Hi!I develop a module DLL for FS9 and I need a callback which is called before every frame of the graphic engine. I know that I can get such a call in a gauge, but how do I do that in a module?Thanks Stefan

Hi Stefan,such callbacks are not documented in the FS SDKs. However, Pete Dowson (the author of FSUIPC) found the way to get FS callbacks by hacking into FS own modules. Go to his forum http://forums.simflight.com/viewforum.php?f=54 and do a search for "chain", and you will find some info on that topic. But, to get it working, you probably will need some knowledge about how the Linkage and ImportTable structures, which are exported by FS modules, work, and also about pointers to functions.If you have any questions feel free to contact me.Regards, Matthias

Hi Matthias,thanks for the link. That looks interesting, though not really trivial. Maybe there is another solution for my problem: I want to set the aircraft position using my own flight data, i.e. without any effect of FS9's flight model. Now I have some logic inside of my gauges which tries to callback my flight model code once per frame. This works most of the time, but fails if there is no gauge visible. I use FSUIPC to update the position of the aircraft in the callback using some inter/extrapolation of the known aircraft positions during time.Schimmi

Stefan,I started developing a recorder module, which records and plays back flights like the FS instant replay last year. It records aircraft position (and other data) in certain intervals. During playback position has to be interpolated and written on every frame, so thats very similar to what you want to do.In the first version I tried to use a timer to get the function called about once per frame. At first that seemed to work rather well, but then I sent the module to some other people for testing, and some of them reported heavy stuttering during playback. Later I got the LevelD 767 and with that aircraft got the same stuttering problems. So, using a timer will produce various results depending on aircraft, system and FS configuration.Some months ago I read those posts in Pete's forum and got the chain callbacks working. Now my playback works much better. If you want to try to get it working I could give you some hints. Otherwise you can also try the timer solution, maybe it performs good on your setup, but if you want to share the module with other people that's not the way to go.Regards, Matthias