Thanks for releasing this!

You have the animation taking place by moving along a PNG based on each image of the PNG representing the next clip of animation. Basically using it as the bitmap data in your inputs. Problem I have with this is I have a number of images I have used that are being drawn by hand.

Lets use my very simple example of where this becomes a problem for me. I have a bullet that is drawn from my ship as well as enemy ships. The bullet is a Sprite that draws itself differently depending on where it is shot from. Also, the bullet has an explosion animation which is different also based on where it is fired from. The differences are suttle and by using the graphics class off of the Sprite was easy to do. With this to get similar graphics I would have to create multiple bitmaps (pngs) for each version of the bullet along with frames for each explosion style.

So, for rendering items on the screen I am already using a renderer class to handle this change in animation state and would like to incorporate the described changes with your animation player. I would think that the exact same behavior of your animation could be accomplished without requiring an actual bitmap but instead be wrapped around a simple Sprite. Basically abstracting it one level further to include a Sprite which could represent an image or could be extended to draw based on frame location.

Basically, instead of the Animation class drawing the image you have a class that can draw an underlying bitmap based upon a strip as done here. Or could also draw based upon a frame as is done in a MovieClip (Flex nono) or something similar. Meaning that the frame actually advances and the location inside the bitmap is determined by the frame along with something else could use the frame to decide what to draw next.

I hope this made sense and I really do like the stuff you are building and this is great for animating long pngs inside of something. The other place I am going with this is that alot of animation I do on things is just using effects, meaning applying filters that change over a certain period. This type of animation gives no leeway with that kind of strategy whether I am using an img or not.