add throw signal to player

data/scripts/classes/player.lua

@@ -1,5 +1,6 @@
 local Vector3 = require("types.vector3")
 local util = require("util")
+local Signal = require("types.signal")
 
 local Player = {
   position = Vector3(0, 1, 0),
@@ -10,6 +11,8 @@ local Player = {
 
   yaw = 0,
   yaw_speed = 0.05,
+
+  ThrowPressed = Signal.new(),
 }
 
 function Player:tick(ctx)
@@ -18,6 +21,8 @@ function Player:tick(ctx)
   input_action{name = "forward", control = "W"}
   input_action{name = "back", control = "S"}
 
+  input_action{name = "throw", control = "SPACE"}
+
   local camera_forward = Vector3(draw_camera_from_principal_axes(self).direction)
   camera_forward.y = 0
   camera_forward = camera_forward:normalized()
@@ -29,6 +34,10 @@ function Player:tick(ctx)
   local direction = ((camera_forward * forward_input) + (camera_right * strafe_input)):normalized()
   self.velocity = direction * self.speed
 
+  if input_action_just_pressed{name = "throw"} then
+    self.ThrowPressed:emit(self.position:copy(), camera_forward:copy())
+  end
+
   if ctx.mouse_capture then
     self.yaw = self.yaw + self.mouse_sensitivity * ctx.mouse_movement.x
   end

data/scripts/game.lua

@@ -1,6 +1,7 @@
 local player = require "classes.player"
 local util = require "util"
 local Vector3 = require "types.vector3"
+local Signal = require("types.signal")
 
 -- called every frame, with constant delta time
 function game_tick()
@@ -10,6 +11,11 @@ function game_tick()
     ctx.udata = {
       capture = false
     }
+    player.ThrowPressed:connect(
+      function (position, direction)
+        print(position, " ", direction)
+      end
+    )
   end
 
   ctx.mouse_capture = ctx.udata.capture

data/scripts/types/signal.lua

@@ -0,0 +1,30 @@
+local util = require "util"
+
+local Signal = {}
+
+Signal.__index = Signal
+
+function Signal:connect(f)
+  util.list_insert_once(self._connections, f)
+end
+
+function Signal:disconnect(f)
+  util.list_remove_value(self._connections, f)
+end
+
+function Signal:emit(...)
+  -- don't care about order
+  for _, v in pairs(self._connections) do
+    v(...)
+  end
+end
+
+function Signal.new()
+  local s = {
+    _connections = {},
+  }
+  
+  return setmetatable(s, Signal)
+end
+
+return Signal

data/scripts/types/vector3.lua

@@ -211,6 +211,11 @@ function Vector3:rotated(axis, angle)
   return Vector3(v)
 end
 
+---Returns a copy of this vector.
+---@return Vector3
+function Vector3:copy()
+  return Vector3(self)
+end
 ---- CONSTANTS
 
 Vector3.UP = Vector3(0, 1, 0)

data/scripts/util.lua

@@ -65,4 +65,36 @@ function util.merge(t1, t2, overwrite)
   return t3
 end
 
+---Finds the index of value in list t. If the value does not exist in the list, returns -1.
+---@param t table
+---@param value any
+---@return integer
+function util.list_find(t, value)
+  local idx = -1
+  for i, v in ipairs(t) do
+    if v == value then
+      idx = i
+      break
+    end
+  end
+  return idx
+end
+
+---Removes an element from a list, if it exists. Does nothing if the value doesn't exist.
+---@param t table
+---@param value any
+function util.list_remove_value(t, value)
+  local idx = util.list_find(t, value)
+  if idx ~= -1 then
+    table.remove(t, idx)
+  end
+end
+
+---Inserts value into the list only if it does not exist.
+---@param t table
+---@param value any
+function util.list_insert_once(t, value)
+  if util.list_find(t, value) ~= -1 then return end
+  table.insert(t, value)
+end
 return util