new function

functions/maze.lua

@@ -0,0 +1,140 @@
+local function coord_string(x, y)
+	str = tostring(x) .. "_"
+	str = str .. tostring(y)
+	return str
+end
+
+local function draw_cell(surface, cell, cell_size, wall_entity_name)
+	local r = math.floor(cell_size * 0.5)
+	if cell.north then
+		for x = r * -1, r, 1 do
+			surface.create_entity({position = {cell.position.x + x, cell.position.y - r}, name = wall_entity_name})
+		end
+	end
+	if cell.south then
+		for x = r * -1, r, 1 do
+			surface.create_entity({position = {cell.position.x + x, cell.position.y + r}, name = wall_entity_name})
+		end
+	end
+	if cell.east then
+		for y = r * -1, r, 1 do
+			surface.create_entity({position = {cell.position.x + r, cell.position.y + y}, name = wall_entity_name})
+		end
+	end
+	if cell.west then
+		for y = r * -1, r, 1 do
+			surface.create_entity({position = {cell.position.x - r, cell.position.y - y}, name = wall_entity_name})
+		end
+	end
+end
+
+local function draw_maze(surface, position, size, cell_size, wall_entity_name)
+	for _, cell in pairs(maze_cells) do
+		draw_cell(surface, cell, cell_size, wall_entity_name)
+	end
+end
+
+local function get_random_occupied_cell()
+	local occupied_cells = {}
+	for c, cell in pairs(maze_cells) do
+		if cell.occupied then
+			if not cell.dead then
+				occupied_cells[#occupied_cells + 1] = c
+			end
+		end
+	end
+	if not occupied_cells[1] then return end
+	return occupied_cells[math.random(1, #occupied_cells)]
+end
+
+local function set_dead_cells()
+	local directions = {
+		{0, -1},
+		{0, 1},
+		{1, 0},
+		{-1, 0}
+	}
+	
+	for c, cell in pairs(maze_cells) do
+		if not cell.dead then
+			maze_cells[c].dead = true
+			for i = 1, 4, 1 do
+				local cell_string = coord_string(cell.cell_position.x + directions[i][1], cell.cell_position.y + directions[i][2])
+				if maze_cells[cell_string] then
+					if not maze_cells[cell_string].occupied then
+						maze_cells[c].dead = false
+						break
+					end
+				end		
+			end
+		end
+	end
+end
+
+local function expand_cell(current_cell)
+	local expansion_raffle = {
+			{0, -1, "north", "south"},
+			{0, 1, "south", "north"},
+			{1, 0, "east", "west"},
+			{-1, 0, "west", "east"}
+		}
+	table.shuffle_table(expansion_raffle)
+	for i = 1, 4, 1 do
+		local direction = expansion_raffle[i]
+		local cell_canditate = coord_string(current_cell.cell_position.x + direction[1], current_cell.cell_position.y + direction[2])
+		if maze_cells[cell_canditate] then
+			if not maze_cells[cell_canditate].occupied then
+				maze_cells[cell_canditate].occupied = true
+				current_cell[direction[3]] = false
+				maze_cells[cell_canditate][direction[4]] = false
+				return maze_cells[cell_canditate]
+			end
+		end
+	end
+	return false
+end
+
+local function expand(size)
+	local current_cell = maze_cells[get_random_occupied_cell()]
+	while true do
+		current_cell = expand_cell(current_cell)
+		if not current_cell then
+			set_dead_cells()
+			current_cell = maze_cells[get_random_occupied_cell()] 
+		end
+		if not current_cell then break end
+	end
+end
+
+function create_maze(surface, position, size, cell_size, wall_entity_name)
+	if not surface then game.print("No surface given.") return end
+	if not position then game.print("No position given.") return end
+	if not size then game.print("No size given.") return end
+	if not cell_size then game.print("No cell_size given.") return end
+	if not wall_entity_name then game.print("No wall_entity_name given.") return end
+	
+	maze_cells = {}
+	
+	for x = size * -1, size, 1 do
+		for y = size * -1, size, 1 do
+			maze_cells[coord_string(x, y)] = {
+				position = {x = position.x + x * (cell_size - 1), y = position.y + y * (cell_size - 1)},
+				cell_position = {x = x , y = y},
+				occupied = false,
+				dead = false,
+				north = true,
+				south = true,
+				east = true,
+				west = true
+			}
+		end
+	end
+	
+	maze_cells[coord_string(size, size)].occupied = true
+	maze_cells[coord_string(size, size)].south = false
+	maze_cells[coord_string(size * -1, size * -1)].north = false
+	
+	expand(size)
+	
+	draw_maze(surface, position, size, cell_size, wall_entity_name)
+end