src/tapost.c

   1 /* tapost.c */
   2
   3 /*
   4  * Copyright (C) 2011 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 "ta.h"
  17
  18
  19 #define TTFAUTOHINT_GLYPH "\x0C.ttfautohint" /* first byte is string length */
  20 #define TTFAUTOHINT_GLYPH_LEN 13
  21
  22 FT_Error
  23 TA_sfnt_update_post_table(SFNT* sfnt,
  24                           FONT* font)
  25 {
  26   SFNT_Table* post_table = &font->tables[sfnt->post_idx];
  27   FT_Byte* buf = post_table->buf;
  28   FT_ULong buf_len = post_table->len;
  29   FT_Byte* buf_new;
  30   FT_ULong buf_new_len;
  31
  32   FT_ULong version;
  33
  34
  35   if (post_table->processed)
  36     return TA_Err_Ok;
  37
  38   version = buf[0] << 24;
  39   version += buf[1] << 16;
  40   version += buf[2] << 8;
  41   version += buf[3];
  42
  43   /* since we have to add a non-standard glyph name, */
  44   /* we must convert `name' tables in formats 1.0 and 2.5 into format 2.0 */
  45
  46   if (version == 0x10000)
  47   {
  48     /* XXX */
  49   }
  50   else if (version == 0x20000)
  51   {
  52     FT_UShort num_glyphs;
  53     FT_UShort max_name_idx;
  54     FT_ULong len;
  55     FT_UShort i;
  56     FT_Byte* p;
  57     FT_Byte* p_new;
  58
  59
  60     num_glyphs = buf[32] << 8;
  61     num_glyphs += buf[33];
  62
  63     p = buf + 34;
  64     max_name_idx = 0;
  65
  66     /* get number of glyph names stored in `names' array */
  67     for (i = 0; i < num_glyphs; i++)
  68     {
  69       FT_UShort idx;
  70
  71
  72       idx = *(p++) << 8;
  73       idx += *(p++);
  74       if (idx >= 258)
  75       {
  76         idx -= 257;
  77         if (idx > max_name_idx)
  78           max_name_idx = idx;
  79       }
  80     }
  81
  82     /* we add one entry to the `glyphNameIndex' array, */
  83     /* and append TTFAUTOHINT_GLYPH_LEN bytes to the `names' array */
  84     buf_new_len = post_table->len + 2 + TTFAUTOHINT_GLYPH_LEN;
  85
  86     /* make the allocated buffer length a multiple of 4 */
  87     len = (buf_new_len + 3) & ~3;
  88     buf_new = (FT_Byte*)malloc(len);
  89     if (!buf_new)
  90       return FT_Err_Out_Of_Memory;
  91
  92     /* pad end of buffer with zeros */
  93     buf_new[len - 1] = 0x00;
  94     buf_new[len - 2] = 0x00;
  95     buf_new[len - 3] = 0x00;
  96
  97     /* copy the table and insert the new data */
  98     p = buf;
  99     p_new = buf_new;
 100
 101     memcpy(p_new, p, 32); /* header */
 102     p += 32;
 103     p_new += 32;
 104
 105     *p_new = HIGH(num_glyphs + 1);
 106     *(p_new + 1) = LOW(num_glyphs + 1);
 107     p += 2;
 108     p_new += 2;
 109
 110     memcpy(p_new, p, num_glyphs * 2); /* glyphNameIndex */
 111     p += num_glyphs * 2;
 112     p_new += num_glyphs * 2;
 113
 114     *p_new = HIGH(max_name_idx + 1); /* new entry */
 115     *(p_new + 1) = LOW(max_name_idx + 1);
 116     p_new += 2;
 117
 118     memcpy(p_new, p, buf + buf_len - p); /* names */
 119     p_new += buf + buf_len - p;
 120
 121     strncpy((char*)p_new, TTFAUTOHINT_GLYPH,
 122             TTFAUTOHINT_GLYPH_LEN); /* new entry */
 123
 124     free(buf);
 125     post_table->buf = buf_new;
 126     post_table->len = buf_new_len;
 127   }
 128   else if (version == 0x28000)
 129   {
 130     /* XXX */
 131   }
 132   else
 133     goto Done; /* nothing to do for format 3.0 */
 134
 135   post_table->checksum = TA_table_compute_checksum(post_table->buf,
 136                                                    post_table->len);
 137 Done:
 138   post_table->processed = 1;
 139
 140   return TA_Err_Ok;
 141 }
 142
 143 /* end of tapost.c */