Component Based Game Engine Muckery

main.go

package main

import (
	"github.com/veandco/go-sdl2/sdl"
	"log"
	"os"
)

type WindowDetails struct {
	Title  string
	Width  int
	Height int
}

type Entity struct {
	Components map[string]Component
}

func (e *Entity) Initialize() {
	e.Components = make(map[string]Component)
}

func (e *Entity) Update() {
	var component Component
	for _, component = range e.Components {
		component.Update()
		component.Render()
	}

}

func (e *Entity) AddComponent(component Component) {
	e.Components[component.GetName()] = component
}

func (e *Entity) GetComponent(name string) Component {
	var component Component

	for _, component = range e.Components {
		if component.GetName() == name {
			return component
		}
	}

	return component
}

type Component interface {
	GetName() string
	GetOwner() Entity
	Update()
	Render()
}

type BaseComponent struct {
	owner string
}

func (bc BaseComponent) GetName() string {
	return "Base Component"
}

func (bc BaseComponent) Update() {

}

func (bc BaseComponent) Render() {
	// owner := bc.GetOwner()
	// component := owner.GetComponent("Position")
	// x, y := component.GetPosition()
	// component.SetPosition(x+1, y+1)
	// // log.Printf("%v %v", x, y)
	// w, h := int32(100), int32(100)
	// renderer.SetDrawColor(0, 255, 200, 255)
	// renderer.DrawRect(&sdl.Rect{x, y, (x + w), y + h})
}

func (bc BaseComponent) GetOwner() Entity {
	return entityPool[bc.owner]
}

type PositionComponent struct {
	owner string
	x     int32
	y     int32
}

func (pc *PositionComponent) GetPosition() (int32, int32) {
	return pc.x, pc.y
}

func (pc *PositionComponent) SetPosition(x int32, y int32) {
	pc.x = x
	pc.y = y
}

func (pc PositionComponent) GetName() string {
	return "Position"
}

func (pc PositionComponent) Update() {
	// log.Printf("[Updating: %v]", pc.GetName())
}

func (pc PositionComponent) Render() {

}

func (pc PositionComponent) GetOwner() Entity {
	return entityPool[pc.owner]
}

var (
	window     *sdl.Window
	renderer   *sdl.Renderer
	entityPool = make(map[string]Entity)
)

func main() {

	specs := WindowDetails{"Intrinsic", 960, 480}
	window = sdl.CreateWindow(specs.Title, sdl.WINDOWPOS_UNDEFINED, sdl.WINDOWPOS_UNDEFINED, specs.Width, specs.Height, sdl.WINDOW_SHOWN)
	if window == nil {
		log.Fatalln("Unable to create window")
		os.Exit(1)
	}

	renderer = sdl.CreateRenderer(window, -1, sdl.RENDERER_ACCELERATED)
	if renderer == nil {
		log.Fatalln("Unable to create renderer")
		os.Exit(2)
	}

	entity := Entity{}
	entity.Initialize()
	entity.AddComponent(BaseComponent{"01"})
	entity.AddComponent(PositionComponent{"01", 100, 100})
	running := true
	pc := entity.GetComponent("Position").(PositionComponent)
	// pc.SetPosition(100, 200)
	// x, y := pc.GetPosition()
	// log.Printf("%v %v", x, y)

	entityPool["01"] = entity

	for running {
		for event := sdl.PollEvent(); event != nil; event = sdl.PollEvent() {
			switch event.(type) {
			case *sdl.QuitEvent:
				running = false
			}
		}

		renderer.SetDrawColor(255, 0, 100, 255)
		renderer.Clear()

		entity.Update()

		renderer.Present()
	}

	renderer.Destroy()
	window.Destroy()
}