Thanks for the info Logan. Here's basically my problem. My dynamic
heap usage is fairly small, somewhere around 50k or so. The real issue
is the creation of my two window buffers. Of course on a hi-res device
(320x320) each is 204k, so there goes a huge heap of heap :)
The reason I do this, is that there is a complex background that I like
to keep in a "clean" state at all times, thus one of the buffers. Then
I draw what I need when I need it to the second buffer. When something
drastic changes and I need to redraw the whole thing, I just transfer
the buffer from the first "clean" image to the other buffer, then add
my other "dynamic" elements. Now I could just keep the other as a
bitmap resource and do a regular windrawbitmap to the one buffer, but I
have a second requirement.
I might only be updating or clearing a small area at a time during
normal operation. Small areas, maybe 20x20 pixels, and in order to
clear them I basically do a wincopyrectangle from the orginal "clean"
image, to the area I need to clear. So this is why I needed the second
buffer.
Now, is there someone on the web I can find a list of Palm devices and
their respective factory heap sizes?
I see I have two options, forego the second buffer, and when I need to
update only a small space as I do all the time, just redraw the whole
darn thing over again, just to "clear" the one area. I could then just
use one buffer. But this would be slow. Or, I could make a bunch of
resource elements for all of the grid areas that I need to update.
Or,I could check the heap size at runtime, and if enough, just do as
usual, if not, do the one buffer trick.
Any ideas?
(By the way, I also do Pocket PC and Smartphone development, the palm
reminds me of Dos days with 640k limits)
Logan Shaw wrote:
> userforgroups@[EMAIL PROTECTED]
wrote:
> > I was using my Tungsten E simulator, and noticed that it has a 512k
> > heap setting already set when you download and run th esimulator. Is
> > that what is really is?
> > Here's the reason I ask. I noticed that my program I'm developing
> > crashes when running, and after stepping through it, I noticed that a
> > few of my memptrnew's were returning Null, so of course no more
memory.
> > Now, I do create two offscreen buffers (hi-res), so I know I eat
> > through the memory prettyq uickly. Here's the deal...I ran
> > MemHeapFreeBytes(???) I think that is the name, and chose heap id's of
> > 0, 1, and 2. Well, heap 0 is the one that I seem to be alllocating
> > memory from either by creating my offscreen buffer, or by using
> > memptrnew's.
> > But, when I looked at heap id 2, it had over 2 megabytes free (in the
> > simulator), and just wondering if I can go ahead and use that if I
> > want.
>
> I think you can use heap #2 for dynamic memory on that device if
> MemHeapDynamic(2) is true on that device.
>
> If I understand correctly, on all devices after OS 2.0 (or 3.0?),
> there is only one dynamic heap on each device.
>
> It's possible that heap #2 on that device is your storage heap.
> If so, you can't use it because the system write-protects that
> memory. (That way, a crash doesn't overwrite Datebook entries
> or something.)
>
> Anyway, it's sort of a moot point because it's unwise to write
> software for the Palm that relies on there being more than 512K
> of space available anyway. If you need that much space, you should
> look at storing some of your data in the storage heap either by
> putting it into a database or by using a feature pointer. In
> either case, you'll need to use DmWrite() to write to the memory
> since, as I said, it is normally read-only memory.
>
> - Logan
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