Raphael, SpriteLib GPL, And Timers In JavaScript

I tried to hack together a much simplified Arkanoid clone using Raphael in JavaScript. All was well until I tried to set up a fine grained timer to move the ball sprite around the screen. I think it has to be to do with the timeout facility, as updated based on mouse movement are very smooth. Using setTimeout is looked like I was getting max three frames per second. Shame.

Kudos to SpriteLib GPL for making the Arkanoid graphics available. I used this Groovy script to split the images up (copied and pasted from somewhere):

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;

BufferedImage bigImg = ImageIO.read(new File("arkanoid.png"));

final int width = 32;
final int height = 32;
final int rows = 19;
final int cols = 13;
BufferedImage[] sprites = new BufferedImage[rows * cols];

for (int i = 0; i < rows; i++) {
  for (int j = 0; j < cols; j++) {
    def sprite = bigImg.getSubimage(
      i * width + 1,
      j * height + 1,
      width - 1,
      height - 1);
    ImageIO.write(sprite, "PNG", new File("sprites/$i-$j.png"));
  }
}