From dc83946213eb58bb275b1587806bdf26206557f8 Mon Sep 17 00:00:00 2001
From: Wuzzy <almikes@aol.com>
Date: Wed, 24 May 2017 09:46:40 +0200
Subject: [PATCH] Add basic (empty) dungeons

---
 mods/MAPGEN/mcl_dungeons/depends.txt     |   1 +
 mods/MAPGEN/mcl_dungeons/description.txt |   1 +
 mods/MAPGEN/mcl_dungeons/init.lua        | 140 +++++++++++++++++++++++
 mods/MAPGEN/mcl_dungeons/mod.conf        |   1 +
 4 files changed, 143 insertions(+)
 create mode 100644 mods/MAPGEN/mcl_dungeons/depends.txt
 create mode 100644 mods/MAPGEN/mcl_dungeons/description.txt
 create mode 100644 mods/MAPGEN/mcl_dungeons/init.lua
 create mode 100644 mods/MAPGEN/mcl_dungeons/mod.conf

diff --git a/mods/MAPGEN/mcl_dungeons/depends.txt b/mods/MAPGEN/mcl_dungeons/depends.txt
new file mode 100644
index 0000000000..3b355984e2
--- /dev/null
+++ b/mods/MAPGEN/mcl_dungeons/depends.txt
@@ -0,0 +1 @@
+mcl_init
diff --git a/mods/MAPGEN/mcl_dungeons/description.txt b/mods/MAPGEN/mcl_dungeons/description.txt
new file mode 100644
index 0000000000..343cb7bdb1
--- /dev/null
+++ b/mods/MAPGEN/mcl_dungeons/description.txt
@@ -0,0 +1 @@
+Generates random dungeons in the world
diff --git a/mods/MAPGEN/mcl_dungeons/init.lua b/mods/MAPGEN/mcl_dungeons/init.lua
new file mode 100644
index 0000000000..3c6d64e1df
--- /dev/null
+++ b/mods/MAPGEN/mcl_dungeons/init.lua
@@ -0,0 +1,140 @@
+-- FIXME: Rarely, dungoens can overlap and destroy each other
+
+-- Buffer for LuaVoxelManip
+local lvm_buffer = {}
+
+-- Below the bedrock, generate air/void
+minetest.register_on_generated(function(minp, maxp)
+	if maxp.y < mcl_vars.mg_overworld_min or minp.y > mcl_vars.mg_overworld_max then
+		return
+	end
+
+	local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
+	local data = vm:get_data(lvm_buffer)
+	local area = VoxelArea:new({MinEdge=emin, MaxEdge=emax})
+	local lvm_used = false
+
+	local c_air = minetest.get_content_id("air")
+	local c_cobble = minetest.get_content_id("mcl_core:cobble")
+	local c_mossycobble = minetest.get_content_id("mcl_core:mossycobble")
+
+	-- Calculate the number of dungeon spawn attempts
+	local sizevector = vector.subtract(maxp, minp)
+	sizevector = vector.add(sizevector, 1)
+	local chunksize = sizevector.x * sizevector.y * sizevector.z
+
+	-- In Minecraft, there 8 dungeon spawn attempts Minecraft chunk (16*256*16 = 65536 blocks).
+	-- Minetest chunks don't have this size, so scale the number accordingly.
+	local attempts = math.ceil(chunksize / 65536 * 8)
+
+	for a=1, attempts do
+		local x, y, z
+		local b = 7 -- buffer
+		x = math.random(minp.x+b, maxp.x-b)
+
+		local ymin = math.min(mcl_vars.mg_overworld_max, math.max(minp.y, mcl_vars.mg_bedrock_overworld_max) + 7)
+		local ymax = math.min(mcl_vars.mg_overworld_max, math.max(maxp.y, mcl_vars.mg_bedrock_overworld_max) - 4)
+
+		y = math.random(ymin, ymax)
+		z = math.random(minp.z+b, maxp.z-b)
+
+		local dungeonsizes = {
+			{ x=5, y=4, z=5},
+			{ x=5, y=4, z=7},
+			{ x=7, y=4, z=5},
+			{ x=7, y=4, z=7},
+		}
+		local dim = dungeonsizes[math.random(1, #dungeonsizes)]
+
+		-- Check floor and ceiling: Must be *completely* solid
+		local ceilingfloor_ok = true
+		for tx = x, x+dim.x do
+			for tz = z, z+dim.z do
+				local floor = minetest.get_name_from_content_id(data[area:index(tx, y, tz)])
+				local ceiling = minetest.get_name_from_content_id(data[area:index(tx, y+dim.y+1, tz)])
+				if (not minetest.registered_nodes[floor].walkable) or (not minetest.registered_nodes[ceiling].walkable) then
+					ceilingfloor_ok = false
+					break
+				end
+			end
+			if not ceilingfloor_ok then break end
+		end
+
+		-- Check for air openings (2 stacked air at ground level) in wall positions
+		local openings = 0
+		if ceilingfloor_ok then
+
+			local walls = {
+				{ x, x+dim.x+1, "x", "z", z },
+				{ x, x+dim.x+1, "x", "z", z+dim.z+1 },
+				{ z+1, z+dim.z, "z", "x", x },
+				{ z+1, z+dim.z, "z", "x", x+dim.x+1 },
+			}
+
+			for w=1, #walls do
+				local wall = walls[w]
+				for iter = wall[1], wall[2] do
+					local pos = {}
+					pos[wall[3]] = iter
+					pos[wall[4]] = wall[5]
+					pos.y = y+1
+
+					local door1 = area:index(pos.x, pos.y, pos.z)
+					pos.y = y+2
+					local door2 = area:index(pos.x, pos.y, pos.z)
+					local doorname1 = minetest.get_name_from_content_id(data[door1])
+					local doorname2 = minetest.get_name_from_content_id(data[door2])
+					if doorname1 == "air" and doorname2 == "air" then
+						openings = openings + 1
+					end
+				end
+			end
+
+			if openings > 0 then
+				--minetest.log("error", minetest.pos_to_string({x=x,y=y,z=z}).."; openings: "..openings)
+			end
+		end
+
+		-- Check conditions. If okay, start generating
+
+		if ceilingfloor_ok and openings >= 1 and openings <= 5 then
+			-- Ceiling and floor
+			local maxx, maxy, maxz = x+dim.x+1, y+dim.y+1, z+dim.z+1
+			for tx = x, maxx do
+				for tz = z, maxz do
+					for ty = y, maxy do
+						local p_pos = area:index(tx, ty, tz)
+	
+						-- Floor
+						if ty == y then
+							if math.random(1,4) == 1 then
+								data[p_pos] = c_cobble
+							else
+								data[p_pos] = c_mossycobble
+							end
+
+						-- Wall or ceiling
+						elseif ty == maxy or (ty > y and (tx == x or tx == maxx) or (tz == z or tz == maxz)) then
+							data[p_pos] = c_cobble
+
+						-- Room interiour
+						else
+
+							data[p_pos] = c_air
+						end
+					end
+				end
+			end
+		end
+
+		lvm_used = true
+	end
+
+	if lvm_used then
+		vm:set_data(data)
+		vm:calc_lighting()
+		vm:update_liquids()
+		vm:write_to_map()
+	end
+
+end)
diff --git a/mods/MAPGEN/mcl_dungeons/mod.conf b/mods/MAPGEN/mcl_dungeons/mod.conf
new file mode 100644
index 0000000000..d6af72a27b
--- /dev/null
+++ b/mods/MAPGEN/mcl_dungeons/mod.conf
@@ -0,0 +1 @@
+name = mcl_dungeons