sokoban, checkers, maze generator, game of life

checkers.lua

@@ -0,0 +1,153 @@
+-- CHECKERS GAME
+
+local checkers ={};
+checkers.piece = "";checkers.time = 0;
+checkers.pos = {} -- bottom left position of 8x8 checkerboard piece
+checkers.piece_pos = {} -- position of pick up piece
+
+--game pieces
+
+local function draw_board() -- pos is bottom left position of checkerboard
+	
+	local pos = checkers.pos;
+	local node;
+	for i = 1,8 do
+		for j =1,8 do
+			node = minetest.get_node({x=pos.x+i-1,y=pos.y,z=pos.z-1}).name;
+			if (i+j) % 2 == 1 then 
+				if node~="games:board_black" then minetest.set_node({x=pos.x+i-1,y=pos.y,z=pos.z+j-1},{name = "games:board_black"}) end
+				else
+				if node~="games:board_white" then minetest.set_node({x=pos.x+i-1,y=pos.y,z=pos.z+j-1},{name = "games:board_white"}) end
+			end
+			node = minetest.get_node({x=pos.x+i-1,y=pos.y+1,z=pos.z+j-1}).name;
+			if node~="air" then minetest.set_node({x=pos.x+i-1,y=pos.y+1,z=pos.z+j-1},{name = "air"}) end
+		end
+	end
+
+	for i = 1,4 do -- place pieces
+		minetest.set_node({x=pos.x+2*i-1,y=pos.y+1,z=pos.z},{name = "games:checkers_red"})
+		minetest.set_node({x=pos.x+2*i-2,y=pos.y+1,z=pos.z+1},{name = "games:checkers_red"})
+		
+		minetest.set_node({x=pos.x+2*i-1,y=pos.y+1,z=pos.z+6},{name = "games:checkers_blue"})
+		minetest.set_node({x=pos.x+2*i-2,y=pos.y+1,z=pos.z+7},{name = "games:checkers_blue"})
+	end
+	
+	for i = 1,8 do -- place kings
+		node = minetest.get_node({x=pos.x+i-1,y=pos.y+1,z=pos.z-2}).name;
+		if node~="games:checkers_red_queen" then minetest.set_node({x=pos.x+i-1,y=pos.y+1,z=pos.z-2},{name = "games:checkers_red_queen"}) end
+		node = minetest.get_node({x=pos.x+i-1,y=pos.y,z=pos.z-2}).name;
+		if node~="games:board_white" then minetest.set_node({x=pos.x+i-1,y=pos.y,z=pos.z-2},{name = "games:board_white"}) end
+		
+		node = minetest.get_node({x=pos.x+i-1,y=pos.y+1,z=pos.z+9}).name;
+		if node~="games:checkers_blue_queen" then minetest.set_node({x=pos.x+i-1,y=pos.y+1,z=pos.z+9},{name = "games:checkers_blue_queen"}) end
+		node = minetest.get_node({x=pos.x+i-1,y=pos.y,z=pos.z+9}).name;
+		if node~="games:board_white" then minetest.set_node({x=pos.x+i-1,y=pos.y,z=pos.z+9},{name = "games:board_white"}) end
+
+	end
+	
+end
+
+minetest.register_node("games:checkers", {
+description = "checkers crate",
+	tiles = {"moreblocks_iron_checker.png","crate.png","crate.png","crate.png","crate.png","crate.png"},
+	groups = {oddly_breakable_by_hand=1},
+	is_ground_content = false,
+	paramtype = "light",
+	light_source = 14,
+	sounds = default.node_sound_wood_defaults(),
+	on_construct = function(pos)
+		local meta = minetest.get_meta(pos)
+		meta:set_string("infotext","checkers game block, admin only")
+		meta:set_int("time", minetest.get_gametime());
+		checkers.pos = {x = pos.x+1, y=pos.y-1, z=pos.z+1}
+	end, 
+	on_punch = function(pos, node, player)
+		local name = player:get_player_name(); if name==nil then return end
+		local privs = minetest.get_player_privs(name); 
+		if not privs.kick then return end -- only admin
+		checkers.pos = {x = pos.x+1, y=pos.y, z=pos.z+1}
+		draw_board()
+	end
+	}
+	)
+
+
+minetest.register_chatcommand("checkers", {
+    description = "Start a game of checkers and refresh board display",
+    privs = {kick=true},
+    func = function(name,param)
+		draw_board();checkers.piece = ""
+	end
+	}
+)
+
+
+function register_piece(name, desc, tiles, punch)
+	minetest.register_node(name, {
+		description = desc,
+		drawtype = "nodebox",
+		paramtype = "light",
+		tiles = tiles,
+		groups = {snappy=2,choppy=2,oddly_breakable_by_hand=3},
+		sounds = default.node_sound_defaults(),
+		node_box = {
+		type = "fixed",
+		fixed = {-0.5, -0.5, -0.5, 0.5, -0.3, 0.5},
+		},
+		selection_box = {
+			type = "fixed",
+			fixed = {-0.5, -0.5, -0.5, 0.5, -0.3, 0.5},
+					
+		},
+		on_punch= punch,
+	}) 
+end
+function register_board(name,desc,tiles)
+	minetest.register_node(name, {
+			description = desc,
+			tiles = tiles,
+			groups = {snappy=2,choppy=2,oddly_breakable_by_hand=3},
+			sounds = default.node_sound_defaults(),
+			on_punch = function(pos, node, player) -- place piece on board
+					local name = player:get_player_name(); if name == nil then return end
+					if checkers.pos.x == nil then minetest.chat_send_player(name,"punch checkers game block before playing.") return end
+					if checkers.piece == "" then return end
+					local t = minetest.get_gametime(); if t-checkers.time <1 then return end; checkers.time = t;
+					local above = {x=pos.x,y=pos.y+1;z=pos.z};
+					local x,y; x= above.z-checkers.pos.z+1; y=above.x-checkers.pos.x+1;
+					minetest.set_node(above, {name = checkers.piece});
+					
+					minetest.chat_send_all(
+					"#CHECKERS : " .. name .." moved: ".. checkers.piece_pos.z-checkers.pos.z+1 .. "," .. checkers.piece_pos.x-checkers.pos.x+1 .. " to " ..
+					x .. "," .. y )
+					checkers.piece = ""
+			end,
+			on_rightclick = function(pos, node, player, itemstack, pointed_thing) -- capture piece 
+				local name = player:get_player_name(); if name == nil then return end
+					if checkers.pos.x == nil then minetest.chat_send_player(name,"punch checkers game block before playing.") return end
+					if checkers.piece == "" then return end
+					minetest.chat_send_all(name .." captured piece at ".. checkers.piece_pos.z-checkers.pos.z+1 .. ","..checkers.piece_pos.x-checkers.pos.x+1)
+					checkers.piece = "" return 
+			end
+			
+	}) 
+end
+
+local piece_punch  = function(pos, node, player) -- pick up piece
+	local name = player:get_player_name(); if name == nil then return end
+	if checkers.pos.x == nil then minetest.chat_send_player(name,"punch checkers game block before playing (need kick priv).") return end
+	if checkers.piece~="" then return end -- dont pick up another piece before last one was put down
+	
+	local t = minetest.get_gametime(); if t-checkers.time <1 then return end; checkers.time = t;
+	checkers.piece = node.name; minetest.set_node(pos, {name="air"});
+	checkers.piece_pos = {x=pos.x,y=pos.y,z=pos.z};
+end
+
+register_board("games:board_white","white board",{"wool_white.png"})
+register_board("games:board_black","black board",{"wool_black.png"})
+
+register_piece("games:checkers_blue","blue piece",{"wool_blue.png"},piece_punch)
+register_piece("games:checkers_blue_queen","blue queen piece",{"queen_blue.png"},piece_punch)
+
+register_piece("games:checkers_red","red piece",{"wool_red.png"},piece_punch)
+register_piece("games:checkers_red_queen","red piece",{"queen_red.png"},piece_punch)

depends.txt

@@ -0,0 +1 @@
+default

init.lua

@@ -0,0 +1,6 @@
+-- rnd: collection of puzzle games for minetest
+dofile(minetest.get_modpath("games").."/maze.lua")
+dofile(minetest.get_modpath("games").."/sokoban.lua")
+dofile(minetest.get_modpath("games").."/checkers.lua")
+dofile(minetest.get_modpath("games").."/life.lua")
+print("[games] loaded")

life.lua

@@ -0,0 +1,104 @@
+-- game of life
+
+local life_table = {};
+local dim = 5;
+
+minetest.register_abm(
+	{nodenames = {"games:life"},
+	interval = 5.0,
+	chance = 1,
+	action = function(pos)
+	
+	local meta = minetest.get_meta(pos); local infotext = meta:get_string("infotext");
+	if infotext~="RUN" then return end
+	
+	if life_table[0]==nil then return end--  punch node again to initialize
+	
+	local table_new = {};
+	local i,j,k,c,n,p;
+	local dp = {{-1,-1},{0,-1},{1,-1},{-1,0},{1,0},{-1,1},{0,1},{1,1}};
+	for i = -dim,dim do
+		table_new[i]={};
+		for j = -dim,dim do
+			c = life_table[i][j];
+			n=0;
+			for k = 1,8 do
+				p={i+dp[k][1],j+dp[k][2]};
+				if p[1]<-dim then p[1]=dim elseif p[1]>dim then p[1]=-dim end;
+				if p[2]<-dim then p[2]=dim elseif p[2]>dim then p[2]=-dim end;
+				if life_table[ p[1] ][ p[2] ]==1 then n=n+1 end
+			end
+			if c == 1 then --alive
+				if n>=2 and n<=3 then table_new[i][j]=1
+					else
+					table_new[i][j]=0
+				end
+			else -- dead
+				if n==3 then table_new[i][j]=1 else table_new[i][j]=0 end
+			end
+		end
+	end
+	
+	p={x=pos.x,y=pos.y+1,z=pos.z}
+	for i = -dim,dim do
+		for j = -dim,dim do
+			life_table[i][j]=table_new[i][j]
+			p.x = pos.x+i;p.z=pos.z+j;
+			if minetest.get_node(p).name=="air" then
+				if life_table[i][j]==1 then minetest.set_node(p,{name="stairs:slab_stone"}) end
+			else
+				if life_table[i][j]==0 then minetest.set_node(p,{name="air"}) end
+			end
+		end
+	end
+		
+	end,
+}) 
+
+local function init_game(pos)
+	local name; local i,j;local p = {x=pos.x;y=pos.y+1,z=pos.z};
+	for i = -dim,dim do
+		life_table[i]={};
+		for j = -dim,dim do
+			p.x = pos.x+i;p.z=pos.z+j
+			name = minetest.get_node(p).name;
+			if name == "air" then life_table[i][j]=0 else life_table[i][j]=1 end
+			if life_table[i][j]==1 then minetest.set_node(p,{name="stairs:slab_stone"}) end
+			
+		end
+	end
+end
+
+minetest.register_node("games:life", {
+	description = "game of life, game field is 1 above ",
+	inventory_image = "pipeworks_red.png",
+	wield_image = "pipeworks_red.png",
+	wield_scale = {x=0.8,y=2.5,z=1.3},
+	tiles = {"pipeworks_red.png"},
+	stack_max = 1,
+	groups = {oddly_breakable_by_hand=3},
+	
+	on_punch = function(pos, node, puncher, pointed_thing)
+		
+		local name = puncher:get_player_name();if name == nil then return end
+		local privs = minetest.get_player_privs(name);
+		if not privs.ban then return end
+		
+		local meta = minetest.get_meta(pos)
+		local infotext = meta:get_string("infotext");
+		if infotext=="RUN" then infotext ="STOP" else infotext="RUN" end
+		meta:set_string("infotext", infotext) 
+		init_game(pos)
+	end
+	}
+)
+
+
+ -- minetest.register_craft({
+	-- output = "games:life",
+	-- recipe = {
+		-- {"default:stone","","default:stone"},
+		-- {"","default:stone",""},
+		-- {"default:stone","","default:stone"},
+	-- }
+-- })

maze.lua

@@ -0,0 +1,189 @@
+-- maze generation
+-- http://en.wikipedia.org/wiki/Maze_generation_algorithm#Depth-first_search, recursive backtracker
+-- representation of node coordinate (row,coloumn)=(i,j) -> (i-1)*n+j, i=1..n, j=1...m
+-- representation of walls: below node k --> k, left of node k --> k+m.n
+
+-- good overview of maze generation algorithms using javascript/html5
+-- http://www.jamisbuck.org/presentations/rubyconf2011/index.html#recursive-backtracker
+
+-- helper functions
+--stack in lua
+local stack={};
+function stack.push(s,e) s[#s+1]=e end
+function stack.pop(s) local r = s[#s];s[#s]=nil;return r end
+--function table2string(s) local r = ""; for i,v in pairs(s) do r = r.. " ["..i.."]=".. v ; end return r end
+
+function maze_deep_first_search(m,n,start,seed) -- returns a table of strings representing line renders
+
+    local steps,maxsteps; steps= 0; maxsteps = 999999;
+    local maze = {}
+    maze.m = m; maze.n = n;
+    maze.unvisited = {};maze.stack = {}; maze.walls = {};
+    maze.free = maze.m*maze.n; 
+    local i,j,k
+    local nb,wall -- unvisited neighbbors, walls
+
+    --init structures
+    for i=1,maze.m do 
+      for j =1,maze.n do
+        k=(i-1)*maze.n+j;maze.unvisited[k]=true -- initially all cells unvisited
+        maze.walls[k]=true;maze.walls[k+maze.n*maze.m]=true; -- walls are there
+      end
+    end
+
+    math.randomseed(seed)
+    maze.current = start
+    maze.unvisited [ maze.current ] = false;
+    maze.free = maze.free-1; maze.stack[1+#maze.stack] = maze.current
+
+    while maze.free>0 and steps<maxsteps do -- main loop
+      steps=steps+1
+      -- check current node neighbors
+      k=maze.current
+      j = k % maze.n;i=math.ceil(k/maze.n); -- get coords back from index
+      if j==0 then j = maze.n end
+      --print("coords current node "..k .. " = " .. i .. " " ..j)
+
+      nb={};wall={}-- check unvisited neighbors & wall removals
+
+      if i>1 then -- down 
+        k=(i-2)*maze.n+j; if maze.unvisited[k] then wall[#wall+1]=k+maze.n;nb[#nb+1]=k end
+      end
+      if i<maze.m then -- up
+        k=(i)*maze.n+j; if maze.unvisited[k] then wall[#wall+1]=k;nb[#nb+1]=k end
+      end
+      if j<maze.n then --right
+        k=(i-1)*maze.n+j+1; if maze.unvisited[k] then wall[#wall+1]=k+maze.n*maze.m; nb[#nb+1]=k end
+      end
+      if j>1 then --left
+        k=(i-1)*maze.n+j-1; if maze.unvisited[k] then wall[#wall+1]=k+1+maze.n*maze.m;nb[#nb+1]=k end
+      end
+
+      --print("           unvisited neighbors " .. table2string(nb))
+      if (#nb)>0 then -- if unvisited neighbors, choose random one as next current node
+        stack.push(maze.stack,maze.current) -- remember previous current node
+        k=math.random(#nb); -- pick random unvisited neighbor
+        maze.walls[wall[k]]=false; -- remove wall
+        --print("      removed wall ".. wall[k])
+        k=nb[k];
+        maze.current = k; -- new current cell
+        maze.unvisited[k]=false; maze.free =  maze.free-1 -- one less unvisited
+        --print("new explore " .. k);
+
+      elseif (#maze.stack)~=0 then -- no unvisited neighbors, backtrack using stack
+
+        maze.current = stack.pop(maze.stack)
+        --print("backtrack to "..maze.current)
+
+      else -- even stack is empty, just pick random unvisited cell
+        k = math.random(maze.free);	j=1;
+        for i =1,maze.m*maze.n do
+          if maze.unvisited[i] then
+            if j==k then k=i; break end -- pick node
+            j=j+1
+          end
+        end
+        --print(" stack empty, random pick " ..k)
+        maze.current=k;maze.unvisited[k]=false; maze.free = maze.free -1;
+      end
+    end -- of do
+
+    -- render maze with chars, row by row
+    maze.ret = {};
+    local hor;local vert;
+    local wall = "1"
+
+    for i=1,maze.m do
+      hor="";vert="";
+      k= (i-1)*maze.n;
+      -- horizontal
+      for j = 1, maze.n do 
+        k=k+1;		
+        --    if maze.walls[k+maze.n*maze.m] then vert=vert.."X." else vert=vert.. "0." end
+        --    if maze.walls[k] then hor=hor.."XX" else hor=hor.."X0" end
+        if maze.walls[k+maze.n*maze.m] then vert=vert..wall.."0" else vert=vert.. "00" end
+        if maze.walls[k] then hor=hor..wall..wall else hor=hor..wall.."0" end
+      end
+      maze.ret[1+#maze.ret]=hor..wall;maze.ret[1+#maze.ret]=vert..wall;
+    end
+    maze.ret[1+#maze.ret] = string.rep(wall,2*maze.n+1)
+    return maze.ret
+  end
+
+-- RUN PROGRAM
+  local maze=maze_deep_first_search(10,30,1,2015)
+  --for _,v in pairs(maze) do print(v) end
+  
+  
+  
+  core.register_privilege("maze", "Can create mazes") 
+  minetest.register_chatcommand("maze", {
+    description = "/maze (optional m,n,start,seed) generates maze at players position, directed towards positive x,z axix",
+    privs = {maze = true},
+    func = function(name, param)
+		local m,n,start, seed
+		if param == "" then m=10;n=10;start=1;seed=1 else
+			local words = {}; local word
+			for word in param:gmatch("%w+") do words[1+#words]= word end
+				if words[1]~=nil then m = tonumber(words[1]) else m = 10 end
+				if words[2]~=nil then n = tonumber(words[2]) else n = 10 end
+				if words[3]~=nil then start = tonumber(words[3]) else start =  1 end
+				if words[4]~=nil then seed = tonumber(words[4]) else seed =  1 end
+		end
+		if m*n>1000000 then minetest.chat_send_player(name, "limit maze size to 1000000 cells") return end
+        local player = minetest.env:get_player_by_name(name); if player==nil then return end
+		local pos =  player:getpos();local p
+		local maze=maze_deep_first_search(m,n,start,seed) -- m,n,start,seed
+		local i,j,k;local p = {x=pos.x,y=pos.y,z=pos.z};
+		for i,v in pairs(maze) do 
+			p.x = pos.x+i
+			for k = 1,string.len(v) do
+				p.z=pos.z+k
+					if string.sub(v,k,k)=="1" then
+						minetest.set_node(p,{name="games:stone_maze"})
+						else minetest.set_node(p,{name="air"})
+					end
+				end
+		end
+	
+		
+end,	
+})
+
+minetest.register_node("games:glass_maze", {
+	description = "maze_glass",
+	drawtype = "glasslike_framed_optional",
+	tiles = {"maze_glass.png"},
+	inventory_image = minetest.inventorycube("maze_glass.png"),
+	paramtype = "light",
+	sunlight_propagates = true,
+	is_ground_content = false,
+	groups = {immortal = 1,disable_jump=1},
+	sounds = default.node_sound_glass_defaults(),
+})
+
+minetest.register_node("games:stone_maze", {
+	description = "maze_wall",
+	tiles = {"default_brick.png"},
+	is_ground_content = true,
+	groups = {immortal = 1,disable_jump=1},
+	legacy_mineral = true,
+	sounds = default.node_sound_stone_defaults(),
+	on_rightclick = function(pos, node, player, itemstack, pointed_thing)
+		local name = player:get_player_name(); if name == nil then return end
+		if minetest.is_protected(pos, name) then
+			return
+		 end
+		local player_inv = player:get_inventory()
+		if player_inv:room_for_item("main", {"games:stone_maze"}) then
+			player_inv:add_item("main", "games:stone_maze") 
+			minetest.remove_node(pos) -- remove bones
+		end
+
+		
+		
+		
+	end
+})
+
+  

sokoban.lua

@@ -0,0 +1,181 @@
+-- SOKOBAN GAME
+-- basic board game mechanics ( checkers )
+-- by rnd
+
+
+local sokoban = {};
+sokoban.push_time = 0
+sokoban.blocks = 0;sokoban.level = 0; sokoban.moves=0;
+sokoban.load=0;sokoban.playername =""
+local SOKOBAN_WALL = "games:stone_maze"
+local SOKOBAN_FLOOR = "default:stone"
+local SOKOBAN_GOAL = "default:tree"
+
+
+minetest.register_node("games:crate", { -- block that player pushes around, basically main sokoban routine
+	description = "sokoban crate",
+	tiles = {"crate.png"},
+	paramtype = "light",
+	light_source = 10,
+	is_ground_content = false,
+	groups = {immortal = 1},
+	sounds = default.node_sound_wood_defaults(),
+	on_punch = function(pos, node, player)
+		local name = player:get_player_name(); if name==nil then return end
+		if sokoban.playername~=name then 
+			if sokoban.playername == "" then 
+				minetest.chat_send_player(name,"Please right click level loader block to load and play Sokoban")
+				return
+			end
+			minetest.chat_send_player(name,"Only ".. sokoban.playername .. " can play. To play new level please right click loader block and select level.")
+			return
+		end
+		local time = sokoban.push_time; local t = minetest.get_gametime();
+		if t-time<1 then return end;sokoban.push_time = t
+		local p=player:getpos();local q={x=pos.x,y=pos.y,z=pos.z}
+		p.x=p.x-q.x;p.y=p.y-q.y;p.z=p.z-q.z
+		if math.abs(p.y+0.5)>0 then return end
+		if math.abs(p.x)>math.abs(p.z) then
+			if p.z<-0.5 or p.z>0.5 or math.abs(p.x)>1.5 then return end
+			if p.x+q.x>q.x then q.x= q.x-1 
+				else q.x = q.x+1
+			end
+		else
+			if p.x<-0.5 or p.x>0.5 or  math.abs(p.z)>1.5 then return end
+			if p.z+q.z>q.z then q.z= q.z-1 
+				else q.z = q.z+1
+			end
+		end
+		
+		
+		if minetest.get_node(q).name=="air" then -- push crate
+			sokoban.moves = sokoban.moves+1
+			local old_infotext = minetest.get_meta(pos):get_string("infotext");
+			minetest.set_node(pos,{name="air"})
+			minetest.set_node(q,{name="games:crate"})
+			minetest.sound_play("default_dig_dig_immediate", {pos=q,gain=1.0,max_hear_distance = 24,})
+			local meta = minetest.get_meta(q);
+			q.y=q.y-1; 
+			if minetest.get_node(q).name==SOKOBAN_GOAL then  
+				if old_infotext~="GOAL REACHED" then
+					sokoban.blocks = sokoban.blocks -1;
+				end
+				meta:set_string("infotext", "GOAL REACHED") 
+			else 
+				if old_infotext=="GOAL REACHED" then
+					sokoban.blocks = sokoban.blocks +1
+				end
+				meta:set_string("infotext", "push crate on top of goal block") 
+			end
+		end
+		local name = player:get_player_name(); if name==nil then return end
+		if sokoban.blocks~=0 then
+			minetest.chat_send_player(name,"move " .. sokoban.moves .. " : " ..sokoban.blocks .. " crates left ");
+			else minetest.chat_send_all("#SOKOBAN : ".. name .. " just solved sokoban level ".. sokoban.level .. " in " .. sokoban.moves .. " moves.")
+			-- if playerdata~=nil then -- award xp if playerdata exist
+				-- playerdata[name].xp = playerdata[name].xp + (sokoban.level-0.5)*100
+			-- end
+			sokoban.playername = ""; sokoban.level = 1
+		end
+	end,
+})
+
+
+minetest.register_node("games:sokoban", { -- level loader block
+description = "sokoban crate",
+	tiles = {"default_brick.png","crate.png","crate.png","crate.png","crate.png","crate.png"},
+	groups = {oddly_breakable_by_hand=1},
+	is_ground_content = false,
+	paramtype = "light",
+	light_source = 14,
+	sounds = default.node_sound_wood_defaults(),
+	on_construct = function(pos)
+		local meta = minetest.get_meta(pos)
+		
+		local form  = 
+		"size[3,1]" ..  -- width, height
+		"field[0,0.5;3,1;level;enter level 1 to 90;1]"..
+		"button[2.5,0.25;1,1;play;OK]"
+		meta:set_string("formspec", form)
+		meta:set_string("infotext","sokoban level loader, right click to select level")
+		meta:set_int("time", minetest.get_gametime()-300);
+	end, 
+	on_punch = function(pos, node, player) -- make timer ready to enter
+		local name = player:get_player_name(); if name==nil then return end
+		local privs = minetest.get_player_privs(name); 
+		if not privs.ban then return end
+		local meta = minetest.get_meta(pos)
+		local t = minetest.get_gametime(); meta:set_int("time", t-500)		
+		minetest.chat_send_all("Sokoban loader reset. Load level now.")
+	end,
+	on_receive_fields = function(pos, formname, fields, sender) 
+		local name = sender:get_player_name(); if name==nil then return end
+		local privs = minetest.get_player_privs(name); 
+		
+		local meta = minetest.get_meta(pos)
+		local t = minetest.get_gametime();local t_old = meta:get_int("time");
+		if not privs.ban then 
+			if name~=sokoban.playername then
+				if t-t_old<300 then 
+					minetest.chat_send_player(name,"Wait at least 5 minutes to load next level. "..300-(t-t_old) .. " seconds left.");
+					return 
+				end
+			else
+				if t-t_old<60 then 
+					minetest.chat_send_player(name,"Wait at least 1 minute to load next level. "..60-(t-t_old) .. " seconds left.");
+					return 
+				end
+			end
+		end
+		
+		--minetest.chat_send_all("formname " .. formname .. " fields " .. dump(fields))
+		
+		sokoban.playername = name
+		meta:set_int("time", t);
+		local lvl;
+		if fields.play ~= nil and tonumber(fields.level) ~=nil then			
+			lvl = tonumber(fields.level)-1 
+		end
+		if lvl == nil then return end
+		if lvl <0 or lvl >89 then return end
+		
+		local file = io.open(minetest.get_modpath("games").."/sokoban.txt","r")
+		if not file then minetest.chat_send_player(name,"failed to open sokoban.txt") return end
+		local str = ""; local s; local p = {x=pos.x,y=pos.y,z=pos.z}; local i,j;i=0;
+		local lvl_found = false
+		while str~= nil do
+			str = file:read("*line"); 
+			if str~=nil and str =="; "..lvl then lvl_found=true break end
+		end
+		if not lvl_found then file:close();return end
+		
+		sokoban.blocks = 0;sokoban.level = lvl+1; sokoban.moves=0;
+		while str~= nil do
+			str = file:read("*line"); 
+			if str~=nil then 
+				if string.sub(str,1,1)==";" then
+					file:close(); minetest.chat_send_all("Sokoban level "..sokoban.level .." loaded by ".. name .. ". It has " .. sokoban.blocks  .. " boxes to push. "); return 
+				end
+				i=i+1;
+				for j = 1,string.len(str) do
+					p.x=pos.x+i;p.y=pos.y; p.z=pos.z+j; s=string.sub(str,j,j);
+					p.y=p.y-1; 
+					if minetest.get_node(p).name~=SOKOBAN_FLOOR then minetest.set_node(p,{name=SOKOBAN_FLOOR}); end -- clear floor
+					p.y=p.y+1;
+					if s==" " and minetest.get_node(p).name~="air" then minetest.set_node(p,{name="air"}) end
+					if s=="#" and minetest.get_node(p).name~=SOKOBAN_WALL then minetest.set_node(p,{name=SOKOBAN_WALL}) end
+					if s=="$" then minetest.set_node(p,{name="games:crate"});sokoban.blocks=sokoban.blocks+1 end
+					if s=="." then p.y=p.y-1;minetest.set_node(p,{name=SOKOBAN_GOAL}); p.y=p.y+1;minetest.set_node(p,{name="air"}) end
+					--starting position
+					if s=="@" then p.y=p.y-1;minetest.set_node(p,{name="default:glass"}); p.y=p.y+1;minetest.set_node(p,{name="air"}) end
+					if s~="@" then p.y = pos.y+2;minetest.set_node(p,{name="games:glass_maze"});  
+						else p.y=pos.y+2;minetest.set_node(p,{name="default:ladder"})
+					end -- roof above to block jumps
+					
+				end
+			end
+		end
+		
+		file:close();		
+	end,
+})