Gecs

An Entity-Component-System storage implement with golang. It's a sparse sets based inspired by EnTT.

• Fast iterator.
• Reuse entity id.
• Combine include/exclude Component query supported.

All the technique/features/idea are from EnTT. (use the amazing ecs implement Entt if you code cpp.)

As go does not support generic now. So we should add extra info to identify different component type.(It's called component id in the project)

Getting Started

go get github.com/tutumagi/gecs

Example

package main

import (
	"fmt"
	"github.com/tutumagi/gecs"
)
// pre define your component data type
type Name string
type Age int
type Position struct {
	X int
	Y int
	Z int
}

func main() {
	// create a registry
	registry := gecs.NewRegistry()

	// register all components what you will use later
	// It's to identify component type
	NameID := registry.RegisterComponent("name")
	AgeID := registry.RegisterComponent("age")
	PositionID := registry.RegisterComponent("position")

	// create an entity
	entity := registry.Create()

	// assign component data
	registry.Assign(entity, NameID, Name("tufei"))
	registry.Assign(entity, AgeID, Age(12))

	// check whether an entity has given components data or not
	fmt.Printf("entity %v has <Name>: %v\n", entity, registry.Has(entity, NameID))              // true
	fmt.Printf("entity %v has <Name & Age>: %v\n", entity, registry.Has(entity, NameID, AgeID)) // true
	fmt.Printf("entity %v has <Position>: %v\n", entity, registry.Has(entity, PositionID))      // false

	// iterator entities by givin component
	registry.View(NameID, AgeID).Each(func(entity gecs.EntityID, datas map[gecs.ComponentID]interface{}) {
		name := datas[NameID].(Name) // the component type bind componentID must be consistent with you assign before
		age := datas[AgeID].(Age)

		fmt.Printf("name is %v\n", name)
		fmt.Printf("age is %v\n", age)
	})
}

Prerequisites

GO 1.14 and above

TODO

• exclude test
• avoid gc as much as possible
• notify when update component data(create/update/remove)
• avoid iterate empty component data
• snapshot
• group
• database backend
• benchmark

License

This project is licensed under the MIT License - see the LICENSE file for details