/*
 * usage:  makeelement box <width> <height>
 *         makeelement disk <diameter>
 *         makeelement ring <diameter>
 *
 * creates (on stdout) simple binary PGMs suitable for use as
 * structuring elements in binary morphology operations.
 */

#include "port.h"

#include <stdio.h>
#ifndef UNIX
#include <io.h>
#endif
#include <fcntl.h>

void write_pgm( FILE* f, int width, int height, unsigned char* data );

main( int argc, char **argv )
{
	unsigned char* image;
	int width, height;

#ifndef UNIX
	_setmode( _fileno( stdin ), _O_BINARY );
	_setmode( _fileno( stdout ), _O_BINARY );
#endif

	if ( argc < 2 )
	{
		fprintf( stderr, "usage: %0 type [ ... ]\n", argv[0] );
		fprintf( stderr, "    box <width> <height>\n" );
		fprintf( stderr, "    disk <diameter>\n" );
		fprintf( stderr, "    ring <diameter>\n" );
		exit( 1 );
	}

	if ( strcmp( argv[1], "box" ) == 0 )
	{
		if ( argc != 4 )
		{
			fprintf( stderr, "box type must specify with and height.\n" );
			exit( 1 );
		}
		width = atoi( argv[2] );
		height = atoi( argv[3] );

		if ( width < 1 || height < 1 )
		{
			fprintf( stderr, "invalid box dimensions.\n" );
			exit( 1 );
		}

		image = (unsigned char *)malloc( width * height );
		memset( image, 255, width*height );

		write_pgm( stdout, width, height, image );
		free( image );
	}
	else if ( strcmp( argv[1], "disk" ) == 0 || strcmp( argv[1], "ring" ) == 0 )
	{
		int i, j;

		if ( argc != 3 )
		{
			fprintf( stderr, "disk/ring type must specify diameter.\n" );
			exit( 1 );
		}
		width = height = atoi( argv[2] );

		if ( width < 1 )
		{
			fprintf( stderr, "invalid disk/ring diameter.\n" );
			exit( 1 );
		}

		image = (unsigned char *)malloc( width * height );
		memset( image, 0, width*height );

		for ( i = 0; i < width; ++i )
			for ( j = 0; j < height; ++j )
				if ( (width/2.0 - (i+0.5)) * (width/2.0 - (i+0.5)) + (height/2.0 - (j+0.5)) * (height/2.0 - (j+0.5)) <=	(width/2.0)*(width/2.0) )
					image[j*width+i] = 255;

		if ( strcmp( argv[1], "ring" ) == 0 )
		{
			for ( i = 1; i < width-1; ++i )
				for ( j = 1; j < height-1; ++j )
				{
					if ( image[(j-1)*width+i] &&
						image[(j+1)*width+i] &&
						image[j*width+i+1] &&
						image[j*width+i-1] )
						image[j*width+i] = 128;
				}
			for ( i = 0; i < width*height; ++i )
				if ( image[i] != 255 ) image[i] = 0;
		}

		write_pgm( stdout, width, height, image );
		free( image );
	}
	else
	{
		fprintf( stderr, "unknown element type.\n" );
		exit( 1 );
	}

	return 0;
}
			 
			 
	  
     
void write_pgm( FILE* f, int width, int height, unsigned char* data )
{
	fprintf( f, "P5\n%d %d\n%d\n", width, height, 255 );
	fwrite( data, width*height, 1, f );
	fclose( f );
}