Path: utzoo!utgpu!watmath!iuvax!ndcheg!uceng!mfinegan
From: mfinegan@uceng.UC.EDU (michael k finegan)
Newsgroups: comp.graphics
Subject: Re: mtv raytracer displayed on targa 16
Summary: the short program follows ...
Message-ID: <825@uceng.UC.EDU>
Date: 31 Mar 89 15:41:16 GMT
References: <VALDIS.89Mar30121134@alchemy.mcs.clarkson.edu> <824@uceng.UC.EDU>
Distribution: comp
Organization: Univ. of Cincinnati, College of Engg.
Lines: 60


 I just compiled the mtv raytracing package on a 3B2/400 (SYS_V) and
 decided to display the "balls.pic" test output on a targa 16. It
 apparently works! For anyone who has a targa, but is lazier than I am,
 here is a simplistic routine to display mtv output files (assume <= 400x512)
 compile with targa tools library, and check my coordinate choice ...
 
 		mfinegan@uceng.uc.edu

Sorry - I forgot to include the program! 

/*
 *	Display mtv rendered output image file on targa 16
 *	copyright (c) Michael K. Finegan, 3/1989
 *	but do what ever you want with it!
 */
#include <stdio.h>
#include <string.h>
#include "tardev.h"

extern struct TARStruct *targa;

unsigned char pixels[1024*3];

main(argc,argv)
int argc;
char **argv;
{
    unsigned x, xmax, y, ymax, R, G, B, color;
    FILE *fp, *fopen();

    if(GraphInit(-1) == -1) {
	printf("unable to initialize targa ...\n");
	exit(0);
    }
    if(argc != 2 || (fp = fopen(argv[1],"rb")) == (FILE *)NULL) {
        printf("disp_ray file_name\n");
	exit(0);
    }
    if(fscanf(fp,"%d %d\n",&ymax,&xmax) != 2)
        fprintf(stderr,"Error reading rows, cols\n");
    else
	printf("Assuming %d rows x %d cols\n",ymax,xmax);
    for(y=0;y<ymax;y++) {
        if(fread(pixels,sizeof(unsigned char),3*xmax,fp) != 3*xmax) {
	    printf("Error reading row %d\n",y);
	    exit(0);
        }
	for(x=0;x<xmax;x++) {
	    /* truncate to 5 bits/pixel/color - nothing sophisticated */
	    R = pixels[x*3]/8;
	    G = pixels[x*3 + 1]/8;
	    B = pixels[x*3 + 2]/8;
	    color = (R<<10) | (G<<5) | B;
	    /* graphics coordinate system? x across, y down ? */
	    /* assume origin at 400th line, so will display if 400 line mode */
	    PutPix(&color,x,400-y,-1);
        }
    }
}