Quelle  cairo-scaled-font-subsets.c   Sprache: C

/* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */
/* cairo - a vector graphics library with display and print output
 *
 * Copyright © 2003 University of Southern California
 * Copyright © 2005 Red Hat, Inc
 * Copyright © 2006 Keith Packard
 * Copyright © 2006 Red Hat, Inc
 *
 * This library is free software; you can redistribute it and/or
 * modify it either under the terms of the GNU Lesser General Public
 * License version 2.1 as published by the Free Software Foundation
 * (the "LGPL") or, at your option, under the terms of the Mozilla
 * Public License Version 1.1 (the "MPL"). If you do not alter this
 * notice, a recipient may use your version of this file under either
 * the MPL or the LGPL.
 *
 * You should have received a copy of the LGPL along with this library
 * in the file COPYING-LGPL-2.1; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
 * You should have received a copy of the MPL along with this library
 * in the file COPYING-MPL-1.1
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
 * OF ANY KIND, either express or implied. See the LGPL or the MPL for
 * the specific language governing rights and limitations.
 *
 * The Original Code is the cairo graphics library.
 *
 * The Initial Developer of the Original Code is University of Southern
 * California.
 *
 * Contributor(s):
 * Carl D. Worth <cworth@cworth.org>
 * Kristian Høgsberg <krh@redhat.com>
 * Keith Packard <keithp@keithp.com>
 * Adrian Johnson <ajohnson@redneon.com>
 */

#define _DEFAULT_SOURCE /* for snprintf(), strdup() */
#include "cairoint.h"
#include "cairo-error-private.h"

#if CAIRO_HAS_FONT_SUBSET

#include "cairo-scaled-font-subsets-private.h"
#include "cairo-user-font-private.h"

#define MAX_GLYPHS_PER_SIMPLE_FONT 256
#define MAX_GLYPHS_PER_COMPOSITE_FONT 65536

typedef enum {
    CAIRO_SUBSETS_SCALED,
    CAIRO_SUBSETS_SIMPLE,
    CAIRO_SUBSETS_COMPOSITE
} cairo_subsets_type_t;

typedef enum {
    CAIRO_SUBSETS_FOREACH_UNSCALED,
    CAIRO_SUBSETS_FOREACH_SCALED,
} cairo_subsets_foreach_type_t;

typedef struct _cairo_sub_font {
    cairo_hash_entry_t base;

    cairo_bool_t is_scaled;
    cairo_bool_t is_composite;
    cairo_bool_t use_latin_subset;
    cairo_bool_t reserve_notdef;
    cairo_scaled_font_subsets_t *parent;
    cairo_scaled_font_t *scaled_font;
    unsigned int font_id;

    int current_subset;
    int num_glyphs_in_current_subset;
    int num_glyphs_in_latin_subset;
    int max_glyphs_per_subset;
    char latin_char_map[256];

    cairo_hash_table_t *sub_font_glyphs;
    struct _cairo_sub_font *next;
} cairo_sub_font_t;

struct _cairo_scaled_font_subsets {
    cairo_subsets_type_t type;
    cairo_bool_t use_latin_subset;

    int max_glyphs_per_unscaled_subset_used;
    cairo_hash_table_t *unscaled_sub_fonts;
    cairo_sub_font_t *unscaled_sub_fonts_list;
    cairo_sub_font_t *unscaled_sub_fonts_list_end;

    int max_glyphs_per_scaled_subset_used;
    cairo_hash_table_t *scaled_sub_fonts;
    cairo_sub_font_t *scaled_sub_fonts_list;
    cairo_sub_font_t *scaled_sub_fonts_list_end;

    int num_sub_fonts;
};

typedef struct _cairo_sub_font_glyph {
    cairo_hash_entry_t base;

    unsigned int subset_id;
    unsigned int subset_glyph_index;
    double       x_advance;
    double       y_advance;

    cairo_bool_t is_latin;
    int   latin_character;
    cairo_bool_t is_mapped;
    uint32_t     unicode;
    char   *utf8;
    int          utf8_len;
} cairo_sub_font_glyph_t;

typedef struct _cairo_sub_font_collection {
    unsigned long *glyphs; /* scaled_font_glyph_index */
    char       **utf8;
    unsigned int glyphs_size;
    int           *to_latin_char;
    unsigned long *latin_to_subset_glyph_index;
    unsigned int max_glyph;
    unsigned int num_glyphs;

    unsigned int subset_id;

    cairo_status_t status;
    cairo_scaled_font_subset_callback_func_t font_subset_callback;
    void *font_subset_callback_closure;
} cairo_sub_font_collection_t;

typedef struct _cairo_string_entry {
    cairo_hash_entry_t base;
    char *string;
} cairo_string_entry_t;

static cairo_status_t
_cairo_sub_font_map_glyph (cairo_sub_font_t *sub_font,
      unsigned long  scaled_font_glyph_index,
      const char *   utf8,
      int    utf8_len,
                           cairo_scaled_font_subsets_glyph_t *subset_glyph);

static void
_cairo_sub_font_glyph_init_key (cairo_sub_font_glyph_t  *sub_font_glyph,
    unsigned long   scaled_font_glyph_index)
{
    sub_font_glyph->base.hash = scaled_font_glyph_index;
}

static cairo_sub_font_glyph_t *
_cairo_sub_font_glyph_create (unsigned long scaled_font_glyph_index,
         unsigned int subset_id,
         unsigned int subset_glyph_index,
                              double            x_advance,
                              double            y_advance,
         int         latin_character,
         uint32_t          unicode,
         char             *utf8,
         int           utf8_len)
{
    cairo_sub_font_glyph_t *sub_font_glyph;

    sub_font_glyph = _cairo_malloc (sizeof (cairo_sub_font_glyph_t));
    if (unlikely (sub_font_glyph == NULL)) {
 _cairo_error_throw (CAIRO_STATUS_NO_MEMORY);
 return NULL;
    }

    _cairo_sub_font_glyph_init_key (sub_font_glyph, scaled_font_glyph_index);
    sub_font_glyph->subset_id = subset_id;
    sub_font_glyph->subset_glyph_index = subset_glyph_index;
    sub_font_glyph->x_advance = x_advance;
    sub_font_glyph->y_advance = y_advance;
    sub_font_glyph->is_latin = (latin_character >= 0);
    sub_font_glyph->latin_character = latin_character;
    sub_font_glyph->is_mapped = FALSE;
    sub_font_glyph->unicode = unicode;
    sub_font_glyph->utf8 = utf8;
    sub_font_glyph->utf8_len = utf8_len;

    return sub_font_glyph;
}

static void
_cairo_sub_font_glyph_destroy (cairo_sub_font_glyph_t *sub_font_glyph)
{
    free (sub_font_glyph->utf8);

    free (sub_font_glyph);
}

static void
_cairo_sub_font_glyph_pluck (void *entry, void *closure)
{
    cairo_sub_font_glyph_t *sub_font_glyph = entry;
    cairo_hash_table_t *sub_font_glyphs = closure;

    _cairo_hash_table_remove (sub_font_glyphs, &sub_font_glyph->base);
    _cairo_sub_font_glyph_destroy (sub_font_glyph);
}

static void
_cairo_sub_font_glyph_collect (void *entry, void *closure)
{
    cairo_sub_font_glyph_t *sub_font_glyph = entry;
    cairo_sub_font_collection_t *collection = closure;
    unsigned long scaled_font_glyph_index;
    unsigned int subset_glyph_index;

    if (sub_font_glyph->subset_id != collection->subset_id)
 return;

    scaled_font_glyph_index = sub_font_glyph->base.hash;
    subset_glyph_index = sub_font_glyph->subset_glyph_index;

    /* Ensure we don't exceed the allocated bounds. */
    assert (subset_glyph_index < collection->glyphs_size);

    collection->glyphs[subset_glyph_index] = scaled_font_glyph_index;
    collection->utf8[subset_glyph_index] = sub_font_glyph->utf8;
    collection->to_latin_char[subset_glyph_index] = sub_font_glyph->latin_character;
    if (sub_font_glyph->is_latin)
 collection->latin_to_subset_glyph_index[sub_font_glyph->latin_character] = subset_glyph_index;

    if (subset_glyph_index > collection->max_glyph)
 collection->max_glyph = subset_glyph_index;

    collection->num_glyphs++;
}

static cairo_bool_t
_cairo_sub_fonts_equal (const void *key_a, const void *key_b)
{
    const cairo_sub_font_t *sub_font_a = key_a;
    const cairo_sub_font_t *sub_font_b = key_b;
    cairo_scaled_font_t *a = sub_font_a->scaled_font;
    cairo_scaled_font_t *b = sub_font_b->scaled_font;

    if (sub_font_a->is_scaled)
        return a == b;
    else
 return a->font_face == b->font_face || a->original_font_face == b->original_font_face;
}

static void
_cairo_sub_font_init_key (cairo_sub_font_t *sub_font,
     cairo_scaled_font_t *scaled_font)
{
    if (sub_font->is_scaled)
    {
        sub_font->base.hash = (uintptr_t) scaled_font;
        sub_font->scaled_font = scaled_font;
    }
    else
    {
        sub_font->base.hash = (uintptr_t) scaled_font->font_face;
        sub_font->scaled_font = scaled_font;
    }
}

static cairo_status_t
_cairo_sub_font_create (cairo_scaled_font_subsets_t *parent,
   cairo_scaled_font_t  *scaled_font,
   unsigned int    font_id,
   int     max_glyphs_per_subset,
                        cairo_bool_t                     is_scaled,
   cairo_bool_t                     is_composite,
   cairo_sub_font_t               **sub_font_out)
{
    cairo_sub_font_t *sub_font;
    int i;

    sub_font = _cairo_malloc (sizeof (cairo_sub_font_t));
    if (unlikely (sub_font == NULL))
 return _cairo_error (CAIRO_STATUS_NO_MEMORY);

    sub_font->is_scaled = is_scaled;
    sub_font->is_composite = is_composite;
    sub_font->reserve_notdef = !sub_font->is_scaled;
    _cairo_sub_font_init_key (sub_font, scaled_font);

    sub_font->parent = parent;
    sub_font->scaled_font = scaled_font;
    sub_font->font_id = font_id;

    sub_font->use_latin_subset = parent->use_latin_subset;

    /* latin subsets of Type 3 and CID CFF fonts are not supported */
    if (sub_font->is_scaled ||
 _cairo_cff_scaled_font_is_cid_cff (scaled_font) )
    {
 sub_font->use_latin_subset = FALSE;
    }

    if (sub_font->use_latin_subset)
 sub_font->current_subset = 1; /* reserve subset 0 for latin glyphs */
    else
 sub_font->current_subset = 0;

    sub_font->num_glyphs_in_current_subset = 0;
    sub_font->num_glyphs_in_latin_subset = 0;
    sub_font->max_glyphs_per_subset = max_glyphs_per_subset;
    for (i = 0; i < 256; i++)
 sub_font->latin_char_map[i] = FALSE;

    sub_font->sub_font_glyphs = _cairo_hash_table_create (NULL);
    if (unlikely (sub_font->sub_font_glyphs == NULL)) {
 free (sub_font);
 return _cairo_error (CAIRO_STATUS_NO_MEMORY);
    }
    sub_font->next = NULL;
    *sub_font_out = sub_font;
    return CAIRO_STATUS_SUCCESS;
}

static void
_cairo_sub_font_destroy (cairo_sub_font_t *sub_font)
{
    _cairo_hash_table_foreach (sub_font->sub_font_glyphs,
          _cairo_sub_font_glyph_pluck,
          sub_font->sub_font_glyphs);
    _cairo_hash_table_destroy (sub_font->sub_font_glyphs);
    cairo_scaled_font_destroy (sub_font->scaled_font);
    free (sub_font);
}

static void
_cairo_sub_font_pluck (void *entry, void *closure)
{
    cairo_sub_font_t *sub_font = entry;
    cairo_hash_table_t *sub_fonts = closure;

    _cairo_hash_table_remove (sub_fonts, &sub_font->base);
    _cairo_sub_font_destroy (sub_font);
}

/* Characters 0x80 to 0x9f in the winansi encoding.
 * All other characters in the range 0x00 to 0xff map 1:1 to unicode */
static unsigned int _winansi_0x80_to_0x9f[] = {
    0x20ac, 0x0000, 0x201a, 0x0192, 0x201e, 0x2026, 0x2020, 0x2021,
    0x02c6, 0x2030, 0x0160, 0x2039, 0x0152, 0x0000, 0x017d, 0x0000,
    0x0000, 0x2018, 0x2019, 0x201c, 0x201d, 0x2022, 0x2013, 0x2014,
    0x02dc, 0x2122, 0x0161, 0x203a, 0x0153, 0x0000, 0x017e, 0x0178
};

int
_cairo_unicode_to_winansi (unsigned long uni)
{
    int i;

    /* exclude the extra "hyphen" at 0xad to avoid duplicate glyphnames */
    if ((uni >= 0x20 && uni <= 0x7e) ||
 (uni >= 0xa1 && uni <= 0xff && uni != 0xad) ||
 uni == 0)
        return uni;

    for (i = 0; i < 32; i++)
 if (_winansi_0x80_to_0x9f[i] == uni)
     return i + 0x80;

    return -1;
}

static cairo_status_t
_cairo_sub_font_glyph_lookup_unicode (cairo_scaled_font_t    *scaled_font,
          unsigned long       scaled_font_glyph_index,
          uint32_t           *unicode_out,
          char        **utf8_out,
          int                *utf8_len_out)
{
    uint32_t unicode;
    char buf[8];
    int len;
    cairo_status_t status;

    /* Do a reverse lookup on the glyph index. unicode is -1 if the
     * index could not be mapped to a unicode character. */
    unicode = -1;
    status = _cairo_truetype_index_to_ucs4 (scaled_font,
         scaled_font_glyph_index,
         &unicode);
    if (_cairo_status_is_error (status))
 return status;

    if (unicode == (uint32_t)-1 && scaled_font->backend->index_to_ucs4) {
 status = scaled_font->backend->index_to_ucs4 (scaled_font,
            scaled_font_glyph_index,
            &unicode);
 if (unlikely (status))
     return status;
    }

    *unicode_out = unicode;
    *utf8_out = NULL;
    *utf8_len_out = 0;
    if (unicode != (uint32_t) -1) {
 len = _cairo_ucs4_to_utf8 (unicode, buf);
 if (len > 0) {
            *utf8_out = _cairo_strndup (buf, len);
            if (unlikely (*utf8_out == NULL))
                return _cairo_error (CAIRO_STATUS_NO_MEMORY);

     *utf8_len_out = len;
 }
    }

    return CAIRO_STATUS_SUCCESS;
}

static cairo_status_t
_cairo_sub_font_glyph_map_to_unicode (cairo_sub_font_glyph_t *sub_font_glyph,
          const char      *utf8,
          int        utf8_len,
          cairo_bool_t      *is_mapped)
{
    *is_mapped = FALSE;

    if (utf8_len < 0)
 return CAIRO_STATUS_SUCCESS;

    if (utf8 != NULL && utf8_len != 0 && utf8[utf8_len - 1] == '\0')
 utf8_len--;

    if (utf8 != NULL && utf8_len != 0) {
 if (sub_font_glyph->utf8 != NULL) {
     if (utf8_len == sub_font_glyph->utf8_len &&
  strncmp (utf8, sub_font_glyph->utf8, utf8_len) == 0)
     {
  /* Requested utf8 mapping matches the existing mapping */
  *is_mapped = TRUE;
     }
 } else {
     /* No existing mapping. Use the requested mapping */
            sub_font_glyph->utf8 = _cairo_strndup (utf8, utf8_len);
            if (unlikely (sub_font_glyph->utf8 == NULL))
                return _cairo_error (CAIRO_STATUS_NO_MEMORY);

     sub_font_glyph->utf8_len = utf8_len;
     *is_mapped = TRUE;
 }
    }

    return CAIRO_STATUS_SUCCESS;
}

static cairo_int_status_t
_cairo_sub_font_lookup_glyph (cairo_sub_font_t                 *sub_font,
                              unsigned long                  scaled_font_glyph_index,
         const char   *utf8,
         int     utf8_len,
                              cairo_scaled_font_subsets_glyph_t *subset_glyph)
{
    cairo_sub_font_glyph_t key, *sub_font_glyph;
    cairo_int_status_t status;

    _cairo_sub_font_glyph_init_key (&key, scaled_font_glyph_index);
    sub_font_glyph = _cairo_hash_table_lookup (sub_font->sub_font_glyphs,
           &key.base);
    if (sub_font_glyph != NULL) {
        subset_glyph->font_id = sub_font->font_id;
        subset_glyph->subset_id = sub_font_glyph->subset_id;
 if (sub_font_glyph->is_latin)
     subset_glyph->subset_glyph_index = sub_font_glyph->latin_character;
 else
     subset_glyph->subset_glyph_index = sub_font_glyph->subset_glyph_index;

        subset_glyph->is_scaled = sub_font->is_scaled;
        subset_glyph->is_composite = sub_font->is_composite;
 subset_glyph->is_latin = sub_font_glyph->is_latin;
        subset_glyph->x_advance = sub_font_glyph->x_advance;
        subset_glyph->y_advance = sub_font_glyph->y_advance;
 status = _cairo_sub_font_glyph_map_to_unicode (sub_font_glyph,
             utf8, utf8_len,
             &subset_glyph->utf8_is_mapped);
 subset_glyph->unicode = sub_font_glyph->unicode;

 return status;
    }

    return CAIRO_INT_STATUS_UNSUPPORTED;
}

static cairo_status_t
_cairo_sub_font_add_glyph (cairo_sub_font_t    *sub_font,
      unsigned long     scaled_font_glyph_index,
      cairo_bool_t      is_latin,
      int       latin_character,
      uint32_t       unicode,
      char      *utf8,
      int        utf8_len,
      cairo_sub_font_glyph_t **sub_font_glyph_out)
{
    cairo_scaled_glyph_t *scaled_glyph;
    cairo_sub_font_glyph_t *sub_font_glyph;
    int *num_glyphs_in_subset_ptr;
    double x_advance;
    double y_advance;
    cairo_int_status_t status;

    _cairo_scaled_font_freeze_cache (sub_font->scaled_font);
    status = _cairo_scaled_glyph_lookup (sub_font->scaled_font,
      scaled_font_glyph_index,
      CAIRO_SCALED_GLYPH_INFO_METRICS,
      NULL, /* foreground color */
      &scaled_glyph);
    assert (status != CAIRO_INT_STATUS_UNSUPPORTED);
    if (unlikely (status)) {
 _cairo_scaled_font_thaw_cache (sub_font->scaled_font);
 return status;
    }

    x_advance = scaled_glyph->metrics.x_advance;
    y_advance = scaled_glyph->metrics.y_advance;
    _cairo_scaled_font_thaw_cache (sub_font->scaled_font);

    if (!is_latin && sub_font->num_glyphs_in_current_subset == sub_font->max_glyphs_per_subset)
    {
 sub_font->current_subset++;
 sub_font->num_glyphs_in_current_subset = 0;
    }

    if (is_latin)
 num_glyphs_in_subset_ptr = &sub_font->num_glyphs_in_latin_subset;
    else
 num_glyphs_in_subset_ptr = &sub_font->num_glyphs_in_current_subset;

    if ((*num_glyphs_in_subset_ptr == 0) && sub_font->reserve_notdef)
 (*num_glyphs_in_subset_ptr)++;

    sub_font_glyph = _cairo_sub_font_glyph_create (scaled_font_glyph_index,
         is_latin ? 0 : sub_font->current_subset,
         *num_glyphs_in_subset_ptr,
         x_advance,
         y_advance,
         is_latin ? latin_character : -1,
         unicode,
         utf8,
         utf8_len);

    if (unlikely (sub_font_glyph == NULL))
 return _cairo_error (CAIRO_STATUS_NO_MEMORY);

    status = _cairo_hash_table_insert (sub_font->sub_font_glyphs, &sub_font_glyph->base);
    if (unlikely (status)) {
 _cairo_sub_font_glyph_destroy (sub_font_glyph);
 return status;
    }

    (*num_glyphs_in_subset_ptr)++;
    if (sub_font->is_scaled) {
 if (*num_glyphs_in_subset_ptr > sub_font->parent->max_glyphs_per_scaled_subset_used)
     sub_font->parent->max_glyphs_per_scaled_subset_used = *num_glyphs_in_subset_ptr;
    } else {
 if (*num_glyphs_in_subset_ptr > sub_font->parent->max_glyphs_per_unscaled_subset_used)
     sub_font->parent->max_glyphs_per_unscaled_subset_used = *num_glyphs_in_subset_ptr;
    }

    *sub_font_glyph_out = sub_font_glyph;

    return CAIRO_STATUS_SUCCESS;
}

static cairo_status_t
_cairo_sub_font_map_glyph (cairo_sub_font_t *sub_font,
      unsigned long  scaled_font_glyph_index,
      const char  *text_utf8,
      int    text_utf8_len,
                           cairo_scaled_font_subsets_glyph_t *subset_glyph)
{
    cairo_sub_font_glyph_t key, *sub_font_glyph;
    cairo_status_t status;

    _cairo_sub_font_glyph_init_key (&key, scaled_font_glyph_index);
    sub_font_glyph = _cairo_hash_table_lookup (sub_font->sub_font_glyphs,
            &key.base);
    if (sub_font_glyph == NULL) {
 uint32_t font_unicode;
 char *font_utf8;
 int font_utf8_len;
 cairo_bool_t is_latin;
 int latin_character;

 status = _cairo_sub_font_glyph_lookup_unicode (sub_font->scaled_font,
          scaled_font_glyph_index,
          &font_unicode,
          &font_utf8,
          &font_utf8_len);
 if (unlikely(status))
     return status;

 /* If the supplied utf8 is a valid single character, use it
 * instead of the font lookup */
 if (text_utf8 != NULL && text_utf8_len > 0) {
     uint32_t  *ucs4;
     int ucs4_len;

     status = _cairo_utf8_to_ucs4 (text_utf8, text_utf8_len,
       &ucs4, &ucs4_len);
     if (status == CAIRO_STATUS_SUCCESS) {
  if (ucs4_len == 1) {
      font_unicode = ucs4[0];
      free (font_utf8);
                    font_utf8 = _cairo_strndup (text_utf8, text_utf8_len);
                    if (font_utf8 == NULL) {
                        free (ucs4);
                        return _cairo_error (CAIRO_STATUS_NO_MEMORY);
      }
      font_utf8_len = text_utf8_len;
  }
  free (ucs4);
     }
 }

 /* If glyph is in the winansi encoding and font is not a scaled
 * font, put glyph in the latin subset. */
 is_latin = FALSE;
 latin_character = -1;
 if (sub_font->use_latin_subset && !sub_font->is_scaled)
 {
     latin_character = _cairo_unicode_to_winansi (font_unicode);
     if (latin_character > 0)
     {
  if (!sub_font->latin_char_map[latin_character]) {
      sub_font->latin_char_map[latin_character] = TRUE;
      is_latin = TRUE;
  }
     }
 }

 status = _cairo_sub_font_add_glyph (sub_font,
         scaled_font_glyph_index,
         is_latin,
         latin_character,
         font_unicode,
         font_utf8,
         font_utf8_len,
         &sub_font_glyph);
 if (unlikely(status))
     return status;
    }

    subset_glyph->font_id = sub_font->font_id;
    subset_glyph->subset_id = sub_font_glyph->subset_id;
    if (sub_font_glyph->is_latin)
 subset_glyph->subset_glyph_index = sub_font_glyph->latin_character;
    else
 subset_glyph->subset_glyph_index = sub_font_glyph->subset_glyph_index;

    subset_glyph->is_scaled = sub_font->is_scaled;
    subset_glyph->is_composite = sub_font->is_composite;
    subset_glyph->is_latin = sub_font_glyph->is_latin;
    subset_glyph->x_advance = sub_font_glyph->x_advance;
    subset_glyph->y_advance = sub_font_glyph->y_advance;
    status = _cairo_sub_font_glyph_map_to_unicode (sub_font_glyph,
         text_utf8, text_utf8_len,
         &subset_glyph->utf8_is_mapped);
    subset_glyph->unicode = sub_font_glyph->unicode;

    return status;
}

static void
_cairo_sub_font_collect (void *entry, void *closure)
{
    cairo_sub_font_t *sub_font = entry;
    cairo_sub_font_collection_t *collection = closure;
    cairo_scaled_font_subset_t subset;
    int i;
    unsigned int j;

    if (collection->status)
 return;

    collection->status = sub_font->scaled_font->status;
    if (collection->status)
 return;

    for (i = 0; i <= sub_font->current_subset; i++) {
 collection->subset_id = i;
 collection->num_glyphs = 0;
 collection->max_glyph = 0;
 memset (collection->latin_to_subset_glyph_index, 0, 256*sizeof(unsigned long));

 if (sub_font->reserve_notdef) {
     // add .notdef
     collection->glyphs[0] = 0;
     collection->utf8[0] = 0;
     collection->to_latin_char[0] = 0;
     collection->latin_to_subset_glyph_index[0] = 0;
     collection->num_glyphs++;
 }

 _cairo_hash_table_foreach (sub_font->sub_font_glyphs,
       _cairo_sub_font_glyph_collect, collection);
 if (collection->status)
     break;

 if (collection->num_glyphs == 0)
     continue;

 if (sub_font->reserve_notdef && collection->num_glyphs == 1)
     continue;

        /* Ensure the resulting array has no uninitialized holes */
 assert (collection->num_glyphs == collection->max_glyph + 1);

 subset.scaled_font = sub_font->scaled_font;
 subset.is_composite = sub_font->is_composite;
 subset.is_scaled = sub_font->is_scaled;
 subset.font_id = sub_font->font_id;
 subset.subset_id = i;
 subset.glyphs = collection->glyphs;
 subset.utf8 = collection->utf8;
 subset.num_glyphs = collection->num_glyphs;
        subset.glyph_names = NULL;

 subset.is_latin = FALSE;
 if (sub_font->use_latin_subset && i == 0) {
     subset.is_latin = TRUE;
     subset.to_latin_char = collection->to_latin_char;
     subset.latin_to_subset_glyph_index = collection->latin_to_subset_glyph_index;
 } else {
     subset.to_latin_char = NULL;
     subset.latin_to_subset_glyph_index = NULL;
 }

        collection->status = (collection->font_subset_callback) (&subset,
         collection->font_subset_callback_closure);

 if (subset.glyph_names != NULL) {
            for (j = 0; j < collection->num_glyphs; j++)
  free (subset.glyph_names[j]);
     free (subset.glyph_names);
 }

 if (collection->status)
     break;
    }
}

static cairo_scaled_font_subsets_t *
_cairo_scaled_font_subsets_create_internal (cairo_subsets_type_t type)
{
    cairo_scaled_font_subsets_t *subsets;

    subsets = _cairo_malloc (sizeof (cairo_scaled_font_subsets_t));
    if (unlikely (subsets == NULL)) {
 _cairo_error_throw (CAIRO_STATUS_NO_MEMORY);
 return NULL;
    }

    subsets->type = type;
    subsets->use_latin_subset = FALSE;
    subsets->max_glyphs_per_unscaled_subset_used = 0;
    subsets->max_glyphs_per_scaled_subset_used = 0;
    subsets->num_sub_fonts = 0;

    subsets->unscaled_sub_fonts = _cairo_hash_table_create (_cairo_sub_fonts_equal);
    if (! subsets->unscaled_sub_fonts) {
 free (subsets);
 return NULL;
    }
    subsets->unscaled_sub_fonts_list = NULL;
    subsets->unscaled_sub_fonts_list_end = NULL;

    subsets->scaled_sub_fonts = _cairo_hash_table_create (_cairo_sub_fonts_equal);
    if (! subsets->scaled_sub_fonts) {
 _cairo_hash_table_destroy (subsets->unscaled_sub_fonts);
 free (subsets);
 return NULL;
    }
    subsets->scaled_sub_fonts_list = NULL;
    subsets->scaled_sub_fonts_list_end = NULL;

    return subsets;
}

cairo_scaled_font_subsets_t *
_cairo_scaled_font_subsets_create_scaled (void)
{
    return _cairo_scaled_font_subsets_create_internal (CAIRO_SUBSETS_SCALED);
}

cairo_scaled_font_subsets_t *
_cairo_scaled_font_subsets_create_simple (void)
{
    return _cairo_scaled_font_subsets_create_internal (CAIRO_SUBSETS_SIMPLE);
}

cairo_scaled_font_subsets_t *
_cairo_scaled_font_subsets_create_composite (void)
{
    return _cairo_scaled_font_subsets_create_internal (CAIRO_SUBSETS_COMPOSITE);
}

void
_cairo_scaled_font_subsets_destroy (cairo_scaled_font_subsets_t *subsets)
{
    _cairo_hash_table_foreach (subsets->scaled_sub_fonts, _cairo_sub_font_pluck, subsets->scaled_sub_fonts);
    _cairo_hash_table_destroy (subsets->scaled_sub_fonts);

    _cairo_hash_table_foreach (subsets->unscaled_sub_fonts, _cairo_sub_font_pluck, subsets->unscaled_sub_fonts);
    _cairo_hash_table_destroy (subsets->unscaled_sub_fonts);

    free (subsets);
}

void
_cairo_scaled_font_subsets_enable_latin_subset (cairo_scaled_font_subsets_t *font_subsets,
      cairo_bool_t                 use_latin)
{
    font_subsets->use_latin_subset = use_latin;
}

cairo_status_t
_cairo_scaled_font_subsets_map_glyph (cairo_scaled_font_subsets_t *subsets,
          cairo_scaled_font_t  *scaled_font,
          unsigned long    scaled_font_glyph_index,
          const char *    utf8,
          int     utf8_len,
                                      cairo_scaled_font_subsets_glyph_t *subset_glyph)
{
    cairo_sub_font_t key, *sub_font;
    cairo_scaled_glyph_t *scaled_glyph;
    cairo_font_face_t *font_face;
    cairo_matrix_t identity;
    cairo_font_options_t font_options;
    cairo_scaled_font_t *unscaled_font;
    cairo_int_status_t status;
    int max_glyphs;
    cairo_bool_t type1_font;
    cairo_bool_t has_path;
    cairo_bool_t has_color;
    cairo_bool_t is_user;

    /* Lookup glyph in unscaled subsets */
    if (subsets->type != CAIRO_SUBSETS_SCALED) {
        key.is_scaled = FALSE;
        _cairo_sub_font_init_key (&key, scaled_font);
 sub_font = _cairo_hash_table_lookup (subsets->unscaled_sub_fonts,
          &key.base);
        if (sub_font != NULL) {
            status = _cairo_sub_font_lookup_glyph (sub_font,
         scaled_font_glyph_index,
         utf8, utf8_len,
         subset_glyph);
     if (status != CAIRO_INT_STATUS_UNSUPPORTED)
                return status;
        }
    }

    /* Lookup glyph in scaled subsets */
    key.is_scaled = TRUE;
    _cairo_sub_font_init_key (&key, scaled_font);
    sub_font = _cairo_hash_table_lookup (subsets->scaled_sub_fonts,
      &key.base);
    if (sub_font != NULL) {
 status = _cairo_sub_font_lookup_glyph (sub_font,
            scaled_font_glyph_index,
            utf8, utf8_len,
            subset_glyph);
 if (status != CAIRO_INT_STATUS_UNSUPPORTED)
     return status;
    }

    /* Glyph not found. Determine whether the glyph is outline or
     * bitmap and add to the appropriate subset.
     */
    is_user = _cairo_font_face_is_user (scaled_font->font_face);
    _cairo_scaled_font_freeze_cache (scaled_font);
    /* Check if glyph is color */
    status = _cairo_scaled_glyph_lookup (scaled_font,
      scaled_font_glyph_index,
      CAIRO_SCALED_GLYPH_INFO_COLOR_SURFACE,
      NULL, /* foreground color */
      &scaled_glyph);
    has_color = (status == CAIRO_INT_STATUS_SUCCESS);

    /* Check if glyph has a path */
    status = _cairo_scaled_glyph_lookup (scaled_font,
      scaled_font_glyph_index,
      CAIRO_SCALED_GLYPH_INFO_PATH,
      NULL, /* foreground color */
      &scaled_glyph);
    has_path = (status == CAIRO_INT_STATUS_SUCCESS);

    /* glyph_index 0 (the .notdef glyph) is a special case. Some fonts
     * will return CAIRO_INT_STATUS_UNSUPPORTED when doing a
     * _scaled_glyph_lookup(_GLYPH_INFO_PATH). Type1-fallback creates
     * empty glyphs in this case so we can put the glyph in a unscaled
     * subset.
     */
    if (scaled_font_glyph_index == 0 && !is_user)
        has_path = TRUE;

    /* If this fails there is nothing we can do with this glyph. */
    status = _cairo_scaled_glyph_lookup (scaled_font,
      scaled_font_glyph_index,
      CAIRO_SCALED_GLYPH_INFO_SURFACE,
                                             NULL, /* foreground color */
      &scaled_glyph);
    _cairo_scaled_font_thaw_cache (scaled_font);
    if (_cairo_int_status_is_error (status))
        return status;

    /* Type 3 glyphs (is_user and has_color) must be added to scaled subset */
    if (subsets->type != CAIRO_SUBSETS_SCALED &&
 has_path && !has_color && !is_user)
    {
        /* Path available. Add to unscaled subset. */
        key.is_scaled = FALSE;
        _cairo_sub_font_init_key (&key, scaled_font);
 sub_font = _cairo_hash_table_lookup (subsets->unscaled_sub_fonts,
          &key.base);
        if (sub_font == NULL) {
            font_face = cairo_scaled_font_get_font_face (scaled_font);
            cairo_matrix_init_identity (&identity);
            _cairo_font_options_init_default (&font_options);
            cairo_font_options_set_hint_style (&font_options, CAIRO_HINT_STYLE_NONE);
            cairo_font_options_set_hint_metrics (&font_options, CAIRO_HINT_METRICS_OFF);
            unscaled_font = cairo_scaled_font_create (font_face,
                                                      &identity,
                                                      &identity,
                                                      &font_options);
     if (unlikely (unscaled_font->status))
  return unscaled_font->status;

            subset_glyph->is_scaled = FALSE;
            type1_font = _cairo_type1_scaled_font_is_type1 (unscaled_font);
            if (subsets->type == CAIRO_SUBSETS_COMPOSITE && !type1_font) {
                max_glyphs = MAX_GLYPHS_PER_COMPOSITE_FONT;
                subset_glyph->is_composite = TRUE;
            } else {
                max_glyphs = MAX_GLYPHS_PER_SIMPLE_FONT;
                subset_glyph->is_composite = FALSE;
            }

            status = _cairo_sub_font_create (subsets,
          unscaled_font,
          subsets->num_sub_fonts,
          max_glyphs,
          subset_glyph->is_scaled,
          subset_glyph->is_composite,
          &sub_font);

            if (unlikely (status)) {
  cairo_scaled_font_destroy (unscaled_font);
                return status;
     }

            status = _cairo_hash_table_insert (subsets->unscaled_sub_fonts,
                                               &sub_font->base);

            if (unlikely (status)) {
  _cairo_sub_font_destroy (sub_font);
                return status;
     }
     if (!subsets->unscaled_sub_fonts_list)
  subsets->unscaled_sub_fonts_list = sub_font;
     else
  subsets->unscaled_sub_fonts_list_end->next = sub_font;
     subsets->unscaled_sub_fonts_list_end = sub_font;
     subsets->num_sub_fonts++;
        }
    } else {
        /* No path available. Add to scaled subset. */
        key.is_scaled = TRUE;
        _cairo_sub_font_init_key (&key, scaled_font);
 sub_font = _cairo_hash_table_lookup (subsets->scaled_sub_fonts,
          &key.base);
        if (sub_font == NULL) {
            subset_glyph->is_scaled = TRUE;
            subset_glyph->is_composite = FALSE;
            if (subsets->type == CAIRO_SUBSETS_SCALED)
                max_glyphs = INT_MAX;
            else
                max_glyphs = MAX_GLYPHS_PER_SIMPLE_FONT;

            status = _cairo_sub_font_create (subsets,
          cairo_scaled_font_reference (scaled_font),
          subsets->num_sub_fonts,
          max_glyphs,
          subset_glyph->is_scaled,
          subset_glyph->is_composite,
          &sub_font);
            if (unlikely (status)) {
  cairo_scaled_font_destroy (scaled_font);
                return status;
     }

            status = _cairo_hash_table_insert (subsets->scaled_sub_fonts,
                                               &sub_font->base);
            if (unlikely (status)) {
  _cairo_sub_font_destroy (sub_font);
                return status;
     }
     if (!subsets->scaled_sub_fonts_list)
  subsets->scaled_sub_fonts_list = sub_font;
     else
  subsets->scaled_sub_fonts_list_end->next = sub_font;
     subsets->scaled_sub_fonts_list_end = sub_font;
     subsets->num_sub_fonts++;
        }
    }

    return _cairo_sub_font_map_glyph (sub_font,
          scaled_font_glyph_index,
          utf8, utf8_len,
          subset_glyph);
}

static cairo_status_t
_cairo_scaled_font_subsets_foreach_internal (cairo_scaled_font_subsets_t              *font_subsets,
                                             cairo_scaled_font_subset_callback_func_t  font_subset_callback,
                                             void          *closure,
          cairo_subsets_foreach_type_t        type)
{
    cairo_sub_font_collection_t collection;
    cairo_sub_font_t *sub_font;
    cairo_bool_t is_scaled;

    is_scaled = FALSE;

    if (type == CAIRO_SUBSETS_FOREACH_SCALED)
 is_scaled = TRUE;

    if (is_scaled)
        collection.glyphs_size = font_subsets->max_glyphs_per_scaled_subset_used;
    else
        collection.glyphs_size = font_subsets->max_glyphs_per_unscaled_subset_used;

    if (! collection.glyphs_size)
 return CAIRO_STATUS_SUCCESS;

    collection.glyphs = _cairo_malloc_ab (collection.glyphs_size, sizeof(unsigned long));
    collection.utf8 = _cairo_malloc_ab (collection.glyphs_size, sizeof(char *));
    collection.to_latin_char = _cairo_malloc_ab (collection.glyphs_size, sizeof(int));
    collection.latin_to_subset_glyph_index = _cairo_malloc_ab (256, sizeof(unsigned long));
    if (unlikely (collection.glyphs == NULL ||
    collection.utf8 == NULL ||
    collection.to_latin_char == NULL ||
    collection.latin_to_subset_glyph_index == NULL)) {
 free (collection.glyphs);
 free (collection.utf8);
 free (collection.to_latin_char);
 free (collection.latin_to_subset_glyph_index);

 return _cairo_error (CAIRO_STATUS_NO_MEMORY);
    }

    collection.font_subset_callback = font_subset_callback;
    collection.font_subset_callback_closure = closure;
    collection.status = CAIRO_STATUS_SUCCESS;

    if (is_scaled)
 sub_font = font_subsets->scaled_sub_fonts_list;
    else
 sub_font = font_subsets->unscaled_sub_fonts_list;

    while (sub_font) {
 _cairo_sub_font_collect (sub_font, &collection);
 sub_font = sub_font->next;
    }
    free (collection.utf8);
    free (collection.glyphs);
    free (collection.to_latin_char);
    free (collection.latin_to_subset_glyph_index);

    return collection.status;
}

cairo_status_t
_cairo_scaled_font_subsets_foreach_scaled (cairo_scaled_font_subsets_t      *font_subsets,
                                           cairo_scaled_font_subset_callback_func_t  font_subset_callback,
                                           void         *closure)
{
    return _cairo_scaled_font_subsets_foreach_internal (font_subsets,
                                                        font_subset_callback,
                                                        closure,
       CAIRO_SUBSETS_FOREACH_SCALED);
}

cairo_status_t
_cairo_scaled_font_subsets_foreach_unscaled (cairo_scaled_font_subsets_t     *font_subsets,
                                           cairo_scaled_font_subset_callback_func_t  font_subset_callback,
                                           void         *closure)
{
    return _cairo_scaled_font_subsets_foreach_internal (font_subsets,
                                                        font_subset_callback,
                                                        closure,
       CAIRO_SUBSETS_FOREACH_UNSCALED);
}

static cairo_bool_t
_cairo_string_equal (const void *key_a, const void *key_b)
{
    const cairo_string_entry_t *a = key_a;
    const cairo_string_entry_t *b = key_b;

    if (strcmp (a->string, b->string) == 0)
 return TRUE;
    else
 return FALSE;
}

#if DEBUG_SUBSETS

static void
dump_glyph (void *entry, void *closure)
{
    cairo_sub_font_glyph_t *glyph = entry;
    char buf[10];
    int i;

    printf(" font_glyph_index: %ld\n", glyph->base.hash);
    printf(" subset_id: %d\n", glyph->subset_id);
    printf(" subset_glyph_index: %d\n", glyph->subset_glyph_index);
    printf(" x_advance: %f\n", glyph->x_advance);
    printf(" y_advance: %f\n", glyph->y_advance);
    printf(" is_latin: %d\n", glyph->is_latin);
    printf(" latin_character: '%c' (0x%02x)\n", glyph->latin_character, glyph->latin_character);
    printf(" is_latin: %d\n", glyph->is_latin);
    printf(" is_mapped: %d\n", glyph->is_mapped);
    printf(" unicode: U+%04x\n", glyph->unicode);
    memset(buf, 0, sizeof(buf));
    memcpy(buf, glyph->utf8, glyph->utf8_len);
    printf(" utf8: '%s'\n", buf);
    printf(" utf8 (hex):");
    for (i = 0; i < glyph->utf8_len; i++)
 printf(" 0x%02x", glyph->utf8[i]);
    printf("\n\n");
}

static void
dump_subfont (cairo_sub_font_t *sub_font)
{
    while (sub_font) {
 printf(" font_id: %d\n", sub_font->font_id);
 printf(" current_subset: %d\n", sub_font->current_subset);
 printf(" is_scaled: %d\n", sub_font->is_scaled);
 printf(" is_composite: %d\n", sub_font->is_composite);
 printf(" is_user: %d\n", sub_font->is_user);
 printf(" use_latin_subset: %d\n", sub_font->use_latin_subset);
 printf(" reserve_notdef: %d\n", sub_font->reserve_notdef);
 printf(" num_glyphs_in_current_subset: %d\n", sub_font->num_glyphs_in_current_subset);
 printf(" num_glyphs_in_latin_subset: %d\n", sub_font->num_glyphs_in_latin_subset);
 printf(" max_glyphs_per_subset: %d\n\n", sub_font->max_glyphs_per_subset);

 _cairo_hash_table_foreach (sub_font->sub_font_glyphs, dump_glyph, NULL);

 printf("\n");
 sub_font = sub_font->next;
    }
}

void
dump_scaled_font_subsets (cairo_scaled_font_subsets_t *font_subsets)
{
    printf("font subsets\n");
    switch (font_subsets->type)
    {
 case CAIRO_SUBSETS_SCALED:
     printf(" type: CAIRO_SUBSETS_SCALED\n");
     break;
 case CAIRO_SUBSETS_SIMPLE:
     printf(" type: CAIRO_SUBSETS_SIMPLE\n");
     break;
 case CAIRO_SUBSETS_COMPOSITE:
     printf(" type: CAIRO_SUBSETS_COMPOSITE\n");
     break;
    }
    printf(" use_latin_subset: %d\n", font_subsets->use_latin_subset);
    printf(" max_glyphs_per_unscaled_subset_used: %d\n", font_subsets->max_glyphs_per_unscaled_subset_used);
    printf(" max_glyphs_per_scaled_subset_used: %d\n", font_subsets->max_glyphs_per_scaled_subset_used);
    printf(" num_sub_fonts: %d\n\n", font_subsets->num_sub_fonts);

    printf(" scaled subsets:\n");
    dump_subfont (font_subsets->scaled_sub_fonts_list);

    printf("\n unscaled subsets:\n");
    dump_subfont (font_subsets->unscaled_sub_fonts_list);
}

#endif


static void
_cairo_string_init_key (cairo_string_entry_t *key, char *s)
{
    unsigned long sum = 0;
    unsigned int i;

    for (i = 0; i < strlen(s); i++)
        sum += s[i];
    key->base.hash = sum;
    key->string = s;
}

static cairo_status_t
create_string_entry (char *s, cairo_string_entry_t **entry)
{
    *entry = _cairo_malloc (sizeof (cairo_string_entry_t));
    if (unlikely (*entry == NULL))
 return _cairo_error (CAIRO_STATUS_NO_MEMORY);

    _cairo_string_init_key (*entry, s);

    return CAIRO_STATUS_SUCCESS;
}

static void
_pluck_entry (void *entry, void *closure)
{
    _cairo_hash_table_remove (closure, entry);
    free (entry);
}

cairo_int_status_t
_cairo_scaled_font_subset_create_glyph_names (cairo_scaled_font_subset_t *subset)
{
    unsigned int i;
    cairo_hash_table_t *names;
    cairo_string_entry_t key, *entry;
    char buf[30];
    char *utf8;
    uint16_t *utf16;
    int utf16_len;
    cairo_status_t status = CAIRO_STATUS_SUCCESS;

    names = _cairo_hash_table_create (_cairo_string_equal);
    if (unlikely (names == NULL))
 return _cairo_error (CAIRO_STATUS_NO_MEMORY);

    subset->glyph_names = calloc (subset->num_glyphs, sizeof (char *));
    if (unlikely (subset->glyph_names == NULL)) {
 status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
 goto CLEANUP_HASH;
    }

    i = 0;
    if (! subset->is_scaled) {
 subset->glyph_names[0] = strdup (".notdef");
 if (unlikely (subset->glyph_names[0] == NULL)) {
     status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
     goto CLEANUP_HASH;
 }

 status = create_string_entry (subset->glyph_names[0], &entry);
 if (unlikely (status))
     goto CLEANUP_HASH;

 status = _cairo_hash_table_insert (names, &entry->base);
 if (unlikely (status)) {
     free (entry);
     goto CLEANUP_HASH;
 }
 i++;
    }

    for (; i < subset->num_glyphs; i++) {
 utf8 = subset->utf8[i];
 utf16 = NULL;
 utf16_len = 0;
 if (utf8 && *utf8) {
     status = _cairo_utf8_to_utf16 (utf8, -1, &utf16, &utf16_len);
     if (status == CAIRO_STATUS_INVALID_STRING) {
  utf16 = NULL;
  utf16_len = 0;
     } else if (unlikely (status)) {
  goto CLEANUP_HASH;
     }
 }

 if (utf16_len == 1) {
     int ch = _cairo_unicode_to_winansi (utf16[0]);
     if (ch > 0 && _cairo_winansi_to_glyphname (ch)) {
  strncpy (buf, _cairo_winansi_to_glyphname (ch), sizeof (buf));
  buf[sizeof (buf)-1] = '\0';
     } else {
  snprintf (buf, sizeof (buf), "uni%04X", (int) utf16[0]);
     }

     _cairo_string_init_key (&key, buf);
     entry = _cairo_hash_table_lookup (names, &key.base);
     if (entry != NULL)
  snprintf (buf, sizeof (buf), "g%d", i);
 } else {
     snprintf (buf, sizeof (buf), "g%d", i);
 }
 free (utf16);

 subset->glyph_names[i] = strdup (buf);
 if (unlikely (subset->glyph_names[i] == NULL)) {
     status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
     goto CLEANUP_HASH;
 }

 status = create_string_entry (subset->glyph_names[i], &entry);
 if (unlikely (status))
     goto CLEANUP_HASH;

 status = _cairo_hash_table_insert (names, &entry->base);
 if (unlikely (status)) {
     free (entry);
     goto CLEANUP_HASH;
 }
    }

CLEANUP_HASH:
    _cairo_hash_table_foreach (names, _pluck_entry, names);
    _cairo_hash_table_destroy (names);

    if (likely (status == CAIRO_STATUS_SUCCESS))
 return CAIRO_STATUS_SUCCESS;

    if (subset->glyph_names != NULL) {
 for (i = 0; i < subset->num_glyphs; i++) {
     free (subset->glyph_names[i]);
 }

 free (subset->glyph_names);
 subset->glyph_names = NULL;
    }

    return status;
}

cairo_int_status_t
_cairo_escape_ps_name (char **ps_name)
{
    cairo_status_t status = CAIRO_STATUS_SUCCESS;

    /* Ensure PS name is a valid PDF/PS name object. In PDF names are
     * treated as UTF8 and non ASCII bytes, ' ', and '#' are encoded
     * as '#' followed by 2 hex digits that encode the byte. By also
     * encoding the characters in the reserved string we ensure the
     * name is also PS compatible. */
    if (*ps_name) {
 static const char *reserved = "()<>[]{}/%#\\";
 char buf[128]; /* max name length is 127 bytes */
 char *src = *ps_name;
 char *dst = buf;

 while (*src && dst < buf + 127) {
     unsigned char c = *src;
     if (c < 0x21 || c > 0x7e || strchr (reserved, c)) {
  if (dst + 4 > buf + 127)
      break;

  snprintf (dst, 4, "#%02X", c);
  src++;
  dst += 3;
     } else {
  *dst++ = *src++;
     }
 }
 *dst = 0;
 free (*ps_name);
 *ps_name = strdup (buf);
 if (*ps_name == NULL) {
     status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
 }
    }

    return status;
}

#endif /* CAIRO_HAS_FONT_SUBSET */