many worldgen mods and gonna try technic now

mods/dfcaverns/mapgen_helper/noise_manager.lua

@@ -0,0 +1,114 @@
+local perlin_buffers = {}
+
+mapgen_helper.register_perlin = function(name, perlin_params)
+	perlin_buffers[name] = perlin_buffers[name] or {}
+	if perlin_buffers[name].perlin_params then
+		minetest.log("error", "mapgen_helper.register_perlin3d called for " .. name .. " when perlin parameters were already registered.")
+		return
+	end
+	perlin_buffers[name].perlin_params = perlin_params
+end
+
+local get_buffer = function(name, sidelen, perlin_params)
+	perlin_buffers[name] = perlin_buffers[name] or {}
+	local buffer = perlin_buffers[name]
+	
+	if buffer.sidelen ~= nil and buffer.sidelen ~= sidelen then
+		buffer.nobj_perlin = nil -- parameter changed, force regenerate of object
+	end
+	buffer.sidelen = sidelen
+	
+	if perlin_params then
+		if buffer.perlin_params then
+			for k, v in pairs(buffer.perlin_params) do
+				if perlin_params[k] ~= v then
+					buffer.nobj_perlin = nil -- parameter changed, force regenerate of object
+				end
+			end
+		end
+		buffer.perlin_params = perlin_params -- record provided parameters
+	elseif buffer.perlin_params == nil then
+		minetest.log("error", "mapgen_helper.register_perlin3d called for " .. name .. " with no registered or provided perlin parameters.")
+		return
+	else
+		perlin_params = buffer.perlin_params -- retrieve recorded parameters
+	end
+	
+	buffer.last_used = minetest.get_gametime()
+	return buffer, perlin_params
+end
+
+mapgen_helper.perlin3d = function(name, minp, maxp, perlin_params)
+	local minx = minp.x
+	local minz = minp.z
+	local sidelen = maxp.x - minp.x + 1 --length of a mapblock
+	local chunk_lengths = {x = sidelen, y = sidelen, z = sidelen} --table of chunk edges
+
+	local buffer, perlin_params = get_buffer(name, sidelen, perlin_params)
+	
+	buffer.nvals_perlin_buffer = buffer.nvals_perlin_buffer or {}
+	buffer.nobj_perlin = buffer.nobj_perlin or minetest.get_perlin_map(perlin_params, chunk_lengths)
+	if buffer.nobj_perlin.get_3d_map_flat then
+		return buffer.nobj_perlin:get_3d_map_flat(minp, buffer.nvals_perlin_buffer), VoxelArea:new{MinEdge=minp, MaxEdge=maxp}
+	else
+		return buffer.nobj_perlin:get3dMap_flat(minp, buffer.nvals_perlin_buffer), VoxelArea:new{MinEdge=minp, MaxEdge=maxp}
+	end	
+end
+
+mapgen_helper.perlin2d = function(name, minp, maxp, perlin_params)
+	local minx = minp.x
+	local minz = minp.z
+	local sidelen = maxp.x - minp.x + 1 --length of a mapblock
+	local chunk_lengths = {x = sidelen, y = sidelen, z = sidelen} --table of chunk edges
+
+	local buffer, perlin_params = get_buffer(name, sidelen, perlin_params)
+	
+	buffer.nvals_perlin_buffer = perlin_buffers[name].nvals_perlin_buffer or {}
+	buffer.nobj_perlin = perlin_buffers[name].nobj_perlin or minetest.get_perlin_map(perlin_params, chunk_lengths)
+	if buffer.nobj_perlin.get_2d_map_flat then
+		return buffer.nobj_perlin:get_2d_map_flat({x=minp.x, y=minp.z}, perlin_buffers[name].nvals_perlin_buffer)
+	else
+		return buffer.nobj_perlin:get2dMap_flat({x=minp.x, y=minp.z}, perlin_buffers[name].nvals_perlin_buffer)
+	end	
+end
+
+mapgen_helper.index2d = function(minp, maxp, x, z) 
+	return x - minp.x +
+		(maxp.x - minp.x + 1) -- sidelen
+		*(z - minp.z)
+		+ 1
+end
+
+mapgen_helper.index2dp = function(minp, maxp, pos)
+	return mapgen_helper.index2d(minp, maxp, pos.x, pos.z)
+end
+
+-- Takes an index into a 3D area and returns the corresponding 2D index
+-- assumes equal edge lengths
+mapgen_helper.index2di = function(minp, maxp, area, vi)
+	local MinEdge = area.MinEdge
+	local zstride = area.zstride
+	local minpx = minp.x
+	local i = vi - 1
+	local z = math.floor(i / zstride) + MinEdge.z
+	local x = math.floor((i % zstride) % area.ystride) + MinEdge.x
+	return x - minpx +
+		(maxp.x - minpx + 1) -- sidelen
+		*(z - minp.z)
+		+ 1
+end
+
+-- If a noise buffer hasn't been used in 60 seconds, let garbage collection take it.
+local time_elapsed = 0
+minetest.register_globalstep(function(dtime)
+	time_elapsed = time_elapsed + dtime
+	if time_elapsed > 60 then
+		local current_time = minetest.get_gametime()
+		time_elapsed = 0
+		for _, buffer in pairs(perlin_buffers) do
+			if current_time - buffer.last_used > 60 then
+				buffer.nvals_perlin_buffer = nil
+			end
+		end
+	end
+end)