_blob_t *head_blob = OT::Sanitizer<OT::head>::sanitize (face->reference_table (HB_OT_TAG_head));
+    const OT::head *head = OT::Sanitizer<OT::head>::lock_instance (head_blob);
+    if ((unsigned int) head->indexToLocFormat > 1 || head->glyphDataFormat != 0)
+    {
+      /* Unknown format.  Leave num_glyphs=0, that takes care of disabling us. */
+      hb_blob_destroy (head_blob);
+      return;
+    }
+    this->short_offset = 0 == head->indexToLocFormat;
+    hb_blob_destroy (head_blob);
+
+    this->loca_blob = OT::Sanitizer<OT::loca>::sanitize (face->reference_table (HB_OT_TAG_loca));
+    this->loca = OT::Sanitizer<OT::loca>::lock_instance (this->loca_blob);
+    this->glyf_blob = OT::Sanitizer<OT::glyf>::sanitize (face->reference_table (HB_OT_TAG_glyf));
+    this->glyf = OT::Sanitizer<OT::glyf>::lock_instance (this->glyf_blob);
+
+    this->num_glyphs = MAX (1u, hb_blob_get_length (this->loca_blob) / (this->short_offset ? 2 : 4)) - 1;
+    this->glyf_len = hb_blob_get_length (this->glyf_blob);
+  }
+
+  inline void fini (void)
+  {
+    hb_blob_destroy (this->loca_blob);
+    hb_blob_destroy (this->glyf_blob);
+  }
+
+  inline bool get_extents (hb_codepoint_t glyph,
+                           hb_glyph_extents_t *extents) const
+  {
+    if (unlikely (glyph >= this->num_glyphs))
+      return false;
+
+    unsigned int start_offset, end_offset;
+    if (this->short_offset)
+    {
+      start_offset = 2 * this->loca->u.shortsZ[glyph];
+      end_offset   = 2 * this->loca->u.shortsZ[glyph + 1];
+    }
+    else
+    {
+      start_offset = this->loca->u.longsZ[glyph];
+      end_offset   = this->loca->u.longsZ[glyph + 1];
+    }
+
+    if (start_offset > end_offset || end_offset > this->glyf_len)
+      return false;
+
+    if (end_offset - start_offset < OT::glyfGlyphHeader::static_size)
+      return true; /* Empty glyph; zero extents. */
+
+    const OT::glyfGlyphHeader &glyph_header = OT::StructAtOffset<OT::glyfGlyphHeader> (this->glyf, start_offset);
+
+    extents->x_bearing = MIN (glyph_header.xMin, glyph_header.xMax);
+    extents->y_bearing = MAX (glyph_header.yMin, glyph_header.yMax);
+    extents->width     = MAX (glyph_header.xMin, glyph_header.xMax) - extents->x_bearing;
+    extents->height    = MIN (glyph_header.yMin, glyph_header.yMax) - extents->y_bearing;
+
+    return true;
+  }
+};
+
 struct hb_ot_face_cmap_accelerator_t
 {
   const OT::CmapSubtable *table;
   const OT::CmapSubtable *uvs_table;
   hb_blob_t *blob;
 
   inline void init (hb_face_t *face)
   {
     this->blob = OT::Sanitizer<OT::cmap>::sanitize (face->reference_table (HB_OT_TAG_cmap));
     const OT::cmap *cmap = OT::Sanitizer<OT::cmap>::lock_instance (this->blob);
@@ skipping 47 matching lines @@
     return this->table->get_glyph (unicode, glyph);
   }
 };
 
 
 struct hb_ot_font_t
 {
   hb_ot_face_cmap_accelerator_t cmap;
   hb_ot_face_metrics_accelerator_t h_metrics;
   hb_ot_face_metrics_accelerator_t v_metrics;
+  hb_ot_face_glyf_accelerator_t glyf;
 };
 
 
 static hb_ot_font_t *
-_hb_ot_font_create (hb_font_t *font)
+_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));
-  hb_face_t *face = font->face;
 
   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->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 ();
   ot_font->v_metrics.fini ();
+  ot_font->glyf.fini ();
 
   free (ot_font);
 }
 
 
 static hb_bool_t
 hb_ot_get_glyph (hb_font_t *font HB_UNUSED,
                  void *font_data,
                  hb_codepoint_t unicode,
                  hb_codepoint_t variation_selector,
@@ skipping 71 matching lines @@
   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)
 {
-  /* TODO */
-  return false;
+  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)
@@ skipping 43 matching lines @@
   return const_cast<hb_font_funcs_t *> (&ot_ffuncs);
 }
 
 
 /**
  * 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);
+  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);
 }