mods/MAPGEN/mcl_structures/ruined_portal.lua

@@ -1,11 +1,8 @@
-local modname = minetest.get_current_modname()
-local modpath = minetest.get_modpath(modname)
-
 local chance_per_chunk = 400
 local noise_multiplier = 2.5
 local random_offset    = 9159
 local scanning_ratio   = 0.001
-local struct_threshold = 396
+local struct_threshold = 393.91
 
 local mcl_structures_get_perlin_noise_level = mcl_structures.get_perlin_noise_level
 local minetest_find_nodes_in_area = minetest.find_nodes_in_area
@@ -13,6 +10,223 @@ local minetest_swap_node = minetest.swap_node
 local math_round = math.round
 local math_abs = math.abs
 
+local function insert_times(how_many_times, what, where)
+	for i = 1, how_many_times do
+		where[#where + 1] = what
+	end
+end
+
+local function create_probability_picker(table_of_how_many_times_what)
+	local picker = {}
+	for _, v in pairs(table_of_how_many_times_what) do
+		insert_times(v[1], v[2], picker)
+	end
+	return picker
+end
+
+local STONE_DECOR = {
+	"mcl_core:stonebrickcarved",
+	"mcl_blackstone:blackstone_chiseled_polished",
+}
+local PANE_OR_CHAIN = {
+	"xpanes:bar",
+	"mcl_lanterns:chain",
+}
+local PANE_OR_CHAIN_FLAT = {
+	"xpanes:bar_flat",
+	"mcl_lanterns:chain",
+}
+local STAIR1 = {
+	"mcl_stairs:stair_stonebrickcracked",
+
+	-- TODO: stair_blackstone_brick_polished_cracked:
+	"mcl_stairs:stair_deepslate_bricks",
+}
+local STAIR2 = {
+	"mcl_stairs:stair_stonebrickmossy",
+	"mcl_stairs:stair_blackstone_brick_polished",
+}
+local STAIR3 = {
+	"mcl_stairs:stair_stone_rough",
+	"mcl_stairs:stair_blackstone_chiseled_polished",
+}
+local STAIR4 = {
+	"mcl_stairs:stair_stonebrick",
+	"mcl_stairs:stair_blackstone_brick_polished",
+}
+local STAIR_OUTER1 = {
+	"mcl_stairs:stair_stonebrickcracked_outer",
+
+	-- TODO: stair_blackstone_brick_polished_cracked_outer:
+	"mcl_stairs:stair_deepslate_bricks_outer",
+}
+local STAIR_OUTER2 = {
+	"mcl_stairs:stair_stonebrickmossy_outer",
+	"mcl_stairs:stair_blackstone_brick_polished_outer",
+}
+local STAIR_OUTER3 = {
+	"mcl_stairs:stair_stone_rough_outer",
+	"mcl_stairs:stair_blackstone_chiseled_polished_outer",
+}
+local STAIR_OUTER4 = {
+	"mcl_stairs:stair_stonebrick_outer",
+	"mcl_stairs:stair_blackstone_brick_polished_outer",
+}
+local TOP_DECOR1 = {
+	"mcl_core:goldblock",
+	"mcl_core:goldblock",
+}
+local TOP_DECOR2 = {
+	"mcl_core:stone_with_gold",
+	"mcl_core:stone_with_gold",
+}
+local STONE1 = {
+	"mcl_core:stonebrickcracked",
+
+	-- TODO: polished_blackstone_brick_cracked:
+	"mcl_deepslate:deepslate_bricks_cracked",
+}
+local STONE2 = {
+	"mcl_core:stonebrickmossy",
+	"mcl_blackstone:blackstone_brick_polished",
+}
+local STONE3 = {
+	"mcl_nether:magma",
+	"mcl_core:packed_ice",
+}
+local STONE4 = {
+	"mcl_core:stonebrick",
+	"mcl_blackstone:blackstone_brick_polished",
+}
+local STONE5 = {
+	"mcl_core:stone",
+	"mcl_blackstone:blackstone",
+}
+local STONE6 = {
+	"mcl_core:cobble",
+	"mcl_blackstone:basalt_polished",
+}
+local STONE7 = {
+	"mcl_core:mossycobble",
+	"mcl_blackstone:blackstone_chiseled_polished",
+}
+local SLAB_TOP1 = {
+	"mcl_stairs:slab_stonebrickcracked_top",
+
+	-- TODO: slab_polished_blackstone_brick_cracked_top:
+	"mcl_stairs:slab_goldblock_top",
+}
+local SLAB_TOP2 = {
+	"mcl_stairs:slab_stonebrickmossy_top",
+	"mcl_stairs:slab_blackstone_brick_polished_top",
+}
+local SLAB_TOP3 = {
+	"mcl_stairs:slab_stone_top",
+	"mcl_stairs:slab_blackstone_top",
+}
+local SLAB_TOP4 = {
+	"mcl_stairs:slab_stonebrick_top",
+	"mcl_stairs:slab_blackstone_brick_polished_top",
+}
+local SLAB1 = {
+	"mcl_stairs:slab_stone",
+	"mcl_stairs:slab_blackstone",
+}
+local SLAB2 = {
+	"mcl_stairs:slab_stonebrick",
+	"mcl_stairs:slab_blackstone_brick_polished",
+}
+local SLAB3 = {
+	"mcl_stairs:slab_stonebrickcracked",
+
+	-- TODO: slab_polished_blackstone_brick_cracked:
+	"mcl_stairs:slab_goldblock",
+}
+local SLAB4 = {
+	"mcl_stairs:slab_stonebrickmossy",
+	"mcl_stairs:slab_blackstone_brick_polished",
+}
+local GARBAGE1 = {
+	"mcl_nether:netherrack",
+	"mcl_core:stone",
+}
+local LAVA_SOURCE = {
+	"mcl_nether:nether_lava_source",
+	"mcl_core:lava_source",
+}
+local GARBAGE3 = {
+	"mcl_nether:magma",
+	"mcl_nether:magma",
+}
+
+local stair_set_for_frame = create_probability_picker({
+	{ 3, STAIR1,},
+	{ 1, STAIR2,},
+	{ 1, STAIR3,},
+	{10, STAIR4,},
+})
+local stone_set_for_frame = create_probability_picker({
+	{ 3, STONE1,},
+	{ 1, STONE2,},
+	{ 1, STONE3,},
+	{10, STONE4,},
+})
+local slab_set_for_frame = create_probability_picker({
+	{ 3, SLAB_TOP1,},
+	{ 1, SLAB_TOP2,},
+	{ 1, SLAB_TOP3,},
+	{10, SLAB_TOP4,},
+})
+local stair_set_for_stairs = create_probability_picker({
+	{ 1, STAIR1,},
+	{ 2, STAIR2,},
+	{ 7, STAIR3,},
+	{ 3, STAIR4,},
+})
+local top_decoration_list = create_probability_picker({
+	{ 2, TOP_DECOR1,},
+	{ 1, TOP_DECOR2,},
+})
+local node_garbage = create_probability_picker({
+	{ 4, GARBAGE1,},
+	{ 1, LAVA_SOURCE,},
+	{ 1, GARBAGE3,},
+})
+local stair_replacement_list = {
+	"air",
+	"group:water",
+	"group:lava",
+	"group:buildable_to",
+	"group:deco_block",
+}
+local stair_outer_names = {
+	STAIR_OUTER1,
+	STAIR_OUTER2,
+	STAIR_OUTER3,
+	STAIR_OUTER4,
+}
+local stair_content = create_probability_picker({
+	{1, LAVA_SOURCE,},
+	{5, STONE5,},
+	{1, STONE4,},
+	{1, STONE3,},
+	{2, GARBAGE1,},
+})
+local stair_content_bottom = create_probability_picker({
+	{2, STONE3,},
+	{4, GARBAGE1,},
+})
+local slabs = create_probability_picker({
+	{5, SLAB1,},
+	{2, SLAB2,},
+	{1, SLAB3,},
+	{1, SLAB4,},
+})
+local stones = create_probability_picker({
+	{3, STONE5,},
+	{1, STONE6,},
+	{1, STONE7,},
+})
 
 local rotation_to_orientation = {
 	["0"]   = 1,
@@ -28,39 +242,11 @@ local rotation_to_param2 = {
 	["270"] = 2,
 }
 
-local node_top = {
-	"mcl_core:goldblock",
-	"mcl_core:stone_with_gold",
-	"mcl_core:goldblock",
-}
-
-local node_garbage = {
-	"mcl_nether:netherrack",
-	"mcl_core:lava_source",
-	"mcl_nether:netherrack",
-	"mcl_nether:netherrack",
-	"mcl_nether:magma",
-	"mcl_nether:netherrack",
-}
-
-local stone1 = {name = "mcl_core:stonebrickcracked"}
-local stone2 = {name = "mcl_core:stonebrickmossy"}
-local stone3 = {name = "mcl_nether:magma"}
-local stone4 = {name = "mcl_core:stonebrick"}
-
-local slab1 = {name = "mcl_stairs:slab_stonebrickcracked_top"}
-local slab2 = {name = "mcl_stairs:slab_stonebrickmossy_top"}
-local slab3 = {name = "mcl_stairs:slab_stone_top"}
-local slab4 = {name = "mcl_stairs:slab_stonebrick_top"}
-
-local stair1 = "mcl_stairs:stair_stonebrickcracked"
-local stair2 = "mcl_stairs:stair_stonebrickmossy"
-local stair3 = "mcl_stairs:stair_stone_rough"
-local stair4 = "mcl_stairs:stair_stonebrick"
 
 
-local function draw_frame(frame_pos, frame_width, frame_height, orientation, pr, is_chain, rotation)
+local function draw_frame(frame_pos, frame_width, frame_height, orientation, pr, is_chain, rotation, is_blackstone)
 	local param2 = rotation_to_param2[rotation]
+	local variant = is_blackstone and 2 or 1
 
 	local function set_ruined_node(pos, node)
 		if pr:next(1, 5) == 4 then return end
@@ -68,28 +254,20 @@ local function draw_frame(frame_pos, frame_width, frame_height, orientation, pr,
 	end
 
 	local function get_random_stone_material()
-		local rnd = pr:next(1, 15)
-		if rnd < 4 then	return stone1 end
-		if rnd == 4 then return stone2 end
-		if rnd == 5 then return stone3 end
-		return stone4
+		local rnd = pr:next(1, #stone_set_for_frame)
+		return {name = stone_set_for_frame[rnd][variant]}
 	end
 
 	local function get_random_slab()
 		local rnd = pr:next(1, 15)
-		if rnd < 4 then	return slab1 end
-		if rnd == 4 then return slab2 end
-		if rnd == 5 then return slab3 end
-		return slab4
+		return {name = slab_set_for_frame[rnd][variant]}
 	end
 
 	local function get_random_stair(param2_offset)
 		local param2 = (param2 + (param2_offset or 0)) % 4
-		local rnd = pr:next(1, 15)
-		if rnd < 4 then	return {name = stair1, param2 = param2} end
-		if rnd == 4 then return {name = stair2, param2 = param2} end
-		if rnd == 5 then return {name = stair3, param2 = param2} end
-		return {name = stair4, param2 = param2}
+		local rnd = pr:next(1, #stair_set_for_frame)
+		local stare_name = stair_set_for_frame[rnd][variant]
+		return {name = stare_name, param2 = param2}
 	end
 
 	local function set_frame_stone_material(pos)
@@ -118,7 +296,6 @@ local function draw_frame(frame_pos, frame_width, frame_height, orientation, pr,
 	local air_nodes = frame_nodes - obsidian_nodes
 
 	local function set_frame_node(pos)
-		-- local node_choice = pr:next(1, air_nodes + obsidian_nodes)
 		local node_choice = math_round(mcl_structures_get_perlin_noise_level(pos) * (air_nodes + obsidian_nodes))
 		if node_choice > obsidian_nodes and air_nodes > 0 then
 			air_nodes = air_nodes - 1
@@ -141,7 +318,7 @@ local function draw_frame(frame_pos, frame_width, frame_height, orientation, pr,
 			local is_top_hole = is_top and frame_width > 5 and ((pos2.x == x1 + slide_x * 2 and pos2.z == z1 + slide_z * 2) or (pos2.x == last_x - slide_x * 2 and pos2.z == last_z - slide_z * 2))
 			if is_top_hole then
 				if pr:next(1, 7) > 1 then
-					minetest_swap_node(pos2, {name = "xpanes:bar_flat", param2 = orientation})
+					minetest_swap_node(pos2, {name = PANE_OR_CHAIN_FLAT[variant], param2 = orientation})
 				end
 			else
 				set_frame_stone_material(pos2)
@@ -152,18 +329,18 @@ local function draw_frame(frame_pos, frame_width, frame_height, orientation, pr,
 		local pos = def.pos_outer1
 		local is_decor_here = not is_top and pos.y % 3 == 2
 		if is_decor_here then
-			minetest_swap_node(pos, {name = "mcl_core:stonebrickcarved"})
+			minetest_swap_node(pos, {name = STONE_DECOR[variant]})
 		elseif is_chain then
 			if not is_top and not is_obsidian then
-				minetest_swap_node(pos, {name = "xpanes:bar"})
+				minetest_swap_node(pos, {name = PANE_OR_CHAIN[variant]})
 			else
-				minetest_swap_node(pos, {name = "xpanes:bar_flat", param2 = orientation})
+				minetest_swap_node(pos, {name = PANE_OR_CHAIN_FLAT[variant], param2 = orientation})
 			end
 		else
 			if pr:next(1, 5) == 3 then
-				minetest_swap_node(pos, {name = "mcl_core:stonebrickcracked"})
+				minetest_swap_node(pos, {name = STONE1[variant]})
 			else
-				minetest_swap_node(pos, {name = "mcl_core:stonebrick"})
+				minetest_swap_node(pos, {name = STONE4[variant]})
 			end
 		end
 	end
@@ -253,7 +430,7 @@ local function draw_frame(frame_pos, frame_width, frame_height, orientation, pr,
 		})
 	end end
 
-	local node_top = {name = node_top[pr:next(1, #node_top)]}
+	local node_top = {name = top_decoration_list[pr:next(1, #top_decoration_list)][variant]}
 	if is_chain then
 		set_ruined_frame_stone_material({x = x1     + slide_x * 2, y = last_y + 3, z = z1     + slide_z * 2})
 		set_ruined_frame_stone_material({x = x1     + slide_x    , y = last_y + 3, z = z1     + slide_z    })
@@ -281,7 +458,9 @@ end
 
 local possible_rotations = {"0", "90", "180", "270"}
 
-local function draw_trash(pos, width, height, lift, orientation, pr)
+local function draw_trash(pos, width, height, lift, orientation, pr, is_blackstone)
+	local variant = is_blackstone and 2 or 1
+	local pos = pos
 	local slide_x = (1 - orientation)
 	local slide_z = orientation
 	local x1 = pos.x - lift - 1
@@ -297,7 +476,7 @@ local function draw_trash(pos, width, height, lift, orientation, pr)
 		for x = x1 + pr:next(0, 2), x2 - pr:next(0, 2) do
 			for z = z1 + pr:next(0, 2), z2 - pr:next(0, 2) do
 				if inverted_opacity_0_5 == 0 or (x % inverted_opacity_0_5 ~= pr:next(0, 1) and z % inverted_opacity_0_5 ~= pr:next(0, 1)) then
-					minetest_swap_node({x = x, y = y, z = z}, {name = node_garbage[pr:next(1, #node_garbage)]})
+					minetest_swap_node({x = x, y = y, z = z}, {name = node_garbage[pr:next(1, #node_garbage)][variant]})
 				end
 			end
 		end
@@ -305,77 +484,6 @@ local function draw_trash(pos, width, height, lift, orientation, pr)
 	end
 end
 
-local stair_replacement_list = {
-	"air",
-	"group:water",
-	"group:lava",
-	"group:buildable_to",
-	"group:deco_block",
-}
-
-local stair_names = {
-	"mcl_stairs:stair_stonebrickcracked",
-	"mcl_stairs:stair_stonebrickmossy",
-	"mcl_stairs:stair_stone_rough",
-	"mcl_stairs:stair_stone_rough",
-	"mcl_stairs:stair_stone_rough",
-	"mcl_stairs:stair_stone_rough",
-	"mcl_stairs:stair_stone_rough",
-	"mcl_stairs:stair_stone_rough",
-	"mcl_stairs:stair_stone_rough",
-	"mcl_stairs:stair_stonebrick",
-	"mcl_stairs:stair_stonebrick",
-	"mcl_stairs:stair_stonebrick",
-}
-local stair_outer_names = {
-	"mcl_stairs:stair_stonebrickcracked_outer",
-	"mcl_stairs:stair_stonebrickmossy_outer",
-	"mcl_stairs:stair_stone_rough_outer",
-	"mcl_stairs:stair_stonebrick_outer",
-}
-
-local stair_content = {
-	{name = "mcl_core:lava_source"},
-	{name = "mcl_core:stone"},
-	{name = "mcl_core:stone"},
-	{name = "mcl_core:stone"},
-	{name = "mcl_core:stone"},
-	{name = "mcl_core:stone"},
-	{name = "mcl_core:stonebrick"},
-	{name = "mcl_nether:magma"},
-	{name = "mcl_nether:netherrack"},
-	{name = "mcl_nether:netherrack"},
-}
-
-local stair_content_bottom = {
-	{name = "mcl_nether:magma"},
-	{name = "mcl_nether:magma"},
-	{name = "mcl_nether:netherrack"},
-	{name = "mcl_nether:netherrack"},
-	{name = "mcl_nether:netherrack"},
-	{name = "mcl_nether:netherrack"},
-}
-
-local slabs = {
-	{name = "mcl_stairs:slab_stone"},
-	{name = "mcl_stairs:slab_stone"},
-	{name = "mcl_stairs:slab_stone"},
-	{name = "mcl_stairs:slab_stone"},
-	{name = "mcl_stairs:slab_stone"},
-	{name = "mcl_stairs:slab_stonebrick"},
-	{name = "mcl_stairs:slab_stonebrick"},
-	{name = "mcl_stairs:slab_stonebrickcracked"},
-	{name = "mcl_stairs:slab_stonebrickmossy"},
-}
-
-local stones = {
-	{name = "mcl_core:stone"},
-	{name = "mcl_core:stone"},
-	{name = "mcl_core:stone"},
-	{name = "mcl_core:cobble"},
-	{name = "mcl_core:mossycobble"},
-}
-
 local stair_selector = {
 	[-1] = {
 		[-1] = {
@@ -383,7 +491,7 @@ local stair_selector = {
 			param2 = 1,
 		},
 		[0] = {
-			names = stair_names,
+			names = stair_set_for_stairs,
 			param2 = 1,
 		},
 		[1] = {
@@ -393,14 +501,14 @@ local stair_selector = {
 	},
 	[0] = {
 		[-1] = {
-			names = stair_names,
+			names = stair_set_for_stairs,
 			param2 = 0,
 		},
 		[0] = {
 			names = stair_content,
 		},
 		[1] = {
-			names = stair_names,
+			names = stair_set_for_stairs,
 			param2 = 2,
 		},
 	},
@@ -410,7 +518,7 @@ local stair_selector = {
 			param2 = 0,
 		},
 		[0] = {
-			names = stair_names,
+			names = stair_set_for_stairs,
 			param2 = 3,
 		},
 		[1] = {
@@ -422,25 +530,14 @@ local stair_selector = {
 
 local stair_offset_from_bottom = 2
 
-local function draw_stairs(pos, width, height, lift, orientation, pr, is_chain, param2)
-
+local function draw_stairs(pos, width, height, lift, orientation, pr, is_chain, param2, is_blackstone)
+	local variant = is_blackstone and 2 or 1
 	local current_stair_content = stair_content
 	local current_stones = stones
-
-	local function set_ruined_node(pos, node)
-		if pr:next(1, 7) < 3 then return end
-		minetest_swap_node(pos, node)
-		return true
-	end
-
 	local param2 = param2
 	local mirror = param2 == 1 or param2 == 2
-	if mirror then
-		param2 = (param2 + 2) % 4
-	end
-
+	if mirror then param2 = (param2 + 2) % 4 end
 	local chain_offset = is_chain and 1 or 0
-
 	local lift = lift + stair_offset_from_bottom
 	local slide_x = (1 - orientation)
 	local slide_z = orientation
@@ -455,52 +552,63 @@ local function draw_stairs(pos, width, height, lift, orientation, pr, is_chain,
 	local y = y2
 	local place_slabs = true
 	local x_key, z_key
-	local need_to_place_chest = true
 	local chest_pos
-	local bad_nodes_ratio = 0
-	while (y >= y1) or (bad_nodes_ratio > 0.07) do
-		local good_nodes_counter = 0
-		for x = x1, x2 do
-			x_key = (x == x1) and -1 or (x == x2) and 1 or 0
-			for z = z1, z2 do
-				local pos = {x = x, y = y, z = z}
-				if #minetest_find_nodes_in_area(pos, pos, stair_replacement_list, false) > 0 then
-					z_key = (z == z1) and -1 or (z == z2) and 1 or 0
-					local stair_coverage = (x_key ~= 0) or (z_key ~= 0)
-					if stair_coverage then
-						if stair_layer then
-							local stair = stair_selector[x_key][z_key]
-							local names = stair.names
-							set_ruined_node(pos, {name = names[pr:next(1, #names)], param2 = stair.param2})
-						elseif place_slabs then
-							set_ruined_node(pos, slabs[pr:next(1, #slabs)])
-						else
-							local placed = set_ruined_node(pos, current_stones[pr:next(1, #current_stones)])
-							if need_to_place_chest and placed then
-								chest_pos = {x = pos.x, y = pos.y + 1, z = pos.z}
-								minetest_swap_node(chest_pos, {name = "mcl_chests:chest_small"})
-								need_to_place_chest = false
-							end
+	local ruinity = height + lift
+	local y_layer_to_start_squeezing = y1 - 2 * lift
+	while (true) do
+		local x11 = math_round(x1)
+		local x22 = math_round(x2)
+		local z11 = math_round(z1)
+		local z22 = math_round(z2)
+		local good_nodes = minetest_find_nodes_in_area({x = x11, y = y, z = z11}, {x = x22, y = y, z = z22}, stair_replacement_list, false)
+		local good_nodes_ratio =  #good_nodes / (x22 - x11 + 1) / (z22 - z11 + 1)
+		if y < y1 and good_nodes_ratio <= 0.07 then return chest_pos end
+		for _, pos in pairs(good_nodes) do
+			if pr:next(1, ruinity) > 1 then
+				local x, z = pos.x, pos.z
+				x_key = (x == x11) and -1 or (x == x22) and 1 or 0
+				z_key = (z == z11) and -1 or (z == z22) and 1 or 0
+				local should_be_a_stair_here = (x_key ~= 0) or (z_key ~= 0)
+				if should_be_a_stair_here then
+					if stair_layer then
+						local stair = stair_selector[x_key][z_key]
+						local names = stair.names
+						minetest_swap_node(pos, {name = names[pr:next(1, #names)][variant], param2 = stair.param2})
+					elseif place_slabs then
+						minetest_swap_node(pos, {name = slabs[pr:next(1, #slabs)][variant]})
+					else
+						minetest_swap_node(pos, {name = current_stones[pr:next(1, #current_stones)][variant]})
+						if not chest_pos then
+							chest_pos = {x = pos.x, y = pos.y + 1, z = pos.z}
+							minetest_swap_node(chest_pos, {name = "mcl_chests:chest_small"})
 						end
-					elseif not stair_layer then
-						set_ruined_node(pos, current_stair_content[pr:next(1, #current_stair_content)])
 					end
-				else
-					good_nodes_counter = good_nodes_counter + 1
+				elseif not stair_layer then
+					minetest_swap_node(pos, {name = current_stair_content[pr:next(1, #current_stair_content)][variant]})
 				end
 			end
 		end
-		bad_nodes_ratio = 1 - good_nodes_counter / ((x2 - x1 + 1) * (z2 - z1 + 1))
-		if y >= y1 then
+		if y >= y1 - lift then
 			x1 = x1 - 1
 			x2 = x2 + 1
 			z1 = z1 - 1
 			z2 = z2 + 1
+		elseif y < y_layer_to_start_squeezing then
+			local noise = mcl_structures_get_perlin_noise_level(pos) + 0.5
+			x1 = x1 + noise * pr:next(0,2)
+			x2 = x2 - noise * pr:next(0,2)
+			z1 = z1 + noise * pr:next(0,2)
+			z2 = z2 - noise * pr:next(0,2)
+			if x1 >= x2 then return chest_pos end
+			if z1 >= z2 then return chest_pos end
+		elseif y == y_layer_to_start_squeezing then
+			current_stones = stair_content_bottom
+		end
+		if y >= y1 then
 			if (stair_layer or place_slabs) then
 				y = y - 1
 				if y <= y1 then
 					current_stair_content = stair_content_bottom
-					current_stones = stair_content_bottom
 				end
 			end
 			place_slabs = not place_slabs
@@ -508,19 +616,9 @@ local function draw_stairs(pos, width, height, lift, orientation, pr, is_chain,
 		else
 			place_slabs = false
 			y = y - 1
-			local dx1 = pr:next(0, 10)
-			if dx1 < 3 then x1 = x1 + dx1 end
-			local dx2 = pr:next(0, 10)
-			if dx2 < 3 then x2 = x2 - dx1 end
-			if x1 >= x2 then return chest_pos end
-			local dz1 = pr:next(0, 10)
-			if dz1 < 3 then z1 = z1 + dz1 end
-			local dz2 = pr:next(0, 10)
-			if dz2 < 3 then z2 = z2 - dz1 end
-			if z1 >= z2 then return chest_pos end
 		end
+		if ruinity > 2 then ruinity = math.max(ruinity - pr:next(0,2), 2) end
 	end
-	return chest_pos
 end
 
 local function enchant(stack, pr)
@@ -533,19 +631,18 @@ local function enchant_armor(stack, pr)
 	mcl_enchanting.enchant_randomly(stack, 30, false, false, false, pr)
 end
 
-local function place(pos, rotation, pr)
-	local width = pr:next(2, 10)
-	local height = pr:next(((width < 3) and 3 or 2), 10)
-	local lift = pr:next(0, 4)
-	local rotation = rotation or possible_rotations[pr:next(1, #possible_rotations)]
+local function common_place(pos, rotation, pr, width, height, lift, is_blackstone)
+	local pos = pos
+	local width = width
+	local height = height
+	local lift = lift
+	local rotation = rotation
 	local orientation = rotation_to_orientation[rotation]
-	assert(orientation)
 	local param2 = rotation_to_param2[rotation]
-	assert(param2)
 	local is_chain = pr:next(1, 3) > 1
-	draw_trash(pos, width, height, lift, orientation, pr)
-	local chest_pos = draw_stairs(pos, width, height, lift, orientation, pr, is_chain, param2)
-	draw_frame({x = pos.x, y = pos.y + lift, z = pos.z}, width + 2, height + 2, orientation, pr, is_chain, rotation)
+	draw_trash(pos, width, height, lift, orientation, pr, is_blackstone)
+	local chest_pos = draw_stairs(pos, width, height, lift, orientation, pr, is_chain, param2, is_blackstone)
+	draw_frame({x = pos.x, y = pos.y + lift, z = pos.z}, width + 2, height + 2, orientation, pr, is_chain, rotation, is_blackstone)
 	if not chest_pos then return end
 
 	local lootitems = mcl_loot.get_loot(
@@ -575,7 +672,7 @@ local function place(pos, rotation, pr)
 				{itemstring = "mcl_clock:clock",                                 weight =  5},
 				{itemstring = "mesecons_pressureplates:pressure_plate_gold_off", weight =  5},
 				{itemstring = "mobs_mc:gold_horse_armor",                        weight =  5},
-				{itemstring = "mcl_core:goldblock",                              weight =  1, amount_min = 1, amount_max =  2},
+				{itemstring = TOP_DECOR1,                                        weight =  1, amount_min = 1, amount_max =  2},
 				{itemstring = "mcl_bells:bell",                                  weight =  1},
 				{itemstring = "mcl_core:apple_gold_enchanted",                   weight =  1},
 			}
@@ -588,6 +685,24 @@ local function place(pos, rotation, pr)
 	mcl_loot.fill_inventory(inv, "main", lootitems, pr)
 end
 
+local function place(pos, rotation, pr)
+	local width = pr:next(2, 10)
+	local height = pr:next(((width < 3) and 3 or 2), math.floor((10 + width/2)))
+	local lift = pr:next(0, 2)
+	local rotation = rotation or possible_rotations[pr:next(1, #possible_rotations)]
+	common_place(pos, rotation, pr, width, height, lift, false)
+	minetest.log("action","Ruined portal generated at " .. minetest.pos_to_string(pos))
+end
+
+local function place_blackstone(pos, rotation, pr)
+	local width = pr:next(2, 5)
+	local height = pr:next(((width < 3) and 3 or 2), math.floor((5 + width/2)))
+	local lift = pr:next(0, 1)
+	local rotation = rotation or possible_rotations[pr:next(1, #possible_rotations)]
+	common_place(pos, rotation, pr, width, height, lift, true)
+	minetest.log("action","Ruined portal v2 generated at " .. minetest.pos_to_string(pos))
+end
+
 local function get_place_rank(pos)
 	local x, y, z = pos.x, pos.y, pos.z
 	local p1 = {x = x    , y = y, z = z    }
@@ -630,3 +745,35 @@ mcl_structures.register_structure({
 	end,
 	place_function = place,
 })
+
+mcl_structures.register_structure({
+	name = "ruined_portal_black",
+	decoration = {
+		deco_type = "simple",
+		flags = "all_floors",
+		fill_ratio = scanning_ratio,
+		height = 1,
+		place_on = {"mcl_nether:netherrack", "mcl_nether:soul_sand", "mcl_nether:nether_lava_source", "mcl_core:lava_source"},
+	},
+	on_finished_chunk = function(minp, maxp, seed, vm_context, pos_list)
+		if minp.y > mcl_mapgen.nether.max then return end
+		local pr = PseudoRandom(seed + random_offset)
+		local random_number = pr:next(1, chance_per_chunk)
+		local noise = mcl_structures_get_perlin_noise_level(minp) * noise_multiplier
+		if (random_number + noise) < struct_threshold then return end
+		local pos = pos_list[1]
+		if #pos_list > 1 then
+			local count = get_place_rank(pos)
+			for i = 2, #pos_list do
+				local pos_i = pos_list[i]
+				local count_i = get_place_rank(pos_i)
+				if count_i > count then
+					count = count_i
+					pos = pos_i
+				end
+			end
+		end
+		place_blackstone(pos, nil, pr)
+	end,
+	place_function = place_blackstone,
+})