/* qrttoppm.c - read a QRT ray-tracer output file and produce a portable pixmap

**

** Copyright (C) 1989 by Jef Poskanzer.

**

** Permission to use, copy, modify, and distribute this software and its

** documentation for any purpose and without fee is hereby granted, provided

** that the above copyright notice appear in all copies and that both that

** copyright notice and this permission notice appear in supporting

** documentation.  This software is provided "as is" without express or

** implied warranty.

*/

#include "ppm.h"

int

main( argc, argv )

    int argc;

    char* argv[];

    {

    FILE* ifp;

    register pixel* pixelrow;

    int rows, cols, row, col;

    pixval maxval;

    unsigned char* buf;

    ppm_init( &argc, argv );

    if ( argc > 2 )

	pm_usage( "[qrtfile]" );

    if ( argc == 2 )

	ifp = pm_openr( argv[1] );

    else

	ifp = stdin;

    /* Read in the QRT file.  First the header. */

    cols = getc( ifp );

    cols += getc( ifp ) << 8;

    rows = getc( ifp );

    rows += getc( ifp ) << 8;

    if ( cols <= 0 || rows <= 0 )

	pm_error( "invalid size: %d %d", cols, rows );

    maxval = 255;

    ppm_writeppminit( stdout, cols, rows, maxval, 0 );

    pixelrow = ppm_allocrow( cols );

    buf = (unsigned char *) malloc2( 3 , cols );

    if ( buf == (unsigned char *) 0 )

	pm_error( "out of memory" );

    for ( row = 0; row < rows; row++ )

	{

        (void) getc( ifp );	/* discard */

        (void) getc( ifp );	/* linenum */

	if ( fread( buf, 3 * cols, 1, ifp ) != 1 )

	    pm_error( "EOF / read error" );

	for ( col = 0; col < cols; col++ )

	    PPM_ASSIGN(

		pixelrow[col], buf[col], buf[cols + col], buf[2 * cols + col] );

	ppm_writeppmrow( stdout, pixelrow, cols, maxval, 0 );

	}

    pm_close( ifp );

    pm_close( stdout );

    exit( 0 );

    }