cmoore@amdimage.UUCP (chris moore) (08/12/86)
The following is a modification of Steve Hawley's dithering
program modified to work on an HP LaserJet printer. It
reads stdin and writes stdout, and doesn't take any arguments.
The input format is that used by Version 2.0 of Friedrich Knauss'
ray tracing program: a one line header with a width and height,
followed by 8 bit pixel values.
Chris Moore
amdimage!cmoore
================CUT HERE ====================
#include <stdio.h>
#define WHITE 0
#define BLACK 1
#define ENDSCAN 2
int xsize,ysize;
main()
{
int x,y,level;
scanf("%d %d",&ysize,&xsize);
printf("\033*t100R\n");
printf("\033*r0A\n");
for (x=0;x<xsize;x++) {
for (y=0;y<ysize;y++) {
level = getchar();
if (dither(x, y, level)) makedot(WHITE);
else makedot(BLACK);
}
makedot(ENDSCAN);
}
printf("\033*rB\n");
}
dither (x,y,level) /* dithering function */
register int x, y, level;
{
/* 8 x 8 dithering matrix */
static int matrix[8][8] = {
{ 0,128, 32,160, 8,136, 40,168},
{192, 64,224, 96,200, 72,232,104},
{ 48,176, 16,144, 56,184, 24,152},
{240,112,208, 80,248,120,216, 88},
{ 12,140, 44,174, 4,132, 36,164},
{204, 76,236,108,196, 68,228,100},
{ 60,188, 28,156, 52,180, 20,148},
{252,124,210, 92,244,116,212, 84}
};
/* dithering by area access to matrix by using
the MOD function on the x and y coordinates */
return(level > matrix[x % 8][y % 8]);
}
makedot(color)
int color;
{
static int i,
whichbyte = 0,
whichbit = 0,
nbytes,
thisbyte = 0;
nbytes = (ysize/8)+1;
if (color == ENDSCAN) {
/* end of scan line. We have to send 'thisbyte',
and any other bytes required to make up a full
line (nbytes - whichbyte) */
putchar(thisbyte);
for (i=whichbyte+1;i<nbytes;i++) putchar(0);
whichbyte = 0;
whichbit = 0;
thisbyte = 0;
} else {
if ((whichbyte == 0) & (whichbit == 0))
printf("\033*b%dW",nbytes);
thisbyte |= (color << (7 - whichbit++));
if (whichbit > 7) {
whichbyte++;
whichbit = 0;
putchar(thisbyte);
thisbyte = 0;
}
if (whichbyte >= nbytes) {
whichbyte = 0;
}
}
}
--
===========================================================
Any project can be built with a handful of parts if you have
big enough hands.
Chris Moore (408) 749-4692
UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!amdimage!cmoore