如何检测java中的形状交集?

时间:2015-02-17 19:01:01

标签: java intersection shapes line-intersection

我想知道如何让java检测椭圆是否链接到一条线或一个矩形,程序还应检测它所链接的形状。

绘制椭圆,绘制线条和矩形。 Java必须检测是否存在与椭圆相关联的内容,如果是,则通过该行查找链接到它的内容。

enter image description here

这是我绘制形状的代码。



import java.awt.AlphaComposite;
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Scanner;

import javax.imageio.ImageIO;
import javax.swing.Box;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JColorChooser;
import javax.swing.JComponent;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JSeparator;
import javax.swing.JSlider;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.filechooser.FileNameExtensionFilter;

public class Lesson49_1 extends JFrame {

    private static final long serialVersionUID = -140274271716086522L;

    JMenuBar menubar;
    JMenu File, Exit;
    JMenuItem New, Open;
    JComponent DrawingBoard;

    JButton  lineBut, ellipseBut, rectBut, strokeBut;

    DecimalFormat dec = new DecimalFormat("#.##");

    // Contains all of the rules for drawing

    Graphics2D graphSettings;

   
    // Going to be used to monitor what shape to draw next

    int currentAction = 1;

    // Transparency of the shape

    // Default stroke and fill colors

    Color strokeColor = Color.BLACK;

    public static void main(String[] args) {
        new Lesson49_1();
    }

    public Lesson49_1() {
        // Define the defaults for the JFrame

        this.setSize(800, 600);
        this.setTitle("ERD BUILDER");
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setJMenuBar(menubar);

        JMenuBar menuBar = new JMenuBar();

        // Add the menubar to the frame
        setJMenuBar(menuBar);

        // Define and add two drop down menu to the menubar
        JMenu fileMenu = new JMenu("File");
        JMenu editMenu = new JMenu("Edit");
        JMenu dbMenu = new JMenu("Database");
        JMenu ToolsMenu = new JMenu("Tools");
        JMenu HelpMenu = new JMenu("Help");
        menuBar.add(fileMenu);
        menuBar.add(editMenu);
        menuBar.add(dbMenu);
        menuBar.add(ToolsMenu);
        menuBar.add(HelpMenu);
        // Create and add simple menu item to one of the drop down menu
        JMenuItem newAction = new JMenuItem("New Project");
        JMenuItem openAction = new JMenuItem("Open File");
        JMenuItem exitAction = new JMenuItem("Quit");
        JMenuItem cutAction = new JMenuItem("Cut");
        JMenuItem copyAction = new JMenuItem("Copy");
        JMenuItem pasteAction = new JMenuItem("Paste");
        JMenuItem UndoAction = new JMenuItem("Undo");
        JMenuItem RedoAction = new JMenuItem("Redo");
        JMenuItem clearAction = new JMenuItem("Clear");
        JMenuItem saveAction = new JMenuItem("Save");
        JMenuItem exportAction = new JMenuItem("Export");
        JMenuItem printAction = new JMenuItem("Print");
        JMenuItem ConvertAction = new JMenuItem("Convert To Tables");
        JMenuItem ColorAction = new JMenuItem("Color Picker");
        JMenuItem ZoomAction = new JMenuItem("Zoom");
        JMenuItem EntityAction = new JMenuItem("Entity & Attributes");
        JMenuItem RelationshipAction = new JMenuItem("Relationship Attributes");
        JMenuItem HelpAction = new JMenuItem("Help");
        JMenuItem AboutAction = new JMenuItem("About");

        fileMenu.add(newAction);
        fileMenu.addSeparator();
        fileMenu.add(openAction);
        fileMenu.addSeparator();
        fileMenu.add(saveAction);
        fileMenu.addSeparator();
        fileMenu.add(exportAction);
        fileMenu.addSeparator();
        fileMenu.add(printAction);
        fileMenu.addSeparator();
        fileMenu.add(exitAction);

        editMenu.add(UndoAction);
        editMenu.addSeparator();
        editMenu.add(RedoAction);
        editMenu.addSeparator();
        editMenu.add(cutAction);
        editMenu.addSeparator();
        editMenu.add(copyAction);
        editMenu.addSeparator();
        editMenu.add(pasteAction);
        editMenu.addSeparator();
        editMenu.add(clearAction);

        dbMenu.add(ConvertAction);

        ToolsMenu.add(ColorAction);
        ToolsMenu.addSeparator();
        ToolsMenu.add(ZoomAction);
        ToolsMenu.addSeparator();
        ToolsMenu.add(EntityAction);
        ToolsMenu.addSeparator();
        ToolsMenu.add(RelationshipAction);

        HelpMenu.add(HelpAction);
        HelpMenu.addSeparator();
        HelpMenu.add(AboutAction);
        
        
        exitAction.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
               
        }}
        );
        
        
        
        
        
        
        ConvertAction.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                
               new ConvertForm().setVisible(true);
                
                
               
        }}
        );
        
        
        

        newAction.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {

                new Lesson49_1().setVisible(true);
            }
        });
        
        

        JPanel buttonPanel = new JPanel();
       
        JPanel FieldPanel = new JPanel();

        // Swing box that will hold all the buttons

        Box theBox = Box.createVerticalBox();
        Box theBoxs = Box.createVerticalBox();

        // Make all the buttons in makeMeButtons by passing the
        // button icon.

        
        lineBut = makeMeButtons("./src/line.png", 2);
        ellipseBut = makeMeButtons("./src/ellipse.png", 3);
        rectBut = makeMeButtons("./src/rectangle.png", 4);

        // Make all the buttons in makeMeColorButton by passing the
        // button icon and true for stroke color or false for fill

        strokeBut = makeMeColorButton("./src/stroke.png", 5, true);


        // Add the fields to the boxs

        

        //theBox.add(brushBut);
        theBox.add(lineBut);
        theBox.add(ellipseBut);
        theBox.add(rectBut);
        theBox.add(strokeBut);
       
        buttonPanel.add(theBox);
        FieldPanel.add(theBoxs);
        

        this.add(buttonPanel, BorderLayout.WEST);
        this.add(FieldPanel, BorderLayout.EAST);
        buttonPanel.setPreferredSize(new Dimension(200,480));        
        FieldPanel.setPreferredSize(new Dimension(200,480));
        // Make the drawing area take up the rest of the frame

        // this.add(new DrawingBoard(), BorderLayout.CENTER);
        final DrawingBoard drawPanel = new DrawingBoard();
        this.add(drawPanel, BorderLayout.CENTER);
        this.getContentPane().setBackground(Color.WHITE);

        
        
        
        
        
        exportAction.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent arg0) {
                BufferedImage image = new BufferedImage(drawPanel.getWidth(),
                        drawPanel.getHeight(), BufferedImage.TYPE_INT_ARGB);
                Graphics2D g = image.createGraphics();
                drawPanel.paint(g);
                g.dispose();

                JFileChooser fileChooser = new JFileChooser();
                File theDirectory = new File("C:/Users/Wenda/Desktop");
                fileChooser.setCurrentDirectory(theDirectory);
                FileNameExtensionFilter pngFilter = new FileNameExtensionFilter(
                        "PNG file (*.png)", "png");
                fileChooser.addChoosableFileFilter(pngFilter);
                fileChooser.setFileFilter(pngFilter);

                int status = fileChooser.showSaveDialog(Lesson49_1.this);

                if (status == JFileChooser.APPROVE_OPTION) {
                    try {
                        ImageIO.write(image, "png",
                                fileChooser.getSelectedFile());
                        JOptionPane.showMessageDialog(null, "Image saved to "
                                + fileChooser.getSelectedFile().getName());
                    } catch (Exception ex) {
                        ex.printStackTrace();
                    }
                }
            }
        });
        // Show the frame
        this.setVisible(true);
    }

    public JButton makeMeButtons(String iconFile, final int actionNum) {
        JButton theBut = new JButton();
        Icon butIcon = new ImageIcon(iconFile);
        theBut.setIcon(butIcon);

         theBut.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {
                currentAction = actionNum;
            }
        });
        return theBut;
    }

    // Spits out buttons based on the image supplied and
    // whether a stroke or fill is to be defined

    public JButton makeMeColorButton(String iconFile, final int actionNum,
            final boolean stroke) {
        JButton theBut = new JButton();
        Icon butIcon = new ImageIcon(iconFile);
        theBut.setIcon(butIcon);

        theBut.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {

                if (stroke) {

                    // JColorChooser is a popup that lets you pick a color

                    strokeColor = JColorChooser.showDialog(null,
                            "Pick a Stroke", Color.BLACK);
                } else {
                                    }
            }
        });

        return theBut;
    }
    public class DrawingBoard extends JComponent {

        private static final long serialVersionUID = -4431176095451940075L;

        // ArrayLists that contain each shape drawn along with
        // that shapes stroke and fill
        ArrayList<Shape> shapes = new ArrayList<Shape>();
        ArrayList<Color> shapeStroke = new ArrayList<Color>();
        
        Point drawStart, drawEnd;
        // Monitors events on the drawing area of the frame

        public DrawingBoard() {

            this.addMouseListener(new MouseAdapter() {

                public void mousePressed(MouseEvent e) {

                    if (currentAction != 1) {

                        // When the mouse is pressed get x & y position

                        drawStart = new Point(e.getX(), e.getY());
                        drawEnd = drawStart;
                        repaint();
                    }
                }
            
                public void mouseReleased(MouseEvent e) {

                    if (currentAction != 1) {
                        Shape aShape = null;
                        
                        if (currentAction == 2) {
                            aShape = drawLine(drawStart.x, drawStart.y,
                            e.getX(), e.getY());
                            shapes.add(aShape);
                            shapeStroke.add(strokeColor);
                            drawStart = null;
                            drawEnd = null;
                            repaint();
                        } else

                        if (currentAction == 3) {
                            aShape = drawEllipse(drawStart.x, drawStart.y,
                             e.getX(), e.getY());
                            shapes.add(aShape);
                            shapeStroke.add(strokeColor);
                            drawStart = null;
                            drawEnd = null;
                            repaint();
                            new AttributeForm().setVisible(true);
                        } else

                        if (currentAction == 4) {

                            // Create a new rectangle using x & y coordinates

                            aShape = drawRectangle(drawStart.x, drawStart.y,
                            e.getX(), e.getY());
                            shapes.add(aShape);
                            shapeStroke.add(strokeColor);
                            drawStart = null;
                            drawEnd = null;
                            repaint();
                            new EntityForm().setVisible(true);
                        }

                        // Add shapes, fills and colors to there ArrayLists

                                              

                    }

                }
            });
            
              this.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent me) {
                JTextField name = new JTextField(15);
                super.mouseClicked(me);
                for (Shape s : shapes) {

                    if (s.contains(me.getPoint())) {//check if mouse is clicked within shape

                        //we can either just print out the object class name
                        System.out.println("Clicked a "+s.getClass().getName());

                        //or check the shape class we are dealing with using instance of with nested if
                        if (s instanceof Rectangle2D) {
                            
                            //create table  
                            
                        } 
                         else if (s instanceof Ellipse2D) {
                            
                           
                             
                            
                            
                            
                        }

                    }
                }
            }
        });

            this.addMouseMotionListener(new MouseMotionAdapter() {

                public void mouseDragged(MouseEvent e) {

                    // If this is a brush have shapes go on the screen quickly

                    if (currentAction == 1) {

                        int x = e.getX();
                        int y = e.getY();

                        Shape aShape = null;
                        shapes.add(aShape);

                        shapeStroke.add(strokeColor);

                        // Add the transparency value
                    }

                    // Get the final x & y position after the mouse is dragged

                    drawEnd = new Point(e.getX(), e.getY());
                    repaint();
                }
            });
        }

        public void paint(Graphics g) {
            // Class used to define the shapes to be drawn

            graphSettings = (Graphics2D) g;

            // Antialiasing cleans up the jagged lines and defines rendering
            // rules

            graphSettings.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                    RenderingHints.VALUE_ANTIALIAS_ON);

            // Defines the line width of the stroke

            graphSettings.setStroke(new BasicStroke(4));

            // Iterators created to cycle through strokes and fills
            Iterator<Color> strokeCounter = shapeStroke.iterator();
            for (Shape s : shapes) {
 
                // Grabs the next stroke from the color arraylist
                graphSettings.setPaint(strokeCounter.next());

                graphSettings.draw(s);

            }

            // Guide shape used for drawing
            if (drawStart != null && drawEnd != null) {
                // Makes the guide shape transparent

                graphSettings.setComposite(AlphaComposite.getInstance(
                        AlphaComposite.SRC_OVER, 0.40f));

                // Make guide shape gray for professional look

                graphSettings.setPaint(Color.LIGHT_GRAY);

                Shape aShape = null;

                if (currentAction == 2) {
                    aShape = drawLine(drawStart.x, drawStart.y, drawEnd.x,
                            drawEnd.y);
                } else

                if (currentAction == 3) {
                    aShape = drawEllipse(drawStart.x, drawStart.y, drawEnd.x,
                            drawEnd.y);
                } else

                if (currentAction == 4) {

                    // Create a new rectangle using x & y coordinates

                    aShape = drawRectangle(drawStart.x, drawStart.y, drawEnd.x,
                            drawEnd.y);
                }

                graphSettings.draw(aShape);
            }
        }

    
        private Rectangle2D.Float drawRectangle(int x1, int y1, int x2, int y2) {
            // Get the top left hand corner for the shape
            // Math.min returns the points closest to 0

            int x = Math.min(x1, x2);
            int y = Math.min(y1, y2);

            // Gets the difference between the coordinates and

            int width = Math.abs(x1 - x2);
            int height = Math.abs(y1 - y2);

            return new Rectangle2D.Float(x, y, width, height);
        }

           private Ellipse2D.Float drawEllipse(int x1, int y1, int x2, int y2) {
            int x = Math.min(x1, x2);
            int y = Math.min(y1, y2);
            int width = Math.abs(x1 - x2);
            int height = Math.abs(y1 - y2);

            return new Ellipse2D.Float(x, y, width, height);
        }

        private Line2D.Float drawLine(int x1, int y1, int x2, int y2) {

            return new Line2D.Float(x1, y1, x2, y2);
        }
           }
    
    }
    
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有人可以帮帮我吗?

1 个答案:

答案 0 :(得分:0)

有两种情况。

  1. 根据您所显示的内容,如果一条线与您的椭圆相关联,它似乎只链接在顶部的中心,或者它可能位于一侧的中心,我们可以看到,如果你的线与一个边的中心的椭圆相交,那么你可以将椭圆视为一个矩形。然后在java中你可以使用
    Rectangle yourLine = new Rectangle(line.x, line.y, line.width, line.height); Rectangle ellipse = new Rectangle(ellipse.upperLeft.x, ellipse.upperLeft.y, ellipse.width, ellipse.height); boolean isThereAnIntersection = yourLine.intersects(ellipse);

  2. 对于通用方法,在处理复杂形状时,您可以使用BufferedImage作为图形的缓冲区,然后在BufferedImage方法中显示paint(Graphics g)。通过使用此BufferedImage绘制椭圆和线条,您可以直接检查线条的边界是否将绘制在彩色像素或背景像素上,这意味着如果在彩色像素上绘制已经存在对象在该位置绘制,因此您最终必须根据其位置获取对象。