Complex enemy behaviors and patterns - ios

Question

I'd like to switch things up a bit with my enemies in my SpriteKit game. They're just so... predictable. I've been inspired by the sorts of enemies that are encountered in The Binding of Isaac: Rebirth.
For example, let's say I'd like to implement enemies which split into two smaller enemies when enemy.health < 50.0f. In a simple scenario, this could be done from my main scene update loop by iterating through all my enemies. Something like:
if(enemy.health < 50 && enemy.type == kEnemyTypeSplitsIntoTwo) {
CGPoint position1 = CGPointMake(enemy.position.x+20,enemy.position.y);
CGPoint position2 = CGPointMake(enemy.position.x-20,enemy.position.y);
[enemy killEnemy];
[self spawnNewEnemyWithType:enemyType andHealth:50 atPosition:position1];
[self spawnNewEnemyWithType:enemyType andHealth:50 atPosition:position2];
}
This will probably work for simple cases. But this is something that I definitely want to keep out of my main scene update loop. The problem is that my enemy class is effectively a subclass of SKSpriteNode.
For situations like this, ideally I'd like a new class such as a ComplexEnemy or EnemyGroup class to handle this so I can implement more complex enemy behaviours and patterns (think epic boss fights with multiple phases). I'd imagine this new class would likely derive from SKNode (or even NSObject?) and generate multiple Enemy instances at certain points.
Am I thinking down the right path? I'd be interested to hear what means people have used to achieve this sort of behaviour, preferably with a couple of examples.
-DC
tl;dr - Groups of enemies, bosses with multiple phases. How do you guys do it?

Answer 1

There's nothing wrong with using SKSpriteNode as an enemy class. I do it all the time. If you want to add a health bar, for example, you can simply add it as child.
Your question is primarily opinion based so expect it to be closed soon enough. However, it is a good question nonetheless. I suggest you use one or more enemy SKSpriteNode classes to handle your workload as it can make things easier for a beginner. You can of course get away with just using one enemy class and have its update method handle various aspects based on properties. For example:
-(void)update:(NSTimeInterval)currentTime {
if(self.enemyType == kDragon) {
// do big stuff
}
if(self.enemyType == kDwarf) {
// do small stuff
}
}
I am currently working on a project which has 10 different kinds of enemies and 4 behavior options for each one. It is all being handled from one class (SKSpriteNode).
It all boils down to what you want and how you arrange your code to do the job. I suggest you think about exactly what it is you are trying to do and if you get stuck, ask for help on a more specific issue.

Answer 2

In your situation, I would subclass the ComplexEnemy as a simple object. This object would be responsible for the instantiation and the adding and removing to the scene of the various enemies that could appear.
Then in your scene update method, I'd call a checking method in that object. The checking method would do the rest of the heavy lifting. You can put that call (the one in the update method) in an array of methods and when the ComplexEnemy gets instantiated, it would register itself in that array so it can be checked. It would remove itself from the array before being removed from memory..