snakemodel.java

一个简单的java application编写的贪吃蛇小游戏

import java.util.LinkedList;
import java.util.Random;

import javax.swing.JOptionPane;

class Node {
	int x;

	int y;

	public Node(int x, int y) {
		this.x = x;
		this.y = y;
	}
}

public class SnakeModel implements Runnable {
	boolean matrix[][];

	LinkedList nodeArray = new LinkedList();

	Node food;

	int direction = 2;

	int timeInterval = 200;

	int initArrayLen;

	int maxX;

	int maxY;

	boolean running = false;

	int countMove = 0;

	int score = 0;

	boolean paused = false;

	GreedSnake gs;

	double speedChangeRate = 0.75;

	public static final int UP = 2;

	public static final int DOWN = 4;

	public static final int LEFT = 1;

	public static final int RIGHT = 3;

	public SnakeModel(GreedSnake gs, int maxX, int maxY) {
		this.maxX = maxX;
		this.maxY = maxY;
		this.gs = gs;
		matrix = new boolean[maxX][maxY];
		for (int i = 0; i < maxX; i++) {
			for (int j = 0; j < maxY; j++) {
				matrix[i][j] = false;
			}
		}
		initArrayLen = maxX > 20 ? 10 : maxX / 2;
		for (int i = 0; i < initArrayLen; i++) {
			int x = maxX / 2 + i;
			int y = maxY / 2;
			Node n = new Node(x, y);
			nodeArray.addLast(n);
			matrix[x][y] = true;
		}
		food = createFood();
		matrix[food.x][food.y] = true;
	}

	private Node createFood() {
		int x = 0;
		int y = 0;

		Random r = new Random();
		do {
			x = r.nextInt(maxX);
			y = r.nextInt(maxY);
		} while (matrix[x][y] == true);
		return new Node(x, y);
	}

	public void changeDirection(int newDirection) {
		if (direction % 2 != newDirection % 2) {
			direction = newDirection;
		}
	}

	public boolean moveOn() {
		Node n = (Node) nodeArray.getFirst();
		int x = n.x;
		int y = n.y;
		switch (direction) {
		case UP:
			y--;
			break;
		case DOWN:
			y++;
			break;
		case LEFT:
			x--;
			break;
		case RIGHT:
			x++;
			break;
		}
		if ((0 <= x && x < maxX) && (0 <= y && y < maxY)) {
			if (matrix[x][y]) {
				if (x == food.x && y == food.y) {
					nodeArray.addFirst(food);
					int scoreGet = (10000 - 200 * countMove) / timeInterval;
					score += scoreGet > 0 ? scoreGet : 10;
					countMove = 0;
					food = createFood();
					matrix[food.x][food.y] = true;
					return true;
				} else
					return false;
			} else {
				nodeArray.addFirst(new Node(x, y));
				matrix[x][y] = true;
				n = (Node) nodeArray.removeLast();
				matrix[n.x][n.y] = false;
				countMove++;
				return true;
			}

		} else
			return false;
	}

	public void run() {
		running = true;
		while (running) {
			try {
				Thread.sleep(timeInterval);
			} catch (Exception e) {
				break;
			}
			if (!paused) {
				if (moveOn()) {
					gs.repaint();
				} else {
					JOptionPane.showMessageDialog(null, "GAME OVER",
							"Game Over", JOptionPane.INFORMATION_MESSAGE);
					break;
				}
			}

		}
		running = false;
	}

	public void speedUp() {
		timeInterval *= speedChangeRate;
	}

	public void speedDown() {
		timeInterval /= speedChangeRate;
	}

	public void changePauseState() {
		paused = !paused;
	}
}