gistfile1.lua

map = {}
map.width = 79
map.height = 21

map.cellWidth = 13
map.cellHeight = 7

map.rooms = {}

function isLegal( x, y )
	return x > 0 and y > 0 and x <= map.width and y <= map.height
end

function initMap()
	for i = 1, map.width do
		map[i] = {}
		for j = 1, map.height do
			map[i][j] = "#"
		end
	end

	map.rooms = {}
end

function showMap()
	for j = 1, map.height do
		for i =1, map.width do
			io.write( map[i][j] )
		end
		io.write( "\n" )
	end
end

function digRoom( x, y, w, h )
	for i = x, x+w do
		for j = y, y+h do
			if isLegal( i, j ) then map[i][j] = "." end
		end
	end
end

function digCooridor( x1, y1, x2, y2 )
	local cx, cy, xo, yo = x1, y1, 0, 0

	if x2 > x1 then
		xo = 1
	else
		xo = -1
	end

	if y2 > y1 then
		yo = 1
	else
		yo = -1
	end

	while cx ~= x2 do
		if isLegal( cx, cy ) then
			if map[cx][cy] == "#" then
				map[cx][cy] = ","
			end
		end
		cx = cx + xo
	end

	while cy ~= y2 do
		if isLegal( cx, cy ) then
			if map[cx][cy] == "#" then
				map[cx][cy] = ","
			end
		end
		cy = cy + yo
	end
end

function closestRoom( r, loopChance )
	local bd, bi = 999, 0
	local z = 0
	for i = 1, #map.rooms do
		z = math.sqrt( math.pow( map.rooms[i].x-map.rooms[r].x, 2 ) + math.pow( map.rooms[i].y-map.rooms[r].y, 2 ) )
		if i ~= r and z < bd and ( not map.rooms[i].linked or math.random() < loopChance ) then
			bd = z
			bi = i
		end
	end
	return bi
end

function allRoomsLinked()
	for i = 1, #map.rooms do
		if not map.rooms[i].linked then
			return false
		end
	end
	return true
end

--[[
	makeMap - the main dungeon building function
	arguments:
		roomChance - chance that a room will be placed in a cell, as the algorithm travels through all the cells
		loopChance - the chance of making a cooridor loop
]]

function makeMap( roomChance, loopChance )
	local rx, ry, rw, rh = 0, 0, 0, 0
	local roomCount = 0

	for i = 0, math.floor( map.width / map.cellWidth )-1 do
		for j = 0, math.floor( map.height / map.cellHeight )-1 do
			if math.random() < roomChance then 
				while true do
					rx = math.random( 2, map.cellWidth-1 )
					ry = math.random( 2, map.cellHeight-1 )
					rw = math.random( 2, map.cellWidth-1 )
					rh = math.random( 2, map.cellHeight-1 )

					if rx+rw < map.cellWidth and ry+rh < map.cellHeight then
						break
					end
				end

				digRoom( i*map.cellWidth+rx, j*map.cellHeight+ry, rw, rh )
				table.insert( map.rooms, {
					x = i*map.cellWidth+rx + math.floor( rw/2 ),
					y = j*map.cellHeight+ry + math.floor( rh/2 ),
					linked = false
				} )
				roomCount = roomCount + 1
			end
		end
	end

	local ra = math.random( 1, #map.rooms )
	local rb = 0

	map.rooms[ra].linked = true

	while not allRoomsLinked() do
		rb = closestRoom( ra, loopChance )
		if rb ~= 0 then
			digCooridor( map.rooms[ra].x, map.rooms[ra].y, map.rooms[rb].x, map.rooms[rb].y )
			if map.rooms[ra].linked then
				map.rooms[rb].linked = true
			end
			ra = rb
		end
	end
	return roomCount 
end

function countNeighbours( x, y, t )
	local r = 0
	for i = x-1, x+1 do
		for j = y-1, y+1 do
			if isLegal( i, j ) then
				if map[i][j] == t then r = r + 1 end
			end
		end
	end
	return r
end

function postProcess()
	for i = 2, map.width-1 do
		for j = 2, map.height-1 do
			if	countNeighbours( i, j, "." ) > 1 and countNeighbours( i, j, "," ) < 4 and map[i][j] == "," and
				(	( map[i-1][j] == "#" and map[i+1][j] == "#" ) or
					( map[i][j-1] == "#" and map[i][j+1] == "#" ) ) then
				map[i][j] = "+"
			end
		end
	end

	for i = 1, map.width do
		for j = 1, map.height do
			if map[i][j] == "," then map[i][j] = "." end
		end
	end

	for i = 1, map.width do
		for j = 1, map.height do
			if countNeighbours( i, j, "." ) == 0 then
				map[i][j] = " "
			end
		end
	end
end

math.randomseed( os.time() )

initMap()
r = makeMap( 0.5, 0.5 )
postProcess()
showMap()
print( r .. " rooms dug" )