/* * * Copyright (c) 2007 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. *//* * WormLink.java * * Created on March 30, 2001, 16:15 * @version *//** * WormLink represents one sub-section of a worm. Because the * worm will usually contain a few straight segments, this is * a relatively cost effective way to store the entire worm. * The [X,Y] coordinates are the "tail" of the worm. The link * is drawn starting at the tail and proceeding "len" spaces * in direction "dir". */public class WormLink {    private int x;    private int y;    private int len;    private byte dir;    private WormLink() {    }    public WormLink(int startX, int startY, int length, byte direction) {        x = startX;        y = startY;        dir = direction;        len = length - 1;    }    /**     * Create a worm link with a length of 1. This constructor is     * used when the worm changes direction.     */    public WormLink(int startX, int startY, byte direction) {        this(startX, startY, 1, direction);    }    /**     * Add one cell length to the head of this segment.     */    public void increaseLength() {        len++;    }    /**     * Remove one cell length from the tail of this segment.     */    public void decreaseLength() {        len--;        switch (dir) {        case Worm.LEFT:            x--;            break;        case Worm.RIGHT:            x++;            break;        case Worm.UP:            y--;            break;        case Worm.DOWN:            y++;            break;        }    }    /**     * Get the length, in cells, of this segment.     */    public int getLength() {        return len + 1;    }    /**     * Get the X coordinate of the cell that contains the head of this     * worm segment.     */    public int getX() {        return x;    }    /**     * Get the Y coordinate of the cell that contains the head of this     * worm segment.     */    public int getY() {        return y;    }    /**     * Get the X coordinate of the cell that contains the tail of this     * worm segment.     */    public int getEndX() {        if (dir == Worm.LEFT) {            return x - len;        }        if (dir == Worm.RIGHT) {            return x + len;        }        return x;    }    /**     * Get the Y coordinate of the cell that contains the tail of this     * worm segment.     */    public int getEndY() {        if (dir == Worm.DOWN) {            return y + len;        }        if (dir == Worm.UP) {            return y - len;        }        return y;    }    /**     * Get the direction this worm segment is pointing.     */    public byte getDirection() {        return dir;    }    /**     * Returns true if the worm segment is at the given cell     */    public boolean contains(int x, int y) {        switch (dir) {        case Worm.LEFT:            return ((y == this.y) && ((x <= this.x) && (x >= getEndX())));        case Worm.RIGHT:            return ((y == this.y) && ((x >= this.x) && (x <= getEndX())));        case Worm.UP:            return ((x == this.x) && ((y <= this.y) && (y >= getEndY())));        case Worm.DOWN:            return ((x == this.x) && ((y >= this.y) && (y <= getEndY())));        }        return false;    }    /**     * Debug method.     */    public String toString() {        String dirString;        switch (dir) {        case Worm.LEFT:            dirString = "Left";            break;        case Worm.RIGHT:            dirString = "Right";            break;        case Worm.UP:            dirString = "Up";            break;        case Worm.DOWN:            dirString = "Down";            break;        default:            dirString = "UNKNOWN -- " + dir;        }        return " pos == [" + x + "," + y + "]" + " - [" + getEndX() + "," + getEndY() + "]" +        "   len == " + getLength() + "   dir == " + dirString;    }}