// a function which recovers from a malformed command.
static int hpgl_recover(hpgs_reader *reader)
{
size_t pos;
if (hpgs_istream_tell(reader->in,&pos))
return -1;
reader->bytes_ignored = 0;
while (reader->bytes_ignored < 256 &&
(reader->last_byte = hpgs_getc(reader->in)) != ';')
{
if (reader->last_byte == EOF)
return hpgs_set_error(hpgs_i18n("EOF during recovery from malformed HPGL command at file position %lu."),(unsigned long)pos);
++reader->bytes_ignored;
}
if (reader->bytes_ignored >= 256)
return hpgs_set_error(hpgs_i18n("No semicolon in the next 256 bytes during recovery from malformed HPGL command at file position %lu."),(unsigned long)pos);
reader->bytes_ignored = 0;
reader->eoc = 1;
return 0;
}
static int base64_decode (hpgs_reader *reader, unsigned *value)
{
int digit;
int i=0;
*value=0;
while (i<6)
{
if (reader->last_byte == EOF) return -1;
if (reader->last_byte > 190)
digit = reader->last_byte - 191;
else
digit = reader->last_byte - 63;
if (digit >= 0 && digit <= 63)
{
*value |= digit << (6*i);
if (reader->last_byte > 190) return 0;
++i;
}
else
// ignore all escape characters, including space.
if (reader->last_byte > 32) return -1;
reader->last_byte = hpgs_getc(reader->in);
}
return -1;
}
/*
HPGL command PE (Polyline Encoded)
*/
static int base32_decode (hpgs_reader *reader, unsigned *value)
{
int digit;
int i=0;
*value=0;
while (i<7)
{
if (reader->last_byte == EOF) return -1;
reader->last_byte &= 0x7f;
if (reader->last_byte > 94)
digit = reader->last_byte - 95;
else
digit = reader->last_byte - 63;
if (digit >= 0 && digit <= 31)
{
*value |= digit << (5*i);
if (reader->last_byte > 94) return 0;
++i;
}
else
// ignore all escape characters, including space.
if (reader->last_byte > 32) return -1;
reader->last_byte = hpgs_getc(reader->in);
}
return -1;
}
// skip until we reach 'ENDMF;'
static int skip_MF_block (hpgs_reader *reader, const char *stop_seq)
{
while (1)
{
if (reader->bytes_ignored > 0)
{
if (reader->last_byte != stop_seq[reader->bytes_ignored-1])
reader->bytes_ignored = 0;
}
if (stop_seq[reader->bytes_ignored] == '\0')
{
reader->bytes_ignored = 0;
return 0;
}
reader->last_byte = hpgs_getc(reader->in);
if (reader->last_byte == EOF)
return 1;
++reader->bytes_ignored;
}
}
static int skip_ESC_block (hpgs_reader *reader)
{
int arg = 0;
int arg_sign = 0;
int r;
while (1)
{
switch (reader->bytes_ignored)
{
case 1:
if (reader->last_byte != HPGS_ESC)
reader->bytes_ignored = 0;
break;
case 2:
if (reader->last_byte == '.')
{
reader->last_byte = hpgs_getc(reader->in);
if (reader->last_byte == EOF)
return 1;
// <ESC>.( or <ESC>.Y interpretation.
if (reader->last_byte == '(' ||
reader->last_byte == 'Y' )
return 0;
reader->bytes_ignored = 0;
break;
}
if (reader->last_byte != '%')
reader->bytes_ignored = 0;
break;
case 3:
switch (hpgs_reader_read_pcl_int(reader,&arg,&arg_sign))
{
case -1:
return 1;
case 1:
break;
default:
reader->bytes_ignored = 0;
}
break;
case 4:
reader->bytes_ignored = 0;
switch (reader->last_byte)
{
case 'B':
return 0;
case 'A':
r = hpgs_reader_do_PCL(reader,arg);
if (r <= 0) return r;
if (r==2) return 1;
case 'X':
r=1;
while (r)
switch (hpgs_reader_do_PJL(reader))
{
case 0: // ESC found.
r = 0;
break;
case 1: // Enter HPGL mode.
return 0;
case 2: // plotsize found. skip rest of file.
return 1;
case 3: // Enter PCL mode.
r = hpgs_reader_do_PCL(reader,arg);
if (r <= 0) return r;
if (r==2) return 1;
break;
default: /* EOF, error */
return 1;
}
}
break;
default:
reader->bytes_ignored = 0;
}
if (reader->bytes_ignored != 2)
{
reader->last_byte = hpgs_getc(reader->in);
if (reader->last_byte == EOF)
return 1;
}
++reader->bytes_ignored;
}
}