src/larc.c

   1 /* ------------------------------------------------------------------------ */
   2 /* LHa for UNIX                                                                                                                         */
   3 /*                              larc.c -- extra *.lzs                                                                           */
   4 /*                                                                                                                                                      */
   5 /*              Modified                        Nobutaka Watazaki                                                       */
   6 /*                                                                                                                                                      */
   7 /*      Ver. 1.14       Source All chagned                              1995.01.14      N.Watazaki              */
   8 /* ------------------------------------------------------------------------ */
   9 #include "lha.h"
  10
  11 /* ------------------------------------------------------------------------ */
  12 static int      flag, flagcnt, matchpos;
  13 /* ------------------------------------------------------------------------ */
  14 unsigned short
  15 decode_c_lzs( /*void*/ )
  16 {
  17         if (getbits(1)) {
  18                 return getbits(8);
  19         }
  20         else {
  21                 matchpos = getbits(11);
  22                 return getbits(4) + 0x100;
  23         }
  24 }
  25
  26 /* ------------------------------------------------------------------------ */
  27 unsigned short
  28 decode_p_lzs( /*void*/ )
  29 {
  30         return (loc - matchpos - MAGIC0) & 0x7ff;
  31 }
  32
  33 /* ------------------------------------------------------------------------ */
  34 void
  35 decode_start_lzs( /*void*/ )
  36 {
  37         init_getbits();
  38 }
  39
  40 /* ------------------------------------------------------------------------ */
  41 unsigned short
  42 decode_c_lz5( /*void*/ )
  43 {
  44         int             c;
  45
  46         if (flagcnt == 0) {
  47                 flagcnt = 8;
  48                 flag = getc(infile);
  49         }
  50         flagcnt--;
  51         c = getc(infile);
  52         if ((flag & 1) == 0) {
  53                 matchpos = c;
  54                 c = getc(infile);
  55                 matchpos += (c & 0xf0) << 4;
  56                 c &= 0x0f;
  57                 c += 0x100;
  58         }
  59         flag >>= 1;
  60         return c;
  61 }
  62
  63 /* ------------------------------------------------------------------------ */
  64 unsigned short
  65 decode_p_lz5( /*void*/ )
  66 {
  67         return (loc - matchpos - MAGIC5) & 0xfff;
  68 }
  69
  70 /* ------------------------------------------------------------------------ */
  71 void
  72 decode_start_lz5( /*void*/ )
  73 {
  74         int             i;
  75
  76         flagcnt = 0;
  77         for (i = 0; i < 256; i++)
  78                 memset(&text[i * 13 + 18], i, 13);
  79         for (i = 0; i < 256; i++)
  80                 text[256 * 13 + 18 + i] = i;
  81         for (i = 0; i < 256; i++)
  82                 text[256 * 13 + 256 + 18 + i] = 255 - i;
  83         memset(&text[256 * 13 + 512 + 18], 0, 128);
  84         memset(&text[256 * 13 + 512 + 128 + 18], ' ', 128 - 18);
  85 }