Drawing in Java - why my code is so slow? - performance

Question

Background
Im trying to create fancy, smooth and fast analog gauge with some dial inertia simulation etc. I want to avoid OpenGL if this is possible.
Problem
My code in Java is much slower than I expect.
I want my dial to move in time shorter than 0.5 second from minimum value (0) to maximum value (1024, i can change this, but I need smoothness).
I tried to measure time spent on repaint and paintComponent methods to find problem.
Repaint takes about 40us, paintComponent takes 300us, on my machine (Core Duo 2GHz, Windows 7).
It seems to be fast enough (1/0.000340s = ~3000 "runs" per second).
I think that video card is bottleneck and it slows my code, but I have no idea what to do with it.
Question
How to make my code faster and keep animation smooth as possible?
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.Stroke;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Point2D;
import java.awt.image.BufferedImage;
import javax.swing.*;
public class Main extends JPanel {
private static final Point2D CENTER = new Point2D.Double(PREF_W / 2.0,
PREF_W / 2.0);
private static final double RADIUS = PREF_W / 2.0;
private static final Color LARGE_TICK_COLOR = Color.DARK_GRAY;
private static final Color CENTER_HUB_COLOR = Color.DARK_GRAY;
private static final Stroke LARGE_TICK_STROKE = new BasicStroke(4f);
private static final Stroke LINE_TICK_STROKE = new BasicStroke(8f);
private static final int LRG_TICK_COUNT = 18;
private static final double TOTAL_LRG_TICKS = 24;
private static final double LRG_TICK_OUTER_RAD = 0.9;
private static final double LRG_TICK_INNER_RAD = 0.8;
private static final int START_TICK = 10;
private static final double CENTER_HUB_RADIUS = 10;
private static final double DIAL_INNER_RAD = 0.00;
private static final double DIAL_OUTER_RAD = 0.75;
private static final Color DIAL_COLOR = Color.DARK_GRAY;
private BufferedImage backgroundImg;
private static final int PREF_W = 400; //
private static final int PREF_H = 400;
private static final double INIT_VALUE = 0;
public static final int MAX_VALUE = 1024; // resolution
public static int delay = 1; // delay (ms) between value changes
private double theta;
private double cosTheta;
private double sinTheta;
private static long microtime;
public Main() {
setBackground(Color.white);
backgroundImg = createBackgroundImg();
setSpeed(INIT_VALUE);
}
public void setSpeed(double speed) {
if (speed < 0) {
speed = 0;
} else if (speed > MAX_VALUE) {
speed = MAX_VALUE;
}
this.theta = ((speed / MAX_VALUE) * LRG_TICK_COUNT * 2.0 + START_TICK)
* Math.PI / TOTAL_LRG_TICKS;
cosTheta = Math.cos(theta);
sinTheta = Math.sin(theta);
microtime = System.nanoTime()/1000;
repaint();
System.out.println("Repaint (us) = " + (System.nanoTime()/1000 - microtime));
}
private BufferedImage createBackgroundImg() {
BufferedImage img = new BufferedImage(PREF_W, PREF_H,
BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = img.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(LARGE_TICK_COLOR);
g2.setStroke(LARGE_TICK_STROKE);
for (double i = 0; i < LRG_TICK_COUNT; i++) {
double theta = (i * 2.0 + START_TICK) * Math.PI / TOTAL_LRG_TICKS;
double cosTheta = Math.cos(theta);
double sinTheta = Math.sin(theta);
int x1 = (int) (LRG_TICK_INNER_RAD * RADIUS * cosTheta + CENTER.getX());
int y1 = (int) (LRG_TICK_INNER_RAD * RADIUS * sinTheta + CENTER.getY());
int x2 = (int) (LRG_TICK_OUTER_RAD * RADIUS * cosTheta + CENTER.getX());
int y2 = (int) (LRG_TICK_OUTER_RAD * RADIUS * sinTheta + CENTER.getY());
g2.drawLine(x1, y1, x2, y2);
}
g2.setColor(CENTER_HUB_COLOR);
int x = (int) (CENTER.getX() - CENTER_HUB_RADIUS);
int y = (int) (CENTER.getY() - CENTER_HUB_RADIUS);
int width = (int) (2 * CENTER_HUB_RADIUS);
int height = width;
g2.fillOval(x, y, width, height);
g2.dispose();
return img;
}
#Override
protected void paintComponent(Graphics g) {
System.out.println("Paint component (us) = " + (System.nanoTime()/1000 - microtime));
super.paintComponent(g);
if (backgroundImg != null) {
g.drawImage(backgroundImg, 0, 0, this);
}
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setStroke(LINE_TICK_STROKE);
g.setColor(DIAL_COLOR);
int x1 = (int) (DIAL_INNER_RAD * RADIUS * cosTheta + CENTER.getX());
int y1 = (int) (DIAL_INNER_RAD * RADIUS * sinTheta + CENTER.getY());
int x2 = (int) (DIAL_OUTER_RAD * RADIUS * cosTheta + CENTER.getX());
int y2 = (int) (DIAL_OUTER_RAD * RADIUS * sinTheta + CENTER.getY());
g.drawLine(x1, y1, x2, y2);
microtime = System.nanoTime()/1000;
}
#Override
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
private static void createAndShowGui() {
final Main mainPanel = new Main();
JFrame frame = new JFrame("DailAnimation");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
new Timer(delay, new ActionListener() {
double speed = 0;
#Override
public void actionPerformed(ActionEvent evt) {
speed ++;
if (speed > Main.MAX_VALUE) {
speed = 0;
}
mainPanel.setSpeed(speed);
}
}).start();
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Little code description:
There is a timer, that changes gauge value. Timer interval is defined by delay variable at the beginning.
This is complete, one file code, you can just paste it in your IDE and compile.

Answer 1

You could try the following:
Switch from BufferedImage to VolatileImage
Precalculate your sin and cos function results and store them in arrays
Switch to Active painting instead of calling repaint