SpriteKit Detect Ranges

Question

I am making small/mid RTS game, I have the following need:

I want Enemy Players to Attack allies and vice versa when they are in each attack range.

My question is: what would be a better approach finding if enemy units are in attack range of allied or vice versa of course ?

What have I tried:

For now I tried to add SKNodes with SKPhysicsBodies for each unit Node.

I can see that FPS are going down when the contact happens... I guess it wasn't the best way to know detect whether enemies are in range.

I guess my alternative is to run some Nested Loop within Update method and check if there are enemy units within the Radius. I am not sure if it is the best approach, however with this approach I may play with some parameters and maybe optimize the routine for my own needs.

I would like to know if there is some better alternatives.

Answer 1

Look into GamePlayKit,

It may have some things you want.

Otherwise I would just use the Euclidiean Distance Formula https://math.stackexchange.com/questions/139600/euclidean-manhattan-distance without the square root, and use this value based on squads, not individual troops. (So if a group of 4 soldiers is attacking an enemy of 5 soldiers, only 1 distance check is done).

The reason why you do not square root, is because you should know the squared allowable distance. If an enemy 10 pixels away attracts soldiers, then use 100.

The best way to treat your soldiers like squads, add them all to an SKNode (sub class to add better functionality), then you just need to compare those squad SKNodes

If you want to reduce the number of checks you make, consider turning your play area into a grid (Like a chess board). Since you know the size of your tiles, you could easily check to see if the units are close enough to warrant a distance check. E.G. You have a unit at a1, and an enemy at i9, then you know just by tile distance that the units are too far apart to attack each other