rosapps/smartpdf/fitz/stream/filt_a85e.c

   1 #include "fitz-base.h"
   2 #include "fitz-stream.h"
   3
   4 typedef struct fz_a85e_s fz_a85e;
   5
   6 struct fz_a85e_s
   7 {
   8         fz_filter super;
   9         int c;
  10 };
  11
  12 fz_error *
  13 fz_newa85e(fz_filter **fp, fz_obj *params)
  14 {
  15         FZ_NEWFILTER(fz_a85e, f, a85e);
  16         f->c = 0;
  17         return nil;
  18 }
  19
  20 void
  21 fz_dropa85e(fz_filter *f)
  22 {
  23 }
  24
  25 fz_error *
  26 fz_processa85e(fz_filter *filter, fz_buffer *in, fz_buffer *out)
  27 {
  28         fz_a85e *f = (fz_a85e*)filter;
  29         unsigned long word;
  30         int count;
  31         int n;
  32
  33         n = 0;
  34
  35         while (1)
  36         {
  37                 if (f->c >= 70) {
  38                         if (out->wp + 1 > out->ep)
  39                                 return fz_ioneedout;
  40                         *out->wp++ = '\n';
  41                         f->c = 0;
  42                         n ++;
  43                 }
  44
  45                 if (in->rp + 4 <= in->wp)
  46                 {
  47                         word =  (in->rp[0] << 24) |
  48                                         (in->rp[1] << 16) |
  49                                         (in->rp[2] << 8) |
  50                                         (in->rp[3]);
  51                         if (word == 0) {
  52                                 if (out->wp + 1 > out->ep)
  53                                         return fz_ioneedout;
  54                                 *out->wp++ = 'z';
  55                                 f->c ++;
  56                                 n ++;
  57                         }
  58                         else {
  59                                 unsigned long v1, v2, v3, v4;
  60
  61                                 if (out->wp + 5 > out->ep)
  62                                         return fz_ioneedout;
  63
  64                                 v4 = word / 85;
  65                                 v3 = v4 / 85;
  66                                 v2 = v3 / 85;
  67                                 v1 = v2 / 85;
  68
  69                                 *out->wp++ = (v1 % 85) + '!';
  70                                 *out->wp++ = (v2 % 85) + '!';
  71                                 *out->wp++ = (v3 % 85) + '!';
  72                                 *out->wp++ = (v4 % 85) + '!';
  73                                 *out->wp++ = (word % 85) + '!';
  74                                 f->c += 5;
  75                                 n += 5;
  76                         }
  77                         in->rp += 4;
  78                 }
  79
  80                 else if (in->eof)
  81                 {
  82                         unsigned long divisor;
  83
  84                         if (in->rp == in->wp)
  85                                 goto needinput; /* handle clean eof here */
  86
  87                         count = in->wp - in->rp;
  88
  89                         if (out->wp + count + 3 > out->ep)
  90                                 return fz_ioneedout;
  91
  92                         word = 0;
  93                         switch (count) {
  94                                 case 3: word |= in->rp[2] << 8;
  95                                 case 2: word |= in->rp[1] << 16;
  96                                 case 1: word |= in->rp[0] << 24;
  97                         }
  98                         in->rp += count;
  99
 100                         divisor = 85L * 85 * 85 * 85;
 101                         while (count-- >= 0) {
 102                                 *out->wp++ = ((word / divisor) % 85) + '!';
 103                                 divisor /= 85;
 104                         }
 105
 106                         *out->wp++ = '~';
 107                         *out->wp++ = '>';
 108                         out->eof = 1;
 109                         return fz_iodone;
 110                 }
 111
 112                 else {
 113                         goto needinput;
 114                 }
 115         }
 116
 117 needinput:
 118         if (in->eof) {
 119                 if (out->wp + 2 > out->ep)
 120                         return fz_ioneedout;
 121                 *out->wp++ = '~';
 122                 *out->wp++ = '>';
 123                 out->eof = 1;
 124                 return fz_iodone;
 125         }
 126         return fz_ioneedin;
 127 }
 128