[racket] Facing some flickering problems

From: Robby Findler (robby at eecs.northwestern.edu)
Date: Thu Jul 22 21:27:17 EDT 2010

On Thu, Jul 22, 2010 at 8:21 PM, Mathew Kurian <bluejamesbond at gmail.com> wrote:
> If someone has a bit of spare time, can he/she explain how these images are
> loaded (time, allocation, garbage collection, etc) and then reproduced again
> during the redraws, it would be extremely useful.

That particular aspect of the system is unlikely to be able to be
improved (altho there may be some windows-specific strangeness I
suppose; if you try on a mac and see the same behavior that would
confirm my opinion).

Instead, the question will be how to avoid doing the drawing that often.

But to answer your question, the images are loaded by reading the
file, interpreting the data stored there and creating a bitmap% object
that records an flat array of the colors. Then, during drawing that
data is (efficiently) copied onto the screen.


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