don't rely on shallow copy to construct new classes. also multiple ducks

data/scripts/classes/duck.lua

@@ -12,32 +12,34 @@ local States = {
 local WANDER_TIME = 1.0
 local IDLE_TIME = 1.0
 
-local Duck = {
-  position = {},
-  velocity = {},
-  direction = {},
-
-  target = nil,
-  state = States.IDLE,
-
-  wander_timer = 0,
-
-  speed = 0.02,
-  chase_speed = 0.04,
-  accel = 0.5,
-
-  STATES = States,
-
-  AteFeed = Signal.new()
-}
+local Duck = {}
 
 Duck.__index = Duck
 
 function Duck.new(position)
-  local d = util.shallow_copy(Duck)
-  d.position = position
-  d.velocity = Vector3()
-  d.direction = Vector3(0, 0, -1):rotated(Vector3.UP, util.random_float(-math.pi, math.pi))
+  -- local d = util.shallow_copy(Duck)
+  local d = {
+    position = position:copy(),
+    velocity = Vector3(),
+    direction = Vector3(0, 0, -1):rotated(Vector3.UP, util.random_float(-math.pi, math.pi)),
+  
+    target = nil,
+    state = States.IDLE,
+  
+    wander_timer = 0,
+  
+    speed = 0.02,
+    chase_speed = 0.04,
+    accel = 0.5,
+  
+    STATES = States,
+  
+    AteFeed = Signal.new(),
+    SeekFeed = Signal.new(),
+    
+    index = 1,
+  }
+  d.position.y = 0.4
 
   return setmetatable(d, Duck)
 end
@@ -68,6 +70,7 @@ function Duck:wander(delta)
   if self.wander_timer >= WANDER_TIME then
     self.state = States.IDLE
     self.wander_timer = 0
+    self.SeekFeed:emit(self)
     return
   end
 
@@ -96,6 +99,7 @@ end
 
 function Duck:start_chase(feed)
   if self.state == States.CHASE then return end
+  print("duck " .. self.index .. " starting chase")
   self.state = States.CHASE
   self.target = feed
   feed.occupied = true

data/scripts/classes/feed.lua

@@ -2,22 +2,20 @@ local Vector3 = require "types.vector3"
 
 local TEXTURE = "images/tongue.png"
 
-local Feed = {
-  position = {},
-  direction = {},
-  velocity = {},
-  landed = false,
-  occupied = false,
-
-  speed = 0.15,
-}
+local Feed = {}
 
 Feed.__index = Feed
 
-function Feed.new(p_position, p_direction)
-  local f = util.shallow_copy(Feed)
-  f.position = p_position:copy()
-  f.direction = p_direction:copy()
+function Feed.new(position, direction)
+  local f = {
+    position = position:copy(),
+    direction = direction:copy(),
+    velocity = Vector3(),
+    landed = false,
+    occupied = false,
+
+    speed = 0.15,
+  }
   f.velocity = f.direction * f.speed
   f.velocity.y = 0.1
 

data/scripts/game.lua

@@ -7,23 +7,33 @@ local Feed = require "classes.feed"
 local feed = List()
 
 local Duck = require "classes.duck"
-local ducks = List{Duck.new(Vector3(0, 0.4, 3))}
+local ducks = List()
 
 local function create_feed(position, direction)
+  print("?")
   local f = Feed.new(position, direction)
   feed:push(f)
   local eligible_ducks = ducks:filter(
     function (duck)
-      return duck.state ~= Duck.STATES.CHASE
+      return duck.state ~= duck.STATES.CHASE
     end
   )
-  if #eligible_ducks == 0 then return end
+  if eligible_ducks:is_empty() then return end
   eligible_ducks[1]:start_chase(f)
-  f.occupied = true
 end
 
 local function delete_feed(f)
-  util.list_remove_value(feed, f)
+  feed:remove_value(f)
+end
+
+local function duck_seek_feed(duck)
+  local eligible_feeds = feed:filter(
+    function (f)
+      return feed.occupied == false
+    end
+  )
+  if eligible_feeds:is_empty() then return end
+  duck:start_chase(eligible_feeds[1])
 end
 
 -- called every frame, with constant delta time
@@ -35,9 +45,18 @@ function game_tick()
       capture = false,
     }
     player.ThrowPressed:connect(create_feed)
-    for _, v in ipairs(ducks) do
-      v.AteFeed:connect(delete_feed)
+
+    -- spawn some ducks
+    for i = 1, 5 do
+      local duck = Duck.new(Vector3(0, 0, -math.random() * 10.0):rotated(Vector3.UP, util.random_float(-math.pi, math.pi)))
+      ducks:push(duck)
+      duck.AteFeed:connect(delete_feed)
+      duck.SeekFeed:connect(duck_seek_feed)
+      duck.index = i
     end
+    print(ducks[1].AteFeed._connections)
+    print(ducks[2].AteFeed._connections)
+
   end
 
   ctx.mouse_capture = ctx.udata.capture

data/scripts/types/list.lua

@@ -55,10 +55,11 @@ function List:__tostring()
   return s
 end
 
----Appends v to the end of the list.
----@param v any
-function List:push(v)
-  table.insert(self, v)
+---Appends value to the end of the list.
+---@param value any
+function List:push(value)
+  if self:has(value) then return end
+  table.insert(self, value)
 end
 
 ---Removes the last element in the list and returns it.
@@ -82,6 +83,13 @@ function List:filter(predicate)
   return filter(self, predicate)
 end
 
+---Removes the value at the given index.
+---@param idx integer
+---@return any
+function List:remove_at(idx)
+  return table.remove(self, idx)
+end
+
 ---Returns the index of value, if it exists in the list, -1 otherwise.
 ---@param value any
 ---@return integer
@@ -95,4 +103,27 @@ function List:find(value)
   end
   return idx
 end
+
+---Returns true if the value exists in the list.
+---@param value any
+---@return boolean
+function List:has(value)
+  return self:find(value) ~= -1
+end
+
+---Removes the value from the list, if it exists.
+---@param value any
+function List:remove_value(value)
+  local idx = self:find(value)
+  if idx ~= -1 then
+    table.remove(self, idx)
+  end
+end
+
+---Returns true if the list is empty.
+---@return boolean
+function List:is_empty()
+  return #self == 0
+end
+
 return List

data/scripts/types/signal.lua

@@ -1,10 +1,19 @@
 ---@class Signal
-local Signal = {
-  _connections = {}
-}
+---@field private _connections table
+local Signal = {}
 
 Signal.__index = Signal
 
+---Constructs a new signal.
+---@return Signal
+function Signal.new()
+  local s = {
+    _connections = {},
+  }
+  
+  return setmetatable(s, Signal)
+end
+
 ---Connects f to this signal. When the signal is emmitted, this function will be called.
 ---@param f function
 function Signal:connect(f)
@@ -26,14 +35,4 @@ function Signal:emit(...)
   end
 end
 
----Constructs a new signal.
----@return Signal
-function Signal.new()
-  local s = {
-    _connections = {},
-  }
-  
-  return setmetatable(s, Signal)
-end
-
 return Signal