tor-browser

hb-ot-font.cc (30620B)

---

/*
* 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.
*
* 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): Behdad Esfahbod, Roozbeh Pournader
*/

#include "hb.hh"

#ifndef HB_NO_OT_FONT

#include "hb-ot.h"

#include "hb-cache.hh"
#include "hb-font.hh"
#include "hb-machinery.hh"
#include "hb-ot-face.hh"

#include "hb-ot-cmap-table.hh"
#include "hb-ot-glyf-table.hh"
#include "hb-ot-var-gvar-table.hh"
#include "hb-ot-cff2-table.hh"
#include "hb-ot-cff1-table.hh"
#include "hb-ot-hmtx-table.hh"
#include "hb-ot-post-table.hh"
#include "hb-ot-stat-table.hh"
#include "hb-ot-var-varc-table.hh"
#include "hb-ot-vorg-table.hh"
#include "OT/Color/CBDT/CBDT.hh"
#include "OT/Color/COLR/COLR.hh"
#include "OT/Color/sbix/sbix.hh"
#include "OT/Color/svg/svg.hh"


/**
* SECTION:hb-ot-font
* @title: hb-ot-font
* @short_description: OpenType font implementation
* @include: hb-ot.h
*
* Functions for using OpenType fonts with hb_shape().  Note that fonts returned
* by hb_font_create() default to using these functions, so most clients would
* never need to call these functions directly.
**/

using hb_ot_font_advance_cache_t = hb_cache_t<24, 16>;
static_assert (sizeof (hb_ot_font_advance_cache_t) == 1024, "");

using hb_ot_font_origin_cache_t = hb_cache_t<20, 20>;
static_assert (sizeof (hb_ot_font_origin_cache_t) == 1024, "");

struct hb_ot_font_t
{
 const hb_ot_face_t *ot_face;

 mutable hb_atomic_t<int> cached_serial;
 mutable hb_atomic_t<int> cached_coords_serial;

 struct direction_cache_t
 {
   mutable hb_atomic_t<hb_ot_font_advance_cache_t *> advance_cache;
   mutable hb_atomic_t<OT::hb_scalar_cache_t *> varStore_cache;

   ~direction_cache_t ()
   {
     clear ();
   }

   hb_ot_font_advance_cache_t *acquire_advance_cache () const
   {
   retry:
     auto *cache = advance_cache.get_acquire ();
     if (!cache)
     {
       cache = (hb_ot_font_advance_cache_t *) hb_malloc (sizeof (hb_ot_font_advance_cache_t));
if (!cache)
  return nullptr;
new (cache) hb_ot_font_advance_cache_t;
return cache;
     }
     if (advance_cache.cmpexch (cache, nullptr))
       return cache;
     else
       goto retry;
   }
   void release_advance_cache (hb_ot_font_advance_cache_t *cache) const
   {
     if (!cache)
       return;
     if (!advance_cache.cmpexch (nullptr, cache))
       hb_free (cache);
   }
   void clear_advance_cache () const
   {
   retry:
     auto *cache = advance_cache.get_acquire ();
     if (!cache)
return;
     if (advance_cache.cmpexch (cache, nullptr))
hb_free (cache);
     else
       goto retry;
   }

   OT::hb_scalar_cache_t *acquire_varStore_cache (const OT::ItemVariationStore &varStore) const
   {
   retry:
     auto *cache = varStore_cache.get_acquire ();
     if (!cache)
return varStore.create_cache ();
     if (varStore_cache.cmpexch (cache, nullptr))
return cache;
     else
goto retry;
   }
   void release_varStore_cache (OT::hb_scalar_cache_t *cache) const
   {
     if (!cache)
return;
     if (!varStore_cache.cmpexch (nullptr, cache))
OT::ItemVariationStore::destroy_cache (cache);
   }
   void clear_varStore_cache () const
   {
   retry:
     auto *cache = varStore_cache.get_acquire ();
     if (!cache)
return;
     if (varStore_cache.cmpexch (cache, nullptr))
OT::ItemVariationStore::destroy_cache (cache);
     else
goto retry;
   }

   void clear () const
   {
     clear_advance_cache ();
     clear_varStore_cache ();
   }

 } h, v;

 struct origin_cache_t
 {
   mutable hb_atomic_t<hb_ot_font_origin_cache_t *> origin_cache;
   mutable hb_atomic_t<OT::hb_scalar_cache_t *> varStore_cache;

   ~origin_cache_t ()
   {
     clear ();
   }

   hb_ot_font_origin_cache_t *acquire_origin_cache () const
   {
   retry:
     auto *cache = origin_cache.get_acquire ();
     if (!cache)
     {
       cache = (hb_ot_font_origin_cache_t *) hb_malloc (sizeof (hb_ot_font_origin_cache_t));
if (!cache)
  return nullptr;
new (cache) hb_ot_font_origin_cache_t;
return cache;
     }
     if (origin_cache.cmpexch (cache, nullptr))
       return cache;
     else
       goto retry;
   }
   void release_origin_cache (hb_ot_font_origin_cache_t *cache) const
   {
     if (!cache)
       return;
     if (!origin_cache.cmpexch (nullptr, cache))
       hb_free (cache);
   }
   void clear_origin_cache () const
   {
   retry:
     auto *cache = origin_cache.get_acquire ();
     if (!cache)
return;
     if (origin_cache.cmpexch (cache, nullptr))
hb_free (cache);
     else
       goto retry;
   }

   OT::hb_scalar_cache_t *acquire_varStore_cache (const OT::ItemVariationStore &varStore) const
   {
   retry:
     auto *cache = varStore_cache.get_acquire ();
     if (!cache)
return varStore.create_cache ();
     if (varStore_cache.cmpexch (cache, nullptr))
return cache;
     else
goto retry;
   }
   void release_varStore_cache (OT::hb_scalar_cache_t *cache) const
   {
     if (!cache)
return;
     if (!varStore_cache.cmpexch (nullptr, cache))
OT::ItemVariationStore::destroy_cache (cache);
   }
   void clear_varStore_cache () const
   {
   retry:
     auto *cache = varStore_cache.get_acquire ();
     if (!cache)
return;
     if (varStore_cache.cmpexch (cache, nullptr))
OT::ItemVariationStore::destroy_cache (cache);
     else
goto retry;
   }

   void clear () const
   {
     clear_origin_cache ();
     clear_varStore_cache ();
   }
 } v_origin;

 struct draw_cache_t
 {
   mutable hb_atomic_t<OT::hb_scalar_cache_t *> gvar_cache;

   ~draw_cache_t ()
   {
     clear ();
   }

   OT::hb_scalar_cache_t *acquire_gvar_cache (const OT::gvar_accelerator_t &gvar) const
   {
   retry:
     auto *cache = gvar_cache.get_acquire ();
     if (!cache)
return gvar.create_cache ();
     if (gvar_cache.cmpexch (cache, nullptr))
return cache;
     else
goto retry;
   }
   void release_gvar_cache (OT::hb_scalar_cache_t *cache) const
   {
     if (!cache)
return;
     if (!gvar_cache.cmpexch (nullptr, cache))
OT::gvar_accelerator_t::destroy_cache (cache);
   }
   void clear_gvar_cache () const
   {
   retry:
     auto *cache = gvar_cache.get_acquire ();
     if (!cache)
return;
     if (gvar_cache.cmpexch (cache, nullptr))
OT::gvar_accelerator_t::destroy_cache (cache);
     else
goto retry;
   }

   void clear () const
   {
     clear_gvar_cache ();
   }
 } draw;

 void check_serial (hb_font_t *font) const
 {
   int font_serial = font->serial_coords.get_acquire ();
   if (cached_serial.get_acquire () != font_serial)
   {
     /* These caches are dependent on scale and synthetic settings.
      * Any change to the font invalidates them. */
     v_origin.clear ();

     cached_serial.set_release (font_serial);
   }

   int font_serial_coords = font->serial_coords.get_acquire ();
   if (cached_coords_serial.get_acquire () != font_serial_coords)
   {
     /* These caches are independent of scale or synthetic settings.
      * Just variation changes will invalidate them. */
     h.clear ();
     v.clear ();
     draw.clear ();

     cached_coords_serial.set_release (font_serial_coords);
   }
 }
};

static hb_ot_font_t *
_hb_ot_font_create (hb_font_t *font)
{
 hb_ot_font_t *ot_font = (hb_ot_font_t *) hb_calloc (1, sizeof (hb_ot_font_t));
 if (unlikely (!ot_font))
   return nullptr;

 ot_font->ot_face = &font->face->table;

 return ot_font;
}

static void
_hb_ot_font_destroy (void *font_data)
{
 hb_ot_font_t *ot_font = (hb_ot_font_t *) font_data;

 ot_font->~hb_ot_font_t ();

 hb_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,
		 void *user_data HB_UNUSED)
{
 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
 const hb_ot_face_t *ot_face = ot_font->ot_face;
 return ot_face->cmap->get_nominal_glyph (unicode, glyph);
}

static unsigned int
hb_ot_get_nominal_glyphs (hb_font_t *font HB_UNUSED,
		  void *font_data,
		  unsigned int count,
		  const hb_codepoint_t *first_unicode,
		  unsigned int unicode_stride,
		  hb_codepoint_t *first_glyph,
		  unsigned int glyph_stride,
		  void *user_data HB_UNUSED)
{
 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
 const hb_ot_face_t *ot_face = ot_font->ot_face;
 return ot_face->cmap->get_nominal_glyphs (count,
				    first_unicode, unicode_stride,
				    first_glyph, glyph_stride);
}

static hb_bool_t
hb_ot_get_variation_glyph (hb_font_t *font HB_UNUSED,
		   void *font_data,
		   hb_codepoint_t unicode,
		   hb_codepoint_t variation_selector,
		   hb_codepoint_t *glyph,
		   void *user_data HB_UNUSED)
{
 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
 const hb_ot_face_t *ot_face = ot_font->ot_face;
 return ot_face->cmap->get_variation_glyph (unicode,
                                            variation_selector, glyph);
}

static void
hb_ot_get_glyph_h_advances (hb_font_t* font, void* font_data,
		    unsigned count,
		    const hb_codepoint_t *first_glyph,
		    unsigned glyph_stride,
		    hb_position_t *first_advance,
		    unsigned advance_stride,
		    void *user_data HB_UNUSED)
{
 // Duplicated in v_advances. Ugly. Keep in sync'ish.

 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
 const hb_ot_face_t *ot_face = ot_font->ot_face;
 const OT::hmtx_accelerator_t &hmtx = *ot_face->hmtx;

 if (unlikely (!hmtx.has_data ()))
 {
   hb_position_t advance = font->face->get_upem () / 2;
   advance = font->em_scale_x (advance);
   for (unsigned int i = 0; i < count; i++)
   {
     *first_advance = advance;
     first_advance = &StructAtOffsetUnaligned<hb_position_t> (first_advance, advance_stride);
   }
   return;
 }

#ifndef HB_NO_VAR
 if (!font->has_nonzero_coords)
 {
 fallback:
#else
 {
#endif
   // Just plain htmx data. No need to cache.
   for (unsigned int i = 0; i < count; i++)
   {
     *first_advance = font->em_scale_x (hmtx.get_advance_without_var_unscaled (*first_glyph));
     first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
     first_advance = &StructAtOffsetUnaligned<hb_position_t> (first_advance, advance_stride);
   }
   return;
 }

#ifndef HB_NO_VAR
 /* has_nonzero_coords. */

 ot_font->check_serial (font);
 hb_ot_font_advance_cache_t *advance_cache = ot_font->h.acquire_advance_cache ();
 if (!advance_cache)
 {
   // malloc failure. Just use the fallback non-variable path.
   goto fallback;
 }

 /* If HVAR is present, use it.*/
 const OT::HVAR &HVAR = *hmtx.var_table;
 if (HVAR.has_data ())
 {
   const OT::ItemVariationStore &varStore = &HVAR + HVAR.varStore;
   OT::hb_scalar_cache_t *varStore_cache = ot_font->h.acquire_varStore_cache (varStore);

   for (unsigned int i = 0; i < count; i++)
   {
     hb_position_t v;
     unsigned cv;
     if (advance_cache->get (*first_glyph, &cv))
v = cv;
     else
     {
       v = hmtx.get_advance_with_var_unscaled (*first_glyph, font, varStore_cache);
advance_cache->set (*first_glyph, v);
     }
     *first_advance = font->em_scale_x (v);
     first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
     first_advance = &StructAtOffsetUnaligned<hb_position_t> (first_advance, advance_stride);
   }

   ot_font->h.release_varStore_cache (varStore_cache);
   ot_font->h.release_advance_cache (advance_cache);
   return;
 }

 const auto &gvar = *ot_face->gvar;
 if (gvar.has_data ())
 {
   const auto &glyf = *ot_face->glyf;
   auto *scratch = glyf.acquire_scratch ();
   if (unlikely (!scratch))
   {
     ot_font->h.release_advance_cache (advance_cache);
     goto fallback;
   }
   OT::hb_scalar_cache_t *gvar_cache = ot_font->draw.acquire_gvar_cache (gvar);

   for (unsigned int i = 0; i < count; i++)
   {
     hb_position_t v;
     unsigned cv;
     if (advance_cache->get (*first_glyph, &cv))
v = cv;
     else
     {
       v = glyf.get_advance_with_var_unscaled (*first_glyph, font, false, *scratch, gvar_cache);
advance_cache->set (*first_glyph, v);
     }
     *first_advance = font->em_scale_x (v);
     first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
     first_advance = &StructAtOffsetUnaligned<hb_position_t> (first_advance, advance_stride);
   }

   ot_font->draw.release_gvar_cache (gvar_cache);
   glyf.release_scratch (scratch);
   ot_font->h.release_advance_cache (advance_cache);
   return;
 }

 ot_font->h.release_advance_cache (advance_cache);
 // No HVAR or GVAR.  Just use the fallback non-variable path.
 goto fallback;
#endif
}

#ifndef HB_NO_VERTICAL
static void
hb_ot_get_glyph_v_advances (hb_font_t* font, void* font_data,
		    unsigned count,
		    const hb_codepoint_t *first_glyph,
		    unsigned glyph_stride,
		    hb_position_t *first_advance,
		    unsigned advance_stride,
		    void *user_data HB_UNUSED)
{
 // Duplicated from h_advances. Ugly. Keep in sync'ish.

 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
 const hb_ot_face_t *ot_face = ot_font->ot_face;
 const OT::vmtx_accelerator_t &vmtx = *ot_face->vmtx;

 if (unlikely (!vmtx.has_data ()))
 {
   hb_font_extents_t font_extents;
   font->get_h_extents_with_fallback (&font_extents);
   hb_position_t advance = font_extents.descender - font_extents.ascender;
   for (unsigned int i = 0; i < count; i++)
   {
     *first_advance = advance;
     first_advance = &StructAtOffsetUnaligned<hb_position_t> (first_advance, advance_stride);
   }
   return;
 }

#ifndef HB_NO_VAR
 if (!font->has_nonzero_coords)
 {
 fallback:
#else
 {
#endif
   // Just plain vtmx data. No need to cache.
   for (unsigned int i = 0; i < count; i++)
   {
     *first_advance = font->em_scale_y (- (int) vmtx.get_advance_without_var_unscaled (*first_glyph));
     first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
     first_advance = &StructAtOffsetUnaligned<hb_position_t> (first_advance, advance_stride);
   }
   return;
 }

#ifndef HB_NO_VAR
 /* has_nonzero_coords. */

 ot_font->check_serial (font);
 hb_ot_font_advance_cache_t *advance_cache = ot_font->v.acquire_advance_cache ();
 if (!advance_cache)
 {
   // malloc failure. Just use the fallback non-variable path.
   goto fallback;
 }

 /* If VVAR is present, use it.*/
 const OT::VVAR &VVAR = *vmtx.var_table;
 if (VVAR.has_data ())
 {
   const OT::ItemVariationStore &varStore = &VVAR + VVAR.varStore;
   OT::hb_scalar_cache_t *varStore_cache = ot_font->v.acquire_varStore_cache (varStore);

   for (unsigned int i = 0; i < count; i++)
   {
     hb_position_t v;
     unsigned cv;
     if (advance_cache->get (*first_glyph, &cv))
v = cv;
     else
     {
       v = vmtx.get_advance_with_var_unscaled (*first_glyph, font, varStore_cache);
advance_cache->set (*first_glyph, v);
     }
     *first_advance = font->em_scale_y (- (int) v);
     first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
     first_advance = &StructAtOffsetUnaligned<hb_position_t> (first_advance, advance_stride);
   }

   ot_font->v.release_varStore_cache (varStore_cache);
   ot_font->v.release_advance_cache (advance_cache);
   return;
 }

 const auto &gvar = *ot_face->gvar;
 if (gvar.has_data ())
 {
   const auto &glyf = *ot_face->glyf;
   auto *scratch = glyf.acquire_scratch ();
   if (unlikely (!scratch))
   {
     ot_font->v.release_advance_cache (advance_cache);
     goto fallback;
   }
   OT::hb_scalar_cache_t *gvar_cache = ot_font->draw.acquire_gvar_cache (gvar);

   for (unsigned int i = 0; i < count; i++)
   {
     hb_position_t v;
     unsigned cv;
     if (advance_cache->get (*first_glyph, &cv))
v = cv;
     else
     {
       v = glyf.get_advance_with_var_unscaled (*first_glyph, font, true, *scratch, gvar_cache);
advance_cache->set (*first_glyph, v);
     }
     *first_advance = font->em_scale_y (- (int) v);
     first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
     first_advance = &StructAtOffsetUnaligned<hb_position_t> (first_advance, advance_stride);
   }

   ot_font->draw.release_gvar_cache (gvar_cache);
   glyf.release_scratch (scratch);
   ot_font->v.release_advance_cache (advance_cache);
   return;
 }

 ot_font->v.release_advance_cache (advance_cache);
 // No VVAR or GVAR.  Just use the fallback non-variable path.
 goto fallback;
#endif
}
#endif

#ifndef HB_NO_VERTICAL
HB_HOT
static hb_bool_t
hb_ot_get_glyph_v_origins (hb_font_t *font,
		   void *font_data,
		   unsigned int count,
		   const hb_codepoint_t *first_glyph,
		   unsigned glyph_stride,
		   hb_position_t *first_x,
		   unsigned x_stride,
		   hb_position_t *first_y,
		   unsigned y_stride,
		   void *user_data HB_UNUSED)
{
 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
 const hb_ot_face_t *ot_face = ot_font->ot_face;

 /* First, set all the x values to half the advance width. */
 font->get_glyph_h_advances (count,
		      first_glyph, glyph_stride,
		      first_x, x_stride);
 for (unsigned i = 0; i < count; i++)
 {
   *first_x /= 2;
   first_x = &StructAtOffsetUnaligned<hb_position_t> (first_x, x_stride);
 }

 /* The vertical origin business is messy...
  *
  * We allocate the cache, then have various code paths that use the cache.
  * Each one is responsible to free it before returning.
  */
 hb_ot_font_origin_cache_t *origin_cache = ot_font->v_origin.acquire_origin_cache ();

 /* If there is VORG, always use it. It uses VVAR for variations if necessary. */
 const OT::VORG &VORG = *ot_face->VORG;
 if (origin_cache && VORG.has_data ())
 {
#ifndef HB_NO_VAR
   if (!font->has_nonzero_coords)
#endif
   {
     for (unsigned i = 0; i < count; i++)
     {
hb_position_t origin;
unsigned cv;
if (origin_cache->get (*first_glyph, &cv))
  origin = font->y_scale < 0 ? -static_cast<hb_position_t>(cv) : static_cast<hb_position_t>(cv);
else
{
  origin = font->em_scalef_y (VORG.get_y_origin (*first_glyph));
  origin_cache->set (*first_glyph, font->y_scale < 0 ? -origin : origin);
}

*first_y = origin;

first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
first_y = &StructAtOffsetUnaligned<hb_position_t> (first_y, y_stride);
     }
   }
#ifndef HB_NO_VAR
   else
   {
     const OT::VVAR &VVAR = *ot_face->vmtx->var_table;
     const auto &varStore = &VVAR + VVAR.varStore;
     auto *varStore_cache = ot_font->v_origin.acquire_varStore_cache (varStore);
     for (unsigned i = 0; i < count; i++)
     {
hb_position_t origin;
unsigned cv;
if (origin_cache->get (*first_glyph, &cv))
  origin = font->y_scale < 0 ? -static_cast<hb_position_t>(cv) : static_cast<hb_position_t>(cv);
else
{
  origin = font->em_scalef_y (VORG.get_y_origin (*first_glyph) +
			      VVAR.get_vorg_delta_unscaled (*first_glyph,
							    font->coords, font->num_coords,
							    varStore_cache));
  origin_cache->set (*first_glyph, font->y_scale < 0 ? -origin : origin);
}

*first_y = origin;

first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
first_y = &StructAtOffsetUnaligned<hb_position_t> (first_y, y_stride);
     }
     ot_font->v_origin.release_varStore_cache (varStore_cache);
   }
#endif
   ot_font->v_origin.release_origin_cache (origin_cache);
   return true;
 }

 /* If and only if `vmtx` is present and it's a `glyf` font,
  * we use the top phantom point, deduced from vmtx,glyf[,gvar]. */
 const auto &vmtx = *ot_face->vmtx;
 const auto &glyf = *ot_face->glyf;
 if (origin_cache && vmtx.has_data() && glyf.has_data ())
 {
   auto *scratch = glyf.acquire_scratch ();
   if (unlikely (!scratch))
   {
     ot_font->v_origin.release_origin_cache (origin_cache);
     return false;
   }
   OT::hb_scalar_cache_t *gvar_cache = font->has_nonzero_coords ?
				ot_font->draw.acquire_gvar_cache (*ot_face->gvar) :
				nullptr;

   for (unsigned i = 0; i < count; i++)
   {
     hb_position_t origin;
     unsigned cv;
     if (origin_cache->get (*first_glyph, &cv))
origin = font->y_scale < 0 ? -static_cast<hb_position_t>(cv) : static_cast<hb_position_t>(cv);
     else
     {
origin = font->em_scalef_y (glyf.get_v_origin_with_var_unscaled (*first_glyph, font, *scratch, gvar_cache));
origin_cache->set (*first_glyph, font->y_scale < 0 ? -origin : origin);
     }

     *first_y = origin;

     first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
     first_y = &StructAtOffsetUnaligned<hb_position_t> (first_y, y_stride);
   }

   if (gvar_cache)
     ot_font->draw.release_gvar_cache (gvar_cache);
   glyf.release_scratch (scratch);
   ot_font->v_origin.release_origin_cache (origin_cache);
   return true;
 }

 /* Otherwise, use glyph extents to center the glyph vertically.
  * If getting glyph extents failed, just use the font ascender. */
 if (origin_cache && font->has_glyph_extents_func ())
 {
   hb_font_extents_t font_extents;
   font->get_h_extents_with_fallback (&font_extents);
   hb_position_t font_advance = font_extents.ascender - font_extents.descender;

   for (unsigned i = 0; i < count; i++)
   {
     hb_position_t origin;
     unsigned cv;

     if (origin_cache->get (*first_glyph, &cv))
origin = font->y_scale < 0 ? -static_cast<hb_position_t>(cv) : static_cast<hb_position_t>(cv);
     else
     {
hb_glyph_extents_t extents = {0};
if (likely (font->get_glyph_extents (*first_glyph, &extents)))
  origin = extents.y_bearing + ((font_advance - -extents.height) >> 1);
else
  origin = font_extents.ascender;

origin_cache->set (*first_glyph, font->y_scale < 0 ? -origin : origin);
     }

     *first_y = origin;

     first_glyph = &StructAtOffsetUnaligned<hb_codepoint_t> (first_glyph, glyph_stride);
     first_y = &StructAtOffsetUnaligned<hb_position_t> (first_y, y_stride);
   }
 }

 ot_font->v_origin.release_origin_cache (origin_cache);
 return true;
}
#endif

static hb_bool_t
hb_ot_get_glyph_extents (hb_font_t *font,
		 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;
 const hb_ot_face_t *ot_face = ot_font->ot_face;

#if !defined(HB_NO_OT_FONT_BITMAP) && !defined(HB_NO_COLOR)
 if (ot_face->sbix->get_extents (font, glyph, extents)) return true;
 if (ot_face->CBDT->get_extents (font, glyph, extents)) return true;
#endif
#if !defined(HB_NO_COLOR) && !defined(HB_NO_PAINT)
 if (ot_face->COLR->get_extents (font, glyph, extents)) return true;
#endif
#ifndef HB_NO_VAR_COMPOSITES
 if (ot_face->VARC->get_extents (font, glyph, extents)) return true;
#endif
 if (ot_face->glyf->get_extents (font, glyph, extents)) return true;
#ifndef HB_NO_OT_FONT_CFF
 if (ot_face->cff2->get_extents (font, glyph, extents)) return true;
 if (ot_face->cff1->get_extents (font, glyph, extents)) return true;
#endif

 return false;
}

#ifndef HB_NO_OT_FONT_GLYPH_NAMES
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)
{
 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
 const hb_ot_face_t *ot_face = ot_font->ot_face;

 if (ot_face->post->get_glyph_name (glyph, name, size)) return true;
#ifndef HB_NO_OT_FONT_CFF
 if (ot_face->cff1->get_glyph_name (glyph, name, size)) return true;
#endif
 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,
		   hb_codepoint_t *glyph,
		   void *user_data HB_UNUSED)
{
 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
 const hb_ot_face_t *ot_face = ot_font->ot_face;

 if (ot_face->post->get_glyph_from_name (name, len, glyph)) return true;
#ifndef HB_NO_OT_FONT_CFF
   if (ot_face->cff1->get_glyph_from_name (name, len, glyph)) return true;
#endif
 return false;
}
#endif

static hb_bool_t
hb_ot_get_font_h_extents (hb_font_t *font,
		  void *font_data HB_UNUSED,
		  hb_font_extents_t *metrics,
		  void *user_data HB_UNUSED)
{
 return _hb_ot_metrics_get_position_common (font, HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER, &metrics->ascender) &&
 _hb_ot_metrics_get_position_common (font, HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER, &metrics->descender) &&
 _hb_ot_metrics_get_position_common (font, HB_OT_METRICS_TAG_HORIZONTAL_LINE_GAP, &metrics->line_gap);
}

#ifndef HB_NO_VERTICAL
static hb_bool_t
hb_ot_get_font_v_extents (hb_font_t *font,
		  void *font_data HB_UNUSED,
		  hb_font_extents_t *metrics,
		  void *user_data HB_UNUSED)
{
 return _hb_ot_metrics_get_position_common (font, HB_OT_METRICS_TAG_VERTICAL_ASCENDER, &metrics->ascender) &&
 _hb_ot_metrics_get_position_common (font, HB_OT_METRICS_TAG_VERTICAL_DESCENDER, &metrics->descender) &&
 _hb_ot_metrics_get_position_common (font, HB_OT_METRICS_TAG_VERTICAL_LINE_GAP, &metrics->line_gap);
}
#endif

#ifndef HB_NO_DRAW
static hb_bool_t
hb_ot_draw_glyph_or_fail (hb_font_t *font,
		  void *font_data HB_UNUSED,
		  hb_codepoint_t glyph,
		  hb_draw_funcs_t *draw_funcs, void *draw_data,
		  void *user_data)
{
 const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
 hb_draw_session_t draw_session {draw_funcs, draw_data};
 bool ret = false;

 OT::hb_scalar_cache_t *gvar_cache = nullptr;
 if (font->num_coords)
 {
   ot_font->check_serial (font);
   gvar_cache = ot_font->draw.acquire_gvar_cache (*ot_font->ot_face->gvar);
 }

#ifndef HB_NO_VAR_COMPOSITES
 if (font->face->table.VARC->get_path (font, glyph, draw_session)) { ret = true; goto done; }
#endif
 // Keep the following in synch with VARC::get_path_at()
 if (font->face->table.glyf->get_path (font, glyph, draw_session, gvar_cache)) { ret = true; goto done; }

#ifndef HB_NO_CFF
 if (font->face->table.cff2->get_path (font, glyph, draw_session)) { ret = true; goto done; }
 if (font->face->table.cff1->get_path (font, glyph, draw_session)) { ret = true; goto done; }
#endif

done:

 ot_font->draw.release_gvar_cache (gvar_cache);

 return ret;
}
#endif

#ifndef HB_NO_PAINT
static hb_bool_t
hb_ot_paint_glyph_or_fail (hb_font_t *font,
		   void *font_data,
		   hb_codepoint_t glyph,
		   hb_paint_funcs_t *paint_funcs, void *paint_data,
		   unsigned int palette,
		   hb_color_t foreground,
		   void *user_data)
{
#ifndef HB_NO_COLOR
 if (font->face->table.COLR->paint_glyph (font, glyph, paint_funcs, paint_data, palette, foreground)) return true;
 if (font->face->table.SVG->paint_glyph (font, glyph, paint_funcs, paint_data)) return true;
#ifndef HB_NO_OT_FONT_BITMAP
 if (font->face->table.CBDT->paint_glyph (font, glyph, paint_funcs, paint_data)) return true;
 if (font->face->table.sbix->paint_glyph (font, glyph, paint_funcs, paint_data)) return true;
#endif
#endif
 return false;
}
#endif

static inline void free_static_ot_funcs ();

static struct hb_ot_font_funcs_lazy_loader_t : hb_font_funcs_lazy_loader_t<hb_ot_font_funcs_lazy_loader_t>
{
 static hb_font_funcs_t *create ()
 {
   hb_font_funcs_t *funcs = hb_font_funcs_create ();

   hb_font_funcs_set_nominal_glyph_func (funcs, hb_ot_get_nominal_glyph, nullptr, nullptr);
   hb_font_funcs_set_nominal_glyphs_func (funcs, hb_ot_get_nominal_glyphs, nullptr, nullptr);
   hb_font_funcs_set_variation_glyph_func (funcs, hb_ot_get_variation_glyph, nullptr, nullptr);

   hb_font_funcs_set_font_h_extents_func (funcs, hb_ot_get_font_h_extents, nullptr, nullptr);
   hb_font_funcs_set_glyph_h_advances_func (funcs, hb_ot_get_glyph_h_advances, nullptr, nullptr);

#ifndef HB_NO_VERTICAL
   hb_font_funcs_set_font_v_extents_func (funcs, hb_ot_get_font_v_extents, nullptr, nullptr);
   hb_font_funcs_set_glyph_v_advances_func (funcs, hb_ot_get_glyph_v_advances, nullptr, nullptr);
   hb_font_funcs_set_glyph_v_origins_func (funcs, hb_ot_get_glyph_v_origins, nullptr, nullptr);
#endif

#ifndef HB_NO_DRAW
   hb_font_funcs_set_draw_glyph_or_fail_func (funcs, hb_ot_draw_glyph_or_fail, nullptr, nullptr);
#endif

#ifndef HB_NO_PAINT
   hb_font_funcs_set_paint_glyph_or_fail_func (funcs, hb_ot_paint_glyph_or_fail, nullptr, nullptr);
#endif

   hb_font_funcs_set_glyph_extents_func (funcs, hb_ot_get_glyph_extents, nullptr, nullptr);
   //hb_font_funcs_set_glyph_contour_point_func (funcs, hb_ot_get_glyph_contour_point, nullptr, nullptr);

#ifndef HB_NO_OT_FONT_GLYPH_NAMES
   hb_font_funcs_set_glyph_name_func (funcs, hb_ot_get_glyph_name, nullptr, nullptr);
   hb_font_funcs_set_glyph_from_name_func (funcs, hb_ot_get_glyph_from_name, nullptr, nullptr);
#endif

   hb_font_funcs_make_immutable (funcs);

   hb_atexit (free_static_ot_funcs);

   return funcs;
 }
} static_ot_funcs;

static inline
void free_static_ot_funcs ()
{
 static_ot_funcs.free_instance ();
}

static hb_font_funcs_t *
_hb_ot_get_font_funcs ()
{
 return static_ot_funcs.get_unconst ();
}


/**
* hb_ot_font_set_funcs:
* @font: #hb_font_t to work upon
*
* Sets the font functions to use when working with @font to
* the HarfBuzz's native implementation. This is the default
* for fonts newly created.
*
* 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);
 if (unlikely (!ot_font))
   return;

 hb_font_set_funcs (font,
	     _hb_ot_get_font_funcs (),
	     ot_font,
	     _hb_ot_font_destroy);
}

#endif