lib/tapost.c

   1 /* tapost.c */
   2
   3 /*
   4  * Copyright (C) 2011-2022 by Werner Lemberg.
   5  *
   6  * This file is part of the ttfautohint library, and may only be used,
   7  * modified, and distributed under the terms given in `COPYING'.  By
   8  * continuing to use, modify, or distribute this file you indicate that you
   9  * have read `COPYING' and understand and accept it fully.
  10  *
  11  * The file `COPYING' mentioned in the previous paragraph is distributed
  12  * with the ttfautohint library.
  13  */
  14
  15
  16 #include <string.h>
  17
  18 #include "ta.h"
  19
  20
  21 FT_Error
  22 TA_sfnt_update_post_table(SFNT* sfnt,
  23                           FONT* font)
  24 {
  25   SFNT_Table* post_table;
  26   FT_Byte* buf;
  27   FT_ULong buf_len;
  28   FT_Byte* buf_new;
  29   FT_ULong buf_new_len;
  30
  31   FT_ULong version;
  32
  33
  34   if (sfnt->post_idx == MISSING)
  35     return TA_Err_Ok;
  36
  37   post_table = &font->tables[sfnt->post_idx];
  38   buf = post_table->buf;
  39   buf_len = post_table->len;
  40
  41   if (post_table->processed)
  42     return TA_Err_Ok;
  43
  44   version = (FT_ULong)(buf[0] << 24
  45                        | buf[1] << 16
  46                        | buf[2] << 8
  47                        | buf[3]);
  48
  49   /* since we have to add a non-standard glyph name, */
  50   /* we must convert `name' tables in formats 1.0 and 2.5 into format 2.0 */
  51
  52   if (version == 0x10000)
  53   {
  54     /* XXX */
  55   }
  56   else if (version == 0x20000)
  57   {
  58     FT_UShort num_glyphs;
  59     FT_UShort max_name_idx;
  60     FT_ULong len;
  61     FT_UShort i;
  62     FT_Byte* p;
  63     FT_Byte* p_new;
  64
  65
  66     num_glyphs = (FT_UShort)(buf[32] << 8 | buf[33]);
  67
  68     p = buf + 34;
  69     max_name_idx = 0;
  70
  71     /* get number of glyph names stored in `names' array */
  72     for (i = 0; i < num_glyphs; i++)
  73     {
  74       FT_UShort idx;
  75
  76
  77       idx = NEXT_USHORT(p);
  78       if (idx >= 258)
  79       {
  80         idx -= 257;
  81         if (idx > max_name_idx)
  82           max_name_idx = idx;
  83       }
  84     }
  85
  86     /* we add one entry to the `glyphNameIndex' array, */
  87     /* and append TTFAUTOHINT_GLYPH_LEN bytes to the `names' array */
  88     buf_new_len = post_table->len + 2 + TTFAUTOHINT_GLYPH_LEN;
  89
  90     /* make the allocated buffer length a multiple of 4 */
  91     len = (buf_new_len + 3) & ~3U;
  92     buf_new = (FT_Byte*)malloc(len);
  93     if (!buf_new)
  94       return FT_Err_Out_Of_Memory;
  95
  96     /* pad end of buffer with zeros */
  97     buf_new[len - 1] = 0x00;
  98     buf_new[len - 2] = 0x00;
  99     buf_new[len - 3] = 0x00;
 100
 101     /* copy the table and insert the new data */
 102     p = buf;
 103     p_new = buf_new;
 104
 105     memcpy(p_new, p, 32); /* header */
 106     p += 32;
 107     p_new += 32;
 108
 109     *p_new = HIGH(num_glyphs + 1);
 110     *(p_new + 1) = LOW(num_glyphs + 1);
 111     p += 2;
 112     p_new += 2;
 113
 114     memcpy(p_new, p, num_glyphs * 2); /* glyphNameIndex */
 115     p += num_glyphs * 2;
 116     p_new += num_glyphs * 2;
 117
 118     *p_new = HIGH(max_name_idx + 1 + 257); /* new entry */
 119     *(p_new + 1) = LOW(max_name_idx + 1 + 257);
 120     p_new += 2;
 121
 122     memcpy(p_new, p, (size_t)(buf + buf_len - p)); /* names */
 123     p_new += buf + buf_len - p;
 124
 125     strncpy((char*)p_new, TTFAUTOHINT_GLYPH_FIRST_BYTE TTFAUTOHINT_GLYPH,
 126             TTFAUTOHINT_GLYPH_LEN); /* new entry */
 127
 128     free(buf);
 129     post_table->buf = buf_new;
 130     post_table->len = buf_new_len;
 131   }
 132   else if (version == 0x28000)
 133   {
 134     /* XXX */
 135   }
 136   else
 137     goto Done; /* nothing to do for format 3.0 */
 138
 139   post_table->checksum = TA_table_compute_checksum(post_table->buf,
 140                                                    post_table->len);
 141 Done:
 142   post_table->processed = 1;
 143
 144   return TA_Err_Ok;
 145 }
 146
 147 /* end of tapost.c */