apps/irssi/src/fe-text/utf8.c

   1
   2 #define UTF8_COMPUTE(Char, Mask, Len)                                         \
   3   if (Char < 128)                                                             \
   4     {                                                                         \
   5       Len = 1;                                                                \
   6       Mask = 0x7f;                                                            \
   7     }                                                                         \
   8   else if ((Char & 0xe0) == 0xc0)                                             \
   9     {                                                                         \
  10       Len = 2;                                                                \
  11       Mask = 0x1f;                                                            \
  12     }                                                                         \
  13   else if ((Char & 0xf0) == 0xe0)                                             \
  14     {                                                                         \
  15       Len = 3;                                                                \
  16       Mask = 0x0f;                                                            \
  17     }                                                                         \
  18   else if ((Char & 0xf8) == 0xf0)                                             \
  19     {                                                                         \
  20       Len = 4;                                                                \
  21       Mask = 0x07;                                                            \
  22     }                                                                         \
  23   else if ((Char & 0xfc) == 0xf8)                                             \
  24     {                                                                         \
  25       Len = 5;                                                                \
  26       Mask = 0x03;                                                            \
  27     }                                                                         \
  28   else if ((Char & 0xfe) == 0xfc)                                             \
  29     {                                                                         \
  30       Len = 6;                                                                \
  31       Mask = 0x01;                                                            \
  32     }                                                                         \
  33   else                                                                        \
  34     Len = -1;
  35
  36 #define UTF8_GET(Result, Chars, Count, Mask, Len)                             \
  37   (Result) = (Chars)[0] & (Mask);                                             \
  38   for ((Count) = 1; (Count) < (Len); ++(Count))                               \
  39     {                                                                         \
  40       if (((Chars)[(Count)] & 0xc0) != 0x80)                                  \
  41         {                                                                     \
  42           (Result) = -1;                                                      \
  43           break;                                                              \
  44         }                                                                     \
  45       (Result) <<= 6;                                                         \
  46       (Result) |= ((Chars)[(Count)] & 0x3f);                                  \
  47     }
  48
  49 void get_utf8_char(const unsigned char **ptr)
  50 {
  51         int i, mask = 0, len;
  52         unsigned int result;
  53         unsigned char c = (unsigned char) **ptr;
  54
  55         UTF8_COMPUTE(c, mask, len);
  56         if (len == -1)
  57                 return;
  58
  59         UTF8_GET(result, *ptr, i, mask, len);
  60         if (result == -1)
  61                 return;
  62
  63         *ptr += len-1;
  64 }