View source for Tuto tiny-ecs demo Part 4 tiny-ecs Entity

__TOC__

== Entity ==
It is time to create our first Entity.

In your project create three folders which you can call "_E", "_C", "_S".

In the entities folder "_E", create a file called "''ePlayer1.lua''" for example. This will be the player1 entity:
<syntaxhighlight lang="lua">
EPlayer1 = Core.class()

function EPlayer1:init(xspritelayer, x, y)
	-- ids
	self.isplayer1 = true -- id
	self.isactor = true -- id
	-- sprite
	self.spritelayer = xspritelayer
	self.sprite = Pixel.new(0x0000ff, 1, 32, 64)
	-- params
	self.x = x
	self.y = y
end
</syntaxhighlight>

'''The key here is the entity ''id'''''.

An ''''''id'''''' will serve as a filter for a tiny-ecs '''System'''. That is, a System will only apply to an entity with a specific '''id'''.

'''An entity can have multiple ids to make it available to more than one System'''.

After the id, we define a Sprite layer to draw our entity to. In this case our entity is a blue Pixel, with a width of 32 pixels and a height of 64 pixels.

All the entity variables (spritelayer, sprite, x and y position, ...) will be available to the Systems.

<big>In fact, all the entity variables can serve as an id, as we will see later</big>.

'''That's it, we created our first Entity, easy'''!

== World addEntity ==
Now we need to add our first entity to tiny-ecs world.
<syntaxhighlight lang="lua">
	-- ...
	-- tiny-ecs
	self.tiny = require "classes/tiny-ecs"
	self.tiny.tworld = self.tiny.world()
	-- the player (xspritelayer, x, y)
	self.player1 = EPlayer1.new(self.camera, 12*16, 10*16)
	self.tiny.tworld:addEntity(self.player1)
	-- ...
</syntaxhighlight>

First, we set up our player1 as being a new EPlayer1 entity, and we add it to tiny-ecs world.

You can run the project but the player1 will not display yet in Level1!

== Next? ==
In the next part, we will create a System to display our current and '''all''' future entities.


Prev.: [[Tuto tiny-ecs demo Part 3 tiny-ecs World]]</br>
'''Next: [[Tuto tiny-ecs demo Part 5 tiny-ecs System]]'''


'''[[Tutorial - tiny-ecs demo]]'''
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