I have heard a term called "Memory Move", actually I don't know what's that
exactly, but I just know it is a technique to enable speedy bitmap copying.
Does anyone have idea about it and give some explanations?
Oscar
----- Original Message -----
From: "Ben Combee" <[EMAIL PROTECTED]>
Newsgroups: palm-dev-forum
To: "Palm Developer Forum" <[EMAIL PROTECTED]>
Sent: Saturday, February 10, 2001 5:15 AM
Subject: Speedy bitmap copying
> "Steve Mann" <[EMAIL PROTECTED]> wrote in message
> news:38991@palm-dev-forum...
> >
> > >My guess is that ideally the 5 bitmaps will be swapped on the
> > >offscreen region in about a second, so I wonder if that is slow enough
to
> > >fetch them from a resource and then draw to the offscreen region, and
> then
> > >dump that to the screen. I guess the question here is what I should
> > >sacrifice: memory or cpu.
> >
> > Good questions. I would just try it and see what happens.
> >
> > >Since we are talking about bitmaps, here is another question: Would it
> be
> > >better if I, say, make the bitmap dimensions a multiple of 8?
> >
> > I have no idea. That's a good question for someone at Palm.
>
> From the looks of things, the fastest PalmOS 3.5 WinCopyRectangle
situation
> occurs when
>
> 1) both src and dest windows are in the same format
>
> 2) src and dest X addresses are aligned at the same bit offset within a
> 16-bit word; for example, a 1-bit copy from (4,10) to (20, 17) would be
> fast. If you shifted your src to (5,10), it would take longer due to the
> shifting needed.
>
> Having rectangles on 16-bit boundaries with multiples of 16-bits in a row
> seems to be the fastest, but there isn't much overhead for starting and
> ending outside a 16-bit boundary.
>
> This all probably changes if your using Quickbits or on an older OS
version.
> --
> Ben Combee
> Veriprise Wireless <http://www.veriprise.com>
>
>
>
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