Add a Chess Board with game in formspec

chess.lua

@@ -0,0 +1,642 @@
+-- See https://github.com/kilbith/realchess for the main repository
+
+local realchess = {}
+
+local function index_to_xy(index)
+	index = index - 1
+	local x = index % 8
+	local y = (index - x) / 8
+	return x, y
+end
+
+local function xy_to_index(x, y)
+	return x + y * 8 + 1
+end
+
+function realchess.init(pos)
+	local meta = minetest.get_meta(pos)
+	local inv = meta:get_inventory()
+	local slots = "listcolors[#00000000;#00000000;#00000000;#30434C;#FFF]"
+	local formspec
+
+	inv:set_size("board", 64)
+
+	meta:set_string("formspec",
+		"size[8,8.6;]"..
+		"bgcolor[#080808BB;true]"..
+		"background[0,0;8,8;chess_bg.png]"..
+		"button[3.1,7.8;2,2;new;New game]"..
+		"list[context;board;0,0;8,8;]"..
+		slots)
+
+	meta:set_string("infotext", "Chess Board")
+	meta:set_string("playerBlack", "")
+	meta:set_string("playerWhite", "")
+	meta:set_string("lastMove", "")
+	meta:set_int("lastMoveTime", 0)
+	meta:set_string("winner", "")
+	meta:set_int("castlingBlackL", 1)
+	meta:set_int("castlingBlackR", 1)
+	meta:set_int("castlingWhiteL", 1)
+	meta:set_int("castlingWhiteR", 1)
+
+	inv:set_list("board", {
+		"realchess:rook_black_1",
+		"realchess:knight_black_1",
+		"realchess:bishop_black_1",
+		"realchess:queen_black",
+		"realchess:king_black",
+		"realchess:bishop_black_2",
+		"realchess:knight_black_2",
+		"realchess:rook_black_2",
+		"realchess:pawn_black_1",
+		"realchess:pawn_black_2",
+		"realchess:pawn_black_3",
+		"realchess:pawn_black_4",
+		"realchess:pawn_black_5",
+		"realchess:pawn_black_6",
+		"realchess:pawn_black_7",
+		"realchess:pawn_black_8",		
+		"", "", "", "", "", "", "", "",
+		"", "", "", "", "", "", "", "",
+		"", "", "", "", "", "", "", "",
+		"", "", "", "", "", "", "", "",
+		"realchess:pawn_white_1",
+		"realchess:pawn_white_2",
+		"realchess:pawn_white_3",
+		"realchess:pawn_white_4",
+		"realchess:pawn_white_5",
+		"realchess:pawn_white_6",
+		"realchess:pawn_white_7",
+		"realchess:pawn_white_8",
+		"realchess:rook_white_1",
+		"realchess:knight_white_1",
+		"realchess:bishop_white_1",
+		"realchess:queen_white",
+		"realchess:king_white",
+		"realchess:bishop_white_2",
+		"realchess:knight_white_2",
+		"realchess:rook_white_2"
+	})
+end
+
+function realchess.move(pos, from_list, from_index, to_list, to_index, count, player)
+	if from_list ~= "board" and to_list ~= "board" then
+		return 0
+	end
+
+	local playerName = player:get_player_name()
+	local meta = minetest.get_meta(pos)
+
+	if meta:get_string("winner") ~= "" then
+		minetest.chat_send_player(playerName, "This game is over.")
+		return 0
+	end
+
+	local inv = meta:get_inventory()
+	local pieceFrom = inv:get_stack(from_list, from_index):get_name()
+	local pieceTo = inv:get_stack(to_list, to_index):get_name()
+	local lastMove = meta:get_string("lastMove")
+	local thisMove -- will replace lastMove when move is legal
+	local playerWhite = meta:get_string("playerWhite")
+	local playerBlack = meta:get_string("playerBlack")
+
+	if pieceFrom:find("white") then
+		if playerWhite ~= "" and playerWhite ~= playerName then
+			minetest.chat_send_player(playerName, "Someone else plays white pieces!")
+			return 0
+		end		
+		if lastMove ~= "" and lastMove ~= "black" then
+			minetest.chat_send_player(playerName, "It's not your turn, wait for your opponent to play.")
+			return 0
+		end
+		if pieceTo:find("white") then
+			-- Don't replace pieces of same color
+			return 0
+		end
+		playerWhite = playerName
+		thisMove = "white"
+	elseif pieceFrom:find("black") then
+		if playerBlack ~= "" and playerBlack ~= playerName then
+			minetest.chat_send_player(playerName, "Someone else plays black pieces!")
+			return 0
+		end
+		if lastMove ~= "" and lastMove ~= "white" then
+			minetest.chat_send_player(playerName, "It's not your turn, wait for your opponent to play.")
+			return 0
+		end
+		if pieceTo:find("black") then
+			-- Don't replace pieces of same color
+			return 0
+		end
+		playerBlack = playerName
+		thisMove = "black"
+	end
+
+	-- DETERMINISTIC MOVING
+
+	local from_x, from_y = index_to_xy(from_index)
+	local to_x, to_y = index_to_xy(to_index)
+
+	if pieceFrom:find("pawn") then
+		if thisMove == "white" then
+			-- white pawns can go up only
+			if from_y - 1 == to_y then
+				if from_x == to_x then
+					if pieceTo ~= "" then
+						return 0
+					elseif to_index >= 1 and to_index <= 8 then
+						inv:set_stack(from_list, from_index, "realchess:queen_white")
+					end
+				elseif from_x - 1 == to_x or from_x + 1 == to_x then
+					if not pieceTo:find("black") then
+						return 0
+					end
+				else
+					return 0
+				end
+			elseif from_y - 2 == to_y then
+				if pieceTo ~= "" or from_y < 6 or inv:get_stack(from_list, xy_to_index(from_x, from_y - 1)):get_name() ~= "" then
+					return 0
+				end
+			else
+				return 0
+			end
+		elseif thisMove == "black" then
+			-- black pawns can go down only
+			if from_y + 1 == to_y then
+				if from_x == to_x then
+					if pieceTo ~= "" then
+						return 0
+					elseif to_index >= 57 and to_index <= 64 then
+						inv:set_stack(from_list, from_index, "realchess:queen_black")
+					end
+				elseif from_x - 1 == to_x or from_x + 1 == to_x then
+					if not pieceTo:find("white") then
+						return 0
+					end
+				else
+					return 0
+				end
+			elseif from_y + 2 == to_y then
+				if pieceTo ~= "" or from_y > 1 or inv:get_stack(from_list, xy_to_index(from_x, from_y + 1)):get_name() ~= "" then
+					return 0
+				end
+			else
+				return 0
+			end
+
+			-- if x not changed,
+			--   ensure that destination cell is empty
+			-- elseif x changed one unit left or right
+			--   ensure the pawn is killing opponent piece
+			-- else
+			--   move is not legal - abort
+
+			if from_x == to_x then
+				if pieceTo ~= "" then
+					return 0
+				end
+			elseif from_x - 1 == to_x or from_x + 1 == to_x then
+				if not pieceTo:find("white") then
+					return 0
+				end
+			else
+				return 0
+			end
+		else
+			return 0
+		end
+
+	elseif pieceFrom:find("rook") then
+		if from_x == to_x then
+			-- moving vertically
+			if from_y < to_y then
+				-- moving down
+				-- ensure that no piece disturbs the way
+				for i = from_y + 1, to_y - 1 do
+					if inv:get_stack(from_list, xy_to_index(from_x, i)):get_name() ~= "" then
+						return 0
+					end
+				end
+			else
+				-- mocing up
+				-- ensure that no piece disturbs the way
+				for i = to_y + 1, from_y - 1 do
+					if inv:get_stack(from_list, xy_to_index(from_x, i)):get_name() ~= "" then
+						return 0
+					end
+				end
+			end
+		elseif from_y == to_y then
+			-- mocing horizontally
+			if from_x < to_x then
+				-- mocing right
+				-- ensure that no piece disturbs the way
+				for i = from_x + 1, to_x - 1 do
+					if inv:get_stack(from_list, xy_to_index(i, from_y)):get_name() ~= "" then
+						return 0
+					end
+				end
+			else
+				-- mocing left
+				-- ensure that no piece disturbs the way
+				for i = to_x + 1, from_x - 1 do
+					if inv:get_stack(from_list, xy_to_index(i, from_y)):get_name() ~= "" then
+						return 0
+					end
+				end
+			end
+		else
+			-- attempt to move arbitrarily -> abort
+			return 0
+		end
+
+		if thisMove == "white" then
+			if pieceFrom:find("1") then
+				meta:set_int("castlingWhiteL", 0)
+			elseif pieceFrom:find("2") then
+				meta:set_int("castlingWhiteR", 0)
+			end
+		elseif thisMove == "black" then
+			if pieceFrom:find("1") then
+				meta:set_int("castlingWhiteL", 0)
+			elseif pieceFrom:find("2") then
+				meta:set_int("castlingWhiteR", 0)
+			end
+		end
+
+	elseif pieceFrom:find("knight") then
+		-- get relative pos
+		local dx = from_x - to_x
+		local dy = from_y - to_y
+
+		-- get absolute values
+		if dx < 0 then
+			dx = -dx
+		end
+		if dy < 0 then
+			dy = -dy
+		end
+
+		-- sort x and y
+		if dx > dy then
+			dx, dy = dy, dx
+		end
+
+		-- ensure that dx == 1 and dy == 2
+		if dx ~= 1 or dy ~= 2 then
+			return 0
+		end
+		-- just ensure that destination cell does not contain friend piece
+		-- ^ it was done already thus everything ok
+
+	elseif pieceFrom:find("bishop") then
+		-- get relative pos
+		local dx = from_x - to_x
+		local dy = from_y - to_y
+
+		-- get absolute values
+		if dx < 0 then
+			dx = -dx
+		end
+		if dy < 0 then
+			dy = -dy
+		end
+
+		-- ensure dx and dy are equal
+		if dx ~= dy then
+			return 0
+		end
+
+		if from_x < to_x then
+			if from_y < to_y then
+				-- moving right-down
+				-- ensure that no piece disturbs the way
+				for i = 1, dx - 1 do
+					if inv:get_stack(from_list, xy_to_index(from_x + i, from_y + i)):get_name() ~= "" then
+						return 0
+					end
+				end
+			else
+				-- moving right-up
+				-- ensure that no piece disturbs the way
+				for i = 1, dx - 1 do
+					if inv:get_stack(from_list, xy_to_index(from_x + i, from_y - i)):get_name() ~= "" then
+						return 0
+					end
+				end
+			end
+		else
+			if from_y < to_y then
+				-- moving left-down
+				-- ensure that no piece disturbs the way
+				for i = 1, dx - 1 do
+					if inv:get_stack(from_list, xy_to_index(from_x - i, from_y + i)):get_name() ~= "" then
+						return 0
+					end
+				end
+			else
+				-- moving left-up
+				-- ensure that no piece disturbs the way
+				for i = 1, dx - 1 do
+					if inv:get_stack(from_list, xy_to_index(from_x - i, from_y - i)):get_name() ~= "" then
+						return 0
+					end
+				end
+			end
+		end
+
+	elseif pieceFrom:find("queen") then
+		local dx = from_x - to_x
+		local dy = from_y - to_y
+
+		-- get absolute values
+		if dx < 0 then
+			dx = -dx
+		end
+		if dy < 0 then
+			dy = -dy
+		end
+
+		-- ensure valid relative move
+		if dx ~= 0 and dy ~= 0 and dx ~= dy then
+			return 0
+		end
+
+		if from_x == to_x then
+			if from_y < to_y then
+				-- goes down
+				-- ensure that no piece disturbs the way
+				for i = 1, dx - 1 do
+					if inv:get_stack(from_list, xy_to_index(from_x, from_y + i)):get_name() ~= "" then
+						return 0
+					end
+				end
+			else
+				-- goes up
+				-- ensure that no piece disturbs the way
+				for i = 1, dx - 1 do
+					if inv:get_stack(from_list, xy_to_index(from_x, from_y - i)):get_name() ~= "" then
+						return 0
+					end
+				end
+			end		
+		elseif from_x < to_x then
+			if from_y == to_y then
+				-- goes right
+				-- ensure that no piece disturbs the way
+				for i = 1, dx - 1 do
+					if inv:get_stack(from_list, xy_to_index(from_x + i, from_y)):get_name() ~= "" then
+						return 0
+					end
+				end
+			elseif from_y < to_y then
+				-- goes right-down
+				-- ensure that no piece disturbs the way
+				for i = 1, dx - 1 do
+					if inv:get_stack(from_list, xy_to_index(from_x + i, from_y + i)):get_name() ~= "" then
+						return 0
+					end
+				end
+			else
+				-- goes right-up
+				-- ensure that no piece disturbs the way
+				for i = 1, dx - 1 do
+					if inv:get_stack(from_list, xy_to_index(from_x + i, from_y - i)):get_name() ~= "" then
+						return 0
+					end
+				end
+			end				
+		else
+			if from_y == to_y then
+				-- goes left
+				-- ensure that no piece disturbs the way and destination cell does
+				for i = 1, dx - 1 do
+					if inv:get_stack(from_list, xy_to_index(from_x - i, from_y)):get_name() ~= "" then
+						return 0
+					end
+				end
+			elseif from_y < to_y then
+				-- goes left-down
+				-- ensure that no piece disturbs the way
+				for i = 1, dx - 1 do
+					if inv:get_stack(from_list, xy_to_index(from_x - i, from_y + i)):get_name() ~= "" then
+						return 0
+					end
+				end
+			else
+				-- goes left-up
+				-- ensure that no piece disturbs the way
+				for i = 1, dx - 1 do
+					if inv:get_stack(from_list, xy_to_index(from_x - i, from_y - i)):get_name() ~= "" then
+						return 0
+					end
+				end
+			end		
+		end
+
+	elseif pieceFrom:find("king") then
+		local dx = from_x - to_x
+		local dy = from_y - to_y
+		local check = true
+		
+		if thisMove == "white" then
+			if from_y == 7 and to_y == 7 then
+				if to_x == 1 then
+					if meta:get_int("castlingWhiteL") == 1 and inv:get_stack(from_list, 57):get_name() == "realchess:rook_white_1" then
+						for i = 58, from_index - 1 do
+							if inv:get_stack(from_list, i):get_name() ~= "" then
+								return 0
+							end
+						end
+						inv:set_stack(from_list, 57, "")
+						inv:set_stack(from_list, 59, "realchess:rook_white_1")
+						check = false
+					end
+				elseif to_x == 6 then
+					if meta:get_int("castlingWhiteR") == 1 and inv:get_stack(from_list, 64):get_name() == "realchess:rook_white_2" then
+						for i = from_index + 1, 63 do
+							if inv:get_stack(from_list, i):get_name() ~= "" then
+								return 0
+							end
+						end
+						inv:set_stack(from_list, 62, "realchess:rook_white_2")
+						inv:set_stack(from_list, 64, "")
+						check = false
+					end
+				end
+			end
+		elseif thisMove == "black" then
+			if from_y == 0 and to_y == 0 then
+				if to_x == 1 then
+					if meta:get_int("castlingBlackL") == 1 and inv:get_stack(from_list, 1):get_name() == "realchess:rook_black_1" then
+						for i = 2, from_index - 1 do
+							if inv:get_stack(from_list, i):get_name() ~= "" then
+								return 0
+							end
+						end
+						inv:set_stack(from_list, 1, "")
+						inv:set_stack(from_list, 3, "realchess:rook_black_1")
+						check = false
+					end
+				elseif to_x == 6 then
+					if meta:get_int("castlingBlackR") == 1 and inv:get_stack(from_list, 8):get_name() == "realchess:rook_black_2" then
+						for i = from_index + 1, 7 do
+							if inv:get_stack(from_list, i):get_name() ~= "" then
+								return 0
+							end
+						end
+						inv:set_stack(from_list, 6, "realchess:rook_black_2")
+						inv:set_stack(from_list, 8, "")
+						check = false
+					end
+				end
+			end
+		end
+
+		if check then
+			if dx < 0 then
+				dx = -dx
+			end
+			if dy < 0 then
+				dy = -dy
+			end
+			
+			if dx > 1 or dy > 1 then
+				return 0
+			end
+		end
+		
+		if thisMove == "white" then
+			meta:set_int("castlingWhiteL", 0)
+			meta:set_int("castlingWhiteR", 0)
+		elseif thisMove == "black" then
+			meta:set_int("castlingBlackL", 0)		
+			meta:set_int("castlingBlackR", 0)
+		end
+	end
+
+	meta:set_string("playerWhite", playerWhite)
+	meta:set_string("playerBlack", playerBlack)
+	meta:set_string("lastMove", thisMove)
+	meta:set_int("lastMoveTime", minetest.get_gametime())
+
+	if meta:get_string("lastMove") == "black" then
+		minetest.chat_send_player(playerWhite, playerName.." has moved a "..pieceFrom:match("%a+:(%a+)")..", it's now your turn.")
+	elseif meta:get_string("lastMove") == "white" then
+		minetest.chat_send_player(playerBlack, playerName.." has moved a "..pieceFrom:match("%a+:(%a+)")..", it's now your turn.")
+	end
+
+	if pieceTo:find("king") then
+		minetest.chat_send_player(playerBlack, playerName.." won the game.")
+		minetest.chat_send_player(playerWhite, playerName.." won the game.")
+		meta:set_string("winner", thisMove)
+	end
+
+	return 1
+end
+
+function realchess.fields(pos, formname, fields, sender)
+	local playerName = sender:get_player_name()
+	local meta = minetest.get_meta(pos)
+
+	if fields.quit then return end
+
+	-- the chess can't be reset during a started game unless if nobody has played during a while (~5 min. by default)
+	if fields.new and (meta:get_string("playerWhite") == playerName or
+			meta:get_string("playerBlack") == playerName) then
+		realchess.init(pos)
+	elseif fields.new and meta:get_int("lastMoveTime") ~= 0 and
+			minetest.get_gametime() >= meta:get_int("lastMoveTime") + 250 and
+			(meta:get_string("playerWhite") ~= playerName or
+			meta:get_string("playerBlack") ~= playerName) then
+		realchess.init(pos)
+	else
+		minetest.chat_send_player(playerName, "You can't reset the chessboard, a game has been started.\nIf you are not a current player, try again after a while.")
+	end
+end
+
+function realchess.dig(pos, player)
+	local meta = minetest.get_meta(pos)
+	local playerName = player:get_player_name()
+
+	-- the chess can't be dug during a started game unless if nobody has played during a while (~5 min. by default)
+	if meta:get_int("lastMoveTime") ~= 0 and
+			minetest.get_gametime() <= meta:get_int("lastMoveTime") + 250 then
+		minetest.chat_send_player(playerName, "You can't dig the chessboard, a game has been started.\nReset it first if you're a current player, or try digging again after a while.")
+		return false
+	end
+
+	return true
+end
+
+function realchess.on_move(pos, from_list, from_index, to_list, to_index, count, player)
+	local inv = minetest.get_meta(pos):get_inventory()
+	inv:set_stack(from_list, from_index, '')
+	return false
+end
+
+function realchess.take(pos, listname, index, stack, player)
+	return 0
+end
+
+minetest.register_node(":realchess:chessboard", {
+	description = "Chess Board",
+	drawtype = "nodebox",
+	paramtype = "light",
+	paramtype2 = "facedir",
+	inventory_image = "chessboard_top.png",
+	wield_image = "chessboard_top.png",
+	tiles = {"chessboard_top.png", "chessboard_top.png",
+		"chessboard_sides.png", "chessboard_sides.png",
+		"chessboard_top.png", "chessboard_top.png"},
+	groups = {choppy=3, flammable=3},
+	sounds = default.node_sound_wood_defaults(),
+	node_box = {type = "fixed", fixed = {-0.5, -0.5, -0.5, 0.5, -0.4375, 0.5}},
+	sunlight_propagates = true,
+	can_dig = realchess.dig,
+	on_construct = realchess.init,
+	on_receive_fields = realchess.fields,
+	allow_metadata_inventory_move = realchess.move,
+	on_metadata_inventory_move = realchess.on_move,
+	allow_metadata_inventory_take = realchess.take
+})
+
+local function register_piece(name, count)
+	for _, color in pairs({"black", "white"}) do
+	if not count then
+		minetest.register_craftitem(":realchess:"..name.."_"..color, {
+			description = color:gsub("^%l", string.upper).." "..name:gsub("^%l", string.upper),
+			inventory_image = name.."_"..color..".png",
+			stack_max = 1,
+			groups = {not_in_creative_inventory=1}
+		})
+	else
+		for i = 1, count do
+			minetest.register_craftitem(":realchess:"..name.."_"..color.."_"..i, {
+				description = color:gsub("^%l", string.upper).." "..name:gsub("^%l", string.upper),
+				inventory_image = name.."_"..color..".png",
+				stack_max = 1,
+				groups = {not_in_creative_inventory=1}
+			})
+		end
+	end
+	end
+end
+
+register_piece("pawn", 8)
+register_piece("rook", 2)
+register_piece("knight", 2)
+register_piece("bishop", 2)
+register_piece("queen")
+register_piece("king")
+
+minetest.register_craft({ 
+	output = "realchess:chessboard",
+	recipe = {
+		{"dye:black", "dye:white", "dye:black"},
+		{"stairs:slab_wood", "stairs:slab_wood", "stairs:slab_wood"}
+	} 
+})
+

init.lua

@@ -4,6 +4,7 @@ local modpath = minetest.get_modpath("xdecor")
 dofile(modpath.."/handlers/nodeboxes.lua")
 dofile(modpath.."/handlers/registration.lua")
 dofile(modpath.."/aliases.lua")
+dofile(modpath.."/chess.lua")
 dofile(modpath.."/crafts.lua")
 dofile(modpath.."/enchanting.lua")
 dofile(modpath.."/hive.lua")