Game freezes on interceptions

[bluereaper75]

So, whenever I send out stilettos to intercept alien fighter and scout ships, the game freezes when they contact each other. The soundtrack still plays, but I just keep hearing the firing noises of them shooting at each other, just at a very slow pace. It happens almost every single time, and every single time I send out interceptors the game freezes and I have to shut it off.

[ShipIt]

Maybe you can tell what kind of equipment your fighters have.

[HiEv]

I've also seen this.  The game goes to 100% CPU usage and slows down to a crawl, with only brief periodic (once every 5-10 seconds) updates and responsiveness until the combat ends.

The interceptors were equipped with just the basic weapons: Shiva, Sparrowhawk missiles, and the rocket pod.

I think the problem is that the program is going nuts trying to (re)calculate the direction for either the aircraft or the missiles when at zero or near zero distances between the two craft, but that's just a guess.

I suppose I should also note that my computer is ancient, slow, and low on memory: 2 GHz P4, 768 MB RAM, ATI Radeon 9550 / X1050 series dual-video video card (w/latest v10.2 drivers)

[pjvleeuwen]

Dear devs,

Could you please clarify why this issue (as described in ticket https://sourceforge.net/p/ufoai/bugs/3231/ and in many duplicates) does not seem to have any activity for more than a year? I experience the issue once every couple of intercepts and it seems other people as well. This really cripples this nice game, which is a shame.

So what's happening: did this not get any priority for a year ; is it too difficult ; is there a workaround that I do not know of ; ... ?

For me this seems waaaaay more relevant then the improved air-combat features or the android effort that I read about. It seems to me such a waste to focus so much attention on new features while the normal gameplay suffers like this.

Please help me, I already tuned back all performance options: for a long time running 800x600 in very plain-ish mode. Might look even worst then the original game on my old computer: and still keeps hanging like this. Is it something I might have mis-configured?

Hope that you can help me and maybe give some insight in what is keeping this ticket open for so long.

Best regards,
Paul

[Mattn]

the short answer is: because non of the devs can reproduce it.

[pjvleeuwen]

hi, thanks for getting back. Glad to hear what the problem is: for me it is very much reproducible, so maybe we might be able to think of a way in which I could help. Have been playing the game today for some hours and happened multiple times. It really ruins the game so please let's fix this thing. The description in the ticket seems quite plausible to me: indeed the issue only appears when two crafts attach each other and fly the same speed. The out-of-control adjustment of flight-plan seems to be the result when the crafts get very close / in the same spot.

Some suggestions in which I might help:

I could install the game in a VM: save just before reproduction moment (it is all in geoscape, so that is no problem) and then send you the whole VM (I can't imagine we would still get different results).

Maybe I could enable some extra debug info locally while playing the game?

I know a little about code, but do not know the game. Maybe you could lead me to the part of the code where a flight-plan gets recalculated based on a new flight-plan of the target? If so, then I might try some digging myself. But now I wouldn't even know where to start.

Anyway: best person to suggest best how I could help is you, so please let me know how we can best tackle this.

[H-Hour]

I'm not the best person to provide this info, but I believe this is the code that handles aircraft routing. Look for AIR_SendAircraftPursuingUFO.

[Mattn]

it might already help if you could e.g. disable multiple steps in it. e.g. rendering the route. disable it and see whether it still occurs.

entry point would e.g. be CP_CampaignFunctionPeriodicCall in cp_campaign.cpp

stuff like AIR_AircraftMakeMove might be interested, too. Does it also happen for ufos? or only for phalanx craft?