Problem with lag on the Xbox

[rookyard]

Hi all, I have started using the XNA exporter and It seems whenever I have more than about 70 actives (they are duplicates) on a level it lags so much it's unplayable. I only get this lag when testing on the Xbox and never on my PC, this is the case for the other projects I'm working on as well. I have tried changing the frame rate, lowering the screen resolution, removing layers, making the sprites smaller, removing fast loops etc. I have only been able to get very simple games to run without lagging. I'm sure I must be doing something wrong as I haven't noticed anybody else mentioning it. Any advice would be appreciated. Thanks

[Asholay]

Nope, I had this problem as well, it sucks major balls - you have to be really careful how you code things, and it's a right nightmare if you're used to just coding like you would in MMF on an ordinary day.

Few tips from experience:

Try and keep everything in groups, and only activate them when absolutely needed. I mean *really* tuck everything into a deactivated group if you can - I found this was the best way of improving performance.
Don't use the OR conditions, I found these slowed things down loads.
Don't use changing the font size on counters (and possibly text) - this crashes at runtime for me.
Don't use restrict actions condition - it's bugged after 5m and literally just stops working - took weeks to work this out (awesome!)
Alpha-blending seems to be okay for me, so don't be afraid of using that.

I was experiencing slowdown at 1200 events, no extra layers or fast loops and with a low resolution, so I can imaging with these implemented you have to be very careful.

[rookyard]

Thank you for the advice. Sounds like it would be best to start fresh rather than to try cleaning up what I've already done. I've already spent more than two weeks failing at this so If I still can't get anything up and running I might look into the IOS exporter, or just stick with the PC. Thanks again mate.

[Danny]

Just out of interest do you have a quick backdrop in there somewhere?

[rookyard]

No quick backdrops, a few days ago I read somewhere that it was better to use smaller tiles to make up a larger image. Sadly I still get the lag with or without backdrops though. I'll try to simplify things like using ball movement for enemies to keep the amount of events as low as possible. This whole XNA thing is much more restrictive than I was expecting.

[Francois]

Are you using fast loops? They are very time consuming in XNA

[Danny]

No quick backdrops, a few days ago I read somewhere that it was better to use smaller tiles to make up a larger image. Sadly I still get the lag with or without backdrops though. I'll try to simplify things like using ball movement for enemies to keep the amount of events as low as possible. This whole XNA thing is much more restrictive than I was expecting.

That IS strange and I'm not just saying it to 'defend' the product but if anything I found it very responsive no matter what I threw at it. See my blog post here: http://community.clickteam.com/entry.php?b=133 I wrote that back in August.

Please do keep narrowing your MFA down as I would be interested to know what's causing the slowdown.

[colej_uk]

I echo Danny's experience, I've found it to be super smooth even in one of my projects which was quite complex. Comparable to performance on my PC really, and with way more than 70 actives.

I do remember from beta testing there were some bugs that triggered massive slowdown (lower than 1fps). But to my knowledge they were all fixed. I wonder if something you're doing is triggering something similar?

I'm focusing a lot on android atm, but I'm hoping to go back to a bit of xbox development soon so if you like I can help get to the bottom of it.

[Asholay]

I echo Danny's experience, I've found it to be super smooth even in one of my projects which was quite complex. Comparable to performance on my PC really, and with way more than 70 actives.

I do remember from beta testing there were some bugs that triggered massive slowdown (lower than 1fps). But to my knowledge they were all fixed. I wonder if something you're doing is triggering something similar?

I'm focusing a lot on android atm, but I'm hoping to go back to a bit of xbox development soon so if you like I can help get to the bottom of it.

Don't forget that you guys are probably coding to a much better standard than others, including me.

For the first run of coding on my current project, I got stacks of slow-down without using anything too special - but it was coded in a very basic fashion. Now I've re-written everything it works far smoother - and the overall code is actually longer as I've added more features.

I'm not saying you've coded it badly Rookyard - just pointing out that just because others have managed to get something running fast with plenty going on means nothing when there are so many pitfalls you get caught out with by essentially doing nothing wrong! There are so many ways to perform certain actions and some will smash a frame-rate while others will be okay, and there's no telling which is which until you've experienced everything (or really understand coding properly).

Oh, and as Danny says - remove everything in your game piece by piece until the slow-down stops happening. Document it and make a few saves which you overwrite, or it's tricky to work out which bit it was when you fix it. I literally had to remove everything in my game and bring it to about 8 events before I worked out the problems I was having - and it was actually down to event order, which was very peculiar, as there was no logical reason to why the order would make a difference in that scenario.

[colej_uk]

Ah ok. There is definitely a lot to know about how to make things smooth inside MMF.

There's a good thread about optimization in the iOS forum: http://community.clickteam.com/showthread.php?t=65324&page=10 some of it will likely apply here. But there's also a lot of performance threads in the main MMF2 forum like this http://community.clickteam.com/showthread.php?t=73094&highlight=performance. Some quick tips off the top of my head:

-Turn off fine collision detection if you don't need it on an object.
-Order conditions with fast or most likely to be false on top. Things like comparing values are fast, things like collision detection are more expensive.
-The same applies to fast loops. Try to avoid a lot of expensive conditions in a fastloop.
-Organise your code into groups which can be deactivated when not needed.
-Use qualifiers where possible.