[racket] fruit flies

On Sep 13, 2011, at 4:03 AM, Robby Findler wrote:

> That would be a bug (if an entire width*height bitmap were being
> re-created and thrown away each time and the program was just creating
> a few circles instead of creating a bitmap of that size).
> ...
> A 2htdp/image is just a tree where overlays (and things like that) are
> interior nodes and leaf nodes are things like circles.

Right, but at some point it gets rendered to the (presumably pixel-map) graphics device.  IIRC, this is done by a function named "render" that returns a bitmap, and the resulting bitmap is then drawn on the screen, which would indeed mean that an entire width*height bitmap was being re-created and thrown away each time.



Stephen Bloch
sbloch at adelphi.edu