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tBitmap.Dormant and tBitmap.ReleaseHandle

I have an application which seems to be running out of "System
Resources", long before it's running out of memory - the app involves
allowing the user to browse over 100m x 100m (ie, very large) bitmaps,
and where the app for performance reasons, tries to explicitly buffer
the most recently used bitmaps in memory. At doing this it is not
unusual to buffer 100MB in memory [std machines are either 512MB
or 768MB, ie, we're seeing memory usage number btwn 40-55% only].
The problem we are having is {*word*193} red windows messages about
being out of system resources - my question is: noticing Dormant and
ReleaseHandle in the tbitmap help files  - is there anyone in the
group with experience with using them / understanding on how to
use them,  that would care to pontificate on their use? Along the
same lines, if one does only buffer the bitmap arrays and not the
handles etc, what is the performance hit if one has to reacquire
a handle everytime one wants to paint the bitmap? And finally:
are there better online resources talking to the use of these
methods ? (at least more info than the D4 helps... but at one
line that wouldn't be hard to do).

thanks,
greg mushial

 

Re:tBitmap.Dormant and tBitmap.ReleaseHandle


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Simply put, TBitmap (and windows) was not designed to work reliably
with bitmaps that are "some size" larger than the screen. You need a good
DIB Library that uses internal funcitons as opposed to using Windows
resourcces. I privatly sell such an animal.

Joe
--
Jimmy Page is having a charity artwork sale: Action For Brazil's Children Trust: http://www.zeppinhood.net/
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Quote
"greg mushial" <gmush...@gmdr.com> wrote in message news:3bddc87f.25178985@news.shasta.com...
> I have an application which seems to be running out of "System
> Resources", long before it's running out of memory - the app involves
> allowing the user to browse over 100m x 100m (ie, very large) bitmaps,
> and where the app for performance reasons, tries to explicitly buffer
> the most recently used bitmaps in memory. At doing this it is not
> unusual to buffer 100MB in memory [std machines are either 512MB
> or 768MB, ie, we're seeing memory usage number btwn 40-55% only].
> The problem we are having is {*word*193} red windows messages about
> being out of system resources - my question is: noticing Dormant and
> ReleaseHandle in the tbitmap help files  - is there anyone in the
> group with experience with using them / understanding on how to
> use them,  that would care to pontificate on their use? Along the
> same lines, if one does only buffer the bitmap arrays and not the
> handles etc, what is the performance hit if one has to reacquire
> a handle everytime one wants to paint the bitmap? And finally:
> are there better online resources talking to the use of these
> methods ? (at least more info than the D4 helps... but at one
> line that wouldn't be hard to do).

> thanks,
> greg mushial

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