Unit Manager Code Snippet

Just about every strategy game needs a way to manage all the units on the field. Like all the enemy units, all of the player’s units and even neutral entities.

That also means a way for you to easily identify which unit is friendly with each other or enemies.

So here is the pattern I currently use for Riflestorm.

It contains three classes:

• TeamList - Contains all three teams (or how many you want) with helper methods. Only one is needed.
• Team - Contains all the team members with helper methods.
• Entity - This is the individual unit. It’s a dumby file just to illustrate how it’s used.

Usage

// create one teamlist for the whole game
TeamList teamList = new TeamList();

// teams are automatically made
teamList.misc; // neutral team
teamList.teamOne; // team one
teamList.teamTwo; // team two

// create an entity and add it to the class
GameObject entityObj = (GameObject)Instantiate(entityPrefab);
Entity entity = entityObj.GetComponent<Entity>();

// add to team one
teamList.teamOne.AddEntity(entity);

// entity now has access to it's team
entity.team; // teamList.teamOne
entity.teamId; // can check index in team

// can find entities in the world
teamList.FindEntityAt(new Vector2(0, 0)); // entity

// or find based on team
teamList.teamOne.FindEntityAt(new Vector2(0, 0)); // entity

// entities has it's team instance
entitiy.team.Count; // 1

// can even get the team list instance
entity.team.teamList.FindEntityAt(new Vector2(0, 1)); // null

// can also check if an other entity is friendly
if (entity.IsTeammate(otherEntity)) {
  // true
}

// can do checks on the team like
teamList.teamOne.IsAllDead(); // false

// or check if at least one is at a location
teamList.teamOne.Some((e) => e.transform.position == Vector2.zero); // true

Handling The Player’s Team

One thing you’ll notice is the teams are not named playerTeam or enemyTeam. That’s because – at least in Riflestorm – the teams are decided at run time, which I feel is best.

I created an other class called level which stores the player team and enemy team – among other things.

if (swapTeams) {
  level.playerTeam = teamList.teamOne;
  level.enemyTeam = teamList.teamTwo;
} else {
  level.playerTeam = teamList.teamTwo;
  level.enemyTeam = teamList.teamOne;
}

// access like so
if (level.playerTeam.OnTeam(entity)) {
  // on player's team
}

That’s all, feel free to modify the code to suit your needs.

Download source code:

• TeamList.cs
• Team.cs
• Entity.cs