ECS2/ecs/ECS.lua

local ffi = require("ffi")
local class, object =  require("class"), require("class.object")
local fficlass =  require("class.fficlass")
local LuaComponent = require("ecs.LuaComponent")
require("ecs")

local ECS = class(object)
ECS.N_ENTITIES = 100
function ECS:init()
    self.entities = ffi.new("entity_t[?]", ECS.N_ENTITIES)
    -- Making sure that everything is set
    for i=0,ECS.N_ENTITIES-1 do
        self.entities[i] = false
    end

    self.components = {}
    self.components_classes = {}
    self.n_components = 0

end

function ECS.debug_register()
    debug_overlay:register_menu("ECS", {ECS=require("ecs.debug"):new()})
end

function ECS:create_ffi_component(name, structdef)
    assert(not self.components_classes[name])
    local new_component = fficlass("bool _alive;"..structdef)
    self.components_classes[name] = new_component
    self.components[name] = new_component:new_array(ECS.N_ENTITIES)
    self.n_components = self.n_components + 1
    return new_component
end

function ECS:create_lua_component(name, ...)
    assert(not self.components_classes[name])
    local new_component = class(... or LuaComponent)
    self.components_classes[name] = new_component
    self.components[name] = {}
    for i=0,ECS.N_ENTITIES-1 do
        self.components[name][i] = self.components_classes[name]:new()
    end
    self.n_components = self.n_components + 1
    return new_component
end

function ECS:get_component(name, id)
    return self.components[name][id]
end

return ECS