Various bugfixes and workarounds

Now working in pure Lua!
Some parts of the code are very hacky (e.g. noise) and the way new and old codes have been glued together is sometimes to be rewritten.
But at least it works.

generate.lua

@@ -1,15 +1,16 @@
-local EvolutionModel = dofile(mapgen_rivers.modpath .. '/erosion.lua')
+local EvolutionModel = dofile(mapgen_rivers.modpath .. '/terrainlib_lua/erosion.lua')
-local twist = dofile(mapgen_rivers.modpath .. '/twist.lua')
+local twist = dofile(mapgen_rivers.modpath .. '/terrainlib_lua/twist.lua')
 
 local size = {x=1000, y=1000}
 local blocksize = 12
+local variation_speed = 70
 
 local np_base = {
 	offset = 0,
 	scale = 200,
 	seed = 2469,
 	octaves = 8,
-	spread = {x=4000/blocksize, y=4000/blocksize, z=5},
+	spread = {x=4000/blocksize, y=4000/blocksize, z=4000/blocksize},
 	persist = 0.6,
 	lacunarity = 2,
 }
@@ -20,10 +21,14 @@ local niter = math.ceil(time/time_step)
 time_step = time / niter
 
 local function generate()
-	local nobj_base = minetest.get_perlin_map(np_base, size)
+	local seed = tonumber(minetest.get_mapgen_setting("seed"))
-	nobj_base:calc_3d_map({x=0, y=0, z=0})
+	np_base.seed = (np_base.seed or 0) + seed
 
-	local dem = nobj_base:get_map_slice({z=1}, {z=1})
+	local nobj_base = PerlinNoiseMap(np_base, {x=size.x, y=1, z=size.y})
+	--nobj_base:calc_3d_map({x=0, y=0, z=0})
+
+	--local dem = nobj_base:get_map_slice({z=1}, {z=1})
+	local dem = nobj_base:get_3d_map_flat({x=0, y=0, z=0})
 	dem.X = size.x
 	dem.Y = size.y
 
@@ -31,8 +36,10 @@ local function generate()
 	model.dem = dem
 	local ref_dem = model:define_isostasy(dem)
 
+	local variation_step = variation_speed * time_step
 	for i=1, niter do
-		nobj_base:get_map_slice({z=i+1}, {z=1}, ref_dem)
+		--nobj_base:get_map_slice({z=i+1}, {z=1}, ref_dem)
+		nobj_base:get_3d_map_flat({x=0, y=variation_step*i, z=0}, ref_dem)
 
 		model:diffuse(time_step)
 		model:flow()
@@ -44,9 +51,12 @@ local function generate()
 	local mfloor = math.floor
 	local mmin, mmax = math.min, math.max
 	local offset_x, offset_y = twist(model.dirs, model.rivers, 5)
-	for i=1, X*Y do
+	local dirs = model.dirs
+	local converter = {2, 1, 4, 3, [0]=0}
+	for i=1, size.x*size.y do
 		offset_x[i] = mmin(mmax(offset_x[i]*256, -128), 127)
 		offset_y[i] = mmin(mmax(offset_y[i]*256, -128), 127)
+		dirs[i] = converter[dirs[i]] -- TODO Fix this
 	end
 
 	mapgen_rivers.write_map('dem', model.dem, 2)
@@ -56,7 +66,7 @@ local function generate()
 	mapgen_rivers.write_map('offset_x', offset_x, 1)
 	mapgen_rivers.write_map('offset_y', offset_y, 1)
 	local sfile = io.open(mapgen_rivers.world_data_path .. 'size', "w")
-	sfile:write(X..'\n'..Y)
+	sfile:write(size.x..'\n'..size.y)
 	sfile:close()
 end
 

init.lua

@@ -2,7 +2,7 @@ mapgen_rivers = {}
 
 local modpath = minetest.get_modpath(minetest.get_current_modname()) .. '/'
 mapgen_rivers.modpath = modpath
-mapgen_rivers.world_data_path = minetest.get_worldpath() .. '/river_data'
+mapgen_rivers.world_data_path = minetest.get_worldpath() .. '/river_data/'
 
 dofile(modpath .. 'settings.lua')
 

load.lua

@@ -1,4 +1,4 @@
-local worldpath = minetest.world_data_path
+local worldpath = mapgen_rivers.world_data_path
 
 function mapgen_rivers.load_map(filename, bytes, signed, size)
 	local file = io.open(worldpath .. filename, 'rb')

polygons.lua

@@ -4,7 +4,7 @@ if not io.open(mod_data_path .. 'size', 'r') then
 	mod_data_path = modpath .. 'demo_data/'
 end
 
-local world_data_path = minetest.world_data_path
+local world_data_path = mapgen_rivers.world_data_path
 minetest.mkdir(world_data_path)
 
 dofile(modpath .. 'load.lua')
@@ -26,15 +26,15 @@ sfile:close()
 
 local dem = mapgen_rivers.load_map('dem', 2, true, X*Z)
 local lakes = mapgen_rivers.load_map('lakes', 2, true, X*Z)
-local dirs = mapen_rivers.load_map('dirs', 1, false, X*Z)
+local dirs = mapgen_rivers.load_map('dirs', 1, false, X*Z)
 local rivers = mapgen_rivers.load_map('rivers', 4, false, X*Z)
 
-local offset_x = load_map('offset_x', 1, true, X*Z)
+local offset_x = mapgen_rivers.load_map('offset_x', 1, true, X*Z)
 for k, v in ipairs(offset_x) do
 	offset_x[k] = (v+0.5)/256
 end
 
-local offset_z = load_map('offset_y', 1, true, X*Z)
+local offset_z = mapgen_rivers.load_map('offset_y', 1, true, X*Z)
 for k, v in ipairs(offset_z) do
 	offset_z[k] = (v+0.5)/256
 end

terrainlib_lua/erosion.lua

@@ -110,7 +110,7 @@ end
 
 local modpath = ""
 if minetest then
-    if minetest.global_exists(mapgen_rivers) then
+    if minetest.global_exists('mapgen_rivers') then
         modpath = mapgen_rivers.modpath .. "terrainlib_lua/"
     else
         modpath = minetest.get_modpath(minetest.get_current_modname()) .. "terrainlib_lua/"

terrainlib_lua/rivermapper.lua

@@ -29,7 +29,7 @@ local flow_methods = {
 
 local function flow_routing(dem, dirs, lakes, method)
 	method = method or 'semirandom'
-	flow_local = flow_methods[method] or flow_local_semirandom
+	local flow_local = flow_methods[method] or flow_local_semirandom
 
 	dirs = dirs or {}
 	lakes = lakes or {}
@@ -194,7 +194,7 @@ local function flow_routing(dem, dirs, lakes, method)
 		end
 	end
 
-	basin_graph = {}
+	local basin_graph = {}
 	for n=1, nbasins do
 		--print(n, nbasins)
 		local b1, lnk1 = next(lowlevel)