[jazzplusplus-devel] some notes about flickering background in jazzpp

[joakim v. <jo...@ve...>]

Hello,

Here are some things I figured out about the background flicker that 
might or might not be news to you:

- Double buffering is easily achieved by the method Patrick suggested. 
(drawing to a temp dc and blitting)

- Sadly, this doesnt really help!

- Nowadays there is a "background erase event", that you can catch.
The default implementation of the event catcher should fill the 
background with grey.

Jazzpp fills the background with black however. I dont know why. This is 
why the flicker is so annoying,
at least for me.

- When I implement a dummy "bg erase" handler that does nothing, I get 
grey background erase,
which is much less annoying.

- implementing the "erase" handler and also implementing "double buffering"
seems achieve rock-solid redraw, but my implementation currently has 
other problems:
a) you need a background bitmap to draw in, and I havent figured out how 
to know the right size for it yet
b) events doesnt get drawn for some reason

Anyway, I think I'm on the right track, and we can at some future time 
have beautiful screen
updates like Rosegarden :-P


Cheers,
/Joakim