Question

我正在尝试创建一个程序，使得有一个正方形进入另一个正方形（稍微旋转），另一个正方形进入内部，依此类推。我设法创建了一个程序来做到这一点。但我希望程序可以制作几个这样的盒子。看看插图以获得更好的想法：

我的问题是，在绘制第一个框后，然后尝试绘制第二个框时，绘制线条的“光标”有点卡在最后一点，所以它从第一个方格的最后一个点绘制线条到第二个方块的第一点，像这样：

因为你可以看到里面的pointPanel构造函数我已经尝试清除列表，并重置计数器和i变量，但没有运气。我可以做任何修改，以便我没有这个问题吗？我已经尝试将clear（） - 指令放在其他地方。但也许我错过了一些东西。

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.util.ArrayList;

import javax.swing.JFrame;
import javax.swing.JPanel;




public class Art {
    ArrayList<Point> points = new ArrayList<>();
    int i =0;
    public static void main(String[] args) {
        new Art();
    }

    public Art() {
        JFrame frame = new JFrame("Art");
        frame.add(new pointPanel());

        frame.pack();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);


    }

    public class pointPanel extends JPanel{
        //Constructor
        public pointPanel(){
            points(0, 100);
            //points.clear();
            points(500, 200);

        }

        @Override
        //Dimension
        public Dimension getPreferredSize() {
            return new Dimension(800, 600);
        }



        public void points(double x, double y){
            double t=0.1;   //constant
            final int side = 100;
            int counter=0;

            while (counter<20){
                 //Init the first points-->
                Point p  = new Point((int)(x),      (int) (y)           );
                Point p1 = new Point((int)(x+side), (int)(y)            );
                Point p2 = new Point((int)(x+side), (int) (y-side)      );
                Point p3 = new Point((int)(x),      (int)(y-side)       );
                Point p4 = new Point((int)(x),      (int)(y)            );
                //-->and adding them to the list
                if (counter == 0) {
                    points.add(p);
                    points.add(p1);
                    points.add(p2);
                    points.add(p3);
                    points.add(p4);
                }


                //Dynamic part: 
                //If the method has been run earlier - place points making it possible to draw lines
                if (counter>0){
                    x=(1-t)*points.get(i).x + t * points.get(i+1).x;
                    y=(1-t)*points.get(i).y + t * points.get(i+1).y;
                    points.add(  new Point( (int) x, (int) y)  );
                    i++;    
                }

                if (counter>0){
                    x=(1-t)*points.get(i).x + t * points.get(i+1).x;
                    y=(1-t)*points.get(i).y + t * points.get(i+1).y;
                    points.add(  new Point( (int) x, (int) y)  );
                    i++;
                }

                if (counter>0){
                    x=(1-t)*points.get(i).x + t * points.get(i+1).x;
                    y=(1-t)*points.get(i).y + t * points.get(i+1).y;
                    points.add(  new Point( (int) x, (int) y)  );
                    i++;
                }

                if (counter>0){
                    x=(1-t)*points.get(i).x + t * points.get(i+1).x;
                    y=(1-t)*points.get(i).y + t * points.get(i+1).y;
                    points.add(  new Point( (int) x, (int) y)  );
                    i++;
                }

                if (counter>0){
                    x=(1-t)*points.get(i).x + t * points.get(i-3).x;
                    y=(1-t)*points.get(i).y + t * points.get(i-3).y;    
                    points.add(  new Point( (int) x, (int) y)  );       
                    i++;
                }



                counter++;

            }//while
        //counter=0;
        //i=0;
        x=0;
        y=0;

        }//metode

        //Paint-method
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g;

            g2d.setColor(Color.RED);
            for (int i = 0; i < points.size()-1; i++) {
                g2d.drawLine(points.get(i).x, points.get(i).y, points.get(i+1).x, points.get(i+1).y);
            }

           g2d.dispose();
        }   
    }
}

Answer 1

你必须分开你的方块的点，例如创建一个具有四个点的类Square和一个在Graphics2d中绘制该正方形的方法。你是如何做到的，无论它是否属于同一个方块，每一点都与它的继承者有关。

public class Square {
    private final Point v1;
    private final Point v2;
    private final Point v3;
    private final Point v4;

    public Square(Point v1, Point v2, Point v3, Point v4) {
        this.v1 = v1;
        this.v2 = v2;
        this.v3 = v3;
        this.v4 = v4;
    }

    public void paint(Graphics2D g) {
        g.setColor(Color.RED);
        g.drawLine(v1.x, v1.y, v2.x, v2.y);
        g.drawLine(v2.x, v2.y, v3.x, v3.y);
        g.drawLine(v3.x, v3.y, v4.x, v4.y);
        g.drawLine(v4.x, v4.y, v1.x, v1.y);
    }

    public void nextSquare() {
        int x1=(1-t)*v1.x + t * v2.x;
        int y1=(1-t)*v1.y + t * v2.y;

        int x2=(1-t)*v2.x + t * v3.x;
        int y2=(1-t)*v2.y + t * v3.y;

        int x3=(1-t)*v3.x + t * v4.x;
        int y3=(1-t)*v3.y + t * v4.y;

        int x4=(1-t)*v4.x + t * v1.x;
        int y4=(1-t)*v4.y + t * v1.y;

        return new Square(
            new Point(x1, y1),
            new Point(x2, y2),
            new Point(x3, y3),
            new Point(x4, y4));
     }
 }

创建正方形：

List<Square> squares = new ArrayList<>();
Point p  = new Point((int)(x),      (int) (y)           );
Point p1 = new Point((int)(x+side), (int)(y)            );
Point p2 = new Point((int)(x+side), (int) (y-side)      );
Point p3 = new Point((int)(x),      (int)(y-side)       );
Square s = new Square(p, p1, p2, p3);

squares.add(s);
for (int i = 1; i < 20; i++) {
    s = s.nextSquare();
    squares.add(s);
}

代码不是100％，因为我在我的手机上输入了这个...

Paint-method，假设square是一个实例变量：

//Paint-method
protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    Graphics2D g2d = (Graphics2D) g;
    for (Square s : squares) {
        s.paint(g2d);
    }
    g2d.dispose(); 
}

我该怎么办才能让程序从最后一点开始画出来？

1 个答案: