Wednesday 30 June 2021

Events Dear Boy, Events

 So this month I have been coding a "Mission Events System" loosely based on how Descent: Freespace did it.

Chief amongst this creating a system that read all of the spawnPoint data which held all the info for various events, and anything inside the mission's own custom event file, then tried to organize all of that into something which wasn't gibberish.

I can give you a quick rundown ...

   //this is where the mission relevant data is started
   //all missions related events are controlled from here
   //before we spawn the player we need to load the MissionEventFile (MEF) and all it's functions
   //to do this we need to find out how many players we have
   //treat this number as 1 for single player game and start the mission with the first client joining
   //MissionEventFile holds the missionEventList (arrayObject) and all mission event functions
   //spawnPoints inside the missionEvents folder are for spawning and events
      //spawnStart;
         //1 timed or immediate spawn from player arrival; 1 = spawn immediately
      //spawnNear;
         //object that we should spawn near, if spawnDistance > 0; this overrides our spawnPoint location; defaults to player
      //spawnDistance;
         //distance from spawnNear object in kilometers;
      //dataBlock; <<<<< spawnDatablock
         //literally datablock name for player; eg: F11Goshawk, etc. Never AiF11Goshawk though, Ai gets added later
      //dataType; <<<<< spawnClass
         //type of datablock; eg: aeronautVehicle, etc. Never AiAeronautVehicle though, Ai gets added later
      //startingThrust;
         //starting engine setting as F32, default 0.6
      //team;
         //0 greenFor(neutral); 1 blueFor(ally); 2 redFor(enemy); 3 yellowFor(aggressor);
      //skillLevel;
         //Ai skillLevel 1-10; modified with difficulty
      //callsign;
         //name for vehicle or wing of aircraft based on wingNum and isWing number;
         //eg: solitary isWing0 "bob"
         //eg: isWing 2, wingNum 3 "bob3_2"
      //isWing;
         //0 = no not a wing only 1 vehicle or was a wing which has already been reduced to 0
         //1+ = is a wing, this number goes down everytime the wing is destroyed
         //wings respawn with wingDelayMin/Max time when reduced to wingMin number of remaining aircraft
         //a new arrayObject is created for the wing and all aircraft are added to this from that wing
         //eg: callsign "bob", arrayObject "bob_wing"
      //wingNum;
         //number of aircraft in the wing
      //spawnedNum;
         //number of the aircraft spawned in a wing, ++ until > wingNum then back to 1; this is set by scripts not editor
      //wingDelayMin;
         //minimum number in seconds for the wing to wait before spawning another wing and reducing isWing value by 1
      //wingDelayMax;
         //maximum number in seconds for the wing to wait before spawning another wing and reducing isWing value by 1
      //wingMin;
         //number of surviving aircraft when a new wing will spawn with wingDelayMin/Max. Default is 0, but best set to 1;
      //mainTask;
         //mainTask; 0 do waypoints; 1 dogfight anything; 2 strike target; 3 escort;
      //mainTaskTgt;
         //object for mainTask, can be vehicle, arrayObject list of targets, waypoint or path
      //eventTrigger#;
         //type of event to happen
            //onArrive - has spawned
            //onDepart - has departed
            //onDamagePercent - damage has gone below threshold
            //onDestroyed - uses callback onDisabled and onDestroyed for second check
            //onWaypoint - has moved to waypoint position
            //onPathComplete - has completed the total path
      //eventObject#;
         //object id; eg: onWaypoint = waypoint id; default blank/0/"" is spawnDatablock's object
      //eventDelay#;
         //delay in seconds from the eventTrigger# being completed
      //eventResult#;
         //result of the eventTrigger# occuring
            //script name; function to be activated from missionEventFile (MEF)
      //eventTarget#;
         //target of the event to do something, specifically used for spawn;
         //if no target then it should refer to a local wing or aircraft
         //eg: scorpio wing now spawns in 10 seconds due to eventTrigger1 "onWaypoint", eventObject1 "player", eventResult1 "spawn", eventDelay1 10, eventTarget1 scorpio wing
So that's my own comment notes in the file, though some of that has since been changed ... probably.

Part of this is "wings"; groups of aircraft that spawn together and can respawn in "waves" when their number has been depleted to a certain amount.

Contextual Messaging about Events in the top left

And what are events without victory and defeat conditions? Not very interesting that's what.

Events - hurray you didn't bugger it all up!

So with all of this in place it was time to create something which looked like a proper game mission. And here it is!

Here's a quick overview of what happens:

  • Victory Condition: All enemy are destroyed
  • Failure Condition: All allied reinforcements are destroyed
  • Player Spawns Event
  • First enemy wing SCORPIO spawns with a delay in response
  • Enemy wing SCORPIO is destroyed
  • Allied wing of reinforcements spawn in response to SCORPIO onDestroyed
  • Enemy wing LIBRA spawns after delay of reinforcements arriving. Also enemy wing TAURUS spawns with an even longer delay, near reinforcements.
  • After losing 3 out of 4 reinforcements I go and help out the last one before completing the mission.

In this playthrough the reinforcements were not very effective and got pounced on early by the enemy fighters, in other tests they accounted for some kills and assists.

When the mission is over status of all aircarft is printed to the console, detailing kills, assists, damage and the such. Eventually this will be part of a debriefing screen.


So that is the month that was. Roll on July.