Games.ECS

This is the top-level interface to OhhECS. A brief tutorial should probably go here.

  
 import GHC.Generics
 import Control.Lens
   
 data Position = Position Int Int
   deriving stock (Generic, Eq, Show)
     
 instance Num Position where
  (Position a b) + (Position c d) = Position (a + c) (b + d)
  (*) = undefined
  abs = undefined
  signum = undefined
  fromInteger = undefined
  negate = undefined
    
 instance Component Position where
   type CanonicalName Position = "position"
     
 makeHasComponentClass ''Position
   
 data GameWorld s where
   GameWorld ::
     EntRefField s ->
     AComponent "position" s Position ->
     GameWorld s
  deriving stock (Generic)     
 deriving instance Show (GameWorld Individual)
 deriving instance Show (GameWorld Storing)
 deriving instance Eq (GameWorld Individual)
 deriving instance Eq (GameWorld Storing)    
 makeWorld ''GameWorld   
  
 data MovementSystem = MovementSystem deriving (Eq, Show, Generic)
   
 instance (UsingPosition worldType Individual, Monad m) => System "MovementSystem" MovementSystem worldType m where
   type ComponentFilters "MovementSystem" MovementSystem worldType m = (UsingPosition worldType Individual)   
   runSystem world = traverseOf (entitiesWith (withPosition)) processCritter world
     where
       processCritter :: worldType Individual -> m (worldType Individual)
       processCritter oldCritter = do
         let newCritter = oldCritter & position .~ (Position 1 0)
         pure newCritter
           
 someEntity :: GameWorld Individual
 someEntity = (createNewEntityWithRef (EntRef 123))  & addPosition .~ Position 4 5
   
 myWorld :: GameWorld Storing
 myWorld = newWorld & storeEntity someEntity
   
 changed :: IO (GameWorld Storing)
 changed = runSystem @"MovementSystem" myWorld

Documentation

type EntityFilter (worldType :: Access -> Type) = IndexedTraversal' Entity (worldType 'Storing) (worldType 'Individual)

A filter over entities in a world is just an IndexedTraversal' that preserves the selection predicate.

module Games.ECS.Util.Misc

module Games.ECS.Component

module Games.ECS.Serialisation

module Games.ECS.Component.Store

module Games.ECS.Component.TH

module Games.ECS.World

module Games.ECS.World.TH

module Games.ECS.Entity

module Games.ECS.SaveLoad

module Games.ECS.System

module Games.ECS.Slot

module Games.ECS.Prototype

module Games.ECS.Prototype.PrototypeID

module Games.ECS.Prototype.SpawnedFromPrototype

module Games.ECS.MessageQueue