Merge branch 'master' into develop

control.lua

@@ -17,6 +17,7 @@ require "custom_commands"
 require "nuke_control"
 require "walk_distance"
 require "on_tick"
+require "follow"
 
 
 

custom_commands.lua

@@ -281,6 +281,21 @@ local function tag(cmd)
   end
 end
 
+local function follow(cmd)
+  if cmd.parameter ~= nil and game.players[cmd.parameter] ~= nil then
+    global.follows[game.player.name] = cmd.parameter
+    global.follows.n_entries = global.follows.n_entries + 1
+  else
+    game.player.print("<player> makes you follow the player. Use /unfollow to stop following a player.")
+  end
+end
+
+local function unfollow(cmd)
+  if global.follows[game.player.name] ~= nil then
+    global.follows[game.player.name] = nil
+    global.follows.n_entries = global.follows.n_entries - 1
+  end
+end
 
 
 commands.add_command("kill", "Will kill you.", kill)
@@ -298,3 +313,5 @@ commands.add_command("mods", 'Prints a list of game mods.', print_mods)
 commands.add_command("mod", '<promote, demote>, <player> Changes moderator status of a player. (Admins only)', mod)
 commands.add_command("afktime", 'Shows how long players have been afk.', afk)
 commands.add_command("tag", '<player> <tag> Sets a players tag. (Admins only)', tag)
+commands.add_command("follow", '<player> makes you follow the player. Use /unfollow to stop following a player.', follow)
+commands.add_command("unfollow", 'stops following a player.', unfollow)

follow.lua

@@ -0,0 +1,64 @@
+global.follows = {}
+global.follows.n_entries = 0
+
+function get_direction(follower, target)
+  local delta_x = target.position.x - follower.position.x
+  local delta_y = follower.position.y - target.position.y --reversed x axis
+  local a = delta_y/delta_x
+  if a >= -1.5 and a < -0.5 then
+    --SE OR NW
+    if delta_x > 0 then
+      return defines.direction.southeast
+    else
+      return defines.direction.northwest
+    end
+  elseif a >= -0.5 and a < 0.5  then
+    --E OR W
+    if delta_x > 0 then
+      return defines.direction.east
+    else
+      return defines.direction.west
+    end
+  elseif a >= 0.5 and a < 1.5 then
+    --NE OR SW
+    if delta_x > 0 then
+      return defines.direction.northeast
+    else
+      return defines.direction.southwest
+    end
+  else
+    -- N or S
+    if a < 0 then delta_x = - delta_x end -- mirrow x axis if  player is NNW or SSE
+    if  delta_x > 0 then
+      return defines.direction.north
+    else
+      return defines.direction.south
+    end
+  end
+end
+
+local function distance(player_1, player_2)
+  local d_x = player_1.position.x - player_2.position.x
+  local d_y = player_1.position.y - player_2.position.y
+  return math.sqrt(d_x*d_x + d_y + d_y)
+end
+function walk_on_tick()
+  if global.follows.n_entries > 0 then
+    for k,v in pairs(global.follows) do
+      local follower = game.players[k]
+      local target = game.players[v]
+      if follower ~= nil and target ~= nil then
+        local d = distance(follower, target)
+        if follower.connected and target.connected and d < 32 then
+          if d > 5 then
+            direction = get_direction(follower, target)
+            follower.walking_state = {walking = true, direction = direction}
+          end
+        else
+          global.follows[follower.name] = nil
+          global.follows.n_entries = global.follows.n_entries - 1
+        end
+      end
+    end
+  end
+end

on_tick.lua

@@ -1,4 +1,5 @@
 local function on_tick()
+	walk_on_tick()
 	if game.tick % 60 == 0 then
     poll_on_second()
 		walk_distance_on_second()