/src/mupdf/source/pdf/pdf-font.c

Source (jump to first uncovered line)
// Copyright (C) 2004-2022 Artifex Software, Inc.
//
// This file is part of MuPDF.
//
// MuPDF is free software: you can redistribute it and/or modify it under the
// terms of the GNU Affero General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option)
// any later version.
//
// MuPDF is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
// details.
//
// You should have received a copy of the GNU Affero General Public License
// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>
//
// Alternative licensing terms are available from the licensor.
// For commercial licensing, see <https://www.artifex.com/> or contact
// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,
// CA 94129, USA, for further information.

#include "mupdf/fitz.h"
#include "mupdf/pdf.h"

#include <assert.h>

#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_ADVANCES_H
#ifdef FT_FONT_FORMATS_H
#include FT_FONT_FORMATS_H
#else
#include FT_XFREE86_H
#endif
#include FT_TRUETYPE_TABLES_H

#ifndef FT_SFNT_HEAD
#define FT_SFNT_HEAD ft_sfnt_head
#endif

void
pdf_load_encoding(const char **estrings, const char *encoding)
{
  const char * const *bstrings = NULL;
  int i;

  if (!strcmp(encoding, "StandardEncoding"))
    bstrings = fz_glyph_name_from_adobe_standard;
  if (!strcmp(encoding, "MacRomanEncoding"))
    bstrings = fz_glyph_name_from_mac_roman;
  if (!strcmp(encoding, "MacExpertEncoding"))
    bstrings = fz_glyph_name_from_mac_expert;
  if (!strcmp(encoding, "WinAnsiEncoding"))
    bstrings = fz_glyph_name_from_win_ansi;

  if (bstrings)
    for (i = 0; i < 256; i++)
      estrings[i] = bstrings[i];
}

static void pdf_load_font_descriptor(fz_context *ctx, pdf_document *doc, pdf_font_desc *fontdesc, pdf_obj *dict,
  const char *collection, const char *basefont, int iscidfont);

static const char *base_font_names[][10] =
{
  { "Courier", "CourierNew", "CourierNewPSMT", NULL },
  { "Courier-Bold", "CourierNew,Bold", "Courier,Bold",
    "CourierNewPS-BoldMT", "CourierNew-Bold", NULL },
  { "Courier-Oblique", "CourierNew,Italic", "Courier,Italic",
    "CourierNewPS-ItalicMT", "CourierNew-Italic", NULL },
  { "Courier-BoldOblique", "CourierNew,BoldItalic", "Courier,BoldItalic",
    "CourierNewPS-BoldItalicMT", "CourierNew-BoldItalic", NULL },
  { "Helvetica", "ArialMT", "Arial", NULL },
  { "Helvetica-Bold", "Arial-BoldMT", "Arial,Bold", "Arial-Bold",
    "Helvetica,Bold", NULL },
  { "Helvetica-Oblique", "Arial-ItalicMT", "Arial,Italic", "Arial-Italic",
    "Helvetica,Italic", "Helvetica-Italic", NULL },
  { "Helvetica-BoldOblique", "Arial-BoldItalicMT",
    "Arial,BoldItalic", "Arial-BoldItalic",
    "Helvetica,BoldItalic", "Helvetica-BoldItalic", NULL },
  { "Times-Roman", "TimesNewRomanPSMT", "TimesNewRoman",
    "TimesNewRomanPS", NULL },
  { "Times-Bold", "TimesNewRomanPS-BoldMT", "TimesNewRoman,Bold",
    "TimesNewRomanPS-Bold", "TimesNewRoman-Bold", NULL },
  { "Times-Italic", "TimesNewRomanPS-ItalicMT", "TimesNewRoman,Italic",
    "TimesNewRomanPS-Italic", "TimesNewRoman-Italic", NULL },
  { "Times-BoldItalic", "TimesNewRomanPS-BoldItalicMT",
    "TimesNewRoman,BoldItalic", "TimesNewRomanPS-BoldItalic",
    "TimesNewRoman-BoldItalic", NULL },
  { "Symbol", "Symbol,Italic", "Symbol,Bold", "Symbol,BoldItalic",
    "SymbolMT", "SymbolMT,Italic", "SymbolMT,Bold", "SymbolMT,BoldItalic", NULL },
  { "ZapfDingbats", NULL }
};

const unsigned char *
pdf_lookup_substitute_font(fz_context *ctx, int mono, int serif, int bold, int italic, int *len)
{
  if (mono) {
    if (bold) {
      if (italic) return fz_lookup_base14_font(ctx, "Courier-BoldOblique", len);
      else return fz_lookup_base14_font(ctx, "Courier-Bold", len);
    } else {
      if (italic) return fz_lookup_base14_font(ctx, "Courier-Oblique", len);
      else return fz_lookup_base14_font(ctx, "Courier", len);
    }
  } else if (serif) {
    if (bold) {
      if (italic) return fz_lookup_base14_font(ctx, "Times-BoldItalic", len);
      else return fz_lookup_base14_font(ctx, "Times-Bold", len);
    } else {
      if (italic) return fz_lookup_base14_font(ctx, "Times-Italic", len);
      else return fz_lookup_base14_font(ctx, "Times-Roman", len);
    }
  } else {
    if (bold) {
      if (italic) return fz_lookup_base14_font(ctx, "Helvetica-BoldOblique", len);
      else return fz_lookup_base14_font(ctx, "Helvetica-Bold", len);
    } else {
      if (italic) return fz_lookup_base14_font(ctx, "Helvetica-Oblique", len);
      else return fz_lookup_base14_font(ctx, "Helvetica", len);
    }
  }
}

static int is_dynalab(char *name)
{
  if (strstr(name, "HuaTian"))
    return 1;
  if (strstr(name, "MingLi"))
    return 1;
  if ((strstr(name, "DF") == name) || strstr(name, "+DF"))
    return 1;
  if ((strstr(name, "DLC") == name) || strstr(name, "+DLC"))
    return 1;
  return 0;
}

static int strcmp_ignore_space(const char *a, const char *b)
{
  while (1)
  {
    while (*a == ' ')
      a++;
    while (*b == ' ')
      b++;
    if (*a != *b)
      return 1;
    if (*a == 0)
      return *a != *b;
    if (*b == 0)
      return *a != *b;
    a++;
    b++;
  }
}

const char *pdf_clean_font_name(const char *fontname)
{
  int i, k;
  for (i = 0; i < (int)nelem(base_font_names); i++)
    for (k = 0; base_font_names[i][k]; k++)
      if (!strcmp_ignore_space(base_font_names[i][k], fontname))
        return base_font_names[i][0];
  return fontname;
}

/*
 * FreeType and Rendering glue
 */

enum { UNKNOWN, TYPE1, TRUETYPE };

static int ft_kind(fz_context *ctx, FT_Face face)
{
  const char *kind;
  fz_ft_lock(ctx);
#ifdef FT_FONT_FORMATS_H
  kind = FT_Get_Font_Format(face);
#else
  kind = FT_Get_X11_Font_Format(face);
#endif
  fz_ft_unlock(ctx);
  if (!strcmp(kind, "TrueType")) return TRUETYPE;
  if (!strcmp(kind, "Type 1")) return TYPE1;
  if (!strcmp(kind, "CFF")) return TYPE1;
  if (!strcmp(kind, "CID Type 1")) return TYPE1;
  return UNKNOWN;
}

static int ft_cid_to_gid(pdf_font_desc *fontdesc, int cid)
{
  if (fontdesc->to_ttf_cmap)
  {
    cid = pdf_lookup_cmap(fontdesc->to_ttf_cmap, cid);

    /* vertical presentation forms */
    if (fontdesc->font->flags.ft_substitute && fontdesc->wmode)
    {
      switch (cid)
      {
      case 0x0021: cid = 0xFE15; break; /* ! */
      case 0x0028: cid = 0xFE35; break; /* ( */
      case 0x0029: cid = 0xFE36; break; /* ) */
      case 0x002C: cid = 0xFE10; break; /* , */
      case 0x003A: cid = 0xFE13; break; /* : */
      case 0x003B: cid = 0xFE14; break; /* ; */
      case 0x003F: cid = 0xFE16; break; /* ? */
      case 0x005B: cid = 0xFE47; break; /* [ */
      case 0x005D: cid = 0xFE48; break; /* ] */
      case 0x005F: cid = 0xFE33; break; /* _ */
      case 0x007B: cid = 0xFE37; break; /* { */
      case 0x007D: cid = 0xFE38; break; /* } */
      case 0x2013: cid = 0xFE32; break; /* EN DASH */
      case 0x2014: cid = 0xFE31; break; /* EM DASH */
      case 0x2025: cid = 0xFE30; break; /* TWO DOT LEADER */
      case 0x2026: cid = 0xFE19; break; /* HORIZONTAL ELLIPSIS */
      case 0x3001: cid = 0xFE11; break; /* IDEOGRAPHIC COMMA */
      case 0x3002: cid = 0xFE12; break; /* IDEOGRAPHIC FULL STOP */
      case 0x3008: cid = 0xFE3F; break; /* OPENING ANGLE BRACKET */
      case 0x3009: cid = 0xFE40; break; /* CLOSING ANGLE BRACKET */
      case 0x300A: cid = 0xFE3D; break; /* LEFT DOUBLE ANGLE BRACKET */
      case 0x300B: cid = 0xFE3E; break; /* RIGHT DOUBLE ANGLE BRACKET */
      case 0x300C: cid = 0xFE41; break; /* LEFT CORNER BRACKET */
      case 0x300D: cid = 0xFE42; break; /* RIGHT CORNER BRACKET */
      case 0x300E: cid = 0xFE43; break; /* LEFT WHITE CORNER BRACKET */
      case 0x300F: cid = 0xFE44; break; /* RIGHT WHITE CORNER BRACKET */
      case 0x3010: cid = 0xFE3B; break; /* LEFT BLACK LENTICULAR BRACKET */
      case 0x3011: cid = 0xFE3C; break; /* RIGHT BLACK LENTICULAR BRACKET */
      case 0x3014: cid = 0xFE39; break; /* LEFT TORTOISE SHELL BRACKET */
      case 0x3015: cid = 0xFE3A; break; /* RIGHT TORTOISE SHELL BRACKET */
      case 0x3016: cid = 0xFE17; break; /* LEFT WHITE LENTICULAR BRACKET */
      case 0x3017: cid = 0xFE18; break; /* RIGHT WHITE LENTICULAR BRACKET */

      case 0xFF01: cid = 0xFE15; break; /* FULLWIDTH EXCLAMATION MARK */
      case 0xFF08: cid = 0xFE35; break; /* FULLWIDTH LEFT PARENTHESIS */
      case 0xFF09: cid = 0xFE36; break; /* FULLWIDTH RIGHT PARENTHESIS */
      case 0xFF0C: cid = 0xFE10; break; /* FULLWIDTH COMMA */
      case 0xFF1A: cid = 0xFE13; break; /* FULLWIDTH COLON */
      case 0xFF1B: cid = 0xFE14; break; /* FULLWIDTH SEMICOLON */
      case 0xFF1F: cid = 0xFE16; break; /* FULLWIDTH QUESTION MARK */
      case 0xFF3B: cid = 0xFE47; break; /* FULLWIDTH LEFT SQUARE BRACKET */
      case 0xFF3D: cid = 0xFE48; break; /* FULLWIDTH RIGHT SQUARE BRACKET */
      case 0xFF3F: cid = 0xFE33; break; /* FULLWIDTH LOW LINE */
      case 0xFF5B: cid = 0xFE37; break; /* FULLWIDTH LEFT CURLY BRACKET */
      case 0xFF5D: cid = 0xFE38; break; /* FULLWIDTH RIGHT CURLY BRACKET */

      case 0x30FC: cid = 0xFE31; break; /* KATAKANA-HIRAGANA PROLONGED SOUND MARK */
      case 0xFF0D: cid = 0xFE31; break; /* FULLWIDTH HYPHEN-MINUS */
      }
    }

    return ft_char_index(fontdesc->font->ft_face, cid);
  }

  if (fontdesc->cid_to_gid && (size_t)cid < fontdesc->cid_to_gid_len && cid >= 0)
    return fontdesc->cid_to_gid[cid];

  return cid;
}

int
pdf_font_cid_to_gid(fz_context *ctx, pdf_font_desc *fontdesc, int cid)
{
  if (fontdesc->font->ft_face)
  {
    int gid;
    fz_ft_lock(ctx);
    gid = ft_cid_to_gid(fontdesc, cid);
    fz_ft_unlock(ctx);
    return gid;
  }
  return cid;
}

static int ft_width(fz_context *ctx, pdf_font_desc *fontdesc, int cid)
{
  int mask = FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING | FT_LOAD_NO_BITMAP | FT_LOAD_IGNORE_TRANSFORM;
  int gid = ft_cid_to_gid(fontdesc, cid);
  FT_Fixed adv = 0;
  int fterr;
  FT_Face face = fontdesc->font->ft_face;
  FT_UShort units_per_EM;

  fterr = FT_Get_Advance(face, gid, mask, &adv);
  if (fterr && fterr != FT_Err_Invalid_Argument)
    fz_warn(ctx, "FT_Get_Advance(%d): %s", gid, ft_error_string(fterr));

  units_per_EM = face->units_per_EM;
  if (units_per_EM == 0)
    units_per_EM = 2048;

  return adv * 1000 / units_per_EM;
}

static const struct { int code; const char *name; } mre_diff_table[] =
{
  { 173, "notequal" },
  { 176, "infinity" },
  { 178, "lessequal" },
  { 179, "greaterequal" },
  { 182, "partialdiff" },
  { 183, "summation" },
  { 184, "product" },
  { 185, "pi" },
  { 186, "integral" },
  { 189, "Omega" },
  { 195, "radical" },
  { 197, "approxequal" },
  { 198, "Delta" },
  { 215, "lozenge" },
  { 219, "Euro" },
  { 240, "apple" },
};

static int lookup_mre_code(const char *name)
{
  int i;
  for (i = 0; i < (int)nelem(mre_diff_table); ++i)
    if (!strcmp(name, mre_diff_table[i].name))
      return mre_diff_table[i].code;
  for (i = 0; i < 256; i++)
    if (fz_glyph_name_from_mac_roman[i] && !strcmp(name, fz_glyph_name_from_mac_roman[i]))
      return i;
  return -1;
}

static int ft_find_glyph_by_unicode_name(FT_Face face, const char *name)
{
  int unicode, glyph;

  /* Prefer exact unicode match if available. */
  unicode = fz_unicode_from_glyph_name_strict(name);
  if (unicode > 0)
  {
    glyph = ft_char_index(face, unicode);
    if (glyph > 0)
      return glyph;
  }

  /* Fall back to font glyph name if we can. */
  glyph = ft_name_index(face, name);
  if (glyph > 0)
    return glyph;

  /* Fuzzy unicode match as last attempt. */
  unicode = fz_unicode_from_glyph_name(name);
  if (unicode > 0)
    return ft_char_index(face, unicode);

  /* Failed. */
  return 0;
}

/*
 * Load font files.
 */

static void
pdf_load_builtin_font(fz_context *ctx, pdf_font_desc *fontdesc, const char *fontname, int has_descriptor)
{
  FT_Face face;
  const char *clean_name = pdf_clean_font_name(fontname);
  if (clean_name == fontname)
    clean_name = "Times-Roman";

  fontdesc->font = fz_load_system_font(ctx, fontname, 0, 0, !has_descriptor);
  if (!fontdesc->font)
  {
    const unsigned char *data;
    int len;

    data = fz_lookup_base14_font(ctx, clean_name, &len);
    if (!data)
      fz_throw(ctx, FZ_ERROR_SYNTAX, "cannot find builtin font: '%s'", fontname);

    fontdesc->font = fz_new_font_from_memory(ctx, fontname, data, len, 0, 1);
    fontdesc->font->flags.is_serif = !!strstr(clean_name, "Times");
  }

  if (!strcmp(clean_name, "Symbol") || !strcmp(clean_name, "ZapfDingbats"))
    fontdesc->flags |= PDF_FD_SYMBOLIC;

  face = fontdesc->font->ft_face;
  fontdesc->ascent = 1000.0f * face->ascender / face->units_per_EM;
  fontdesc->descent = 1000.0f * face->descender / face->units_per_EM;
}

static void
pdf_load_substitute_font(fz_context *ctx, pdf_font_desc *fontdesc, const char *fontname, int mono, int serif, int bold, int italic)
{
  fontdesc->font = fz_load_system_font(ctx, fontname, bold, italic, 0);
  if (!fontdesc->font)
  {
    const unsigned char *data;
    int len;

    data = pdf_lookup_substitute_font(ctx, mono, serif, bold, italic, &len);
    if (!data)
      fz_throw(ctx, FZ_ERROR_SYNTAX, "cannot find substitute font");

    fontdesc->font = fz_new_font_from_memory(ctx, fontname, data, len, 0, 1);
    fontdesc->font->flags.fake_bold = bold && !fontdesc->font->flags.is_bold;
    fontdesc->font->flags.fake_italic = italic && !fontdesc->font->flags.is_italic;

    fontdesc->font->flags.is_mono = mono;
    fontdesc->font->flags.is_serif = serif;
    fontdesc->font->flags.is_bold = bold;
    fontdesc->font->flags.is_italic = italic;
  }

  fontdesc->font->flags.ft_substitute = 1;
  fontdesc->font->flags.ft_stretch = 1;
}

static void
pdf_load_substitute_cjk_font(fz_context *ctx, pdf_font_desc *fontdesc, const char *fontname, int ros, int serif)
{
  fontdesc->font = fz_load_system_cjk_font(ctx, fontname, ros, serif);
  if (!fontdesc->font)
  {
    const unsigned char *data;
    int size;
    int subfont;

    data = fz_lookup_cjk_font(ctx, ros, &size, &subfont);
    if (!data)
      fz_throw(ctx, FZ_ERROR_SYNTAX, "cannot find builtin CJK font");

    /* A glyph bbox cache is too big for CJK fonts. */
    fontdesc->font = fz_new_font_from_memory(ctx, fontname, data, size, subfont, 0);
  }

  fontdesc->font->flags.ft_substitute = 1;
  fontdesc->font->flags.ft_stretch = 0;
  fontdesc->font->flags.cjk = 1;
  fontdesc->font->flags.cjk_lang = ros;
}

static struct { int ros, serif; const char *name; } known_cjk_fonts[] = {
  { FZ_ADOBE_GB, 1, "SimFang" },
  { FZ_ADOBE_GB, 0, "SimHei" },
  { FZ_ADOBE_GB, 1, "SimKai" },
  { FZ_ADOBE_GB, 1, "SimLi" },
  { FZ_ADOBE_GB, 1, "SimSun" },
  { FZ_ADOBE_GB, 1, "Song" },

  { FZ_ADOBE_CNS, 1, "MingLiU" },

  { FZ_ADOBE_JAPAN, 0, "Gothic" },
  { FZ_ADOBE_JAPAN, 1, "Mincho" },

  { FZ_ADOBE_KOREA, 1, "Batang" },
  { FZ_ADOBE_KOREA, 0, "Gulim" },
  { FZ_ADOBE_KOREA, 0, "Dotum" },
};

static int match_font_name(const char *s, const char *ref)
{
  return !!strstr(s, ref);
}

static void
pdf_load_system_font(fz_context *ctx, pdf_font_desc *fontdesc, const char *fontname, const char *collection)
{
  int bold = 0;
  int italic = 0;
  int serif = 0;
  int mono = 0;

  if (strstr(fontname, "Bold"))
    bold = 1;
  if (strstr(fontname, "Italic"))
    italic = 1;
  if (strstr(fontname, "Oblique"))
    italic = 1;

  if (fontdesc->flags & PDF_FD_FIXED_PITCH)
    mono = 1;
  if (fontdesc->flags & PDF_FD_SERIF)
    serif = 1;
  if (fontdesc->flags & PDF_FD_ITALIC)
    italic = 1;
  if (fontdesc->flags & PDF_FD_FORCE_BOLD)
    bold = 1;

  if (collection)
  {
    if (!strcmp(collection, "Adobe-CNS1"))
      pdf_load_substitute_cjk_font(ctx, fontdesc, fontname, FZ_ADOBE_CNS, serif);
    else if (!strcmp(collection, "Adobe-GB1"))
      pdf_load_substitute_cjk_font(ctx, fontdesc, fontname, FZ_ADOBE_GB, serif);
    else if (!strcmp(collection, "Adobe-Japan1"))
      pdf_load_substitute_cjk_font(ctx, fontdesc, fontname, FZ_ADOBE_JAPAN, serif);
    else if (!strcmp(collection, "Adobe-Korea1"))
      pdf_load_substitute_cjk_font(ctx, fontdesc, fontname, FZ_ADOBE_KOREA, serif);
    else
    {
      size_t i;
      if (strcmp(collection, "Adobe-Identity") != 0)
        fz_warn(ctx, "unknown cid collection: %s", collection);

      // Recognize common CJK fonts when using Identity or other non-CJK CMap
      for (i = 0; i < nelem(known_cjk_fonts); ++i)
      {
        if (match_font_name(fontname, known_cjk_fonts[i].name))
        {
          pdf_load_substitute_cjk_font(ctx, fontdesc, fontname,
            known_cjk_fonts[i].ros, known_cjk_fonts[i].serif);
          return;
        }
      }

      pdf_load_substitute_font(ctx, fontdesc, fontname, mono, serif, bold, italic);
    }
  }
  else
  {
    pdf_load_substitute_font(ctx, fontdesc, fontname, mono, serif, bold, italic);
  }
}

#define TTF_U16(p) ((uint16_t) ((p)[0]<<8) | ((p)[1]))
#define TTF_U32(p) ((uint32_t) ((p)[0]<<24) | ((p)[1]<<16) | ((p)[2]<<8) | ((p)[3]))

static fz_buffer *
pdf_extract_cff_subtable(fz_context *ctx, unsigned char *data, size_t size)
{
  size_t num_tables = TTF_U16(data + 4);
  size_t i;

  if (12 + num_tables * 16 > size)
    fz_throw(ctx, FZ_ERROR_SYNTAX, "invalid TTF header");

  for (i = 0; i < num_tables; ++i)
  {
    unsigned char *record = data + 12 + i * 16;
    if (!memcmp("CFF ", record, 4))
    {
      uint64_t offset = TTF_U32(record + 8);
      uint64_t length = TTF_U32(record + 12);
      uint64_t end = offset + length;
      if (end > size)
        fz_throw(ctx, FZ_ERROR_SYNTAX, "invalid TTF subtable offset/length");
      return fz_new_buffer_from_copied_data(ctx, data + offset, length);
    }
  }

  return NULL;
}

static void
pdf_load_embedded_font(fz_context *ctx, pdf_document *doc, pdf_font_desc *fontdesc, const char *fontname, pdf_obj *stmref)
{
  fz_buffer *buf;
  unsigned char *data;
  size_t size;

  fz_var(buf);

  buf = pdf_load_stream(ctx, stmref);

  fz_try(ctx)
  {
    /* Extract CFF subtable for OpenType fonts: */
    size = fz_buffer_storage(ctx, buf, &data);
    if (size > 12) {
      if (!memcmp("OTTO", data, 4)) {
        fz_buffer *cff = pdf_extract_cff_subtable(ctx, data, size);
        if (cff)
        {
          fz_drop_buffer(ctx, buf);
          buf = cff;
        }
      }
    }

    fontdesc->font = fz_new_font_from_buffer(ctx, fontname, buf, 0, 1);
  }
  fz_always(ctx)
    fz_drop_buffer(ctx, buf);
  fz_catch(ctx)
    fz_rethrow(ctx);

  fontdesc->size += fz_buffer_storage(ctx, buf, NULL);
  fontdesc->is_embedded = 1;
}

/*
 * Create and destroy
 */

pdf_font_desc *
pdf_keep_font(fz_context *ctx, pdf_font_desc *fontdesc)
{
  return fz_keep_storable(ctx, &fontdesc->storable);
}

void
pdf_drop_font(fz_context *ctx, pdf_font_desc *fontdesc)
{
  fz_drop_storable(ctx, &fontdesc->storable);
}

static int
pdf_font_is_droppable(fz_context *ctx, fz_storable *fontdesc)
{
  /* If we aren't holding the FT lock, then we can drop. */
  return !fz_ft_lock_held(ctx);
}

static void
pdf_drop_font_imp(fz_context *ctx, fz_storable *fontdesc_)
{
  pdf_font_desc *fontdesc = (pdf_font_desc *)fontdesc_;

  fz_drop_font(ctx, fontdesc->font);
  pdf_drop_cmap(ctx, fontdesc->encoding);
  pdf_drop_cmap(ctx, fontdesc->to_ttf_cmap);
  pdf_drop_cmap(ctx, fontdesc->to_unicode);
  fz_free(ctx, fontdesc->cid_to_gid);
  fz_free(ctx, fontdesc->cid_to_ucs);
  fz_free(ctx, fontdesc->hmtx);
  fz_free(ctx, fontdesc->vmtx);
  fz_free(ctx, fontdesc);
}

pdf_font_desc *
pdf_new_font_desc(fz_context *ctx)
{
  pdf_font_desc *fontdesc;

  fontdesc = fz_malloc_struct(ctx, pdf_font_desc);
  FZ_INIT_AWKWARD_STORABLE(fontdesc, 1, pdf_drop_font_imp, pdf_font_is_droppable);
  fontdesc->size = sizeof(pdf_font_desc);

  fontdesc->font = NULL;

  fontdesc->flags = 0;
  fontdesc->italic_angle = 0;
  fontdesc->ascent = 800;
  fontdesc->descent = -200;
  fontdesc->cap_height = 800;
  fontdesc->x_height = 500;
  fontdesc->missing_width = 0;

  fontdesc->encoding = NULL;
  fontdesc->to_ttf_cmap = NULL;
  fontdesc->cid_to_gid_len = 0;
  fontdesc->cid_to_gid = NULL;

  fontdesc->to_unicode = NULL;
  fontdesc->cid_to_ucs_len = 0;
  fontdesc->cid_to_ucs = NULL;

  fontdesc->wmode = 0;

  fontdesc->hmtx_cap = 0;
  fontdesc->vmtx_cap = 0;
  fontdesc->hmtx_len = 0;
  fontdesc->vmtx_len = 0;
  fontdesc->hmtx = NULL;
  fontdesc->vmtx = NULL;

  fontdesc->dhmtx.lo = 0x0000;
  fontdesc->dhmtx.hi = 0xFFFF;
  fontdesc->dhmtx.w = 1000;

  fontdesc->dvmtx.lo = 0x0000;
  fontdesc->dvmtx.hi = 0xFFFF;
  fontdesc->dvmtx.x = 0;
  fontdesc->dvmtx.y = 880;
  fontdesc->dvmtx.w = -1000;

  fontdesc->is_embedded = 0;

  return fontdesc;
}

/*
 * Simple fonts (Type1 and TrueType)
 */

static FT_CharMap
select_type1_cmap(FT_Face face)
{
  int i;
  for (i = 0; i < face->num_charmaps; i++)
    if (face->charmaps[i]->platform_id == 7)
      return face->charmaps[i];
  if (face->num_charmaps > 0)
    return face->charmaps[0];
  return NULL;
}

static FT_CharMap
select_truetype_cmap(fz_context *ctx, FT_Face face, int symbolic)
{
  int i;

  /* First look for a Microsoft symbolic cmap, if applicable */
  if (symbolic)
  {
    for (i = 0; i < face->num_charmaps; i++)
      if (face->charmaps[i]->platform_id == 3 && face->charmaps[i]->encoding_id == 0)
        return face->charmaps[i];
  }

  fz_ft_lock(ctx);

  /* Then look for a Microsoft Unicode cmap */
  for (i = 0; i < face->num_charmaps; i++)
    if (face->charmaps[i]->platform_id == 3 && face->charmaps[i]->encoding_id == 1)
      if (FT_Get_CMap_Format(face->charmaps[i]) != -1)
      {
        fz_ft_unlock(ctx);
        return face->charmaps[i];
      }

  /* Finally look for an Apple MacRoman cmap */
  for (i = 0; i < face->num_charmaps; i++)
    if (face->charmaps[i]->platform_id == 1 && face->charmaps[i]->encoding_id == 0)
      if (FT_Get_CMap_Format(face->charmaps[i]) != -1)
      {
        fz_ft_unlock(ctx);
        return face->charmaps[i];
      }

  if (face->num_charmaps > 0)
    if (FT_Get_CMap_Format(face->charmaps[0]) != -1)
    {
      fz_ft_unlock(ctx);
      return face->charmaps[0];
    }

  fz_ft_unlock(ctx);
  return NULL;
}

static FT_CharMap
select_unknown_cmap(FT_Face face)
{
  if (face->num_charmaps > 0)
    return face->charmaps[0];
  return NULL;
}

static int use_s22pdf_workaround(fz_context *ctx, pdf_obj *dict, pdf_obj *descriptor)
{
  if (descriptor)
  {
    if (pdf_dict_get(ctx, dict, PDF_NAME(Encoding)) != PDF_NAME(WinAnsiEncoding))
      return 0;
    if (pdf_dict_get_int(ctx, descriptor, PDF_NAME(Flags)) != 4)
      return 0;
    return 1;
  }
  return 0;
}

static pdf_font_desc *
pdf_load_simple_font(fz_context *ctx, pdf_document *doc, pdf_obj *dict)
{
  const char *basefont;
  pdf_obj *descriptor;
  pdf_obj *encoding;
  pdf_obj *widths;
  unsigned short *etable = NULL;
  pdf_font_desc *fontdesc = NULL;
  pdf_obj *subtype;
  FT_Face face;
  FT_CharMap cmap;
  int symbolic;
  int kind;
  int glyph;

  const char *estrings[256];
  char ebuffer[256][32];
  int i, k, n;
  int fterr;
  int has_lock = 0;

  fz_var(fontdesc);
  fz_var(etable);
  fz_var(has_lock);

  /* Load font file */
  fz_try(ctx)
  {
    fontdesc = pdf_new_font_desc(ctx);

    basefont = pdf_dict_get_name(ctx, dict, PDF_NAME(BaseFont));

    descriptor = pdf_dict_get(ctx, dict, PDF_NAME(FontDescriptor));
    if (descriptor)
      pdf_load_font_descriptor(ctx, doc, fontdesc, descriptor, NULL, basefont, 0);
    else
      pdf_load_builtin_font(ctx, fontdesc, basefont, 0);

    /* Some chinese documents mistakenly consider WinAnsiEncoding to be codepage 936 */
    if (use_s22pdf_workaround(ctx, dict, descriptor))
    {
      char *cp936fonts[] = {
        "\xCB\xCE\xCC\xE5", "SimSun,Regular",
        "\xBA\xDA\xCC\xE5", "SimHei,Regular",
        "\xBF\xAC\xCC\xE5_GB2312", "SimKai,Regular",
        "\xB7\xC2\xCB\xCE_GB2312", "SimFang,Regular",
        "\xC1\xA5\xCA\xE9", "SimLi,Regular",
        NULL
      };
      for (i = 0; cp936fonts[i]; i += 2)
        if (!strcmp(basefont, cp936fonts[i]))
          break;
      if (cp936fonts[i])
      {
        fz_warn(ctx, "workaround for S22PDF lying about chinese font encodings");
        pdf_drop_font(ctx, fontdesc);
        fontdesc = NULL;
        fontdesc = pdf_new_font_desc(ctx);
        pdf_load_font_descriptor(ctx, doc, fontdesc, descriptor, "Adobe-GB1", cp936fonts[i+1], 0);
        fontdesc->encoding = pdf_load_system_cmap(ctx, "GBK-EUC-H");
        fontdesc->to_unicode = pdf_load_system_cmap(ctx, "Adobe-GB1-UCS2");
        fontdesc->to_ttf_cmap = pdf_load_system_cmap(ctx, "Adobe-GB1-UCS2");

        goto skip_encoding;
      }
    }

    face = fontdesc->font->ft_face;
    kind = ft_kind(ctx, face);

    /* Encoding */

    symbolic = fontdesc->flags & 4;
    /* Bug 703273: If non-symbolic, we're not symbolic. */
    if (fontdesc->flags & 32)
      symbolic = 0;

    if (kind == TYPE1)
      cmap = select_type1_cmap(face);
    else if (kind == TRUETYPE)
      cmap = select_truetype_cmap(ctx, face, symbolic);
    else
      cmap = select_unknown_cmap(face);

    if (cmap)
    {
      fz_ft_lock(ctx);
      fterr = FT_Set_Charmap(face, cmap);
      fz_ft_unlock(ctx);
      if (fterr)
        fz_warn(ctx, "freetype could not set cmap: %s", ft_error_string(fterr));
    }
    else
      fz_warn(ctx, "freetype could not find any cmaps");

    /* FIXME: etable may leak on error. */
    etable = Memento_label(fz_malloc_array(ctx, 256, unsigned short), "cid_to_gid");
    fontdesc->size += 256 * sizeof(unsigned short);
    for (i = 0; i < 256; i++)
    {
      estrings[i] = NULL;
      etable[i] = 0;
    }

    encoding = pdf_dict_get(ctx, dict, PDF_NAME(Encoding));
    if (encoding)
    {
      if (pdf_is_name(ctx, encoding))
        pdf_load_encoding(estrings, pdf_to_name(ctx, encoding));

      if (pdf_is_dict(ctx, encoding))
      {
        pdf_obj *base, *diff, *item;

        base = pdf_dict_get(ctx, encoding, PDF_NAME(BaseEncoding));
        if (pdf_is_name(ctx, base))
          pdf_load_encoding(estrings, pdf_to_name(ctx, base));
        else if (!fontdesc->is_embedded && !symbolic)
          pdf_load_encoding(estrings, "StandardEncoding");

        diff = pdf_dict_get(ctx, encoding, PDF_NAME(Differences));
        if (pdf_is_array(ctx, diff))
        {
          n = pdf_array_len(ctx, diff);
          k = 0;
          for (i = 0; i < n; i++)
          {
            item = pdf_array_get(ctx, diff, i);
            if (pdf_is_int(ctx, item))
              k = pdf_to_int(ctx, item);
            if (pdf_is_name(ctx, item) && k >= 0 && k < (int)nelem(estrings))
              estrings[k++] = pdf_to_name(ctx, item);
          }
        }
      }
    }
    else if (!fontdesc->is_embedded && !symbolic)
      pdf_load_encoding(estrings, "StandardEncoding");

    fz_ft_lock(ctx);
    has_lock = 1;

    /* start with the builtin encoding */
    for (i = 0; i < 256; i++)
      etable[i] = ft_char_index(face, i);

    /* built-in and substitute fonts may be a different type than what the document expects */
    subtype = pdf_dict_get(ctx, dict, PDF_NAME(Subtype));
    if (pdf_name_eq(ctx, subtype, PDF_NAME(Type1)))
      kind = TYPE1;
    else if (pdf_name_eq(ctx, subtype, PDF_NAME(MMType1)))
      kind = TYPE1;
    else if (pdf_name_eq(ctx, subtype, PDF_NAME(TrueType)))
      kind = TRUETYPE;
    else if (pdf_name_eq(ctx, subtype, PDF_NAME(CIDFontType0)))
      kind = TYPE1;
    else if (pdf_name_eq(ctx, subtype, PDF_NAME(CIDFontType2)))
      kind = TRUETYPE;

    /* encode by glyph name where we can */
    if (kind == TYPE1)
    {
      for (i = 0; i < 256; i++)
      {
        if (estrings[i])
        {
          glyph = ft_name_index(face, estrings[i]);
          if (glyph > 0)
            etable[i] = glyph;
        }
      }
    }

    /* encode by glyph name where we can */
    if (kind == TRUETYPE)
    {
      /* Unicode cmap */
      if (!symbolic && face->charmap && face->charmap->platform_id == 3)
      {
        for (i = 0; i < 256; i++)
        {
          if (estrings[i])
          {
            glyph = ft_find_glyph_by_unicode_name(face, estrings[i]);
            if (glyph > 0)
              etable[i] = glyph;
          }
        }
      }

      /* MacRoman cmap */
      else if (!symbolic && face->charmap && face->charmap->platform_id == 1)
      {
        for (i = 0; i < 256; i++)
        {
          if (estrings[i])
          {
            int mrcode = lookup_mre_code(estrings[i]);
            glyph = 0;
            if (mrcode > 0)
              glyph = ft_char_index(face, mrcode);
            if (glyph == 0)
              glyph = ft_name_index(face, estrings[i]);
            if (glyph > 0)
              etable[i] = glyph;
          }
        }
      }

      /* Symbolic cmap */
      else if (!face->charmap || face->charmap->encoding != FT_ENCODING_MS_SYMBOL)
      {
        for (i = 0; i < 256; i++)
        {
          if (estrings[i])
          {
            glyph = ft_name_index(face, estrings[i]);
            if (glyph > 0)
              etable[i] = glyph;
          }
        }
      }
    }

    /* try to reverse the glyph names from the builtin encoding */
    for (i = 0; i < 256; i++)
    {
      if (etable[i] && !estrings[i])
      {
        if (FT_HAS_GLYPH_NAMES(face))
        {
          fterr = FT_Get_Glyph_Name(face, etable[i], ebuffer[i], 32);
          if (fterr)
            fz_warn(ctx, "freetype get glyph name (gid %d): %s", etable[i], ft_error_string(fterr));
          if (ebuffer[i][0])
            estrings[i] = ebuffer[i];
        }
        else
        {
          estrings[i] = (char*) fz_glyph_name_from_win_ansi[i]; /* discard const */
        }
      }
    }

    /* symbolic Type 1 fonts with an implicit encoding and non-standard glyph names */
    if (kind == TYPE1 && symbolic)
    {
      for (i = 0; i < 256; i++)
        if (etable[i] && estrings[i] && !fz_unicode_from_glyph_name(estrings[i]))
          estrings[i] = (char*) fz_glyph_name_from_adobe_standard[i];
    }

    fz_ft_unlock(ctx);
    has_lock = 0;

    fontdesc->encoding = pdf_new_identity_cmap(ctx, 0, 1);
    fontdesc->size += pdf_cmap_size(ctx, fontdesc->encoding);
    fontdesc->cid_to_gid_len = 256;
    fontdesc->cid_to_gid = etable;

    fz_try(ctx)
    {
      pdf_load_to_unicode(ctx, doc, fontdesc, estrings, NULL, pdf_dict_get(ctx, dict, PDF_NAME(ToUnicode)));
    }
    fz_catch(ctx)
    {
      fz_rethrow_if(ctx, FZ_ERROR_TRYLATER);
      fz_rethrow_if(ctx, FZ_ERROR_SYSTEM);
      fz_report_error(ctx);
      fz_warn(ctx, "cannot load ToUnicode CMap");
    }

  skip_encoding:

    /* Widths */

    pdf_set_default_hmtx(ctx, fontdesc, fontdesc->missing_width);

    widths = pdf_dict_get(ctx, dict, PDF_NAME(Widths));
    if (widths)
    {
      int first, last;

      first = pdf_dict_get_int(ctx, dict, PDF_NAME(FirstChar));
      last = pdf_dict_get_int(ctx, dict, PDF_NAME(LastChar));

      if (first < 0 || last > 255 || first > last)
        first = last = 0;

      for (i = 0; i < last - first + 1; i++)
      {
        int wid = pdf_array_get_int(ctx, widths, i);
        pdf_add_hmtx(ctx, fontdesc, i + first, i + first, wid);
      }
    }
    else
    {
      fz_ft_lock(ctx);
      has_lock = 1;
      for (i = 0; i < 256; i++)
        pdf_add_hmtx(ctx, fontdesc, i, i, ft_width(ctx, fontdesc, i));
      fz_ft_unlock(ctx);
      has_lock = 0;
    }

    pdf_end_hmtx(ctx, fontdesc);
  }
  fz_catch(ctx)
  {
    if (has_lock)
      fz_ft_unlock(ctx);
    if (fontdesc && etable != fontdesc->cid_to_gid)
      fz_free(ctx, etable);
    pdf_drop_font(ctx, fontdesc);
    fz_rethrow(ctx);
  }
  return fontdesc;
}

static int
hail_mary_make_hash_key(fz_context *ctx, fz_store_hash *hash, void *key_)
{
  hash->u.pi.i = 0;
  hash->u.pi.ptr = NULL;
  return 1;
}

static void *
hail_mary_keep_key(fz_context *ctx, void *key)
{
  return key;
}

static void
hail_mary_drop_key(fz_context *ctx, void *key)
{
}

static int
hail_mary_cmp_key(fz_context *ctx, void *k0, void *k1)
{
  return k0 == k1;
}

static void
hail_mary_format_key(fz_context *ctx, char *s, size_t n, void *key_)
{
  fz_strlcpy(s, "(hail mary font)", n);
}

static int hail_mary_store_key; /* Dummy */

static const fz_store_type hail_mary_store_type =
{
  "hail-mary",
  hail_mary_make_hash_key,
  hail_mary_keep_key,
  hail_mary_drop_key,
  hail_mary_cmp_key,
  hail_mary_format_key,
  NULL
};

pdf_font_desc *
pdf_load_hail_mary_font(fz_context *ctx, pdf_document *doc)
{
  pdf_font_desc *fontdesc;
  pdf_font_desc *existing;

  if ((fontdesc = fz_find_item(ctx, pdf_drop_font_imp, &hail_mary_store_key, &hail_mary_store_type)) != NULL)
  {
    return fontdesc;
  }

  /* FIXME: Get someone with a clue about fonts to fix this */
  fontdesc = pdf_load_simple_font(ctx, doc, NULL);

  existing = fz_store_item(ctx, &hail_mary_store_key, fontdesc, fontdesc->size, &hail_mary_store_type);
  assert(existing == NULL);
  (void)existing; /* Silence warning in release builds */

  return fontdesc;
}

/*
 * CID Fonts
 */

static pdf_font_desc *
load_cid_font(fz_context *ctx, pdf_document *doc, pdf_obj *dict, pdf_obj *encoding, pdf_obj *to_unicode)
{
  pdf_obj *widths;
  pdf_obj *descriptor;
  pdf_font_desc *fontdesc = NULL;
  fz_buffer *buf = NULL;
  pdf_cmap *cmap;
  FT_Face face;
  char collection[256];
  const char *basefont;
  int i, k, fterr;
  pdf_obj *cidtogidmap;
  pdf_obj *obj;
  int dw;

  fz_var(fontdesc);
  fz_var(buf);

  fz_try(ctx)
  {
    /* Get font name and CID collection */

    basefont = pdf_dict_get_name(ctx, dict, PDF_NAME(BaseFont));

    {
      pdf_obj *cidinfo;
      const char *reg, *ord;

      cidinfo = pdf_dict_get(ctx, dict, PDF_NAME(CIDSystemInfo));
      if (cidinfo)
      {
        reg = pdf_dict_get_string(ctx, cidinfo, PDF_NAME(Registry), NULL);
        ord = pdf_dict_get_string(ctx, cidinfo, PDF_NAME(Ordering), NULL);
        fz_snprintf(collection, sizeof collection, "%s-%s", reg, ord);
      }
      else
      {
        fz_warn(ctx, "CIDFont is missing CIDSystemInfo dictionary; assuming Adobe-Identity");
        fz_strlcpy(collection, "Adobe-Identity", sizeof collection);
      }
    }

    /* Encoding */

    if (pdf_is_name(ctx, encoding))
    {
      cmap = pdf_load_system_cmap(ctx, pdf_to_name(ctx, encoding));
    }
    else if (pdf_is_indirect(ctx, encoding))
    {
      cmap = pdf_load_embedded_cmap(ctx, doc, encoding);
    }
    else
    {
      fz_throw(ctx, FZ_ERROR_SYNTAX, "font missing encoding");
    }

    /* Load font file */

    fontdesc = pdf_new_font_desc(ctx);

    fontdesc->encoding = cmap;
    fontdesc->size += pdf_cmap_size(ctx, fontdesc->encoding);

    pdf_set_font_wmode(ctx, fontdesc, pdf_cmap_wmode(ctx, fontdesc->encoding));

    descriptor = pdf_dict_get(ctx, dict, PDF_NAME(FontDescriptor));
    if (!descriptor)
      fz_throw(ctx, FZ_ERROR_SYNTAX, "missing font descriptor");
    pdf_load_font_descriptor(ctx, doc, fontdesc, descriptor, collection, basefont, 1);

    face = fontdesc->font->ft_face;

    /* Apply encoding */

    cidtogidmap = pdf_dict_get(ctx, dict, PDF_NAME(CIDToGIDMap));
    if (pdf_is_stream(ctx, cidtogidmap))
    {
      size_t z, len;
      unsigned char *data;

      buf = pdf_load_stream(ctx, cidtogidmap);

      len = fz_buffer_storage(ctx, buf, &data);
      fontdesc->cid_to_gid_len = len / 2;
      fontdesc->cid_to_gid = Memento_label(fz_malloc_array(ctx, fontdesc->cid_to_gid_len, unsigned short), "cid_to_gid_map");
      fontdesc->size += fontdesc->cid_to_gid_len * sizeof(unsigned short);
      for (z = 0; z < fontdesc->cid_to_gid_len; z++)
        fontdesc->cid_to_gid[z] = (data[z * 2] << 8) + data[z * 2 + 1];
    }
    else if (cidtogidmap && !pdf_name_eq(ctx, PDF_NAME(Identity), cidtogidmap))
    {
      fz_warn(ctx, "ignoring unknown CIDToGIDMap entry");
    }

    /* if font is external, cidtogidmap should not be identity */
    /* so we map from cid to unicode and then map that through the (3 1) */
    /* unicode cmap to get a glyph id */
    else if (fontdesc->font->flags.ft_substitute)
    {
      fz_ft_lock(ctx);
      fterr = FT_Select_Charmap(face, ft_encoding_unicode);
      fz_ft_unlock(ctx);
      if (fterr)
        fz_throw(ctx, FZ_ERROR_SYNTAX, "no unicode cmap when emulating CID font: %s", ft_error_string(fterr));

      if (!strcmp(collection, "Adobe-CNS1"))
        fontdesc->to_ttf_cmap = pdf_load_system_cmap(ctx, "Adobe-CNS1-UCS2");
      else if (!strcmp(collection, "Adobe-GB1"))
        fontdesc->to_ttf_cmap = pdf_load_system_cmap(ctx, "Adobe-GB1-UCS2");
      else if (!strcmp(collection, "Adobe-Japan1"))
        fontdesc->to_ttf_cmap = pdf_load_system_cmap(ctx, "Adobe-Japan1-UCS2");
      else if (!strcmp(collection, "Adobe-Japan2"))
        fontdesc->to_ttf_cmap = pdf_load_system_cmap(ctx, "Adobe-Japan2-UCS2");
      else if (!strcmp(collection, "Adobe-Korea1"))
        fontdesc->to_ttf_cmap = pdf_load_system_cmap(ctx, "Adobe-Korea1-UCS2");
    }

    pdf_load_to_unicode(ctx, doc, fontdesc, NULL, collection, to_unicode);

    /* If we have an identity encoding, we're supposed to use the glyph ids directly.
     * If we only have a substitute font, that won't work.
     * Make a last ditch attempt by using
     * the ToUnicode table if it exists to map via the substitute font's cmap. */
    if (strstr(fontdesc->encoding->cmap_name, "Identity-") && fontdesc->font->flags.ft_substitute)
    {
      if (!fontdesc->to_ttf_cmap)
      {
        if (fontdesc->to_unicode)
        {
          // Use ToUnicode from PDF file if possible.
          fontdesc->to_ttf_cmap = pdf_keep_cmap(ctx, fontdesc->to_unicode);
        }
        else
        {
          // Attempt a generic ToUnicode (default MacRoman ordering for TrueType)
          fontdesc->to_ttf_cmap = pdf_load_builtin_cmap(ctx, "TrueType-UCS2");
        }
      }

      if (fontdesc->to_ttf_cmap)
      {
        fz_warn(ctx, "non-embedded font using identity encoding: %s (mapping via %s)", basefont, fontdesc->to_ttf_cmap->cmap_name);
        if (!fontdesc->to_unicode)
          fontdesc->to_unicode = pdf_keep_cmap(ctx, fontdesc->to_ttf_cmap);
      }
      else
        fz_warn(ctx, "non-embedded font using identity encoding: %s", basefont);
    }

    /* Horizontal */

    dw = pdf_dict_get_int_default(ctx, dict, PDF_NAME(DW), 1000);
    pdf_set_default_hmtx(ctx, fontdesc, dw);

    widths = pdf_dict_get(ctx, dict, PDF_NAME(W));
    if (widths)
    {
      int c0, c1, w, n, m;

      n = pdf_array_len(ctx, widths);
      for (i = 0; i < n; )
      {
        c0 = pdf_array_get_int(ctx, widths, i);
        obj = pdf_array_get(ctx, widths, i + 1);
        if (pdf_is_array(ctx, obj))
        {
          m = pdf_array_len(ctx, obj);
          for (k = 0; k < m; k++)
          {
            w = pdf_array_get_int(ctx, obj, k);
            pdf_add_hmtx(ctx, fontdesc, c0 + k, c0 + k, w);
          }
          i += 2;
        }
        else
        {
          c1 = pdf_to_int(ctx, obj);
          w = pdf_array_get_int(ctx, widths, i + 2);
          pdf_add_hmtx(ctx, fontdesc, c0, c1, w);
          i += 3;
        }
      }
    }

    pdf_end_hmtx(ctx, fontdesc);

    /* Vertical */

    if (pdf_cmap_wmode(ctx, fontdesc->encoding) == 1)
    {
      int dw2y = 880;
      int dw2w = -1000;

      obj = pdf_dict_get(ctx, dict, PDF_NAME(DW2));
      if (obj)
      {
        dw2y = pdf_array_get_int(ctx, obj, 0);
        dw2w = pdf_array_get_int(ctx, obj, 1);
      }

      pdf_set_default_vmtx(ctx, fontdesc, dw2y, dw2w);

      widths = pdf_dict_get(ctx, dict, PDF_NAME(W2));
      if (widths)
      {
        int c0, c1, w, x, y, n;

        n = pdf_array_len(ctx, widths);
        for (i = 0; i < n; )
        {
          c0 = pdf_array_get_int(ctx, widths, i);
          obj = pdf_array_get(ctx, widths, i + 1);
          if (pdf_is_array(ctx, obj))
          {
            int m = pdf_array_len(ctx, obj);
            for (k = 0; k * 3 < m; k ++)
            {
              w = pdf_array_get_int(ctx, obj, k * 3 + 0);
              x = pdf_array_get_int(ctx, obj, k * 3 + 1);
              y = pdf_array_get_int(ctx, obj, k * 3 + 2);
              pdf_add_vmtx(ctx, fontdesc, c0 + k, c0 + k, x, y, w);
            }
            i += 2;
          }
          else
          {
            c1 = pdf_to_int(ctx, obj);
            w = pdf_array_get_int(ctx, widths, i + 2);
            x = pdf_array_get_int(ctx, widths, i + 3);
            y = pdf_array_get_int(ctx, widths, i + 4);
            pdf_add_vmtx(ctx, fontdesc, c0, c1, x, y, w);
            i += 5;
          }
        }
      }

      pdf_end_vmtx(ctx, fontdesc);
    }
  }
  fz_always(ctx)
    fz_drop_buffer(ctx, buf);
  fz_catch(ctx)
  {
    pdf_drop_font(ctx, fontdesc);
    fz_rethrow(ctx);
  }

  return fontdesc;
}

static pdf_font_desc *
pdf_load_type0_font(fz_context *ctx, pdf_document *doc, pdf_obj *dict)
{
  pdf_obj *dfonts;
  pdf_obj *dfont;
  pdf_obj *subtype;
  pdf_obj *encoding;
  pdf_obj *to_unicode;

  dfonts = pdf_dict_get(ctx, dict, PDF_NAME(DescendantFonts));
  if (!dfonts)
    fz_throw(ctx, FZ_ERROR_SYNTAX, "cid font is missing descendant fonts");

  dfont = pdf_array_get(ctx, dfonts, 0);

  subtype = pdf_dict_get(ctx, dfont, PDF_NAME(Subtype));
  encoding = pdf_dict_get(ctx, dict, PDF_NAME(Encoding));
  to_unicode = pdf_dict_get(ctx, dict, PDF_NAME(ToUnicode));

  if (pdf_is_name(ctx, subtype) && pdf_name_eq(ctx, subtype, PDF_NAME(CIDFontType0)))
    return load_cid_font(ctx, doc, dfont, encoding, to_unicode);
  if (pdf_is_name(ctx, subtype) && pdf_name_eq(ctx, subtype, PDF_NAME(CIDFontType2)))
    return load_cid_font(ctx, doc, dfont, encoding, to_unicode);
  fz_throw(ctx, FZ_ERROR_SYNTAX, "unknown cid font type");
}

/*
 * FontDescriptor
 */

static void
pdf_load_font_descriptor(fz_context *ctx, pdf_document *doc, pdf_font_desc *fontdesc, pdf_obj *dict,
  const char *collection, const char *basefont, int iscidfont)
{
  pdf_obj *obj1, *obj2, *obj3, *obj;
  const char *fontname;
  FT_Face face;

  /* Prefer BaseFont; don't bother with FontName */
  fontname = basefont;

  fontdesc->flags = pdf_dict_get_int(ctx, dict, PDF_NAME(Flags));
  fontdesc->italic_angle = pdf_dict_get_real(ctx, dict, PDF_NAME(ItalicAngle));
  fontdesc->ascent = pdf_dict_get_real(ctx, dict, PDF_NAME(Ascent));
  fontdesc->descent = pdf_dict_get_real(ctx, dict, PDF_NAME(Descent));
  fontdesc->cap_height = pdf_dict_get_real(ctx, dict, PDF_NAME(CapHeight));
  fontdesc->x_height = pdf_dict_get_real(ctx, dict, PDF_NAME(XHeight));
  fontdesc->missing_width = pdf_dict_get_real(ctx, dict, PDF_NAME(MissingWidth));

  obj1 = pdf_dict_get(ctx, dict, PDF_NAME(FontFile));
  obj2 = pdf_dict_get(ctx, dict, PDF_NAME(FontFile2));
  obj3 = pdf_dict_get(ctx, dict, PDF_NAME(FontFile3));
  obj = obj1 ? obj1 : obj2 ? obj2 : obj3;

  if (pdf_is_indirect(ctx, obj))
  {
    fz_try(ctx)
    {
      pdf_load_embedded_font(ctx, doc, fontdesc, fontname, obj);
    }
    fz_catch(ctx)
    {
      fz_rethrow_if(ctx, FZ_ERROR_TRYLATER);
      fz_rethrow_if(ctx, FZ_ERROR_SYSTEM);
      fz_report_error(ctx);
      fz_warn(ctx, "ignored error when loading embedded font; attempting to load system font");
      if (!iscidfont && fontname != pdf_clean_font_name(fontname))
        pdf_load_builtin_font(ctx, fontdesc, fontname, 1);
      else
        pdf_load_system_font(ctx, fontdesc, fontname, collection);
    }
  }
  else
  {
    if (!iscidfont && fontname != pdf_clean_font_name(fontname))
      pdf_load_builtin_font(ctx, fontdesc, fontname, 1);
    else
      pdf_load_system_font(ctx, fontdesc, fontname, collection);
  }

  /* Check for DynaLab fonts that must use hinting */
  face = fontdesc->font->ft_face;
  if (ft_kind(ctx, face) == TRUETYPE)
  {
    /* FreeType's own 'tricky' font detection needs a bit of help */
    if (is_dynalab(fontdesc->font->name))
      face->face_flags |= FT_FACE_FLAG_TRICKY;

    if (fontdesc->ascent == 0.0f)
      fontdesc->ascent = 1000.0f * face->ascender / face->units_per_EM;

    if (fontdesc->descent == 0.0f)
      fontdesc->descent = 1000.0f * face->descender / face->units_per_EM;
  }
}

static void
pdf_make_width_table(fz_context *ctx, pdf_font_desc *fontdesc)
{
  fz_font *font = fontdesc->font;
  int i, k, n, cid, gid;

  n = 0;
  for (i = 0; i < fontdesc->hmtx_len; i++)
  {
    for (k = fontdesc->hmtx[i].lo; k <= fontdesc->hmtx[i].hi; k++)
    {
      cid = pdf_lookup_cmap(fontdesc->encoding, k);
      gid = pdf_font_cid_to_gid(ctx, fontdesc, cid);
      if (gid > n)
        n = gid;
    }
  }

  font->width_count = n + 1;
  font->width_table = Memento_label(fz_malloc_array(ctx, font->width_count, short), "font_widths");
  fontdesc->size += font->width_count * sizeof(short);

  font->width_default = fontdesc->dhmtx.w;
  for (i = 0; i < font->width_count; i++)
    font->width_table[i] = -1;

  for (i = 0; i < fontdesc->hmtx_len; i++)
  {
    for (k = fontdesc->hmtx[i].lo; k <= fontdesc->hmtx[i].hi; k++)
    {
      cid = pdf_lookup_cmap(fontdesc->encoding, k);
      gid = pdf_font_cid_to_gid(ctx, fontdesc, cid);
      if (gid >= 0 && gid < font->width_count)
        font->width_table[gid] = fz_maxi(fontdesc->hmtx[i].w, font->width_table[gid]);
    }
  }

  for (i = 0; i < font->width_count; i++)
    if (font->width_table[i] == -1)
      font->width_table[i] = font->width_default;
}

pdf_font_desc *
pdf_load_font(fz_context *ctx, pdf_document *doc, pdf_obj *rdb, pdf_obj *dict)
{
  pdf_obj *subtype;
  pdf_obj *dfonts;
  pdf_obj *charprocs;
  pdf_font_desc *fontdesc = NULL;
  int type3 = 0;

  if ((fontdesc = pdf_find_item(ctx, pdf_drop_font_imp, dict)) != NULL)
  {
    if (fontdesc->t3loading)
    {
      pdf_drop_font(ctx, fontdesc);
      fz_throw(ctx, FZ_ERROR_SYNTAX, "recursive type3 font");
    }
    return fontdesc;
  }

  subtype = pdf_dict_get(ctx, dict, PDF_NAME(Subtype));
  dfonts = pdf_dict_get(ctx, dict, PDF_NAME(DescendantFonts));
  charprocs = pdf_dict_get(ctx, dict, PDF_NAME(CharProcs));

  if (pdf_name_eq(ctx, subtype, PDF_NAME(Type0)))
    fontdesc = pdf_load_type0_font(ctx, doc, dict);
  else if (pdf_name_eq(ctx, subtype, PDF_NAME(Type1)))
    fontdesc = pdf_load_simple_font(ctx, doc, dict);
  else if (pdf_name_eq(ctx, subtype, PDF_NAME(MMType1)))
    fontdesc = pdf_load_simple_font(ctx, doc, dict);
  else if (pdf_name_eq(ctx, subtype, PDF_NAME(TrueType)))
    fontdesc = pdf_load_simple_font(ctx, doc, dict);
  else if (pdf_name_eq(ctx, subtype, PDF_NAME(Type3)))
  {
    fontdesc = pdf_load_type3_font(ctx, doc, rdb, dict);
    type3 = 1;
  }
  else if (charprocs)
  {
    fz_warn(ctx, "unknown font format, guessing type3.");
    fontdesc = pdf_load_type3_font(ctx, doc, rdb, dict);
    type3 = 1;
  }
  else if (dfonts)
  {
    fz_warn(ctx, "unknown font format, guessing type0.");
    fontdesc = pdf_load_type0_font(ctx, doc, dict);
  }
  else
  {
    fz_warn(ctx, "unknown font format, guessing type1 or truetype.");
    fontdesc = pdf_load_simple_font(ctx, doc, dict);
  }

  fz_try(ctx)
  {
    /* Create glyph width table for stretching substitute fonts and text extraction. */
    pdf_make_width_table(ctx, fontdesc);

    pdf_store_item(ctx, dict, fontdesc, fontdesc->size);

    /* Load CharProcs */
    if (type3)
    {
      fontdesc->t3loading = 1;
      fz_try(ctx)
        pdf_load_type3_glyphs(ctx, doc, fontdesc);
      fz_always(ctx)
        fontdesc->t3loading = 0;
      fz_catch(ctx)
      {
        pdf_remove_item(ctx, fontdesc->storable.drop, dict);
        fz_rethrow(ctx);
      }
    }
  }
  fz_catch(ctx)
  {
    pdf_drop_font(ctx, fontdesc);
    fz_rethrow(ctx);
  }

  return fontdesc;
}

void
pdf_print_font(fz_context *ctx, fz_output *out, pdf_font_desc *fontdesc)
{
  int i;

  fz_write_printf(ctx, out, "fontdesc {\n");

  if (fontdesc->font->ft_face)
    fz_write_printf(ctx, out, "\tfreetype font\n");
  if (fontdesc->font->t3procs)
    fz_write_printf(ctx, out, "\ttype3 font\n");

  fz_write_printf(ctx, out, "\twmode %d\n", fontdesc->wmode);
  fz_write_printf(ctx, out, "\tDW %d\n", fontdesc->dhmtx.w);

  fz_write_printf(ctx, out, "\tW {\n");
  for (i = 0; i < fontdesc->hmtx_len; i++)
    fz_write_printf(ctx, out, "\t\t<%04x> <%04x> %d\n",
      fontdesc->hmtx[i].lo, fontdesc->hmtx[i].hi, fontdesc->hmtx[i].w);
  fz_write_printf(ctx, out, "\t}\n");

  if (fontdesc->wmode)
  {
    fz_write_printf(ctx, out, "\tDW2 [%d %d]\n", fontdesc->dvmtx.y, fontdesc->dvmtx.w);
    fz_write_printf(ctx, out, "\tW2 {\n");
    for (i = 0; i < fontdesc->vmtx_len; i++)
      fz_write_printf(ctx, out, "\t\t<%04x> <%04x> %d %d %d\n", fontdesc->vmtx[i].lo, fontdesc->vmtx[i].hi,
        fontdesc->vmtx[i].x, fontdesc->vmtx[i].y, fontdesc->vmtx[i].w);
    fz_write_printf(ctx, out, "\t}\n");
  }
}

Coverage Report

Created: 2024-05-20 06:23