On Thu, May 03, 2007 at 02:28:04AM -0700, ext Arnim Sauerbier wrote: > --- Daniel Stone <[EMAIL PROTECTED]> wrote: > > I don't see the conflict between working on new Xomap versions and > > improving the N800. > > There is none, but look again at the title of this thread. :)
Pretty sure the hacker edition uses the most recent X server anyway, so it should be okay? > > I don't see the point in doing pixel doubling in software. > > The point is to consider alternatives to improve performance for SDL games on > the 770 (and by > extension, the 800). Yes, but if you're doing it _in software_, then surely the performance impact from that would make your lower resolution kind of pointless. > > It's not about memcpy. I think the _maximum theoretical_ rate of screen > > updates is 28 fps > > due to the limited bandwidth between OMAP dispc and Hailstorm. You cannot > > push pixels > > any faster than this, even if you try, and even if you optimise SDL to > > death. > > Thanks for that info. I estimate my action games need roughly 20-25 FPS at > 640x480 and RPGs 8-15 > FPS at 800x480, so available bandwidth would be sufficient, correct? Right. You get 28fps at 800x480, assuming you have one frame queued up to push as soon as the last one has hit. > I'd like to thank Matthew, Eero, Daniel and Tapani for sharing their ideas on > the future of pixel > doubling and Xomap here, but given the status of N770 support, we in the > community can not > reasonably ask or expect Nokia to implement them for IT2006. If this is > correct, I respectfully > request that discussion about future Xomap releases be forked to another > thread and we return here > to the question of how to improve SDL game performance on the current OS. If new Xomap doesn't work on the 770, I'd like to know about it. (I don't have time to constantly test it, but I can -- and will -- fix it.) > To review: > - When UQM updates the full 320x240 screen (as in the intro and settings > menus) Xsp doubling works > as intended. When it updates portions of the screen (main menu, combat, > dialogues) doubling is > getting disabled. I don't understand why this is happening and apparently > nobody else does > either. Presumably this is because it's writing outside the 400x240 area. If you do this on older versions, pixel doubling will get disabled. If you do it using a recent (2007.whatever) version of ITOS2007, you'll just get clipped. > - Given the stated goal (deliver SDL games to current tablet users) and the > known constraints (Xsp > problems, no Xomap fixes for IT2006), I see three potential solutions for the > community (not > Nokia): > > 1) find out and document how to avoid the Xsp-doubling/damage problems for > SDL apps, in general > 2) write a SDL putrect equivalent that can use DSP pixel doubling directly, > without using Xsp > 3) write a fast SDL putrect equivalent direct to framebuffer (cf mplayer) - > optional SW scaling > > There are a number of classic SDL games that are close to playable on the > 770. We could dive into > each one individually and look for performance gains, but speeding-up scaled > SDL surfaces across > the board would yield a bigger payoff. I have doubts whether #1 is possible > and #2 would require > an intrepid coder who can venture into 'here be dragons' DSP-land. I think > #3 (basically > Siarhei's suggestion) looks like the most general and do-able route to speed > up SDL games, since > he's already implemented something like this for mplayer. We don't use the DSP for pixel doubling, it gets done by the graphics hardware (Tornado/hwa742 on 770, Hailstorm/s1d13745 on N800). As I've said before, I think the framebuffer solution is a very poor idea. Cheers, Daniel
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