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/* $Log: pknum.c,v $
* Revision 0.8 92/11/23 19:46:52 19:46:52 bt (Bo Thide')
* Fixed resolution bug. Portable downloading. Added/changed options. PJXL color support
*
* Revision 0.7 92/11/13 02:41:37 02:41:37 bt (Bo Thide')
* More bug fixes and improvements. Support for PaintJet XL
*
* Revision 0.6 92/11/10 21:48:34 21:48:34 bt (Bo Thide')
* Bug fixes. Added -R option. Better font handling.
*
* Revision 0.5 92/11/09 16:25:40 16:25:40 bt (Bo Thide')
* Rewrite of dospecial.c. Extended \special support
*
* Revision 0.4 92/11/08 02:45:56 02:45:56 bt (Bo Thide')
* Changed to portable bit manipulations. Replaced strrstr for non-POSIX compliant C. Fixed numerous bugs. Added support for more \special's.
*
* Revision 0.3 92/08/24 12:45:47 12:45:47 bt (Bo Thide')
* Fixed 8 bit (dc font) support.
*
* Revision 0.2 92/08/23 17:28:59 17:28:59 bt (Bo Thide')
* Source cleaned up. Changed certain function calls. Removed globals.
*
* Revision 0.1 92/08/22 23:58:48 23:58:48 bt (Bo Thide')
* First Release.
* */
/*
* This routine provides the final algorithm for decoding the run counts,
* assuming a procedure (macro) 'getnib()' is available to get the next
* nibble from the 'pkbuffer'. It returns the next run_count as an integer,
* and if the row needs to be repeated it returns additionally the repeat
* value to the global variable 'repeat_count'. Since a repeat count can
* occur only once within a row, namely after the first transition within a
* row, it is the responsibility of the calling procedure to repeat such a
* row and to reset 'repeat_count' to zero, before calling the next run count
* for the next row. The global variable 'c_black' changes from 0 to -1 and
* back to 0 each time 'pknum' is called, indicating a run count for
* black pixels by 'c_black = -1' or for white pixels by 'c_black = 0', resp.
* Note that this routine is recursive, but since a repeat count can never
* directly follow another repeat count, it can only be recursive to one level
*/
#include "globals.h"
#include "macros.h"
#define getnib() ((c_nib = ~c_nib) ? (*pk_ptr & 0xf0) >> 4 : *pk_ptr++ & 0xf)
static char rcsid[] = "$Header: pknum.c,v 0.8 92/11/23 19:46:52 bt Exp $";
pknum()
{
int i,j;
extern int repeat_count;
c_black = ~c_black;
if(!(i = getnib())) {
do
i++;
while(!(j = getnib()));
while(i--)
j = (j << 4) | getnib();
return(j - 15 + ((13 - dyn_f)<<4) + dyn_f);
}
else if(i <= dyn_f)
return(i);
else if(i < 14)
return(((i - dyn_f - 1)<<4) + getnib() + dyn_f + 1);
else {
if(repeat_count)
prerror("Extra repeat count\n");
if(i == 14)
repeat_count = pknum();
else {
repeat_count = 1;
c_black = ~c_black;
}
return(pknum());
}
}
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