使用java实现的Bezier曲线

package report4; import javax.swing.*; import java.awt.*; import java.awt.geom.*; import java.awt.event.*; import java.util.ArrayList; import java.util.Random; class BezierPanel extends JComponent { private static int SIZE = 10; private int current; private static Random generator = new Random(); private Point2D[] points; public BezierPanel() { //initPoints(4); Point2D p1= new Point2D.Double(100,200); Point2D p2= new Point2D.Double(150,100); Point2D p3= new Point2D.Double(200,100); Point2D p4= new Point2D.Double(250,200); points = new Point2D[]{p1,p2,p3,p4}; addMouseListener(new MouseAdapter() { public void mousePressed(MouseEvent event) { Point2D p =event.getPoint(); for(int i = 0; i < points.length; i++) { double x = points[i].getX() - SIZE/2; double y = points[i].getY() - SIZE/2; Rectangle2D r = new Rectangle2D.Double(x, y, SIZE, SIZE); if(r.contains(p)) { current = i; return; } } } public void mouseReleased(MouseEvent event) { current = -1; } }); addMouseMotionListener(new MouseMotionAdapter() { public void mouseDragged(MouseEvent event) { if(current == -1) return; points[current] = event.getPoint(); repaint(); } }); current = -1; } public void initPoints(int num) { points = new Point2D[num]; for(int i = 0; i < points.length; i++) { double x = generator.nextDouble()*600; double y = generator.nextDouble()*600; points[i] = new Point2D.Double(x, y); } } public Point2D cubicBezier(double t, Point2D[] p) { Point2D[] temp = new Point2D[p.length]; for(int k=0; k < p.length; k++) temp[k]=p[k]; for(int i=0; i< 3; i++) { for(int j = 0; j < 4-i-1 ; j++) { double x = (1-t)*temp[j].getX() + t*temp[j+1].getX(); double y = (1-t)*temp[j].getY()+ t*temp[j+1].getY(); temp[j] = new Point2D.Double(x,y); } } return temp[0]; } public void drawBezier(Graphics g, Point2D[] p) { for(double t = 0; t < 1; t+=0.002) { Point2D p1= cubicBezier(t,p); Point2D p2 = cubicBezier(t+0.001,p); g.drawLine((int)p1.getX(),(int)p1.getY(),(int)p2.getX(),(int)p2.getY()); } } public void paintComponent(Graphics g) { if(points == null) return; Graphics2D g2 = (Graphics2D) g; for(int i = 0; i < points.length; i++) { double x = points[i].getX() - SIZE/2; double y = points[i].getY() - SIZE/2; g2.fill(new Rectangle2D.Double(x, y, SIZE, SIZE)); } drawBezier(g,points); } }