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Path: utzoo!watmath!clyde!caip!im4u!ut-sally!husc6!harvard!panda!genrad!decvax!decwrl!sun!saber!imagen!geof
From: geof@imagen.UUCP
Newsgroups: net.graphics,net.sources
Subject: Ray Trace for IMAGEN printers (impress)
Message-ID: <460@imagen.UUCP>
Date: Tue, 5-Aug-86 20:24:51 EDT
Article-I.D.: imagen.460
Posted: Tue Aug  5 20:24:51 1986
Date-Received: Sat, 9-Aug-86 07:34:56 EDT
Distribution: net
Organization: IMAGEN Corporation, Santa Clara, CA 95052-8101
Lines: 113
Xref: watmath net.graphics:1824 net.sources:5412

The following is a quick program to print the ray trace posted recently
to net.source (and net.graphics?) on an IMAGEN printer using IMPRESS.
The program works by quantizing the image into sixteen gray levels.  The
impress file generated defines a "font" of sixteen greyscale glyphs and
outputs the data.dis file as a series of characters.  The file takes a
while to print (200K glyphs).  Some spurious contours are evident.  A
real halftoning program would be better.

In the spirit of the sources posted, this program doesn't take any
arguments :-)

- Geof Cooper
  IMAGEN

------------------CUT HERE--------------------------------
#include <stdio.h>

main(argc, argv)
    char **argv;
{
    int width, height, hskip, threshold;
    int pixel;
    register i, j, k, h, h1;
    register unsigned char b;

    width = 451;
    height = 451;
    fprintf(stderr, "Width %d, height %d\n", width, height);


    printf("@document(language impress)");
    putchar(213);	/* PAGE message- sets up parameters for Impress pg. */

    putchar(135);	/* SET-ABS-H: horiz. offset in points-req. 2 bytes */
    putchar(00) ;	/*offset currently set to 250/300 of in. in */
    putchar(250);	/*consideration of printer's margin error.  */

    putchar(137);	/* SET-ABS-V: horiz. offset in points-req. 2 bytes */
    putchar(00) ;
    putchar(250);	/* offset set to 250/300 of an in. */

    output_grey();
    putchar(209); /* SET_BOL */
    fputw(250, stdout);
    putchar(208); /* SET_IL */
    fputw(4, stdout);

    /* show grey scale */
    for ( i = 0; i < 10; i++ ) {
        for ( j = 0; j < 16; j++ )
            putchar(j+'A');
        putchar(197);
    }
    putchar(197);
    putchar(197);

    for ( i = 0; i < height; i++ ) {
        for ( j = 0; j < width; j++ ) {
            pixel = getchar() >> 4;
            putchar(pixel + 'A');
        }
        putchar(197);/*crlf*/
    }
    fprintf(stderr, "Done\n");
    exit(0);
}

char greys[16*4] = {
    0xf0, 0xf0, 0xf0, 0xf0        /* 1111 1111 1111 1111 */
    0xf0, 0x70, 0xf0, 0x70,       /* 1111 0111 1111 0111 */
    0xf0, 0x70, 0xe0, 0x70,       /* 1111 0111 1110 0111 */
    0xe0, 0x70, 0xe0, 0x70,       /* 1110 0111 1110 0111 */
    0xe0, 0x70, 0xe0, 0x30,       /* 1110 0111 1110 0011 */
    0xe0, 0x30, 0xe0, 0x30,       /* 1110 0011 1110 0011 */
    0xe0, 0x30, 0xc0, 0x30,       /* 1110 0011 1100 0011 */
    0xc0, 0x30, 0xc0, 0x30,       /* 1100 0011 1100 0011 */
    0xc0, 0x30, 0xc0, 0x10,       /* 1100 0011 1100 0001 */
    0xc0, 0x10, 0xc0, 0x10,       /* 1100 0001 1100 0001 */
    0xc0, 0x10, 0xc0, 0x00,       /* 1100 0001 1100 0000 */
    0x80, 0x20, 0x80, 0x20,       /* 1000 0010 1000 0010 */
    0x80, 0x20, 0x80, 0x00,       /* 1000 0010 1000 0000 */
    0x80, 0x00, 0x80, 0x00,       /* 1000 0000 1000 0000 */
    0x80, 0x00, 0x00, 0x00,       /* 1000 0000 0000 0000 */
    0x00, 0x00, 0x00, 0x00,       /* 0000 0000 0000 0000 */
};

output_grey()
{
    int i, j;

    for ( i = 0; i < 16; i++ ) {
        putc(199, stdout);    /* BGLY */
        fputw(i+'A', stdout); /* rotation 0, family, member */
        fputw(4, stdout);     /* advance_width */
        fputw(4, stdout);     /* width */
        fputw(0, stdout);     /* left offset */
        fputw(4, stdout);     /* height */
        fputw(4, stdout);     /* top offset */
        for ( j = 0; j < 4; j++ )
            putchar(greys[(i<<2)+j]);
    }
}

fputw(w, f)
    short w;
    FILE *f;
{
    char c;
    c = w>>8;
    putc(c, f);
    c = w;
    putc(c, f);
}