gistfile1.lua

DroneComponent = class(nil, {});

function DroneComponent:OnInit(parentComponent)
   self.uptime = 0;

   self.parentComponent = parentComponent;
   entity = self.parentComponent:getParent();

   self.position = _G['caracal::ScriptUtil']:getPositionComponent(entity):getPosition();
   self.lightComponent = _G['caracal::ScriptUtil']:getLightComponent(entity);
   self.lightComponent:setBrightness(0);

   -- Get a reference to the player's position
   local playerEntity = _G['caracal::EntityManager']:getInstance():getEntity(
      _G['caracal::Name'].new("player"))
   self.playerPosition = _G['caracal::ScriptUtil'].getPositionComponent(playerEntity):getPosition();

end

function DroneComponent:OnPreUpdate(dt)
   self.uptime = self.uptime + dt;
   
   local xDelta = self.playerPosition:get_x() - self.position:get_x();
   local yDelta = self.playerPosition:get_y() - self.position:get_y();

   if (xDelta*xDelta + yDelta*yDelta) < 20000 then
      self.lightComponent:setBrightness(0.3);

      local y = self.position:get_y();
      self.position:set_y(y + math.sin(2 * math.pi * self.uptime) / 10);
   else
      self.lightComponent:setBrightness(0);   
   end   

end