I’ve updated the tutorial and the zip file to use your suggestion. I’m glad you stopped by! Now to implement this in the game I’m working on…

I had wanted to do something like what you’ve done but for some reason didn’t realize Flash would make it that easy!

I also like the scale and rotation idea you mentioned. Not sure why I never really thought of this before.

I’m going to update the tutorial to include this new, simpler concept.

private function enterFrameListener(e:Event):void {

for (var i:int = 0; i < circles.length; i++) {

circles[i].update();

// pan the viewport
x = -viewportX;
y = -viewportY;
}

}

And then change the Circle class to use x/y rather than worldX/worldY.

This works because an object's position is relative to its parent. Move the parent and you move all its children. I can't immediately find any brilliant examples/tutorials of this, but hopefully the concept makes sense and you can experiment a bit to see how it works.

Are you recommending that I have a dedicated World displayObject or is the Document Class Sprite enough? I guess I have to mess around a little because I am missing something obvious about how Flash handles the stage space apparently.

Thanks for leaving your thoughts! I was hoping someone would be able to present some alternative ideas.

world.x = -viewportX;
world.y = -viewportY;

You can also do easy scaling/rotation like this too, by setting the scale/rotation on the world object.

Storing both the world location and the camera-space location is generally not a good idea IMO.