OpenEuphoria

Re: Needing some Windows programming help

• Posted by DB James <larches at comcast.net> Jun 10, 2007
• 623 views

CChris wrote:
> 
> DB James wrote:
> > 

<SNIP>

> I'd take this problem the other way round:
> 1/ draw your graph on a memory bitmap (Pixmap in win32lib)
> 2/ handle the w32HPaint event fr your graph window and bitBlt() the relevant
> section of the
> graph.
> 3/ To improve smoothness, your bitmap should be wider than the window
> it will update, and, from time to time, just bitBlt() the "later" part onto
> the "earlier" part.
> 
> This is scrolling on a double buffered window.
> 
> CChris

Hi CChris,

Thanks for the ideas on how to handle this.  You gave me a lot to think
about.  I don't know yet how to "draw to a memory bitmap", but am not sure
that is the best way to go.  If I could do that, I wonder if I couldn't go
one better and write directly to the bitmap on the screen such that no
flicker would occur and there would be the sort of automatic refreshing we
expect in, for example, MS Paint.  There we could draw a square, fill it with
color, and it would be refreshed no matter what obscuring happened to the
window it was in.  (Being cautious, I just tried it and of course it worked.)

Unless someone else has a solution to suggest, I guess I'll read Petzold and
poke around with Euphorians' contributions related to bitmaps/pixmaps...

--Quark