/* pgmtofs.c - convert portable graymap to Usenix FaceSaver(tm) format

**

** Copyright (C) 1991 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 "pgm.h"

static void putinit ARGS(( int cols, int rows, int bps ));

static void putitem ARGS(( void ));

static void putgray ARGS(( gray g ));

static void putrest ARGS(( void ));

int

main( argc, argv )

    int argc;

    char* argv[];

{

    FILE* ifp;

    gray** grays;

    register gray* gP;

    int argn, rows, cols, bps, padright, row, col;

    gray maxval, nmaxval;

    const char* const usage = "[pgmfile]";

    pgm_init( &argc, argv );

    argn = 1;

    if ( argn < argc )

	{

        ifp = pm_openr( argv[argn] );

        ++argn;

	}

    else

	{

        ifp = stdin;

	}

    if ( argn != argc )

        pm_usage( usage );

    grays = pgm_readpgm( ifp, &cols, &rows, &maxval );

    pm_close( ifp );

    /* Figure out bps. */

    bps = pm_maxvaltobits( (int) maxval );

    if ( bps > 2 && bps < 4 )

        bps = 4;

    else if ( bps > 4 && bps < 8 )

        bps = 8;

    else if ( bps > 8 )

        pm_error(

            "maxval of %d is too large for FaceSaver(tm)", maxval );

    nmaxval = pm_bitstomaxval( bps );

    /* Compute padding to round cols * bps up to the nearest multiple of 8. */

    padright = ( ( cols * bps + 7 ) / 8 ) * 8 - cols * bps;

    putinit( cols, rows, bps );

    for ( row = rows - 1; row >= 0; --row )

	{

        for ( col = 0, gP = grays[row]; col < cols; ++col, ++gP )

	    {

            if ( maxval != nmaxval )

                *gP = (int) *gP * nmaxval / maxval;

            putgray( *gP );

	    }

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

            putgray( 0 );

    }

    putrest( );

    exit( 0 );

}

static int bitspersample, item, bitsperitem, bitshift, itemsperline, items;

static void

putinit( cols, rows, bps )

    int cols, rows, bps;

{

    printf( "FirstName: \n" );

    printf( "LastName: \n" );

    printf( "E-mail: \n" );

    printf( "Telephone: \n" );

    printf( "Company: \n" );

    printf( "Address1: \n" );

    printf( "Address2: \n" );

    printf( "CityStateZip: \n" );

    printf( "Date: \n" );

    printf( "PicData: %d %d %d\n", cols, rows, bps );

    printf( "Image: %d %d %d\n", cols, rows, bps );

    printf( "\n" );

    bitspersample = bps;

    itemsperline = items = 0;

    item = 0;

    bitsperitem = 0;

    bitshift = 8 - bitspersample;

}

static void

putitem( )

{

    const char* const hexits = "0123456789abcdef";

    if ( itemsperline == 30 )

	{

        putchar( '\n' );

        itemsperline = 0;

	}

    putchar( hexits[item >> 4] );

    putchar( hexits[item & 15] );

    ++itemsperline;

    ++items;

    item = 0;

    bitsperitem = 0;

    bitshift = 8 - bitspersample;

}

static void

putgray( gray g )

{

    if ( bitsperitem == 8 )

        putitem( );

    item += g << bitshift;

    bitsperitem += bitspersample;

    bitshift -= bitspersample;

}

static void

putrest( )

{

    if ( bitsperitem > 0 )

        putitem( );

    printf( "\n" );

}