Pacman in Java questions

For my university assignment I have to make a networkable version of pacman. I thought I would best approach this problem with making a local copy of pacman first and then extend this functionality for network play.

I would have to say that I am relatively new to java GUI development and utilizing such features within java.

I have started following the above links with regards to game development within java and an example of the pacman game.

I decided to represent the maze as an int array with different values meaning different things. However when the paint method inside the main game loop is run i am redrawing the whole maze with this method.

    for (int i : theGame.getMaze())
    {
        if (i == 4)
        {
            g.setColor(mazeWallColour);
            g.fillRect(curX, curY, cellSize, cellSize);
            curX += 25;
        }
        else
        {
            curX += cellSize;
        }

        index++;


        // Move to new row
        if (index == 25)
        {
            index = 0;
            curX = 10;
            curY += cellSize;
        }
    }

However this is providing me with less then 1fps. Although i've noticed the example linked above uses a similar way of redrawing each time the paint method is called and i believe does this on a image that is not viewable (kinda like double buffering [I've used a BufferStrategy like the first link explains]) What would be a better way to redraw the maze?

Any pointers/advice with this would be useful.

Thank you for your time.

http://pastebin.com/m25052d5a - for the main game class.

Edit: I have just noticed something very weird happening after trying to see what code was taking so long to execute.

In the paintClear(Graphics g) method i have added

ocean = sprites.getSprite("oceano.gif");
g.setPaint(new TexturePaint(ocean, new Rectangle(0,t,ocean.getWidth(),ocean.getHeight())));
g.fillRect(10, 10,getWidth() - 20,getHeight() - 110);

which made the whole thing run smoothly - however when i removed these lines the whole thing slowed down? What could have caused this?

Updated code

Solution

It looks like your call to Thread.sleep doesn't do what you intended, but I don't think it's the source of your trouble. You have:

Thread.sleep(Math.max(0, startTime - System.currentTimeMillis()));

startTime will always be less than System.currentTimeMillis(), so startTime - System.currentTimeMillis() will always be negative and thus your sleep will always be for 0 milliseconds. It's different from the example you showed because the example increments startTime by 40 milliseconds before doing the calculation. It is calculating how long to sleep for to pad out the drawing time to 40 milliseconds.

Anyway, back to your problem. I'd recommend measurement to figure out where your time is being spent. There's no point optimising until you know what's slow. You already know how to use System.currentTimeMillis(). Try using that to measure where all the time goes. Is it all spent drawing the walls?

EDIT - I see this got marked as accepted, so should I infer that the problem went away when you fixed the sleep time? I don't have a lot of Java GUI experience, but I can speculate that perhaps your code was starving out other important threads. By setting your thread to have maximum priority and only ever calling sleep(0), you pretty much guarantee that no other thread in your process can do anything. Here's a post from Raymond Chen's blog that explains why.