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Rockbox mail archiveSubject: Re: Another list optimizationRe: Another list optimization
From: Jens Arnold <arnold-j_at_t-online.de>
Date: Sun, 25 Jun 2006 22:18:08 +0200 On 25.06.2006, Dave Hooper wrote: > 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? Yes, that's necessary on the colour targets. While text blitting is already significantly faster than it was in the beginning, there's still a lot to be desired. Unfortunately ¡'ve got no clever idea how to generalise some optimisation ideas of mine (mostly working on pixel blocks at a time, utilising burst mode (known on coldfire, unknown on portalplayer), and using IRAM as a cache. Maybe both methods won't help much on portalplayer, since PP has got data cache. Scrolling the framebuffer instead of redrawing is a bad idea for two reasons: 1) (already mentioned) It interacts badly with bakdrop. 2) While pixel-wise scrolling is reasonably fast and simple on >=8bpp targets, it's more complex on 1bpp and 2bpp. So if we do that for all, it means for b&w & greyscale targets: More complexity, nothing gained. Otherwise it means lots of ifdefing... Regards, Jens Received on 2006-06-25 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |