package game6;

import java.awt.Color;

import java.awt.Graphics;

import javax.swing.JPanel;

/**

 * java游戏开发杂谈

 * ---demo6：有限状态机

 *

 * @author 台哥编程课堂

 * https://www.cnblogs.com/chaohi/

 *

 * @date 2019-04-25

 */

public class GamePanel extends JPanel{

	/** 屏幕的宽和高 */

	private int width,height;

	public GamePanel(int width, int height) {

		this.width = width;

		this.height = height;

		this.setSize(width, height);

		//设置当前画布可以获得焦点。

		this.setFocusable(true);

	}

	/**方块的位置*/

	private int fk_x = 60;

	private int fk_y = 60;

	/**

	 * 画布的绘制

	 */

	public void paintComponent(Graphics g) {

		super.paintComponent(g);

		//画绿色背景

		g.setColor(new Color(0x9391d6));

		g.fillRect(0, 0, width, height);

		//绘制方块，大小为80

		g.setColor(Color.red);

		g.fillRect(fk_x, fk_y, 80, 80);

	}

	//四个状态，对应四个方向的运动

	private static final int stage_left = 0;

	private static final int stage_right = 1;

	private static final int stage_up = 2;

	private static final int stage_down = 3;

	//当前状态，初始为向右

	private int stage = stage_right;

	/**

	 * 游戏逻辑，处理方块的运动，每次横纵坐标都移动1个像素

	 */

	public void logic()

	{

		switch(stage)

		{

		case stage_right:

			if(fk_x < 260){

				fk_x = fk_x + 1; //右移一个像素

			}else{

				stage = stage_down; //超出指定范围，改为向下状态

			}

			break;

		case stage_down:

			if(fk_y < 260){

				fk_y = fk_y + 1;

			}else{

				stage = stage_left;

			}

			break;

		case stage_left:

			if(fk_x > 60){

				fk_x = fk_x - 1;

			}else{

				stage = stage_up;

			}

			break;

		case stage_up:

			if(fk_y > 60){

				fk_y = fk_y - 1;

			}else{

				stage = stage_right;

			}

			break;

		}

	}

}