Particle = Entity:New(x,y)

 function Particle:New(x,y,animation,rotation,speed)
 	local o = Entity:New(x,y)

 	o.pos = {x = x, y = y}
  o.speed = speed or 0
  o.sprite_rotation = rotation or 0

  o.time = 0.5
  o.timer = 0

  o.vel = {
    x = o.speed * math.cos(o.sprite_rotation),
    y = o.speed * math.sin(o.sprite_rotation)
  }

  -- animations
  o.body = Animation:New(animation)
  
  table.insert(LoadedEntities,o)
  o.id = #LoadedEntities

 	setmetatable(o, self)
 	self.__index = self
 	return o
 end

function Particle:Smart()

end

function Particle:HandleAnimation()
  self.body:Animate()
  self.timer = self.timer + current_dt
  self.sprite_alpha = (self.time-self.timer)/self.time
  if self.sprite_alpha < 0 then self:Kill() end
  self:Draw(self.body)
end

function Particle:DoPhysics()
  if not self:isCollidingAt(self.pos.x + self.vel.x, self.pos.y, objects.collisions) then
    self.pos.x = self.pos.x + self.vel.x
  end
  if not self:isCollidingAt(self.pos.x, self.pos.y + self.vel.y, objects.collisions) then
    self.pos.y = self.pos.y + self.vel.y
  end
end