Swing 根据图片设置不规则窗体

import com.sun.awt.AWTUtilities;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.Toolkit;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.geom.Area;
import java.awt.image.PixelGrabber;
import java.io.IOException;
import java.util.ArrayList;
import javax.swing.*;
/**
 *
 * @author 19  */
public class CreateShape {
    private Image img;
    private JFrame jf;
    private Point origin;
    public CreateShape( JFrame jf) throws InterruptedException, IOException {
        this.jf = jf;
        MediaTracker mt = new MediaTracker(jf);
        //获取指定图片
        img = new ImageIcon("src/main/images/bg.png").getImage();
        mt.addImage(img, 0);
        //等待就绪
        mt.waitForAll();
        initialize(); //窗体初始化
    }
    private void initialize() throws IOException {
        //设定窗体大小和图片一样大
        jf.setSize(img.getWidth(null), img.getHeight(null));
        //设定禁用窗体装饰，这样就取消了默认的窗体结构
        jf.setUndecorated(true);
        //初始化用于移动窗体的原点
        origin = new Point();
        //调用AWTUtilities的setWindowShape方法设定本窗体为制定的Shape形状
        AWTUtilities.setWindowShape(jf, getImageShape(img));
        //设定窗体可见度
        AWTUtilities.setWindowOpacity(jf, 0.9f);
        jf.setLocationRelativeTo(null);
    }

    public Shape getImageShape(Image img) {
        ArrayList<Integer> x = new ArrayList<Integer>();
        ArrayList<Integer> y = new ArrayList<Integer>();
        int width = img.getWidth(null);//图像宽度
        int height = img.getHeight(null);//图像高度
        //筛选像素
        //首先获取图像所有的像素信息
        PixelGrabber pgr = new PixelGrabber(img, 0, 0, -1, -1, true);
        try {
            pgr.grabPixels();
        } catch (InterruptedException ex) {
            ex.getStackTrace();
        }
        int pixels[] = (int[]) pgr.getPixels();
        for (int i = 0; i < pixels.length; i++) {
            //筛选，将不透明的像素的坐标加入到坐标ArrayList x和y中
            int alpha = getAlpha(pixels[i]);
            if (alpha == 0) {
                continue;
            } else {
                x.add(i % width > 0 ? i % width - 1 : 0);
                y.add(i % width == 0 ? (i == 0 ? 0 : i / width - 1) : i / width);
            }
        }
        int[][] matrix = new int[height][width];
        for (int i = 0; i < height; i++) {
            for (int j = 0; j < width; j++) {
                matrix[i][j] = 0;
            }
        }
        //导入坐标ArrayList中的不透明坐标信息
        for (int c = 0; c < x.size(); c++) {
            matrix[y.get(c)][x.get(c)] = 1;
        }
        Area rec = new Area();
        int temp = 0;
        for (int i = 0; i < height; i++) {
            for (int j = 0; j < width; j++) {
                if (matrix[i][j] == 1) {
                    if (temp == 0) {
                        temp = j;
                    } else if (j == width) {
                        if (temp == 0) {
                            Rectangle rectemp = new Rectangle(j, i, 1, 1);
                            rec.add(new Area(rectemp));
                        } else {
                            Rectangle rectemp = new Rectangle(temp, i, j - temp, 1);
                            rec.add(new Area(rectemp));
                            temp = 0;
                        }
                    }
                } else {
                    if (temp != 0) {
                        Rectangle rectemp = new Rectangle(temp, i, j - temp, 1);
                        rec.add(new Area(rectemp));
                        temp = 0;
                    }
                }
            }
            temp = 0;
        }
        return rec;
    }
    private int getAlpha(int pixel) {
        return (pixel >> 24) & 0xff;
    }
    public static void main(String[] args) {
        try {
            JFrame jf = new JFrame();
            CreateShape c  = new CreateShape(jf);
            jf.setVisible(true);
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}