hyuntaeng / ecsgo

Cache friendly, Multi threading Entity Component System in Go (with Generic)

ECSGo

ECSGo is an Entity Component System(ECS) in Go. This is made with Generic Go, so it needs Go 1.18 version

• Cache friendly data storage
• Run systems in concurrently with analyzing dependency tree.

Example

package main

import (
    "log"

    "github.com/kongbong/ecsgo"
)

type Position struct {
    X float32
    Y float32
}

type Velocity struct {
    X float32
    Y float32
}

type HP struct {
    Hp    float32
    MaxHp float32
}

type EnemyTag struct{}

func main() {
    registry := ecsgo.New()
    defer registry.Free() // need to call before remove registry to free C malloc memory

    sys := ecsgo.AddSystem1[Velocity](registry, ecsgo.OnTick, func(r *ecsgo.Registry, iter *ecsgo.Iterator) {
        log.Println("This should not called as Entity has Velocity component")
    })
    ecsgo.Exclude[EnemyTag](sys)

    ecsgo.PostTask1[Velocity](registry, ecsgo.OnTick, func(r *ecsgo.Registry, iter *ecsgo.Iterator) {
        for ; !iter.IsNil(); iter.Next() {
            vel := ecsgo.Get[Velocity](iter)
            log.Println("This is one time called system", iter.Entity(), vel)
        }
    })

    sys = ecsgo.AddSystem1[Velocity](registry, ecsgo.OnTick, func(r *ecsgo.Registry, iter *ecsgo.Iterator) {
        for ; !iter.IsNil(); iter.Next() {
            vel := ecsgo.Get[Velocity](iter)
            log.Println("Velocity system", iter.Entity(), vel)
            // Velocity value of Entity is not changed as it is Readonly
            vel.X++
            vel.Y++
        }
    })
    ecsgo.Exclude[HP](sys)
    ecsgo.Readonly[Velocity](sys)

    sys = ecsgo.AddSystem2[Position, Velocity](registry, ecsgo.OnTick, func(r *ecsgo.Registry, iter *ecsgo.Iterator) {
        for ; !iter.IsNil(); iter.Next() {
            pos := ecsgo.Get[Position](iter)
            vel := ecsgo.Get[Velocity](iter)
            log.Println("Position, Velocity system", iter.Entity(), pos, vel, r.DeltaSeconds())
            // Position value is not changed only Velocity value is changed
            pos.X++
            pos.Y++
            vel.X++
            vel.Y++
        }
    })
    sys.SetTickInterval(1)
    ecsgo.Tag[EnemyTag](sys)
    ecsgo.Readonly[Position](sys)

    entity := registry.Create()
    ecsgo.AddComponent(registry, entity, &Position{10, 10})
    ecsgo.AddComponent(registry, entity, &Velocity{20, 20})
    ecsgo.AddTag[EnemyTag](registry, entity)

    registry.Run(ecsgo.FPS(10), ecsgo.FixedTick(true))
}