/* mtvtoppm.c - read an MTV 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;

    pixel* pixelrow;

    register pixel* pP;

    int rows, cols, row, col;

    pixval maxval;

#define MAXLINE 500

    char line[MAXLINE];

    unsigned char buf[3];

    ppm_init( &argc, argv );

    if ( argc > 2 )

	pm_usage( "[mtvfile]" );

    if ( argc == 2 )

	ifp = pm_openr( argv[1] );

    else

	ifp = stdin;

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

    if ( fgets( line, MAXLINE, ifp ) == NULL )

	pm_error( "unable to read MTV file header" );

    if ( sscanf( line, "%d%d", &cols, &rows ) != 2 )

	pm_error( "unable to parse MTV file header" );

    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 );

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

	{

	for ( col = 0, pP = pixelrow; col < cols; col++, pP++ )

	    {

	    if ( fread( buf, sizeof(buf), 1, ifp ) != 1 )

		pm_error( "EOF / read error" );

	    PPM_ASSIGN( *pP, buf[0], buf[1], buf[2] );

	    }

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

	}

    pm_close( ifp );

    pm_close( stdout );

    exit( 0 );

    }