PICO-8 boilerplate

boilerplate.lua

-- gobals and tools

left,right,up,down,fire1,fire2=0,1,2,3,4,5
black,dark_blue,dark_purple,dark_green,brown,dark_gray,light_gray,white,red,orange,yellow,green,blue,indigo,pink,peach=0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15

--
-- simple ecs
-- https://github.com/namuol/pico8-ecs
--
local ecs = {}

function containsall(e, keys)
  for _,name in pairs(keys) do
  if e[name] == nil then
    return false
  end
  end

  return true
end

function ecs.entitieswith(entities, componentnames)
  local results = {}
  for id,entity in pairs(entities) do
  if containsall(entity, componentnames) then
    results[#results+1] = entity
  end
  end

  return results
end

function ecs.world()
  local world = {}

  local componentsbyname = {}
  function world.component(name)
  if not componentsbyname[name] then
    componentsbyname[name] = componentsbyname.size
  end

  return componentsbyname[name]
  end

  local entities = {}
  function world.addentity(components)
  local id = #entities+1
  entities[id] = components
  return id
  end

  function world.removeentity(id)
  entities[id] = nil
  end

  function world.getcomponents(id)
  return entities[id]
  end

  function world.invoke(funcs)
  for n,func in pairs(funcs) do
    entities = func(entities)
  end
  end

  return world
end

function filtered_entities(entities, filters)
  return pairs(ecs.entitieswith(entities, filters))
end

--
-- coroutines manager
--
local coroutines={}

function addcoroutine(key, fn)
  coroutines[key] = cocreate(fn)
end

function getcoroutine(key)
  return coroutines[key]
end

function startcoroutine(key)
  coresume(coroutines[key])
end

function stopcoroutine(key)
  coroutines[key] = nil
end

function _coresolve()
  for k,co in pairs(coroutines) do
    if costatus(co)!='dead' then
      coresume(co)
    else
      stopcoroutine(k)
    end
  end
end

function wait(seconds)
  wait_frames(seconds*60)
end

function wait_frames(frames)
  for i=1,frames do
    yield()
  end
end


-->8
-- systems
-->8
-- game states

gs = nil -- game/global state
function set_state(state)
  gs = state
end

function state_game()
  local world = ecs.world()
  local state = {}

  function state._init()
  end

  function state._update()
  end

  function state._draw()
  end

  return state
end

-->8
-- main

states = {
  game = state_game()
}

function _init()
  set_state(states.game)
  gs._init()
end

function _update60()
  _coresolve()
  gs._update()
end

function _draw()
  gs._draw()
end