시소당

Move the curve control point and redraw the curve

import  java.awt.BorderLayout;
import  java.awt.Color;
import  java.awt.Graphics;
import  java.awt.Graphics2D;
import  java.awt.event.MouseEvent;
import  java.awt.geom.CubicCurve2D;
import  java.awt.geom.Ellipse2D;
import  java.awt.geom.Line2D;
import  java.awt.geom.Point2D;
import  java.awt.geom.QuadCurve2D;

import  javax.swing.JComponent;
import  javax.swing.JFrame;
import  javax.swing.JPanel;
import  javax.swing.event.MouseInputAdapter;

public  class  MainClass  {
    public  static  void  main(String[]  args){
        JFrame  frame  =  new  JFrame();
        frame.getContentPane().add(new  CurveApplet());

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(200,  200);
        frame.setVisible(true);
    }
}

class  CurveApplet  extends  JPanel  {
    public  CurveApplet()  {
        super(new  BorderLayout());
        pane  =  new  CurvePane();
        add(pane,"Center");

        MouseHandler  handler  =  new  MouseHandler();
        pane.addMouseListener(handler);
        pane.addMouseMotionListener(handler);
    }

    class  CurvePane  extends  JComponent  {
        public  CurvePane()  {
            quadCurve  =  new  QuadCurve2D.Double(  
                    startQ.x,  startQ.y,  
                    control.x,  control.y,
                    endQ.x,  endQ.y);

            cubicCurve  =  new  CubicCurve2D.Double(
                    startC.x,  startC.y,  
                    controlStart.x,  controlStart.y,
                    controlEnd.x,  controlEnd.y,
                    endC.x,  endC.y);
        }

        public  void  paint(Graphics  g)  {
            Graphics2D  g2D  =  (Graphics2D)  g;
            quadCurve.ctrlx  =  ctrlQuad.getCenter().x;
            quadCurve.ctrly  =  ctrlQuad.getCenter().y;
            cubicCurve.ctrlx1  =  ctrlCubic1.getCenter().x;
            cubicCurve.ctrly1  =  ctrlCubic1.getCenter().y;
            cubicCurve.ctrlx2  =  ctrlCubic2.getCenter().x;
            cubicCurve.ctrly2  =  ctrlCubic2.getCenter().y;

            g2D.setPaint(Color.BLUE);
            g2D.draw(quadCurve);
            g2D.draw(cubicCurve);

            g2D.setPaint(Color.RED);
            ctrlQuad.draw(g2D);
            ctrlCubic1.draw(g2D);
            ctrlCubic2.draw(g2D);

            Line2D.Double  tangent  =  new  Line2D.Double(startQ,  ctrlQuad.getCenter());
            g2D.draw(tangent);
            tangent  =  new  Line2D.Double(endQ,  ctrlQuad.getCenter());
            g2D.draw(tangent);

            tangent  =  new  Line2D.Double(startC,  ctrlCubic1.getCenter());
            g2D.draw(tangent);
            tangent  =  new  Line2D.Double(endC,  ctrlCubic2.getCenter());
            g2D.draw(tangent);

        }
    }

  
    Point2D.Double  startQ  =  new  Point2D.Double(50,  75);

    Point2D.Double  endQ  =  new  Point2D.Double(150,  75);

    Point2D.Double  control  =  new  Point2D.Double(80,  25);  

    Point2D.Double  startC  =  new  Point2D.Double(50,  150);  

    Point2D.Double  endC  =  new  Point2D.Double(150,  150);  

    Point2D.Double  controlStart  =  new  Point2D.Double(80,  100);

    Point2D.Double  controlEnd  =  new  Point2D.Double(160,  100);  

    Marker  ctrlQuad  =  new  Marker(control);

    Marker  ctrlCubic1  =  new  Marker(controlStart);

    Marker  ctrlCubic2  =  new  Marker(controlEnd);

    QuadCurve2D.Double  quadCurve;  

    CubicCurve2D.Double  cubicCurve;  

    CurvePane  pane  =  new  CurvePane();

    class  Marker  {
        public  Marker(Point2D.Double  control)  {
            center  =  control;  
            circle  =  new  Ellipse2D.Double(control.x  -  radius,  control.y  -  radius,  2.0  *  radius,
                    2.0  *  radius);
        }
        public  void  draw(Graphics2D  g2D)  {
            g2D.draw(circle);
        }

        Point2D.Double  getCenter()  {
            return  center;
        }
        public  boolean  contains(double  x,  double  y)  {
            return  circle.contains(x,  y);
        }
        public  void  setLocation(double  x,  double  y)  {
            center.x  =  x;  
            center.y  =  y;  
            circle.x  =  x  -  radius;  
            circle.y  =  y  -  radius;  
        }

        Ellipse2D.Double  circle;  

        Point2D.Double  center;  

        static  final  double  radius  =  3;
    }

    class  MouseHandler  extends  MouseInputAdapter  {
        public  void  mousePressed(MouseEvent  e)  {
            if  (ctrlQuad.contains(e.getX(),  e.getY()))
                selected  =  ctrlQuad;
            else  if  (ctrlCubic1.contains(e.getX(),  e.getY()))
                selected  =  ctrlCubic1;
            else  if  (ctrlCubic2.contains(e.getX(),  e.getY()))
                selected  =  ctrlCubic2;
        }
        public  void  mouseReleased(MouseEvent  e)  {
            selected  =  null;
        }
        public  void  mouseDragged(MouseEvent  e)  {
            if  (selected  !=  null)  {
                selected.setLocation(e.getX(),  e.getY());
                pane.repaint();  
            }
        }
        Marker  selected  =  null;
    }
}
[2008년  03월  13일  21:06:28  수정되었습니다.]