-- path 0.1.1 by paramat
-- For latest stable Minetest and back to 0.4.8
-- Depends default
-- License: code WTFPL

-- Parameters

-- 2D noise for base terrain

local np_base = {
	offset = 0,
	scale = 1,
	spread = {x=512, y=512, z=512},
	seed = -9111,
	octaves = 4,
	persist = 0.5
}

-- Nodes

minetest.register_node("path:roadblack", {
	description = "Road Black",
	tiles = {"path_roadblack.png"},
	groups = {cracky=2},
	sounds = default.node_sound_stone_defaults(),
})

minetest.register_node("path:roadwhite", {
	description = "Road White",
	tiles = {"path_roadwhite.png"},
	groups = {cracky=2},
	sounds = default.node_sound_stone_defaults(),
})

-- Stuff

path = {}

-- Set mapgen parameters

minetest.register_on_mapgen_init(function(mgparams)
	minetest.set_mapgen_params({mgname="singlenode"})
end)

-- Spawn player

function spawnplayer(player)
	player:setpos({x=0, y=2, z=0})
end

minetest.register_on_newplayer(function(player)
	spawnplayer(player)
end)

minetest.register_on_respawnplayer(function(player)
	spawnplayer(player)
	return true
end)

-- On generated function

minetest.register_on_generated(function(minp, maxp, seed)
	if minp.y ~= -32 then
		return
	end

	local t1 = os.clock()
	local x1 = maxp.x
	local y1 = maxp.y
	local z1 = maxp.z
	local x0 = minp.x
	local y0 = minp.y
	local z0 = minp.z
	
	print ("[path] chunk minp ("..x0.." "..y0.." "..z0..")")
	
	local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
	local area = VoxelArea:new{MinEdge=emin, MaxEdge=emax}
	local data = vm:get_data()
	
	local c_sand = minetest.get_content_id("default:sand")
	local c_roadblack = minetest.get_content_id("path:roadblack")
	local c_roadwhite = minetest.get_content_id("path:roadwhite")
	
	local sidelen = x1 - x0 + 1
	local chulens = {x=sidelen, y=sidelen, z=sidelen}
	local minposxz = {x=x0, y=z0}
	
	local nvals_base = minetest.get_perlin_map(np_base, chulens):get2dMap_flat(minposxz)
	
	local nixz = 1
	for z = z0, z1 do
		for y = y0, y1 do
			local vi = area:index(x0, y, z)
			local n_xprebase = false
			for x = x0, x1 do
				local nodid = data[vi]
				local n_base = nvals_base[nixz]
				local n_zprebase = nvals_base[(nixz - 80)]
				if y == 1 then
					if (x - x0 > 0
					and ((n_base >= 0 and n_xprebase < 0)
					or (n_base < 0 and n_xprebase >= 0)))
					or (z - z0 > 0
					and ((n_base >= 0 and n_zprebase < 0)
					or (n_base < 0 and n_zprebase >= 0))) then
						data[vi] = c_roadwhite
						for i = -3, 3 do
						for k = -3, 3 do
							if (math.abs(i)) ^ 2 + (math.abs(k)) ^ 2 <= 10 then
								local vi = area:index(x+i, y, z+k)
								local nodid = data[vi]
								if nodid ~= c_roadwhite then
									data[vi] = c_roadblack
								end
							end
						end
						end
					elseif nodid ~= c_roadblack and nodid ~= c_roadwhite then
						data[vi] = c_sand
					end
				elseif y <= 0 then
					data[vi] = c_sand
				end
				n_xprebase = n_base
				nixz = nixz + 1
				vi = vi + 1
			end
			nixz = nixz - 80
		end
		nixz = nixz + 80
	end
	
	vm:set_data(data)
	vm:set_lighting({day=0, night=0})
	vm:calc_lighting()
	vm:write_to_map(data)
	local chugent = math.ceil((os.clock() - t1) * 1000)
	print ("[path] "..chugent.." ms")
end)