33. BEZIER CURVE

Code:

import java.awt.*;

import java.applet.*;

import java.awt.geom.GeneralPath;

import java.awt.image.BufferedImage;

public class KBezier extends Applet

{

            Point[] controlPoints,curvePoints;

            public void init()

            {

                        controlPoints=new Point[4];

                        curvePoints=new Point[25];

                        controlPoints[0]=new Point(20,260);

                        controlPoints[1]=new Point(50,10);

                        controlPoints[2]=new Point(250,50);

                        controlPoints[3]=new Point(450,290);

                        for(int i=0;i<curvePoints.length;i++)

                                    curvePoints[i]=new Point(0,0);

            }

            public void SubDivide(Point p1,Point p2,double t)

            {

                        if(p1.x>p2.x)

                                    p1.x-=Math.abs(p1.x-p2.x)*t;

                        else

                                    p1.x+=Math.abs(p1.x-p2.x)*t;

                        if (p1.y>p2.y)

                                    p1.y-=Math.abs(p1.y-p2.y)*t;

                        else

                                    p1.y+=Math.abs(p1.y-p2.y)*t;

            }

            public void Compute()

            {

                        Point[] tmp=new Point[controlPoints.length];

                        for (int i=0; i<tmp.length; i++)

                                    tmp[i] = new Point(0,0);

                        for (int i=0; i<curvePoints.length; i++)

                        {

                                    double t = ((double) i)/(curvePoints.length-1);

                                    for (int j=0; j<controlPoints.length; j++)

                                                tmp[j]=new Point(controlPoints[j].x, controlPoints[j].y);

                                    int Depth = tmp.length;

                                    while (Depth>1)

                                    {

                                                for (int j=0; j<Depth-1; j++)

                                                            SubDivide(tmp[j], tmp[j+1], t);

                                                Depth--;

                                    }

                                    curvePoints[i]=new Point(tmp[0].x, tmp[0].y);

                        }                      

            }

            public void Draw(Graphics2D g2d)

            {

                        g2d.setColor(Color.BLACK);

                        for (int i=0; i<controlPoints.length-1; i++)

                                    g2d.drawLine((int) controlPoints[i].x,(int) controlPoints[i].y,

                                                            (int) controlPoints[i+1].x,(int) controlPoints[i+1].y);

                        GeneralPath path = new GeneralPath();                           // Bezier curve

                        g2d.setColor(Color.RED);

                        path.moveTo(curvePoints[0].x, curvePoints[0].y);

                        for (int i=1; i<curvePoints.length; i++)

                                    path.lineTo(curvePoints[i].x, curvePoints[i].y);

                        g2d.draw(path);

            }

            public void paint(Graphics g)

            {

                        BufferedImage image = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_RGB);

                        Graphics2D g2d = image.createGraphics();

                        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

                        g2d.setColor(Color.WHITE);

                        g2d.fillRect(0, 0, getWidth(), getHeight());

                        Compute();

                        Draw(g2d);

                        g.drawImage(image, 0, 0, this);

            }

}

/*<applet code="KBezier.class" width=500 height=300></applet>*/

/*

OUTPUT:

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Download Link= https://www.dropbox.com/s/wtwti9tjitb01bx/KBezier.docx