coffer dam

init.lua

@@ -17,6 +17,7 @@ dofile(modpath.."/metals.lua")
 dofile(modpath.."/geodes.lua")
 dofile(modpath.."/hotsprings.lua")
 dofile(modpath.."/structures/ziggurat.lua")
+dofile(modpath.."/structures/coffer_dam.lua")
 
 -- core
 dofile(modpath.."/minetunnels.lua")

structures/coffer_dam.lua

@@ -0,0 +1,138 @@
+
+
+
+
+
+
+
+
+
+local function drop_column(pos, node, maxdrop)
+	local maxd = pos.y - maxdrop
+	local p = {x=pos.x, y=pos.y, z=pos.z}
+	
+	while p.y >= maxd do
+		
+		local n = minetest.get_node(p)
+		local def = minetest.registered_nodes[n.name]
+		if def.groups.liquid then
+			minetest.set_node(p, {name=node})
+		else
+			break
+		end
+		
+		p.y = p.y - 1
+	end
+	
+end
+
+
+
+local function drop_wall(start, length, dir, node, maxdrop)
+	local p = {x=start.x, y=start.y, z=start.z}
+	
+	for i = 1,length do
+		drop_column(p, node, maxdrop)
+		
+		p = vector.add(p, dir)
+	end
+	
+end
+
+
+local function drop_octagon(center, rad)
+	
+	drop_wall(vector.add(center, {x=rad*2, y=0, z=rad}), rad*2+1, {x=0,y=0,z=-1}, "default:cobble", 10)
+	drop_wall(vector.add(center, {x=-rad*2, y=0, z=-rad}), rad*2+1, {x=0,y=0,z=1}, "default:cobble", 10)
+	
+	drop_wall(vector.add(center, {x=rad, y=0, z=rad*2}), rad*2+1, {x=-1,y=0,z=0}, "default:cobble", 10)
+	drop_wall(vector.add(center, {x=-rad, y=0, z=-rad*2}), rad*2+1, {x=1,y=0,z=0}, "default:cobble", 10)
+	
+	drop_wall(vector.add(center, {x=rad, y=0, z=-rad*2}), rad, {x=1,y=0,z=1}, "default:cobble", 10)
+	drop_wall(vector.add(center, {x=-rad, y=0, z=rad*2}), rad, {x=-1,y=0,z=-1}, "default:cobble", 10)
+	
+	drop_wall(vector.add(center, {x=-rad, y=0, z=-rad*2}), rad, {x=-1,y=0,z=1}, "default:cobble", 10)
+	drop_wall(vector.add(center, {x=rad, y=0, z=rad*2}), rad, {x=1,y=0,z=-1}, "default:cobble", 10)
+
+-- 	drop_wall(vector.add(center, {x=-rad, y=0, z=rad/2}), rad/2, {x=1,y=0,z=-1}, "default:cobble", 10)
+	
+	
+end
+
+
+local function freeze_top(pos, cb)
+	local stack = {}
+	local out = {}
+	table.insert(stack, pos)
+	
+	local function process()
+		local i = 0
+		while #stack > 0 do
+			local nn = math.random(#stack)
+-- 			print("index "..nn .. " of "..#stack)
+			local p = table.remove(stack, nn)
+-- 			print(dump(p))
+			local n = minetest.get_node(p)
+			if n.name == "default:water_source" then
+				table.insert(out, p)
+				
+				minetest.set_node(p, {name="default:ice"})
+				
+				table.insert(stack, vector.add(p, {x=1, y=0, z=0}))
+				table.insert(stack, vector.add(p, {x=-1, y=0, z=0}))
+				table.insert(stack, vector.add(p, {x=0, y=0, z=1}))
+				table.insert(stack, vector.add(p, {x=0, y=0, z=-1}))
+				
+				if #stack > 0 and i > 5 then
+					minetest.after(1, process)
+					return
+				elseif #stack == 0 then
+					cb(out)
+				end
+				
+				i = i + 1
+			end
+		end
+		
+		cb(out)
+	end
+	
+	process()
+	
+end
+
+
+
+
+local function clear_water(pts, maxd, top_off)
+	for _,p in ipairs(pts) do
+		drop_column({x=p.x, y=p.y-top_off, z=p.z}, "air", maxd - top_off)
+	end
+	
+end
+
+local function remove_points(pts, lvl)
+	
+	for _,p in ipairs(pts) do
+		minetest.set_node({x=p.x, y=p.y-lvl, z=p.z}, {name="air"})
+	end
+end
+
+
+
+minetest.register_node("potions:coffer_dam_seed", {
+	description = "Coffer Dam Seed",
+	drawtype = "node",
+	tiles = {"default_stone_brick.png"},
+	groups = {cracky=3,},
+	liquids_pointable=true,
+	on_construct = function(pos)
+		minetest.set_node(pos, {name="default:water_source"})
+		drop_octagon(pos, 3)
+		freeze_top(pos, function(pts)
+-- 			print("points "..#pts)
+			clear_water(pts, 10, 1)
+			minetest.after(2, remove_points, pts, 0)
+		end)
+	end
+})