/*
 * @(#)BezierAnim.java	1.17 98/06/29
 *
 * Copyright 1998 by Sun Microsystems, Inc.,
 * 901 San Antonio Road, Palo Alto, California, 94303, U.S.A.
 * All rights reserved.
 *
 * This software is the confidential and proprietary information
 * of Sun Microsystems, Inc. ("Confidential Information").  You
 * shall not disclose such Confidential Information and shall use
 * it only in accordance with the terms of the license agreement
 * you entered into with Sun.
 */

package demos.Mix;

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.GeneralPath;
import java.awt.font.FontRenderContext;
import java.awt.font.TextLayout;
import java.io.File;
import java.io.FileReader;
import java.io.BufferedReader;
import java.util.Vector;
import java.net.URL;
import J2DCanvas;


/**
 * Animated Bezier Curve with the README.txt file scrolling up.
 */
public class BezierAnim extends J2DCanvas {

    private static final int NUMPTS = 6;
    private float animpts[] = new float[NUMPTS * 2];
    private float deltas[] = new float[NUMPTS * 2];
    private float staticpts[] = {
	 50.0f,   0.0f,
	150.0f,   0.0f,
	200.0f,  75.0f,
	150.0f, 150.0f,
	 50.0f, 150.0f,
	  0.0f,  75.0f,
    };
    private BufferedReader reader;
    private int nStrs;
    private int strheight;
    private Vector vector;
    private Font fonts[] = { new Font("Times New Roman", Font.PLAIN, 12),
    			     new Font("Times New Roman", Font.ITALIC, 12),
    			     new Font("Times New Roman", Font.BOLD, 12) };
    private int fn = 0;
    private BasicStroke solid = new BasicStroke(10.0f, BasicStroke.CAP_BUTT,
				    BasicStroke.JOIN_ROUND);
    private AlphaComposite ac = AlphaComposite.getInstance(
				    AlphaComposite.SRC_OVER, 0.7f);



    public BezierAnim() {
	setBackground(Color.white);
	runnable = true;
    }


    public void animate(float[] pts, float[] deltas, int index, int limit) {
	float newpt = pts[index] + deltas[index];
	if (newpt <= 0) {
	    newpt = -newpt;
	    deltas[index] = (float) (Math.random() * 4.0 + 2.0);
	} else if (newpt >= (float) limit) {
	    newpt = 2.0f * limit - newpt;
	    deltas[index] = - (float) (Math.random() * 4.0 + 2.0);
	}
	pts[index] = newpt;
    }


    public void getFile() {
	String srcFile = "../../README.txt";
	URL url = BezierAnim.class.getResource(srcFile);
	if (url == null) {
	    System.out.println("File doesn't exist: " + srcFile);
	    return;
	}
	File file = new File(url.getFile());
	try {
	    if ((reader = new BufferedReader(new FileReader(file))) != null)
	        getLine();
	} catch (Exception e) { e.printStackTrace(); reader = null; }
	fn = 0;
    }


    public String getLine() {
	String str = null;
	try {
	    if ((str = reader.readLine()) != null) {
		if (str.length() == 0)
		    str = " ";
		vector.addElement(new TextLayout(str,fonts[fn++%fonts.length],new FontRenderContext(null, false, false)));
	    }
        } catch (Exception e) { e.printStackTrace(); reader = null; }
	return str;
    }


    public void drawDemo(Graphics2D g2) {

	if (newBufferedImage) {
	    for (int i = 0; i < animpts.length; i += 2) {
    	        animpts[i + 0] = (float) (Math.random() * w);
    	        animpts[i + 1] = (float) (Math.random() * h);
    	        deltas[i + 0] = (float) (Math.random() * 6.0 + 4.0);
    	        deltas[i + 1] = (float) (Math.random() * 6.0 + 4.0);
    	        if (animpts[i + 0] > w / 2.0f) {
		    deltas[i + 0] = -deltas[i + 0];
    	        }
    	        if (animpts[i + 1] > h / 2.0f) {
		    deltas[i + 1] = -deltas[i + 1];
    	        }
	    }
	    strheight = g2.getFontMetrics(fonts[0]).getHeight();
	    nStrs = h/strheight;
	    vector = new Vector(nStrs);
        }

        if (vector != null && vector.size() == 0)
	    getFile();

	if (reader != null) {
	    String s = getLine();
	    if (s == null || vector.size() == nStrs && vector.size() != 0)
	        vector.removeElementAt(0);
	    int yy = (s == null) ? 0 : h - vector.size() * strheight-15;
            g2.setComposite(AlphaComposite.SrcOver);
	    g2.setColor(Color.lightGray);
            for (int i = 0; i < vector.size(); i++)
  	        ((TextLayout)vector.get(i)).draw(g2, 1f,(float) (yy += strheight));
	}

	GeneralPath gp = new GeneralPath(GeneralPath.WIND_NON_ZERO);
	float[] ctrlpts;
	for (int i = 0; i < animpts.length; i += 2) {
	    animate(animpts, deltas, i + 0, w);
	    animate(animpts, deltas, i + 1, h);
	}
	ctrlpts = animpts;
	int len = ctrlpts.length;
	gp.reset();
	float prevx = ctrlpts[len - 2];
	float prevy = ctrlpts[len - 1];
	float curx = ctrlpts[0];
	float cury = ctrlpts[1];
	float midx = (curx + prevx) / 2.0f;
	float midy = (cury + prevy) / 2.0f;
	gp.moveTo(midx, midy);
	for (int i = 2; i <= ctrlpts.length; i += 2) {
	    float x1 = (midx + curx) / 2.0f;
	    float y1 = (midy + cury) / 2.0f;
	    prevx = curx;
	    prevy = cury;
	    if (i < ctrlpts.length) {
	        curx = ctrlpts[i + 0];
	        cury = ctrlpts[i + 1];
	    } else {
	        curx = ctrlpts[0];
	        cury = ctrlpts[1];
	    }
	    midx = (curx + prevx) / 2.0f;
	    midy = (cury + prevy) / 2.0f;
	    float x2 = (prevx + midx) / 2.0f;
	    float y2 = (prevy + midy) / 2.0f;
	    gp.curveTo(x1, y1, x2, y2, midx, midy);
	}
	gp.closePath();

        g2.setComposite(ac);
	g2.setColor(Color.blue);
	g2.setStroke(solid);
        g2.draw(gp);
        g2.setColor(Color.green);
        g2.fill(gp);
    }


    public static void main(String s[]) {
	final BezierAnim demo = new BezierAnim();
	WindowListener l = new WindowAdapter() {
	    public void windowClosing(WindowEvent e) {System.exit(0);}
	    public void windowDeiconified(WindowEvent e) { demo.start(); }
	    public void windowIconified(WindowEvent e) { demo.stop(); }
	};
	Frame f = new Frame("Java2D Demo - BezierAnim");
	f.addWindowListener(l);
	f.add("Center", demo);
	f.pack();
	f.setSize(new Dimension(400,400));
	f.show();
	demo.start();
    }
}