First (non-functional) cut at the layer wrapping code. Added some

additional hooks to control the core, overriding bedrock and
skyrock generation. Shadow caster can now be enabled/ disabled.

multi_map_core/core.lua

@@ -2,6 +2,7 @@
 multi_map.number_of_layers = 24		-- How may layers to generate
 multi_map.layers_start_chunk = 0	-- Y level where to start generating layers, in chunks
 multi_map.layer_height_chunks = 32	-- Height of each layer, in chunks
+multi_map.wrap_layers = false
 
 -- Either MT engine defaults or derived from above values, to be used for more readable calculations
 multi_map.layer_height = nil
@@ -17,9 +18,14 @@ multi_map.map_max = 30927
 multi_map.bedrock = "multi_map_core:bedrock"  -- Node to use to fill the bottom of a layer
 multi_map.skyrock = "multi_map_core:skyrock"  -- Node to use to fill the top of a layer
 
--- Whether to generate a bedrock layer under a layer/ skyrock above a layer
+-- Whether to generate a bedrock layer under a layer/ skyrock above a layer/ shadow caster
+-- above undeground mapchunks
 multi_map.generate_bedrock = true
 multi_map.generate_skyrock = true
+multi_map.generate_shadow_caster = true
+
+multi_map.override_bedrock_generator = nil
+multi_map.override_skyrock_generator = nil
 
 -- Table with generator chains
 multi_map.generators = {}
@@ -148,7 +154,9 @@ function multi_map.register_global_2dmap(name, params)
 			spread = {x=params.spread.x, y=params.spread.y, z=params.spread.z},
 			seed = math.random(-1000000000000, 1000000000000),
 			octaves = params.octaves,
-			persist = params.persist
+			persist = params.persist,
+			lacunarity = params.lacunarity,
+			flags = params.flags,
 		}
 		multi_map.global_2d_params[name][i] = new_params
 	end
@@ -159,23 +167,30 @@ end
 -- chulenxz = chunk length in 2 dimensions (xz)
 -- minposxz = minimum 2D position (xz)
 -- current layer = the layer for which to retrieve the map or nil to use multi_map's current layer
-function multi_map.get_global_2dmap_flat(name, chulenxz, minposxz, current_layer)
+function multi_map.get_global_2dmap_flat(name, chulenxz, minposxz, layer)
 	if not multi_map.global_2d_map_arrays[name] then
 		minetest.log("error", "[multi_map] Trying to get an unregistered global 2D map")
 	end
 
+	if multi_map.wrap_layers then
+		if layer then
+			map_cache[name] = multi_map.get_mixed_2dnoise_flat(name, chulenxz, minposxz, layer)
+		else
+			map_cache[name] = multi_map.get_mixed_2dnoise_flat(name, chulenxz, minposxz, multi_map.current_layer)
+		end
+	end
+
 	if not map_cache[name] then
-		if not current_layer then
+		if not layer then
 			if multi_map.current_layer ~= last_used_layer then
 				multi_map.global_2d_maps[name] = minetest.get_perlin_map(multi_map.global_2d_params[name][multi_map.current_layer], chulenxz)
 			end
 			map_cache[name] = multi_map.global_2d_maps[name]:get2dMap_flat(minposxz, multi_map.global_2d_map_arrays[name][multi_map.current_layer])
-			return map_cache[name]
 		else
-			if current_layer ~= last_used_layer then
+			if layer ~= last_used_layer then
-				multi_map.global_2d_maps[name] = minetest.get_perlin_map(multi_map.global_2d_params[name][current_layer], chulenxz)
+				multi_map.global_2d_maps[name] = minetest.get_perlin_map(multi_map.global_2d_params[name][layer], chulenxz)
 			end
-			map_cache[name] = multi_map.global_2d_maps[name]:get2dMap_flat(minposxz, multi_map.global_2d_map_arrays[name][current_layer])
+			map_cache[name] = multi_map.global_2d_maps[name]:get2dMap_flat(minposxz, multi_map.global_2d_map_arrays[name][layer])
 		end
 	end
 
@@ -405,11 +420,18 @@ minetest.register_on_generated(function(minp, maxp)
 		local area = VoxelArea:new({MinEdge = emin, MaxEdge = emax})
 		local vm_data = vm:get_data()
 
+		local skip = false
+		if multi_map.override_bedrock_generator then
+			skip = multi_map.override_bedrock_generator(multi_map.current_layer, vm, area, vm_data, minp, maxp, offset_minp, offset_maxp)
+		end
+
+		if not skip then
 			multi_map.generate_singlenode_chunk(minp, maxp, area, vm_data, multi_map.node[multi_map.bedrock])
 
 			vm:set_data(vm_data)
 			vm:calc_lighting(false)
 			vm:write_to_map(false)
+		end
 	elseif	multi_map.generate_skyrock
 			and (multi_map.map_min + multi_map.layers_start + (multi_map.layer_height * (multi_map.current_layer + 1)) - 80 == minp.y or
 				 multi_map.map_min + multi_map.layers_start + (multi_map.layer_height * (multi_map.current_layer + 1)) - 160 == minp.y
@@ -419,12 +441,19 @@ minetest.register_on_generated(function(minp, maxp)
 		local area = VoxelArea:new({MinEdge = emin, MaxEdge = emax})
 		local vm_data = vm:get_data()
 
+		local skip = false
+		if multi_map.override_skyrock_generator then
+			skip = multi_map.override_skyrock_generator(multi_map.current_layer, vm, area, vm_data, minp, maxp, offset_minp, offset_maxp)
+		end
+
+		if not skip then
 			multi_map.generate_singlenode_chunk(minp, maxp, area, vm_data, multi_map.node[multi_map.skyrock])
 
 			vm:set_lighting({day=15, night=0})
 			vm:set_data(vm_data)
 			vm:calc_lighting(false)
 			vm:write_to_map(false)
+		end
 	else
 		local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
 		local area = VoxelArea:new({MinEdge = emin, MaxEdge = emax})
@@ -432,7 +461,7 @@ minetest.register_on_generated(function(minp, maxp)
 		local remove_shadow_caster = false
 
 		-- Add a temporary stone layer above the chunk to ensure caves are dark
-		if multi_map.get_absolute_centerpoint() >= maxp.y then
+		if multi_map.generate_shadow_caster and multi_map.get_absolute_centerpoint() >= maxp.y then
 			if vm_data[area:index(minp.x, maxp.y + 1, minp.z)] == multi_map.node["ignore"] then
 				remove_shadow_caster = true
 				multi_map.generate_singlenode_plane(minp, maxp, area, vm_data, maxp.y + 1, multi_map.node["multi_map_core:shadow_caster"])

multi_map_core/debug.lua

@@ -5,6 +5,7 @@ function multi_map.log_state()
 	minetest.log("action", "[multi_map]  - Number of layers: "..multi_map.number_of_layers)
 	minetest.log("action", "[multi_map]  - Layers start at: "..(multi_map.map_min + multi_map.layers_start))
 	minetest.log("action", "[multi_map]  - Layer height: "..multi_map.layer_height)
+	minetest.log("action", "[multi_map]  - Wrap layers: "..tostring(multi_map.wrap_layers))
 	minetest.log("action", "[multi_map]  - HUD enabled: "..tostring(multi_map.hud.enabled))
 
 	minetest.log("action", "[multi_map]")

multi_map_core/init.lua

@@ -10,6 +10,7 @@ local multi_map_core_path = minetest.get_modpath("multi_map_core")
 -- The various sourced files contain the remainder of the API, the
 -- settings, node definitions and other core/ helper functionality
 dofile(multi_map_core_path.."/core.lua")
+dofile(multi_map_core_path.."/noise_mixer.lua")
 dofile(multi_map_core_path.."/debug.lua")
 dofile(multi_map_core_path.."/nodes.lua")
 dofile(multi_map_core_path.."/hud.lua")

multi_map_core/noise_mixer.lua

@@ -0,0 +1,204 @@
+multi_map.world_edge = {
+	NEGATIVE_X = 1,
+	POSITIVE_X = 2,
+	NEGATIVE_Z = 3,
+	POSITIVE_Z = 4,
+}
+
+multi_map.linked_layers = {}
+
+function multi_map.register_linked_layer(source_layer, edge, target_layer, link_back)
+	if not multi_map.linked_layers[source_layer] then
+		multi_map.linked_layers[source_layer] = {}
+	end
+
+	if not multi_map.linked_layers[target_layer] then
+		multi_map.linked_layers[target_layer] = {}
+	end
+
+	if link_back == nil then
+		link_back = true
+	end
+
+	if multi_map.world_edge.NEGATIVE_X == edge then
+		multi_map.linked_layers[source_layer][multi_map.world_edge.NEGATIVE_X] = target_layer
+		if link_back then
+			multi_map.linked_layers[target_layer][multi_map.world_edge.POSITIVE_X] = source_layer
+		end
+	elseif multi_map.world_edge.POSITIVE_X == edge then
+		multi_map.linked_layers[source_layer][multi_map.world_edge.POSITIVE_X] = target_layer
+		if link_back then
+			multi_map.linked_layers[target_layer][multi_map.world_edge.NEGATIVE_X] = source_layer
+		end
+	elseif multi_map.world_edge.NEGATIVE_Z == edge then
+		multi_map.linked_layers[source_layer][multi_map.world_edge.NEGATIVE_Z] = target_layer
+		if link_back then
+			multi_map.linked_layers[target_layer][multi_map.world_edge.POSITIVE_Z] = source_layer
+		end
+	elseif multi_map.world_edge.POSITIVE_Z == edge then
+		multi_map.linked_layers[source_layer][multi_map.world_edge.POSITIVE_Z] = target_layer
+		if link_back then
+			multi_map.linked_layers[target_layer][multi_map.world_edge.NEGATIVE_Z] = source_layer
+		end
+	end
+	
+end
+
+function multi_map.get_linked_layer(layer, edge)
+	if multi_map.linked_layers[layer] then
+		return multi_map.linked_layers[layer][edge]
+	end
+end
+
+function multi_map.get_which_world_edge(pos)
+
+	if pos.x < -30912 + 160 then
+		return multi_map.world_edge.NEGATIVE_X
+	elseif pos.x > 30927 - 160 then
+		return multi_map.world_edge.POSITIVE_X
+	elseif pos.y < -30912 + 160 then
+		return multi_map.world_edge.NEGATIVE_Z
+	elseif pos.y > 30927 - 160 then
+		return multi_map.world_edge.POSITIVE_Z
+	else
+		return nil
+	end
+
+end
+
+function multi_map.in_mixing_area(pos)
+	if  pos.x < -30912 + 160 or pos.x > 30927 - 160 or
+		pos.y < -30912 + 160 or pos.y > 30927 - 160 then
+		return true
+	else
+		return false
+	end
+end
+
+function multi_map.in_mirrored_area(pos)
+	if  pos.x < -30912 + 80 or pos.x > 30927 - 80 or
+		pos.y < -30912 + 80 or pos.y > 30927 - 80 then
+		return true
+	else
+		return false
+	end
+end
+
+-- Current
+-- 160      80
+-- [     ]  [     ]
+-- [  L  ]  [  M  ]
+-- [     ]  [     ]
+-- Opposite
+-- 0        80
+-- [     ]  [     ]
+-- [  L  ]  [  M  ]
+-- [     ]  [     ]
+function multi_map.get_mixed_2dnoise_flat(name, chulenxz, minposxz, layer)
+	local edge = multi_map.get_which_world_edge(minposxz)
+	
+	if edge == nil then
+		return
+	end
+	
+	local target_layer = multi_map.get_linked_layer(layer, edge)
+
+	if not target_layer then
+		return nil
+	end
+
+	local opposite_minposxz = { x = minposxz.x, y = minposxz.y }
+
+	if multi_map.in_mirrored_area(minposxz) then
+		if multi_map.world_edge.NEGATIVE_X == edge then
+			opposite_minposxz.x = 30927 - 160
+		elseif multi_map.world_edge.POSITIVE_X == edge then
+			opposite_minposxz.x = -30912 + 160
+		elseif multi_map.world_edge.NEGATIVE_Z == edge then
+			opposite_minposxz.y = 30927 - 160
+		elseif multi_map.world_edge.POSITIVE_Z == edge then
+			opposite_minposxz.y = -30912 + 160
+		end
+		
+		local noise1 = minetest.get_perlin_map(multi_map.global_2d_params[name][layer], chulenxz)
+		local noise2 = minetest.get_perlin_map(multi_map.global_2d_params[name][target_layer], chulenxz)
+		local map1 = noise1:get2dMap_flat(minposxz)
+		local map2 = noise2:get2dMap_flat(opposite_minposxz)
+
+		if multi_map.world_edge.NEGATIVE_X == edge then
+			return multi_map.mix_noise_map_x(map1, map2, opposite_minposxz)
+		elseif multi_map.world_edge.POSITIVE_X == edge then
+			return multi_map.mix_noise_map_x(map2, map1, opposite_minposxz)
+		elseif multi_map.world_edge.NEGATIVE_Z == edge then
+			return multi_map.mix_noise_map_z(map1, map2, opposite_minposxz)
+		elseif multi_map.world_edge.POSITIVE_Z == edge then
+			return multi_map.mix_noise_map_x(map2, map1, opposite_minposxz)
+		end
+
+	elseif multi_map.in_mixing_area(minposxz) then
+		if multi_map.world_edge.NEGATIVE_X == edge then
+			opposite_minposxz.x = 30927 - 80
+		elseif multi_map.world_edge.POSITIVE_X == edge then
+			opposite_minposxz.x = -30912 + 80
+		elseif multi_map.world_edge.NEGATIVE_Z == edge then
+			opposite_minposxz.y = 30927 - 80
+		elseif multi_map.world_edge.POSITIVE_Z == edge then
+			opposite_minposxz.y = -30912 + 80
+		end
+
+		local noise1 = minetest.get_perlin_map(multi_map.global_2d_params[name][layer], chulenxz)
+		local noise2 = minetest.get_perlin_map(multi_map.global_2d_params[name][target_layer], chulenxz)
+		local map1 = noise1:get2dMap_flat(minposxz)
+		local map2 = noise2:get2dMap_flat(opposite_minposxz)
+
+		if multi_map.world_edge.NEGATIVE_X == edge then
+			return multi_map.mix_noise_map_x(map2, map1, minposxz)
+		elseif multi_map.world_edge.POSITIVE_X == edge then
+			return multi_map.mix_noise_map_x(map1, map2, minposxz)
+		elseif multi_map.world_edge.NEGATIVE_Z == edge then
+			return multi_map.mix_noise_map_z(map2, map1, minposxz)
+		elseif multi_map.world_edge.POSITIVE_Z == edge then
+			return multi_map.mix_noise_map_x(map1, map2, minposxz)
+		end
+	else
+		return nil
+	end
+	
+end
+
+function multi_map.mix_noise_map_x(map1, map2, minposxz)
+
+	local new_map = {}
+	local nixz = 1
+
+	for y = minposxz.y, minposxz.y + 79 do
+		local weight_index = 1
+		for x = minposxz.x, minposxz.x + 79 do
+			new_map[nixz] = ( map1[nixz] * (1 - (weight_index / 80)) ) + ( map2[nixz] * (weight_index / 80) )
+			nixz = nixz + 1
+			weight_index = weight_index + 1
+		end
+	end
+
+	return new_map
+
+end
+
+function multi_map.mix_noise_map_z(map1, map2, minposxz)
+
+	local new_map = {}
+	local nixz = 1
+
+	for y = minposxz.y, minposxz.y + 80 do
+		local weight_index = 1
+		for x = minposxz.x, minposxz.x + 80 do
+			new_map[nixz] = ( map1[nixz] * (1 - (weight_index / 160)) ) + ( map2[nixz] * (weight_index / 160) )
+			nixz = nixz + 1
+		end
+		weight_index = weight_index + 1
+		nixz = nixz - 80
+	end
+
+	return new_map
+
+end

multi_map_generators/init.lua

@@ -3,7 +3,7 @@ local multi_map_generators_path = minetest.get_modpath("multi_map_generators")
 dofile(multi_map_generators_path.."/mmgen_levels.lua")
 --dofile(multi_map_generators_path.."/mmgen_lvm_example.lua")
 dofile(multi_map_generators_path.."/mmgen_simple.lua")
---dofile(multi_map_generators_path.."/mmgen_testauri.lua")
+dofile(multi_map_generators_path.."/mmgen_testauri.lua")
 
 --multi_map.register_fallback_generator("Default Simple", mmgen_simple.generate)
 --multi_map.register_generator(9, mmgen_simple.generate, "default:sandstone")
@@ -16,8 +16,19 @@ dofile(multi_map_generators_path.."/mmgen_simple.lua")
 multi_map.number_of_layers = 38
 multi_map.layers_start_chunk = 0
 multi_map.layer_height_chunks = 20
+multi_map.wrap_layers = true
 
-multi_map.register_fallback_generator("Default Levels", mmgen_levels.generate)
+multi_map.register_fallback_generator(mmgen_simple.generate)
-multi_map.register_generator(19, mmgen_levels.generate)
+multi_map.register_generator(18, mmgen_testauri.generate)
-multi_map.set_layer_name(19, "Central Layer")
+multi_map.register_generator(19, mmgen_testauri.generate)
-multi_map.set_layer_name(20, "Remote Levels Land")
+multi_map.register_generator(20, mmgen_testauri.generate)
+
+--multi_map.register_linked_layer(19, multi_map.world_edge.POSITIVE_X, 20, true)
+--multi_map.register_linked_layer(19, multi_map.world_edge.NEGATIVE_X, 18, true)
+
+--multi_map.register_generator(9, mmgen_simple.generate, { nodetype = "default:sandstone", height = 0 })
+--multi_map.register_generator(9, mmgen_simple.generate, { nodetype = "default:sandstone", height = 1 })
+--multi_map.register_fallback_generator("Default Levels", mmgen_levels.generate)
+--multi_map.register_generator(19, mmgen_levels.generate)
+--multi_map.set_layer_name(19, "Central Layer")
+--multi_map.set_layer_name(20, "Remote Levels Land")

multi_map_generators/mmgen_simple.lua

@@ -1,6 +1,10 @@
 mmgen_simple = {}
 
-function mmgen_simple.generate(current_layer, vm, area, vm_data, minp, maxp, offset_minp, offset_maxp, nodetype)
+function mmgen_simple.generate(current_layer, vm, area, vm_data, minp, maxp, offset_minp, offset_maxp, params)
+
+	local nodetype = params.nodetype
+	local height = params.height
+
 	local c_ground
 	if nodetype then
 		c_ground = multi_map.node[nodetype]
@@ -8,7 +12,7 @@ function mmgen_simple.generate(current_layer, vm, area, vm_data, minp, maxp, off
 		c_ground = multi_map.node["default:stone"]
 	end
 
-	if offset_minp.y >= 0 then
+	if offset_minp.y >= height then
 		multi_map.generate_singlenode_chunk(minp, maxp, area, vm_data, multi_map.node["air"])
 	else
 		multi_map.generate_singlenode_chunk(minp, maxp, area, vm_data, c_ground)

multi_map_generators/mmgen_testauri.lua

@@ -93,6 +93,7 @@ local perlin_worm_start_params = {
 function mmgen_testauri.generate(current_layer, vm, area, vm_data, minp, maxp, offset_minp, offset_maxp)
 	local sidelen = maxp.x - minp.x + 1
 	local blocklen = sidelen / 5
+	
 	--3d
 	local chulenxyz = {x = sidelen, y = sidelen, z = sidelen}
 	--2d