// file CatmullRom.java
// Catmull-Rom Spline Demo.
// by Harriet Fell
// fell@ccs.neu.edu
// August 2004

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.*;
import java.awt.image.*;
import java.util.Random;

public class CatmullRom
	extends JComponent 
	implements MouseMotionListener, MouseListener, ActionListener  {
/*
void GetPoints(RPoint P[20], int& numpoints);
void GetPoint(RPoint &P, string name);
int dotsize = 5;
void Bezier(RPoint P, RPoint Q, RPoint R, RPoint S);
double ArchSize(RPoint P, RPoint Q, RPoint R, RPoint S);
bool InDrawWindow(Point T);
bool InDrawWindow(RPoint T);
double Distance(RPoint P, Point T);
const maxPoints = 20;
void MakeArch(RPoint Pts[], int numPoints, int p, RPoint& P, RPoint& Q, RPoint& R, RPoint& S);
*/
	// Control Points
	Point2D.Double [] controlPoints;
	int numCP;	// number of control points
	boolean getControlPoints;
	
	// Arch Points
	Point2D.Double P, Q, R, S;
	
	// dot size
	int dSize;
	// Mouse Points
	int mmX, mmY;  // last mouse moved point coordinates
	int mdX, mdY;  // last mouse dragged point coordinates
		
	// Current Attributes
	Color foreColor; 		// default color
	int   lineWidth = 1; 	// default line width
	
	public CatmullRom(){
		// Listen for mouse motion and clicks
		addMouseMotionListener(this);
		addMouseListener(this);


		// Set foreColor to black
		foreColor = new Color ( 0, 0, 0 );	
		
		// Set dot size
		dSize = 8;
		
		// Array to hold user input control points;
		controlPoints = new Point2D.Double[20];
		numCP = 0;
		
		getControlPoints = true;
		
	}
	
	Bez MakeArch(Point2D.Double [] controlPoints, int numCP, int p){
	Point2D.Double P = new Point2D.Double(controlPoints[p].x, controlPoints[p].y); 
	Point2D.Double S = new Point2D.Double(controlPoints[p+1].x, controlPoints[p+1].y);
	Point2D.Double Q = new Point2D.Double();
	Point2D.Double R = new Point2D.Double();
	if (p == 0)	Q =  P;
	else { 
		Q.x = controlPoints[p].x + (-controlPoints[p-1].x + controlPoints[p+1].x)/6;
		Q.y = controlPoints[p].y + (-controlPoints[p-1].y + controlPoints[p+1].y)/6;
	}
	if (p == numCP -2) R = S;
	else { 
		R.x = controlPoints[p + 1].x - (-controlPoints[p].x + controlPoints[p+2].x)/6;
		R.y = controlPoints[p + 1].y - (-controlPoints[p].y + controlPoints[p+2].y)/6;
	}
	return (new Bez(P, Q, R, S));
	}
	
	public void paintComponent(Graphics g) {
		Graphics2D g2 = (Graphics2D)g;
		// These are not currently used but might be useful.
		int wd = getSize().width;	
		int ht = getSize().height;
		
		//Show Arch with dashed lines in blue
		// Show curve in black
		for (int cp = 0; cp < numCP-1; cp++) {
			g2.setPaint(Color.black);
			g2.setStroke(new BasicStroke(2));
		  	Bez B = MakeArch(controlPoints, numCP, cp); 
			B.draw(g2);
			
			g2.setPaint(Color.blue);
			float[] dashPattern = {10, 5};
	   		g2.setStroke(new BasicStroke(1, BasicStroke.CAP_BUTT,
	                                  BasicStroke.JOIN_MITER, 10,
	                                  dashPattern, 0));
	        g2.drawLine((int)B.P.getX(),(int)B.P.getY(),(int)B.Q.getX(),(int)B.Q.getY());
	        g2.drawLine((int)B.Q.getX(),(int)B.Q.getY(),(int)B.R.getX(),(int)B.R.getY());
	        g2.drawLine((int)B.R.getX(),(int)B.R.getY(),(int)B.S.getX(),(int)B.S.getY());
	        g2.setPaint(Color.red);
	        g2.fillOval((int)B.Q.getX()-dSize/2, (int)B.Q.getY()-dSize/2, dSize, dSize);
	        g2.fillOval((int)B.R.getX()-dSize/2, (int)B.R.getY()-dSize/2, dSize, dSize);
		}
		
		// Show Control Points
		g2.setPaint(Color.blue);
		for (int cp = 0; cp < numCP; cp++) {
			P = controlPoints[cp];
			g2.fillOval((int)P.getX()-dSize, (int)P.getY()-dSize, 2*dSize, 2*dSize);
		}
	}
	
	private boolean close(int x, int y, Point2D p){
		return ((x-p.getX())*(x-p.getX()) + (y-p.getY())*(y-p.getY()) <= dSize*dSize);
	}
	
	public void mouseDragged(MouseEvent e) {
		mdX = e.getX();
		mdY = e.getY();
		for (int cp = 0; cp < numCP; cp++) {
		//System.out.println(mmX + "  " + mmY + "  " + controlPoints[cp].toString());
			if (close(mmX, mmY, controlPoints[cp])) {		
				controlPoints[cp].setLocation(mdX, mdY);
				mmX = mdX; mmY = mdY;
				repaint();
				break;
			}
		}
	}
	
	public void mouseMoved(MouseEvent e) {
		mmX = e.getX();
		mmY = e.getY();
	}
		
	public void mousePressed(MouseEvent e) {}	
	public void mouseReleased(MouseEvent e) {}
	public void mouseExited(MouseEvent e) {}
	public void mouseEntered(MouseEvent e) {}	
	public void mouseClicked(MouseEvent e) {
	//	System.out.println("clicked");
		int x, y;
		x = e.getX();
		y = e.getY();
	//	System.out.println(numCP + "  " + getControlPoints);
		if (getControlPoints && numCP < 20){
			controlPoints[numCP] = new Point2D.Double(x,y);
			numCP++;
			System.out.println(numCP + "  " + controlPoints[numCP-1].toString());
		}
		repaint();
	}
	
	public void actionPerformed(ActionEvent e) {
	}

	public static void main(String[] args){
		JFrame f = new JFrame("CatmullRom Spline - click to place points - move blue points");
		Container c = f.getContentPane();
		c.setLayout(new BorderLayout());
		c.add(new CatmullRom(), BorderLayout.CENTER);

		f.setSize(600, 622);
		f.addWindowListener(new WindowAdapter(){
			public void windowClosing(WindowEvent e) { System.exit(0); }
		});

		f.setVisible(true);
	}

}