java game of life code example

Example: conway's game of life code java

/**

 * Java class for simulation of Conway's Game of Life. 

 * @author G. Cope

 *

 */

public class Conway2D {



	private final int width;



	private final int height;

	

	private final int size;

	

	private int seedCount = 9500;

	/*

	 * Data representing the grid in 1d format. Specified as byte to allow for multiple

	 * phases. 

	 */

	byte[] data;

	

	public Conway2D(){

		this(100, 100);

	}

	/**

	 * Constructs a new Game of Life with the specified dimensions. 

	 * @param width

	 * @param height

	 */

	public Conway2D(int width, int height){

		this.width = width;

		this.height = height;

		this.size = width * height;

		data = new byte[size];

	}



    /**

	 * Iterates the game one step forward

	 */

	public void iterate(){

		byte[] prev = new byte[size];

		System.arraycopy(data, 0, prev, 0, size);



		byte[] next = new byte[size];

		for ( int i = 0; i < width; i++ ){

			for ( int j = 0; j < height; j++ ){

				int type = isAlive(i, j, prev);

				

				if ( type > 0 ){

					next[j * width + i] = 1;

				}else{

					next[j * width + i] = 0;

				}

				

			}

		}

		

		System.arraycopy(next, 0, data, 0, size);

		

	}

	

	/**

	 * Checks if the cell is alive

	 * @param x The x position

	 * @param y The y position

	 * @param d The grid data.

	 * @return

	 */

	protected int isAlive(int x, int y, byte[] d){

		int count = 0;

		int pos1 = y * width + x;

		for ( int i = x-1; i <= x + 1; i++ ){

			for ( int j = y - 1; j <= y + 1; j++ ){

				int pos = j * width + i;

				if ( pos >= 0 && pos < size - 1 && pos != pos1){

					if ( d[pos] == 1 ){

						count++;

					}

				}

			}

		}

		//dead

		if ( d[pos1] == 0 ){

			if ( count == 3 ){//becomes alive.

				return 1;

			}

			return 0;//still dead

		}else{//live

			if ( count < 2 || count > 3 ){//Dies

				return 0;

			}

			return 1;//lives

		}



	}

	

	

	/**

	 * Randomly seeds the grid. 

	 */

	public void randomSeed(){

		for ( int i = 0; i < seedCount; i++ ){

			int x = (int)(Math.random() * width);

			int y = (int)(Math.random() * height);

			data[y * width + x] = 1;



		}

	}

	

	/**

	 * Retrieves the grid data. 

	 * @return

	 */

	public byte[] getData(){

		return data;

	}

}