#include <stdio.h>
#include <string.h>

int	ScanWord();
int	bitvalue[] = { 1, 2, 4, 8, 16, 32, 64, 128 };

/*****************************************************************************/
main ( argc, argv )
	int	argc;
	char   *argv[];
{
	FILE   *fin, *fout;
	int	width, height;
	char	name[80];

	if( argc != 2 ) {
		printf( "Usage: %s base_name\n", argv[0] );
		exit( 1 );
	}
	printf( "Format converter:" );
	printf( " \"%s.xbm\" to \"%s.bm\".\n", argv[1], argv[1] );
	strcpy( name, argv[1] );
	strcat( name, ".xbm" );
	fin = fopen( name, "r" );
	if( fin == NULL ) {
		printf( "%s: Can't open input file: %s\n", argv[0], name );
		exit( 1 );
	}
	ScanWord( fin, "_width" );
	fscanf( fin, "%d", &width );
	ScanWord( fin, "_height" );
	fscanf( fin, "%d", &height );
	printf( "Width=%d, Height=%d\n", width, height );
	ScanWord( fin, "static char" );
	ScanWord( fin, "[]" );
	strcpy( name, argv[1] );
	strcat( name, ".bm" );
	fout = fopen( name, "w" );
	ConvertFile( fin, fout, width, height );
	fclose( fout );
	fclose( fin );
	printf( "Awll done.\n");
}

/*****************************************************************************/
ConvertFile( fin, fout, width, height )
	FILE   *fin, *fout;
	int	width, height;
{
	char	hexhi, hexlo;
	char	binhi, binlo;
	char	rv, v;
	int	i;

	putc( 'B', fout );
	putc( 'M', fout );
	putc( 0xCB, fout );
	putc( 0x02, fout );
	v = width / 256;	putc( v, fout );
	v = width % 256;	putc( v, fout );
	v = height / 256;	putc( v, fout );
	v = height % 256;	putc( v, fout );
	while( ScanWord( fin, "0x" ) != EOF ) {
		/* extract non-inverted binary value */
		hexhi = getc( fin );
		hexlo = getc( fin );
		binhi = hexhi<='9' ? hexhi-'0' : (hexhi - 7) & 0x0F;
		binlo = hexlo<='9' ? hexlo-'0' : (hexlo - 7) & 0x0F;
		v = /*0xFF-*/ (binhi * 16 + binlo);
		/* reverse bit positions */
		rv = 0;
		for( i=0; i<8; i++ ) {
			if( v & bitvalue[i] ) {
				rv |= bitvalue[7 - i];
			}
		}
		putc( rv, fout );
	}
}

/*****************************************************************************/
int ScanWord( fin, word )
	FILE   *fin;
	char	word[];
{
	int	i, c;

	i = 1;
	while( word[i] != '\0' ) {
		c = getc( fin );
		if( c == EOF ) return( EOF );
		if( c == word[i] ) {
			i++;
		} else {
			i = 1;
		}
	}
	return( 'a' );
}