Image Display Issues on Win XP

J. Landman Gay jacque at hyperactivesw.com
Tue Dec 20 12:56:19 EST 2005


Bill Marriott wrote:
> Rob Cozens wrote:
> 
> 
>>Thanks for the additional info.  One question: Does alwaysBuffer really 
>>mean anything if an image is added directly into a stack [as opposed to 
>>adding it by reference]?  It seems to me an image included in a stack file 
>>is always in memory once the stack is opened.
> 
> 
> I really don't know in an authoritative way the specifics of how Rev manages 
> memory for itself, except that "alwaysBuffer" definitely applies to stacks, 
> windows, and images within a stack. I am pretty sure an entire stack is not 
> loaded into RAM on opening though. That would just not be smart ;)

But it *is* very fast. Revolution does load the entire stack into RAM.

To answer Rob's question, the alwaysBuffer setting determines whether an 
offscreen buffer is created before displaying the image. If not, the 
image is drawn directly to the screen. This can cause flickering in some 
cases. If alwaysBuffer is true, the offscreen buffer allows a more 
stable image display at the cost of using more memory and a tiny bit of 
overhead time when opening the image. I believe -- but don't know for 
sure -- that the buffer is created when the card is accessed. So, for 
images that are stored in a stack, the image data is already in memory 
when the stack opens, but the buffer is not created until the card 
containing the image is opened.

-- 
Jacqueline Landman Gay         |     jacque at hyperactivesw.com
HyperActive Software           |     http://www.hyperactivesw.com



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