ingrid.yao@Eng 2000-12-04
-----------------------------

J2SE Version (please include all output from java -version flag):

java version "1.4.0beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0beta-b42)
Java HotSpot(TM) Client VM (build B42, mixed mode)


Does this problem occur on J2SE 1.3? No



Operating System Configuration Information (be specific):
Windows NT 4 Workstation, SP6


Hardware Configuration Information (be specific):
Pentium 166MHz, 96 MB RAM, S3 generic graphic adapter
set 24-bit display


Bug Description:
6x decrease in performance of painting GeneralPath.

Test results:
================
    8-bit 16-bit 24-bit 32-bit
  -----------------------------------------------
     1.3.0 ~114fps ~87fps ~68fps ~53fps
     1.3.1 ~80fps ~69fps ~47fps ~47fps
     1.4 ~83fps ~83fps ~25fps ~82fps
                                  |
V
Very Bad

Test program:
==========================
import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;
import java.awt.event.*;

/**
 * There is big difference in frame rate between JDK1.3 and Merlin b42:
 * JDK1.3 : 40 fps
 * Merlin b42: 5 fps
 *
 * running with Xprof showhs bottleneck in two methods:
 * - sun.dc.pr.PathStroker.endPath (86%)
 * - javax.swing.RepaintManager.addDirtyRegion (21%)
 *
 * Testing machine:
 * Windows NT 4.0, Pentium 166MHz, 96 MB RAM
 *
 * @author ###@###.###
 */
public class SlowPath2D extends JComponent {
    int POINTS = 1000;
    float AM = 100f;
    int currentPos = 0;
    GeneralPath path;
    static Object lock = new Integer(0);
    long lastTime;
    int frames = 0;
    String fps = "";
    
    ComponentListener myListener = new ComponentAdapter() {
        public void componentResized(ComponentEvent e) {
            path = createPath();
        }
    };
    
    GeneralPath createPath() {
        GeneralPath p = new GeneralPath();
        float dx = getWidth() / (float) POINTS;
        p.moveTo(0f, 0);
        for(float x=0; x<getWidth(); x+=dx) {
            p.lineTo(x, (float)( AM*Math.sin(6*Math.PI*x/getWidth())));
        }
        return p;
    }
    
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        if(path == null) return;
        double t = (System.currentTimeMillis() - lastTime) / 1000.0;
        if( t > 3 ) {
            lastTime = System.currentTimeMillis();
            frames = 1;
        } else {
            frames++;
            if( t > 1) fps = String.valueOf((int)(frames / t)) + " fps";
        }
        g.setColor(Color.black);
        g.drawString(fps,10,20);
        
        synchronized(lock) {
            g.translate(0,currentPos);
            ((Graphics2D)g).draw(path);
            g.translate(0,-currentPos);
       }
    }
    
    public Dimension getPreferredSize() {
        return new Dimension(400, 400);
    }
    SlowPath2D() {
        addComponentListener(myListener);
    }
    void cycle() {
        int t = 0;
        while(1>0) {
            synchronized(lock) {
                currentPos = t % getHeight();
            }
            repaint();
            try {
                Thread.sleep(2);
            } catch (Exception ex) {}
            t += 5;
        }
    }
    
    public static void main(String args[]) {
        JFrame f = new JFrame();
        SlowPath2D p = new SlowPath2D();
        f.getContentPane().add(p);
        f.pack();
        f.setVisible(true);
        p.cycle();
    }
}


ingrid.yao@Eng 2000-12-05
--------------------------

more customer's test results:

Pentium 166MHz, S3Trio 2MB
                     8bpp 16bpp 24bpp
-----------------------------------------------------------
1.3.0 ~19fps ~40fps ~22fps
Merlin b42 ~80fps ~6fps ~4fps

Pentium 750MHz, ATI 8MB
                     8bpp 16bpp 24bpp 32bpp
----------------------------------------------------------------------
1.3.0 ~89fps ~100fps ~90fps ~90fps
Merlin b42 ~250fps ~240fps ~27fps ~150fps