Roll HarfBuzz to 1.3.4

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-cbdt-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"
 //#include "hb-ot-post-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;
+  bool has_font_extents;
 
   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 os2_tag)
+                    hb_tag_t os2_tag,
+                    unsigned int default_advance = 0)
   {
-    this->default_advance = face->get_upem ();
+    this->default_advance = default_advance ? 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;
+      got_font_extents = (this->ascender | this->descender) != 0;
     }
     hb_blob_destroy (_hea_blob);
 
+    this->has_font_extents = got_font_extents;
+
     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;
 
     /* We MUST set num_metrics to zero if num_advances is zero.
      * Our get_advance() depends on that. */
@@ skipping 97 matching lines @@
 
     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_cbdt_accelerator_t
+{
+  hb_blob_t *cblc_blob;
+  hb_blob_t *cbdt_blob;
+  const OT::CBLC *cblc;
+  const OT::CBDT *cbdt;
+
+  unsigned int cbdt_len;
+  float upem;
+
+  inline void init (hb_face_t *face)
+  {
+    upem = face->get_upem();
+
+    cblc_blob = OT::Sanitizer<OT::CBLC>::sanitize (face->reference_table (HB_OT_TAG_CBLC));
+    cbdt_blob = OT::Sanitizer<OT::CBDT>::sanitize (face->reference_table (HB_OT_TAG_CBDT));
+    cbdt_len = hb_blob_get_length (cbdt_blob);
+
+    if (hb_blob_get_length (cblc_blob) == 0) {
+      cblc = NULL;
+      cbdt = NULL;
+      return;  /* Not a bitmap font. */
+    }
+    cblc = OT::Sanitizer<OT::CBLC>::lock_instance (cblc_blob);
+    cbdt = OT::Sanitizer<OT::CBDT>::lock_instance (cbdt_blob);
+
+  }
+
+  inline void fini (void)
+  {
+    hb_blob_destroy (this->cblc_blob);
+    hb_blob_destroy (this->cbdt_blob);
+  }
+
+  inline bool get_extents (hb_codepoint_t glyph, hb_glyph_extents_t *extents) const
+  {
+    unsigned int x_ppem = upem, y_ppem = upem; /* TODO Use font ppem if available. */
+
+    if (cblc == NULL)
+      return false;  // Not a color bitmap font.
+
+    const OT::IndexSubtableRecord *subtable_record = this->cblc->find_table(glyph, &x_ppem, &y_ppem);
+    if (subtable_record == NULL)
+      return false;
+
+    if (subtable_record->get_extents (extents))
+      return true;
+
+    unsigned int image_offset = 0, image_length = 0, image_format = 0;
+    if (!subtable_record->get_image_data (glyph, &image_offset, &image_length, &image_format))
+      return false;
+
+    {
+      /* TODO Move the following into CBDT struct when adding more formats. */
+
+      if (unlikely (image_offset > cbdt_len || cbdt_len - image_offset < image_length))
+        return false;
+
+      switch (image_format)
+      {
+        case 17: {
+          if (unlikely (image_length < OT::GlyphBitmapDataFormat17::min_size))
+            return false;
+
+          const OT::GlyphBitmapDataFormat17& glyphFormat17 =
+              OT::StructAtOffset<OT::GlyphBitmapDataFormat17> (this->cbdt, image_offset);
+          glyphFormat17.glyphMetrics.get_extents (extents);
+        }
+        break;
+        default:
+          // TODO: Support other image formats.
+          return false;
+      }
+    }
+
+    /* Convert to the font units. */
+    extents->x_bearing *= upem / (float) x_ppem;
+    extents->y_bearing *= upem / (float) y_ppem;
+    extents->width *= upem / (float) x_ppem;
+    extents->height *= upem / (float) y_ppem;
+
+    return true;
+  }
+};
+
 typedef bool (*hb_cmap_get_glyph_func_t) (const void *obj,
                                           hb_codepoint_t codepoint,
                                           hb_codepoint_t *glyph);
 
 template <typename Type>
 static inline bool get_glyph_from (const void *obj,
                                    hb_codepoint_t codepoint,
                                    hb_codepoint_t *glyph)
 {
   const Type *typed_obj = (const Type *) obj;
@@ skipping 152 matching lines @@
   hb_face_t *face;
   T *instance;
 };
 
 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_lazy_loader_t<hb_ot_face_glyf_accelerator_t> glyf;
+  hb_lazy_loader_t<hb_ot_face_cbdt_accelerator_t> cbdt;
 };
 
 
 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, 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->v_metrics.init (face, HB_OT_TAG_vhea, HB_OT_TAG_vmtx, HB_TAG_NONE,
+                           ot_font->h_metrics.ascender - ot_font->h_metrics.descender); /* TODO Can we do this lazily? */
   ot_font->glyf.init (face);
+  ot_font->cbdt.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 ();
+  ot_font->cbdt.fini ();
 
   free (ot_font);
 }
 
 
 static hb_bool_t
 hb_ot_get_nominal_glyph (hb_font_t *font HB_UNUSED,
                          void *font_data,
                          hb_codepoint_t unicode,
                          hb_codepoint_t *glyph,
@@ skipping 38 matching lines @@
 
 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);
+  if (!ret)
+    ret = ot_font->cbdt->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;
+  return ot_font->h_metrics.has_font_extents;
 }
 
 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;
+  return ot_font->v_metrics.has_font_extents;
 }
 
 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);
 }
@@ skipping 50 matching lines @@
 {
   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);
 }