Question

每当我画画，然后打开反射，然后绘制一切似乎很好，但然后我关闭反射，我现在绘制的点不会出现在我的鼠标光标下。奇怪的是，有时它工作正常，在我打开和关闭反射几次并绘制之后，就会发生错误。我不知道背后的原因是什么。这是代码，如果你能帮助我，我将非常感激。

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentEvent;
import java.awt.event.ComponentListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import java.util.Iterator;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

//3 inner classes because if this code is part of a bigger problem, these classes will not be used anywhere else and need to be encapsulated
public class CWTEST extends JFrame{

    public CWTEST(String title){
        super(title);
    }

    public void initialiseGUI(){
        Container mainPanel = this.getContentPane();
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
        //make the window as big as the screen without covering the windows taskbar
        this.setBounds( 0, 0, screenSize.width, screenSize.height-40);

        //set up the displayPanel where the drawing is done 
        mainPanel.setLayout(new BorderLayout());
        DrawingPanel displayPanel = new DrawingPanel();
        mainPanel.add(displayPanel, BorderLayout.CENTER);

        //set up the controlPanel where the user changes the drawing options
        JPanel controlPanel = new JPanel();
        mainPanel.add(controlPanel, BorderLayout.SOUTH);
        controlPanel.setLayout(new FlowLayout());                                                                                                                           
        controlPanel.setBorder(BorderFactory.createLineBorder(new java.awt.Color(0, 255, 0)));


        JLabel reflectPointsLabel = new JLabel("reflect points");
        controlPanel.add(reflectPointsLabel);

        JCheckBox reflectPointsBox = new JCheckBox();
        reflectPointsBox.addItemListener(new ItemListener(){
            @Override
            public void itemStateChanged(ItemEvent e) {
                if (e.getStateChange() == ItemEvent.SELECTED){
                    displayPanel.reflectPoints = true;
                }else{
                    displayPanel.reflectPoints = false;
                }
            }
        });
        controlPanel.add(reflectPointsBox);
        reflectPointsBox.setSelected(false);



        this.setVisible(true);

        //once the frame is visible we can get the real size of the drawing panel and create a buffered image that matches it
        displayPanel.buffImage = new BufferedImage(displayPanel.getWidth(), displayPanel.getHeight(), BufferedImage.TYPE_3BYTE_BGR);                          
    }




    public class DrawingPanel extends JPanel{
        //default drawing options                                                                                               
        private double circleDiameter = 5; 
        private Color color = Color.BLUE;                                   
        private boolean showSectors;                                        
        private boolean reflectPoints;
        private int numOfSectors = 12;
        //list of points to be drawn
        private ArrayList<MyPoint> pointsList;
        //buffered image on which the drawing is done and then copied to the JPanel
        private BufferedImage buffImage;        

        public DrawingPanel(){
            this.setBackground(Color.BLACK);
            DrawingListener listener = new DrawingListener(this);
            this.addMouseListener(listener);
            this.addMouseMotionListener(listener);
            this.addComponentListener(listener);
            pointsList = new ArrayList<MyPoint>();                          
        }           

        public void paintComponent(Graphics g){
            super.paintComponent(g);
            this.drawBuffImage();
            //copy what's drawn on the buffered image to the JPanel
            g.drawImage(buffImage, 0,0, null);
        }

        public void drawBuffImage(){                                                                                                                                                                                               
            Graphics2D g2d = buffImage.createGraphics();
            g2d.setColor(Color.WHITE);

            //if there are more tan 1 sectors - draw lines to separate them
            if(showSectors && numOfSectors > 1){
                Line2D line = new Line2D.Double(this.getWidth()/2,0,this.getWidth()/2,this.getHeight()/2);

                //draw half a line every time and rotate the next according to the number of sectors
                for(int w = 0; w < numOfSectors; w++){
                    g2d.draw(line);
                    g2d.rotate(Math.toRadians((double) 360/numOfSectors), this.getWidth()/2, this.getHeight()/2);
                }
            }

            //draw each point in the list
            for(int i = 0; i < pointsList.size(); i++){
                MyPoint point = pointsList.get(i);
                g2d.setColor(point.getPointColor());

                Ellipse2D circle = new Ellipse2D.Double(point.getX(), point.getY(), point.getPointDiameter(), point.getPointDiameter());            

                //draw the point once in each sector
                for(int j = 0; j < numOfSectors; j++){                          
                    g2d.fill(circle);
                    g2d.rotate(Math.toRadians(((double) 360/numOfSectors)), this.getWidth()/2, this.getHeight()/2);                                                                
                }                                                                                          

                //if point should be reflected, draw its reflection in each sector
                if(point.isReflected()){
                    g2d.rotate(Math.toRadians((double) 360/(numOfSectors*2)), this.getWidth()/2, this.getHeight()/2);
                    g2d.fill(circle);

                    for(int t = 1; t < numOfSectors; t++){
                        g2d.rotate(Math.toRadians((double) 360/numOfSectors), this.getWidth()/2, this.getHeight()/2);
                        g2d.fill(circle);                                                                                                       
                    }
                }
            }

            g2d.dispose();
        }

        public void wipeScreen(){
            //wipe everything by covering it with black
            Graphics g = buffImage.createGraphics();   
            g.setColor(Color.BLACK);
            g.fillRect(0,0,buffImage.getWidth(),buffImage.getHeight());
            g.dispose();
        }

        public void addPoint(MyPoint p){
            pointsList.add(p);
        }

        public void setColor(Color color){
            this.color = color;
        }

        public void setCircleDiameter(double circleDiameter){
            this.circleDiameter = circleDiameter;
        }
    }

    public class DrawingListener extends MouseAdapter implements ComponentListener{   
        //the panel on which the user draws
        private DrawingPanel dPanel;

        public DrawingListener(DrawingPanel dPanel){
            this.dPanel = dPanel;
        }

        //add a point to the arraylist every time the user draws, and draw
        public void mousePressed(MouseEvent e) {
            dPanel.addPoint(new MyPoint(e.getX(), e.getY(), dPanel.color, dPanel.circleDiameter, dPanel.reflectPoints));
            dPanel.repaint();
        }

        public void mouseDragged(MouseEvent e) {
            dPanel.addPoint(new MyPoint(e.getX(), e.getY(), dPanel.color, dPanel.circleDiameter, dPanel.reflectPoints));
            dPanel.repaint();
        }

        @Override
        public void componentResized(ComponentEvent e) {
            //whenever component is resized, wipe the screen
            //then the system-triggered repaint occurs and the result is that by making the window smaller, the user zooms in 
            dPanel.wipeScreen();
        }

        public void componentHidden(ComponentEvent arg0) {}
        public void componentMoved(ComponentEvent arg0) {}
        public void componentShown(ComponentEvent arg0) {}
    }


    //each point drawn is an object of the class
    public class MyPoint extends Point{
        private Color pointColor;
        private double pointDiameter;
        private boolean reflected;

        public MyPoint(int x, int y, Color c, double pointDiameter, boolean reflected){
            super(x,y);
            this.pointColor = c;
            this.pointDiameter = pointDiameter;
            this.reflected = reflected;
        }

        public Color getPointColor(){
            return this.pointColor;
        }

        public double getPointDiameter(){
            return this.pointDiameter;
        }

        public boolean isReflected(){
            return this.reflected;
        }
    }

}

public class MainTest {

    public static void main(String[] args){
        CWTEST frame = new CWTEST("Digital Doily");  
        frame.initialiseGUI();  
    }
}

修改

当勾选方框时，我得到12分 - 最内圈。然后我勾选框，我得到24分（12个原始和12个反射） - 第二个圆（带反射）。然后我解开盒子，我得到最外面的圆圈--12点，但它们被绘制在前一个圆圈的12个反射点的位置，尽管我的鼠标在第一个圆圈的同一个地方。绿点是反射点的一个例子 - 它在2个法线点之间。红点是我的鼠标光标在每个绘图处的位置。请注意，当我创建第三个圆时，反射被关闭，并且光标下没有绘制点。

Answer 1

我不知道偶尔出错的原因，但似乎使用AffineTransform#getRotateInstance(...)#createTransformedShape(...)代替Graphics2D#rotate(...)会正常绘制。

import java.awt.*;
import java.awt.event.*;
import java.awt.font.*;
import java.awt.geom.*;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import java.util.Iterator;
import javax.swing.*;

public class MainTest2 {
  public static void main(String[] args) {
    CWTEST frame = new CWTEST("Digital Doily");
    frame.initialiseGUI();
  }
}

class CWTEST extends JFrame {

  public CWTEST(String title) {
    super(title);
  }

  public void initialiseGUI() {
    Container mainPanel = this.getContentPane();
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
    //make the window as big as the screen without covering the windows taskbar
    this.setBounds(0, 0, screenSize.width, screenSize.height - 40);

    //set up the displayPanel where the drawing is done
    mainPanel.setLayout(new BorderLayout());
    DrawingPanel displayPanel = new DrawingPanel();
    mainPanel.add(displayPanel, BorderLayout.CENTER);

    //set up the controlPanel where the user changes the drawing options
    JPanel controlPanel = new JPanel();
    mainPanel.add(controlPanel, BorderLayout.SOUTH);
    controlPanel.setLayout(new FlowLayout());
    controlPanel.setBorder(BorderFactory.createLineBorder(new java.awt.Color(0, 255, 0)));


    JLabel reflectPointsLabel = new JLabel("reflect points");
    controlPanel.add(reflectPointsLabel);

    JCheckBox reflectPointsBox = new JCheckBox();
    reflectPointsBox.addItemListener(new ItemListener() {
      @Override
      public void itemStateChanged(ItemEvent e) {
        if (e.getStateChange() == ItemEvent.SELECTED) {
          displayPanel.reflectPoints = true;
        } else {
          displayPanel.reflectPoints = false;
        }
      }
    });
    controlPanel.add(reflectPointsBox);
    reflectPointsBox.setSelected(false);



    this.setVisible(true);

    //once the frame is visible we can get the real size of the drawing panel and create a buffered image that matches it
    displayPanel.buffImage = new BufferedImage(
        displayPanel.getWidth(), displayPanel.getHeight(), BufferedImage.TYPE_3BYTE_BGR);
  }




  public class DrawingPanel extends JPanel {
    //default drawing options
    private double circleDiameter = 5;
    private Color color = Color.BLUE;
    private boolean showSectors;
    private boolean reflectPoints;
    private int numOfSectors = 12;
    //list of points to be drawn
    private ArrayList<MyPoint> pointsList;
    //buffered image on which the drawing is done and then copied to the JPanel
    private BufferedImage buffImage;

    public DrawingPanel() {
      this.setBackground(Color.BLACK);
      DrawingListener listener = new DrawingListener(this);
      this.addMouseListener(listener);
      this.addMouseMotionListener(listener);
      this.addComponentListener(listener);
      pointsList = new ArrayList<MyPoint>();
    }

    public void paintComponent(Graphics g) {
      super.paintComponent(g);
      this.drawBuffImage();
      //copy what's drawn on the buffered image to the JPanel
      g.drawImage(buffImage, 0, 0, null);
    }

    public void drawBuffImage() {
      Graphics2D g2d = buffImage.createGraphics();
      g2d.setColor(Color.WHITE);

////if there are more tan 1 sectors - draw lines to separate them
//if (showSectors && numOfSectors > 1) {
//    Line2D line = new Line2D.Double(this.getWidth() / 2, 0, this.getWidth() / 2, this.getHeight() / 2);
//
//    //draw half a line every time and rotate the next according to the number of sectors
//    for (int w = 0; w < numOfSectors; w++) {
//        g2d.draw(line);
//        g2d.rotate(Math.toRadians((double) 360 / numOfSectors), this.getWidth() / 2, this.getHeight() / 2);
//    }
//    g2d.rotate(0d);
//}

      double angle = 360d / numOfSectors;
      double ancx  = this.getWidth() / 2d;
      double ancy  = this.getHeight() / 2d;

      //draw each point in the list
      for (int i = 0; i < pointsList.size(); i++) {
        MyPoint point = pointsList.get(i);
        g2d.setColor(point.getPointColor());

        Ellipse2D circle = new Ellipse2D.Double(
            point.getX(), point.getY(), point.getPointDiameter(), point.getPointDiameter());

        //draw the point once in each sector
        double rotate = 0d;
        for (int j = 0; j < numOfSectors; j++) {
          rotate += angle;
          AffineTransform at = AffineTransform.getRotateInstance(Math.toRadians(rotate), ancx, ancy);
          g2d.fill(at.createTransformedShape(circle));
          //g2d.rotate(Math.toRadians(((double) 360 / numOfSectors)), this.getWidth() / 2, this.getHeight() / 2);
        }

        //if point should be reflected, draw its reflection in each sector
        if (point.isReflected()) {
          //g2d.rotate(Math.toRadians((double) 360 / (numOfSectors * 2)), this.getWidth() / 2, this.getHeight() / 2);
          //g2d.fill(circle);
          rotate = angle / 2d;
          g2d.setColor(Color.RED);
          for (int t = 0; t < numOfSectors; t++) {
            //g2d.rotate(Math.toRadians((double) 360 / numOfSectors), this.getWidth() / 2, this.getHeight() / 2);
            //g2d.fill(circle);
            rotate += angle;
            AffineTransform at = AffineTransform.getRotateInstance(Math.toRadians(rotate), ancx, ancy);
            g2d.fill(at.createTransformedShape(circle));
          }
        }
      }
      g2d.dispose();
    }

    public void wipeScreen() {
      //wipe everything by covering it with black
      if (buffImage != null) {
        Graphics g = buffImage.createGraphics();
        g.setColor(Color.BLACK);
        g.fillRect(0, 0, buffImage.getWidth(), buffImage.getHeight());
        g.dispose();
      }
    }

    public void addPoint(MyPoint p) {
      pointsList.add(p);
    }

    public void setColor(Color color) {
      this.color = color;
    }

    public void setCircleDiameter(double circleDiameter) {
      this.circleDiameter = circleDiameter;
    }
  }

  public class DrawingListener extends MouseAdapter implements ComponentListener {
    //the panel on which the user draws
    private final DrawingPanel dPanel;

    public DrawingListener(DrawingPanel dPanel) {
      this.dPanel = dPanel;
    }

    //add a point to the arraylist every time the user draws, and draw
    public void mousePressed(MouseEvent e) {
      //System.out.println(e.getPoint());
      dPanel.addPoint(new MyPoint(e.getX(), e.getY(), dPanel.color, dPanel.circleDiameter, dPanel.reflectPoints));
      dPanel.repaint();
    }

    public void mouseDragged(MouseEvent e) {
      dPanel.addPoint(new MyPoint(e.getX(), e.getY(), dPanel.color, dPanel.circleDiameter, dPanel.reflectPoints));
      dPanel.repaint();
    }

    @Override
    public void componentResized(ComponentEvent e) {
      //whenever component is resized, wipe the screen
      //then the system-triggered repaint occurs and the result is that by making the window smaller, the user zooms in
      dPanel.wipeScreen();
    }

    public void componentHidden(ComponentEvent arg0) {}
    public void componentMoved(ComponentEvent arg0) {}
    public void componentShown(ComponentEvent arg0) {}
  }


  //each point drawn is an object of the class
  public class MyPoint extends Point {
    private Color pointColor;
    private double pointDiameter;
    private boolean reflected;

    public MyPoint(int x, int y, Color c, double pointDiameter, boolean reflected) {
      super(x, y);
      this.pointColor = c;
      this.pointDiameter = pointDiameter;
      this.reflected = reflected;
    }

    public Color getPointColor() {
      return this.pointColor;
    }

    public double getPointDiameter() {
      return this.pointDiameter;
    }

    public boolean isReflected() {
      return this.reflected;
    }
  }
}

在错误的地方绘制点

1 个答案: