Java Grahpics2d, Buffered Image, really bad fps when rotating a image10Dpts

Question

Hey, i'm making a spaceship game, and i use buffered .gif that are loaded before they are used.
(The images are only loaded once before anyone says that :D )
However, when i have a reasonably sized image rotating in real time, such as a 533 by 182, at normal scale my fps drops really low, like into the mid teens, and i'm not sure why.
This only seems to happen when the iamge rotates, the fps stays fine when the image is translating.
I use Affine Transforms to do my rotating.
And i'm already using the createCompatibleImage GraphicsConfiguration to help increase performance, but i still get this problem.
I've also noticed if i zoom in realy close (using scaling ffrom affine transform) the same thing happens if i rotate, and my fps drops really low as well.
and the problem with the fps dropping when rotating is alot reduced if i zoom out alot as well.
Anyone got any idea how i can imrpove performance.
I'm buffering images as so:
     public BufferedImage createCompatible(int width, int height, int transparency) {
          GraphicsConfiguration gc = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice().getDefaultConfiguration() ;
          BufferedImage compatible = gc.createCompatibleImage(width,height,transparency);
          return compatible;
     }and the following code block is the one i use to render the spaceships (Actors)
     public void paint(Graphics2D g){
               AffineTransform at = new AffineTransform();
          at.scale(Sector42Main.UNIVSCALE, Sector42Main.UNIVSCALE);
          at.translate(x
                    -(((Actor)Sector42Main.playeractors.get(FOCUS_ID)).x)
                    +((Stage.WIDTH/2)/Sector42Main.UNIVSCALE)
                    - (((Actor)Sector42Main.playeractors.get(FOCUS_ID)).getWidth()/2) ,
                    y
                    -(((Actor)Sector42Main.playeractors.get(FOCUS_ID)).y)
                    + ((Stage.HEIGHT/2)/Sector42Main.UNIVSCALE)
                    - (((Actor)Sector42Main.playeractors.get(FOCUS_ID)).getHeight()/2));
          at.rotate(r,getWidth()/2,getHeight()/2);
     at.scale(xscale, yscale);
          g.drawImage( spriteCache.getSprite(spriteNames[currentFrame]),at, stage);
     }any help would be really welcome.
thanks.
Message was edited by:
MatthewH

Answer 1

I've found that a lot of game development seems to involve working out exactly what you can get away with in terms of display rather than conforming to a strict model. Sure, this is changing these days, but in terms of a bitmapped sprite just how much difference will each incremement make when projected onto pixels?
I tend to find a little experimentation with these things goes a long way - you might find that rounding your model's angle to a display angle with a much lower resolution (say, every 2 or 5 or 10 degrees) doesn't acutally make any real difference to the game (apart from letting you render frames moire quickly) once a number of sprites are flying about the place.
Still, just one suggestion. Let us all know if you find a another way around it.
Cheers,
John