I'm secretly sorta surprised that using two framebuffers (one for the background and one for the foreground/text) would make a significant difference to just blitting the background and rewriting the text (as we currently do).  If it does make a significant difference doesn't it just mean our text blit code is in need of optimising?
----- Original Message -----
Sent: Sunday, June 25, 2006 12:45 PM
Subject: Re: Another list optimization

Isn't the text and the mask the same thing? You just have two framebuffers. The "foreground" which is only drawn in the foreground color and is primarily text. And the actual framebuffer. The backdrop is stored wherever it is currently (which I suppose you could call a framebuffer but it never changes really.) Since the foreground image is always 1-bit, 1 is drawn in the foreground color, 0 uses the pixel at that location from the backdrop buffer instead, right?

I'll admit that I don't know the code at all, but it seems kinda simple since text is always drawn 1-bit. I'm probably missing something.

On 6/25/06, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
[EMAIL PROTECTED] wrote:

> I've now implemented another optimization, used when items "move off"
> the top or bottom of the list. The implementation just copies the
> framebuffer over itself, to move the unchanged items up or down in the
> viewport.

If you have a 60 GB ipod only, you can try it here:
http://diffenbach.org/rockbox/listopt2-noscroll/rockbox.zip

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