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Controlling animation speed of a 2d game

I'm making a small asteroids game, and I'm having some trouble controlling the animation speed.
For example, let's say I have 20 asteroids in my game, when I destroy an asteroid, the amount of asteroids goes down (obviously). Because there are fewer objects in the game, the fps goes up and the animation speed of the asteroids is getting faster and faster.
I fixed it by adjusting the animation speed according to the amount of asteroids I have in the game, but I'm also facing another problem with the explosions when I destroy an asteroid. I could do the same thing I did with the asteroids I suppose, but I just think it's not a very wise way to "solve" it and just seems like bad practice to me.
I thought of capping the fps, but I'm not really sure how to do it. I'd like to get some advices and what's the best way to deal with such situations.
I'll post here my main game class including the game loop, and an example of the explosion class so you'll get the general idea of the code.
Game class and loop:
import com.asteroids.view.*;
public class Game extends Canvas implements Runnable {
private static final long serialVersionUID = -8921419424614180143L;
public static final int WIDTH = 1152, HEIGHT = WIDTH / 8 * 5;
private Thread thread;
private boolean isRunning;
private LoadImages loadImages = new LoadImages();
private Player player = new Player();
private AllObjects objects;
private KeyInput keyInput;
private long delay = 80;
private long currentTime = System.currentTimeMillis();
private long expectedTime = currentTime + delay;
public static BufferedImage test;
public Game() {
new Window(WIDTH, HEIGHT, "Asteroids!", this);
objects = new AllObjects();
objects.addObject(player);
for (int i = 0; i < 20; i++) {
objects.addObject(new Rock((int) (Math.random() * (Game.WIDTH - 64) + 1),
(int) (Math.random() * (Game.HEIGHT - 64) + 1)));
}
keyInput = new KeyInput(player);
this.addKeyListener(keyInput);
}
public void run() {
this.requestFocus();
long lastTime = System.nanoTime();
double amountOfTicks = 60.0;
double ns = 1000000000 / amountOfTicks;
double delta = 0;
long timer = System.currentTimeMillis();
int frames = 0;
// main game loop.
while (isRunning) {
adjustAsteroidsSpeed();
destroyAsteroids();
collisionLoop();
// used to set delay between every bullet(milliseconds)
currentTime = System.currentTimeMillis();
if (KeyInput.shoot && currentTime >= expectedTime) {
// calculates the accurate position of the x,y on the "circumference" of the
// player
float matchedX = player.getX() + 1 + (float) ((player.getRadius() + 32) * Math.cos(player.getRadian()));
float matchedY = player.getY() - 7 + (float) ((player.getRadius() + 32) * Math.sin(player.getRadian()));
objects.addObject(new Bullet(matchedX, matchedY, player));
expectedTime = currentTime + delay;
}
destroyBullets();
long now = System.nanoTime();
delta += (now - lastTime) / ns;
lastTime = now;
while (delta >= 1) {
tick();
delta--;
}
if (isRunning)
render();
frames++;
if (System.currentTimeMillis() - timer > 1000) {
timer += 1000;
System.out.println("FPS: " + frames);
frames = 0;
}
}
render();
stop();
System.exit(1);
}
private void stop() {
try {
thread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
System.exit(1);
}
private void render() {
BufferStrategy bs = this.getBufferStrategy();
if (bs == null) {
this.createBufferStrategy(3);
return;
}
Graphics g = bs.getDrawGraphics();
g.drawImage(LoadImages.getbackground(), 0, 0, getWidth(), getHeight(), this);
objects.render(g);
player.render(g);
g.dispose();
bs.show();
}
private void tick() {
player.tick();
objects.tick();
}
// starting thread and game loop.
public void start() {
thread = new Thread(this);
thread.start();
isRunning = true;
}
// minimum and maximum possible position for object.
public static float Bounds(float value, float min, float max) {
if (value >= max) {
return value = max;
}
if (value <= min) {
return value = min;
} else {
return value;
}
}
// detects collision between two objects
public boolean collision(GameObject a, GameObject b) {
return (b.getX() - a.getX() + 10) * (b.getX() - a.getX() + 10)
+ (b.getY() - a.getY() + 10) * (b.getY() - a.getY() + 10) < (a.getRadius() + b.getRadius())
* (a.getRadius() + b.getRadius());
}
// destroys bullets once they go out of the screen
public void destroyBullets() {
for (int i = 0; i < objects.getSize(); i++) {
if (objects.get(i).getId() == ID.BULLET) {
GameObject bullet = objects.get(i);
if (bullet.getX() > Game.WIDTH || bullet.getX() < 0 || bullet.getY() > Game.HEIGHT
|| bullet.getY() < 0) {
objects.removeObject(bullet);
}
}
}
}
// whenever a collision between an asteroid and a bullet occurs, the asteroid and the bullets are destroyed
public void destroyAsteroids() {
GameObject bullet = null;
GameObject bigRock = null;
for (int i = 0; i < objects.getSize(); i++) {
if (objects.get(i).getId() == ID.BULLET) {
bullet = (Bullet) objects.get(i);
for (int q = 0; q < objects.getSize(); q++) {
if (objects.get(q).getId() == ID.BIGROCK) {
bigRock = objects.get(q);
if (bullet != null && bigRock != null) {
if (collision(bigRock, bullet)) {
objects.addObject(new Explosion(bigRock.getX(), bigRock.getY(), objects));
objects.removeObject(bigRock);
objects.removeObject(bullet);
}
}
}
}
}
}
}
// calculates the amount of asteroids in the game and adjust the asteroids speed
public void adjustAsteroidsSpeed() {
int rocksCount = 0;
Rock rock;
for (GameObject object : objects.link()) {
if (object.getId() == ID.BIGROCK) {
rocksCount++;
}
}
for (GameObject object : objects.link()) {
if (object.getId() == ID.BIGROCK) {
rock = (Rock) object;
rock.setAnimSpeed(rocksCount * 0.002f);
}
}
}
Explosion class:
package com.asteroids.model;
import java.awt.Graphics;
import java.awt.Image;
import com.asteroids.controller.*;
import com.asteroids.view.LoadImages;
public class Explosion extends GameObject {
private AllObjects objects;
private Image explosion;
private float frame = 0;
private float animSpeed = 0.09f;
private int frameCount = 48;
public Explosion(float x, float y, AllObjects objects) {
super(x, y, ID.EXPLOSION, 1);
this.objects = objects;
}
public void render(Graphics g) {
explosion(g);
}
public void explosion(Graphics g) {
frame += animSpeed;
if (frame > frameCount) {
frame -= frameCount;
}
explosion = LoadImages.getExplosion().getSubimage((int) frame * 256, 0, 256, 256);
g.drawImage(explosion, (int) x, (int) y, 110, 110, null);
if (frame >= 47.8f) {
objects.removeObject(this);
}
}
public void tick() {
}
public void setAnimSpeed(float animSpeed) {
this.animSpeed = animSpeed;
}
}

Your main loop is generating uneven updates. If I do nothing, I get anywhere between 7799913 and 8284754 fps, however, if I throw in a 8 millisecond delay (to simulate some work), it drops to around 115-120 fps.
Your intention is to try and get the frame rate to be as even as possible, this will ensure that the animation speed remains the same
Personally, I don't like the "free-wheeling" style of game loop, it means that the loop is been allowed to consume CPU cycles without actually doing anything, where those cycles could be been used to do more important work, like update the UI.
In most cases, I just use a Swing Timer set to something like 5 millisecond intervals and then make use of the date/time API to calculate the difference between now and the last update and make choices about what to do, but, this assumes you're using a Swing based painting path. If you're doing a direct painting path (ie BufferStrategy), you could use a similar idea with a "loop" instead...
public void run() throws InterruptedException {
int frames = 0;
Duration threashold = Duration.ofMillis(1000 / 59);
Duration cycle = Duration.ofSeconds(1);
Instant cycleStart = Instant.now();
// main game loop.
while (isRunning) {
Instant start = Instant.now();
// Some update function...
Thread.sleep(rnd.nextInt(32));
Duration processTime = Duration.between(start, Instant.now());
Duration remainingTime = threashold.minusMillis(processTime.toMillis());
long delay = remainingTime.toMillis();
if (delay > 0) {
Thread.sleep(delay);
} else {
System.out.println("Dropped frame");
}
frames++;
// Render the output
Duration cycleTime = Duration.between(cycleStart, Instant.now());
if (cycleTime.compareTo(cycle) >= 0) {
cycleStart = Instant.now();
System.out.println(frames);
frames = 0;
}
}
}
In this example, your update and paint scheduling code simply have 16 milliseconds to get there job done, otherwise it will drop frames. If the work takes less then 16 milliseconds, the loop will "wait" the remaining time in order to provide some breathing room for the CPU to give time to other threads (and not take update unnecessary time on the CPU)
In the example above, I generate a "random" delay of up to 32 milliseconds for testing. Set it back to 16 and you should get (roughly) 60fps.
Now, I know people are extraordinarily passionate about these things, so if using Thread.sleep and Duration make your skin crawl, you "could" use a "free wheeling" loop, something like the one presented in Java Main Game Loop
Below is a sample implementation, I've set the number of updates and frames per second to 60, but you can change those values to suit your needs...
public void run() throws InterruptedException {
double ups = 60;
double fps = 60;
long initialTime = System.nanoTime();
final double timeU = 1000000000 / ups;
final double timeF = 1000000000 / fps;
double deltaU = 0, deltaF = 0;
int frames = 0, ticks = 0;
long timer = System.currentTimeMillis();
while (isRunning) {
long currentTime = System.nanoTime();
deltaU += (currentTime - initialTime) / timeU;
deltaF += (currentTime - initialTime) / timeF;
initialTime = currentTime;
if (deltaU >= 1) {
Thread.sleep(rnd.nextInt(32));
//getInput();
//update();
ticks++;
deltaU--;
}
if (deltaF >= 1) {
Thread.sleep(rnd.nextInt(32));
//render();
frames++;
deltaF--;
}
if (System.currentTimeMillis() - timer > 1000) {
System.out.println(String.format("UPS: %s, FPS: %s", ticks, frames));
frames = 0;
ticks = 0;
timer += 1000;
}
}
}
Again, the Thread.sleep here is just to inject a random amount of "work". Because it allows for more then 16ms of delay, you will also find it "drops" frames. Your job would be to get you work down to under 16ms per pass

Calculate 'interval and increment' for slide in animation in Java Swing

I'm building an application which has a slideshow in its homepage, currently I use Thread.sleep(10) and add/sub the x position of panel I want to slide.
For example: slideIn(30, panel_1, 10) < this will cause panel_1 to slide in with interval of 30ms and subtracts its x by 10 overtime until the panel is in center/occupy the slideshow_panel. But the con of this method is that the sliding animation won't smooth, I want the sliding animation/transition as smooth as Bootstrap Carousel. Is there a way to calculate the speed and increment/decrement value for slide transition speed?

Actually, I've something that's almost perfect for this. I assume you can create a Path2D for your animation path, right? And it also seems like you want a constant speed. There are a couple of references to my project (http://sourceforge.net/p/tus/code/HEAD/tree/) for calculating distance and showing the JPanel for instance, but it shouldn't be hard to remove them and replace with standard java. Try it out
public abstract class PathAnimation {
private Path2D mPath;
private double totalLength;
/**
* Be careful to call path.closePath before invoking this constructor
* #param path
*/
public PathAnimation(Path2D path) {
mPath = path;
totalLength = 0;
PathIterator iterator = mPath.getPathIterator(null);
//Point2D currentLocation;// = path.getCurrentPoint();
double[] location = new double[6];
iterator.currentSegment(location);
while (!iterator.isDone()) {
double[] loc = new double[6];
iterator.next();
iterator.currentSegment(loc);
if (loc[0] == 0 && loc[1] == 0) continue;
double distance = MathUtils.distance(location[0], location[1], loc[0], loc[1]);
totalLength += distance;
location = loc;
}
}
#Override
public Point2D getLocationAtTime(int time) {
return getLocationAtTime(time / (double) getTotalAnimationTime());
}
public Point2D getLocationAtTime(double pctTime) {
double len = totalLength * pctTime;
PathIterator iterator = mPath.getPathIterator(null);
double[] location = new double[6];
iterator.currentSegment(location);
while (!iterator.isDone()) {
double[] loc = new double[6];
iterator.next();
iterator.currentSegment(loc);
double distance= MathUtils.distance(location[0], location[1], loc[0], loc[1]);
if (distance > len) {
double pctThere = len / distance;
double xSpot = location[0] * (1 - pctThere) + loc[0] * pctThere;
double ySpot = location[1] * (1 - pctThere) + loc[1] * pctThere;
return new Point2D.Double(xSpot, ySpot);
}
len -= distance;
location = loc;
}
throw new ArrayIndexOutOfBoundsException("Path is too short or time is too long!");
}
/**
* Number of milliseconds that this animation spans
* #return
*/
public abstract int getTotalAnimationTime();
public static void main(String args[]) {
Rectangle rect = new Rectangle(10,10,20,20);
final Path2D.Double myPath = new Path2D.Double((Shape)rect);
myPath.closePath();
final PathAnimation myAnimation = new PathAnimation(myPath) {
Area star = new Area(PaintUtils.createStandardStar(15, 15, 5, .5, 0));
#Override
public Dimension getSizeAtTime(int time) {
return new Dimension(15,15);
}
#Override
public void paintAtTime(Graphics2D g, int time) {
Area toPaint = star;
if ((time / 150) % 2 == 1) {
Dimension size = getSizeAtTime(0);
toPaint = new Area(toPaint);
PaintUtils.rotateArea(toPaint, Math.PI / 6);
}
g.setColor(Color.YELLOW);
g.fill(toPaint);
g.setColor(Color.RED);
g.draw(toPaint);
}
#Override
public int getTotalAnimationTime() {
return 10000;
}
};
System.out.println(myAnimation.getLocationAtTime(0));
System.out.println(myAnimation.getLocationAtTime(2500));
System.out.println(myAnimation.getLocationAtTime(4000));
System.out.println(myAnimation.getLocationAtTime(5000));
System.out.println(myAnimation.getLocationAtTime(7000));
System.out.println(myAnimation.getLocationAtTime(7500));
System.out.println(myAnimation.getLocationAtTime(9000));
System.out.println(myAnimation.getLocationAtTime(10000));
final JPanel jp = new JPanel() {
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
int time = ((int) System.currentTimeMillis()) % myAnimation.getTotalAnimationTime();
int time2 = (time + myAnimation.getTotalAnimationTime() / 2) % myAnimation.getTotalAnimationTime();
Point2D pt = myAnimation.getLocationAtTime(time);
Point2D pt2 = myAnimation.getLocationAtTime(time2);
Dimension size = myAnimation.getSizeAtTime(time);
g2.translate(pt.getX() - size.width / 2, pt.getY() - size.height / 2);
myAnimation.paintAtTime(g2, time);
g2.translate(- (pt.getX() - size.width / 2), - (pt.getY() - size.height / 2));
g2.translate(pt2.getX() - size.width / 2, pt2.getY() - size.height / 2);
myAnimation.paintAtTime(g2, time2);
g2.translate(- (pt2.getX() - size.width / 2), - (pt2.getY() - size.height / 2));
g2.setColor(Color.BLACK);
g2.draw(myPath);
}
};
WindowUtilities.visualize(jp);
AbstractAction action = new AbstractAction() {
public void actionPerformed(ActionEvent ae) {
jp.repaint();
}
};
javax.swing.Timer t = new javax.swing.Timer(30, action);
t.start();
}
}

Using the thread.sleep method in painting

I have a working code which basically paints 15 rectangles on the screen that you can drag around. I made it so that the rectangles falls to the bottom of the screen as time passes. While I have the thread.sleep method at bigger numbers such as 500, I can still drag the rectangles around the screen as they fall with no problems. But as I start to decrease the thread.sleep method to smaller numbers such as 50, suddenly problems arises. Problems such as I can only drag up to 2 rectangles before the rectangles start glitching back to the places where I did not drag them. Sometimes I can only drag up to one rectangles, and once I selected that rectangle, I can't select any other rectangles to drag. I know my codes are definitely right, since it works while the thread.sleep method is at at bigger number, so my question is: why does it start glitching when I make thread.sleep to smaller numbers? Here's part of my code.
while (true) {
for (int i = 0; i < 15; i++) {
P.fY[i]++;
}
Thread.sleep(500);
frame.repaint();
} //the 15 stands for 15 rectangles, and the P.fY stands for the position of y.

So based off of your comment, it seems like you just really need a hand with figuring out how to calculate the distance as a function of time.
By adding 1 each frame loop, you're really saying the speed of each square is 1 pixel / 1 frame.
Instead, you should utilize time and update the distance by a function of time, so that it will be 1 pixel / unit of time. This means the velocity of the squares will then be independent of the frames per second.
I whipped up a code example. The important method is the Square#doUpdate() method. This pertains to exactly what you're looking for.
The procedure it follows is:
Calculate time from last update, store it in delta.
Update the time of the last update to the current time
Calculate deltaX, which is deltaX = delta * velocityX
Calculate deltaY, which is deltaY = delta * velocityY
Add deltaX to x - this updates the x coordinate
Add deltaY to y - this updates the y coordinate
The code is as follows:
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
import javax.swing.WindowConstants;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.LinkedList;
/**
* #author Obicere
*/
public class MovingSquare {
private volatile int viewportWidth;
private volatile int viewportHeight;
private final LinkedList<Square> squares = new LinkedList<>();
public MovingSquare() {
final JFrame frame = new JFrame("Moving Square");
final JPanel displayPanel = new JPanel() {
#Override
protected void paintComponent(final Graphics g) {
synchronized (squares) {
for (final Square square : squares) {
// Update the square's locations, ideally this will
// be separate of the painting thread
square.doUpdate();
final int x = (int) square.getX();
final int y = (int) square.getY();
g.setColor(square.getColor());
g.drawRect(x, y, square.squareSize, square.squareSize);
}
}
}
};
displayPanel.addMouseListener(new MouseAdapter() {
#Override
public void mouseReleased(final MouseEvent e) {
final Color nextColor = Color.getHSBColor((float) Math.random(), 1, 0.5f);
final float speedX = (float) Math.random();
final float speedY = (float) Math.random();
synchronized (squares) {
final Square newSquare = new Square(nextColor, speedX, speedY);
squares.add(newSquare);
newSquare.x = e.getX();
newSquare.y = e.getY();
}
}
});
displayPanel.addComponentListener(new ComponentAdapter() {
#Override
public void componentResized(ComponentEvent e) {
viewportWidth = displayPanel.getWidth();
viewportHeight = displayPanel.getHeight();
}
});
final Timer repaintTimer = new Timer(20, null);
repaintTimer.addActionListener(e -> {
if (!frame.isVisible()) {
repaintTimer.stop();
return;
}
frame.repaint();
});
repaintTimer.start();
displayPanel.setPreferredSize(new Dimension(200, 200)); // Sorry MadProgrammer
frame.add(displayPanel);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(final String[] args) {
SwingUtilities.invokeLater(MovingSquare::new);
}
private class Square {
private final int squareSize = 25;
private volatile float x;
private volatile float y;
private volatile long lastUpdateTime;
private volatile boolean negateX;
private volatile boolean negateY;
private final float speedX;
private final float speedY;
private final Color color;
public Square(final Color color, final float speedX, final float speedY) {
this.color = color;
this.speedX = speedX;
this.speedY = speedY;
lastUpdateTime = System.currentTimeMillis();
}
/**
* Important method here!!
* <p>
* This updates the location of the squares based off of a set
* velocity and the difference in times between updates.
*/
public void doUpdate() {
// Gets the change in time from last update
final long currentTime = System.currentTimeMillis();
final long delta = currentTime - lastUpdateTime;
if (delta == 0) {
return;
}
// be sure to update the last time it was updated
lastUpdateTime = currentTime;
// Calculate the speed based off of the change in time
final float deltaX = getSpeedX(delta);
final float deltaY = getSpeedY(delta);
// Move each square by the change of distance, calculated from
// the change in time and the velocity.
final float nextX = x + deltaX;
final float nextY = y + deltaY;
handleBouncing(nextX, nextY);
}
private void handleBouncing(final float nextX, final float nextY) {
if (nextX < 0) {
x = 0;
flipX();
} else if (nextX + squareSize >= viewportWidth) {
x = viewportWidth - squareSize;
flipX();
} else {
x = nextX;
}
if (nextY < 0) {
y = 0;
flipY();
} else if (nextY + squareSize >= viewportHeight) {
y = viewportHeight - squareSize;
flipY();
} else {
y = nextY;
}
}
private float getSpeedX(final long delta) {
return (negateX ? -1 : 1) * delta * speedX;
}
private float getSpeedY(final long delta) {
return (negateY ? -1 : 1) * delta * speedY;
}
protected void flipX() {
negateX = !negateX;
}
protected void flipY() {
negateY = !negateY;
}
public float getX() {
return x;
}
public float getY() {
return y;
}
public Color getColor() {
return color;
}
}
}
And it in action:
This might seem a bit overwhelming. Step through it, change some things up. Go crazy and see what the results are.
There are also some websites that can help with velocity and how to calculate things like this. If you need further help, just drop a comment down below and I'll see what I can do.

How to adjust graphics on Swing progress indicator?

The lower source code, with the pictured example, from the post
Circular Progress Bar for Java Swing not working, is a great Swing feature.
I'd like to be able to use it with a "transparent" JFrame or glass pane
but the graphic "petals", in paint(), want to interact with the background,
so if the opacity of the background is very low, you can barely
see the "petals". Not being familiar with the Graphics2D functions there, I've taken many stabs in the dark to try to adjust the code, but no luck, so could someone who knows how those functions work,
suggest changes so that the "petals" don't interact with the background,
and start out solid white, and gradually fade, as the code does?
I also don't need any fade-in or fade-out delays, and I'm also
having difficulty with that, but if someone could just suggest
modifications for the "petals", that would be great!
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import javax.swing.*;
import javax.swing.plaf.LayerUI;
public class Loading_Test {
static final WaitLayerUI layerUI = new WaitLayerUI();
JFrame frame = new JFrame("JLayer With Animated Gif");
public Loading_Test() {
JPanel panel = new JPanel() {
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 300);
}
};
JLayer<JPanel> jlayer = new JLayer<>(panel, layerUI);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(jlayer);
frame.pack();
frame.setVisible(true);
layerUI.start();
}
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
Loading_Test loading_Test = new Loading_Test();
}
});
}
}
class WaitLayerUI extends LayerUI<JPanel> implements ActionListener {
private boolean mIsRunning;
private boolean mIsFadingOut;
private Timer mTimer;
private int mAngle;
private int mFadeCount;
private int mFadeLimit = 15;
#Override
public void paint(Graphics g, JComponent c) {
int w = c.getWidth();
int h = c.getHeight();
super.paint(g, c); // Paint the view.
if (!mIsRunning) {
return;
}
Graphics2D g2 = (Graphics2D) g.create();
float fade = (float) mFadeCount / (float) mFadeLimit;
Composite urComposite = g2.getComposite(); // Gray it out.
g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, .5f * fade));
g2.fillRect(0, 0, w, h);
g2.setComposite(urComposite);
int s = Math.min(w, h) / 5;// Paint the wait indicator.
int cx = w / 2;
int cy = h / 2;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setStroke(new BasicStroke(s / 4, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
g2.setPaint(Color.white);
g2.rotate(Math.PI * mAngle / 180, cx, cy);
for (int i = 0; i < 12; i++) {
float scale = (11.0f - (float) i) / 11.0f;
g2.drawLine(cx + s, cy, cx + s * 2, cy);
g2.rotate(-Math.PI / 6, cx, cy);
g2.setComposite(AlphaComposite.getInstance(
AlphaComposite.SRC_OVER, scale * fade));
}
g2.dispose();
}
#Override
public void actionPerformed(ActionEvent e) {
if (mIsRunning) {
firePropertyChange("tick", 0, 1);
mAngle += 3;
if (mAngle >= 360) {
mAngle = 0;
}
if (mIsFadingOut) {
if (--mFadeCount == 0) {
mIsRunning = false;
mTimer.stop();
}
} else if (mFadeCount < mFadeLimit) {
mFadeCount++;
}
}
}
public void start() {
if (mIsRunning) {
return;
}
mIsRunning = true;// Run a thread for animation.
mIsFadingOut = false;
mFadeCount = 0;
int fps = 24;
int tick = 1000 / fps;
mTimer = new Timer(tick, this);
mTimer.start();
}
public void stop() {
mIsFadingOut = true;
}
#Override
public void applyPropertyChange(PropertyChangeEvent pce, JLayer l) {
if ("tick".equals(pce.getPropertyName())) {
l.repaint();
}
}
}

One problem I see is that the code is setting the composite in the wrong place in the loop. It works, but as you've discovered, it's difficult to maintain or change.
g2.setComposite is being called at the end of the loop. This sets the alpha for the next petal drawn. This means there is no easy change you can make to adjust the alpha of the very first petal.
First, I would make the code more in line with the way humans think (at least, the way I think): Set the alpha of the line you're about to draw, right before you draw it:
for (int i = 0; i < 12; i++) {
float scale = (12 - i) / 12f;
g2.setComposite(AlphaComposite.getInstance(
AlphaComposite.SRC_OVER, scale * fade));
g2.drawLine(cx + s, cy, cx + s * 2, cy);
g2.rotate(-Math.PI / 6, cx, cy);
}
Now, making it work with any arbitrary background alpha is easy. We merely adjust the value of scale:
float componentAlpha = 0.5f;
for (int i = 0; i < 12; i++) {
float scale = (12 - i) / 12f;
// Give petals the same relative alpha as the component
// they're overlaying.
scale *= componentAlpha;
g2.setComposite(AlphaComposite.getInstance(
AlphaComposite.SRC_OVER, scale * fade));
g2.drawLine(cx + s, cy, cx + s * 2, cy);
g2.rotate(-Math.PI / 6, cx, cy);
}

GUI freezes when drawing Wave from animation on JPanel though i used Swing Timer

plese look at my code snippets , wha is wrong with it , it frrezes GUI when the Swing timer stats which is repeteadly paints on the jpnael ??
class WaveformPanel extends JPanel {
Timer graphTimer = null;
AudioInfo helper = null;
WaveformPanel() {
setPreferredSize(new Dimension(200, 80));
setBorder(BorderFactory.createLineBorder(Color.BLACK));
graphTimer = new Timer(15, new TimerDrawing());
}
/**
*
*/
private static final long serialVersionUID = 969991141812736791L;
protected final Color BACKGROUND_COLOR = Color.white;
protected final Color REFERENCE_LINE_COLOR = Color.black;
protected final Color WAVEFORM_COLOR = Color.red;
protected void paintComponent(Graphics g) {
super.paintComponent(g);
int lineHeight = getHeight() / 2;
g.setColor(REFERENCE_LINE_COLOR);
g.drawLine(0, lineHeight, (int) getWidth(), lineHeight);
if (helper == null) {
return;
}
drawWaveform(g, helper.getAudio(0));
}
protected void drawWaveform(Graphics g, int[] samples) {
if (samples == null) {
return;
}
int oldX = 0;
int oldY = (int) (getHeight() / 2);
int xIndex = 0;
int increment = helper.getIncrement(helper
.getXScaleFactor(getWidth()));
g.setColor(WAVEFORM_COLOR);
int t = 0;
for (t = 0; t < increment; t += increment) {
g.drawLine(oldX, oldY, xIndex, oldY);
xIndex++;
oldX = xIndex;
}
for (; t < samples.length; t += increment) {
double scaleFactor = helper.getYScaleFactor(getHeight());
double scaledSample = samples[t] * scaleFactor;
int y = (int) ((getHeight() / 2) - (scaledSample));
g.drawLine(oldX, oldY, xIndex, y);
xIndex++;
oldX = xIndex;
oldY = y;
}
}
public void setAnimation(boolean turnon) {
if (turnon) {
graphTimer.start();
} else {
graphTimer.stop();
}
}
class TimerDrawing implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
byte[] bytes = captureThread.getTempBuffer();
if (helper != null) {
helper.setBytes(bytes);
} else {
helper = new AudioInfo(bytes);
}
repaint();
}
}
}
I am calling setAnimation of WaveFormPanel from its parent class.when animation starts it does not draw anything but freezes. please , give me solution.
Thank You
Mihir Parekh

The java.swingx.Timer calls the ActionPerformed within the EDT. The question then is, what's taking the time to render. It could be the call to captureThread.getTempBuffer it could be the construction of the help, but I suspect it's just the share amount of data you are trying to paint.
Having playing with this recently, it takes quite a bit of time to process the waveform.
One suggestion might be to reduce the number of samples that you paint. Rather then painting each one, maybe paint every second or forth sample point depending on the width of the component. You should still get the same jest but without all the work...
UPDATED
All samples, 2.18 seconds
Every 4th sample, 0.711 seconds
Every 8th sample, 0.450 seconds
Rather then paint in response to the timer, maybe you need to paint in response to batches of data.
As your loader thread has a "chunk" of data, may be paint it then.
As HoverCraftFullOfEels suggested, you could paint this to a BufferedImage first and then paint that to the screen...
SwingWorker might be able to achieve this for you
UPDATED
This is the code I use to paint the above samples.
// Samples is a 2D int array (int[][]), where the first index is the channel, the second is the sample for that channel
if (samples != null) {
Graphics2D g2d = (Graphics2D) g;
int length = samples[0].length;
int width = getWidth() - 1;
int height = getHeight() - 1;
int oldX = 0;
int oldY = height / 2;
int frame = 0;
// min, max is the min/max range of the samples, ie the highest and lowest samples
int range = max + (min * -2);
float scale = (float) height / (float) range;
int minY = Math.round(((height / 2) + (min * scale)));
int maxY = Math.round(((height / 2) + (max * scale)));
LinearGradientPaint lgp = new LinearGradientPaint(
new Point2D.Float(0, minY),
new Point2D.Float(0, maxY),
new float[]{0f, 0.5f, 1f},
new Color[]{Color.BLUE, Color.RED, Color.BLUE});
g2d.setPaint(lgp);
for (int sample : samples[0]) {
if (sample % 64 == 0) {
int x = Math.round(((float) frame / (float) length) * width);
int y = Math.round((height / 2) + (sample * scale));
g2d.drawLine(oldX, oldY, x, y);
oldX = x;
oldY = y;
}
frame++;
}
}
I use an AudioStream stream to load a Wav file an produce the 2D samples.

I'm guessing that your wave drawing code, which is being called from within a paintComponent(...) method is taking longer than you think and is tying up both Swing painting and the EDT.
If this were my code, I'd consider drawing my waves to BufferedImages once, making ImageIcons from these images and then simply swapping icons in my Swing Timer.