----- Original Message ----- From: "Norman Vine" <[EMAIL PROTECTED]> To: "FlightGear developers discussions" <[EMAIL PROTECTED]> Sent: Sunday, November 09, 2003 6:28 PM Subject: RE: [Flightgear-devel] Multiplayer Server RFC -- Current Status
> John Barrett writes: > > > > If each client instance specified "I'm only interested in events which > > happen within 20deg of my current position" (use a square around current > > lat/lon offset by the range specified, rather than circular) -- should be > > very fast for the server to do that check before forwarding data to a given > > client > > Please - remember FGFS is not a flat earth system so get rid of the degrees > and the square degree block concepts, as these are very inefficient and inaccurate > when operating on a sphere. > > Position is an ECF vector and distance can be degrees of arc if you insist, but > 'chord distance' is a one to one mapping and is *much* quicker to compute. > > http://www.flightgear.org/Docs/Scenery/CoordinateSystem/CoordinateSystem.html > whatever works -- if the computation gets too intense, it can always be handled periodically (every 60-120 seconds perhaps) and keep a list of entities for which we are interested in their updates -- entity IDs are going to be 32 bit integers, so we wont be hitting memory all that hard even with 100s of planes in the air -- or even reverse it -- each entity keeps a list of entities to which it will send updates -- list updated periodically -- then we dont have to walk the list of entities looking for those that are interested _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
