src/tahmtx.c

   1 /* tahmtx.c */
   2
   3 /*
   4  * Copyright (C) 2011-2012 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 FT_Error
  20 TA_sfnt_update_hmtx_table(SFNT* sfnt,
  21                           FONT* font)
  22 {
  23   SFNT_Table* hmtx_table = &font->tables[sfnt->hmtx_idx];
  24   FT_Byte* buf_new;
  25   FT_ULong buf_len;
  26   FT_ULong i;
  27
  28
  29   if (hmtx_table->processed)
  30     return TA_Err_Ok;
  31
  32   /* the metrics of the added composite element doesn't matter; */
  33   /* for this reason, we simply append two zero bytes, */
  34   /* indicating a zero value in the `leftSideBearing' array */
  35   /* (this works because we don't increase the `numberOfHMetrics' field) */
  36
  37   hmtx_table->len += 2;
  38   /* make the allocated buffer length a multiple of 4 */
  39   buf_len = (hmtx_table->len + 3) & ~3;
  40   buf_new = (FT_Byte*)realloc(hmtx_table->buf, buf_len);
  41   if (!buf_new)
  42   {
  43     hmtx_table->len -= 2;
  44     return FT_Err_Out_Of_Memory;
  45   }
  46
  47   /* pad end of buffer with zeros */
  48   for (i = hmtx_table->len - 2; i < buf_len; i++)
  49     buf_new[i] = 0x00;
  50
  51   hmtx_table->buf = buf_new;
  52   hmtx_table->checksum = TA_table_compute_checksum(hmtx_table->buf,
  53                                                    hmtx_table->len);
  54   hmtx_table->processed = 1;
  55
  56   return TA_Err_Ok;
  57 }
  58
  59 /* end of tahmtx.c */