Start implementing //hollow, but it isn't finished yet

worldeditadditions/init.lua

@@ -29,6 +29,7 @@ dofile(worldeditadditions.modpath.."/lib/walls.lua")
 dofile(worldeditadditions.modpath.."/lib/replacemix.lua")
 dofile(worldeditadditions.modpath.."/lib/maze2d.lua")
 dofile(worldeditadditions.modpath.."/lib/maze3d.lua")
+dofile(worldeditadditions.modpath.."/lib/hollow.lua")
 dofile(worldeditadditions.modpath.."/lib/conv/conv.lua")
 dofile(worldeditadditions.modpath.."/lib/erode/erode.lua")
 

worldeditadditions/lib/hollow.lua

@@ -0,0 +1,44 @@
+-- ██   ██  ██████  ██      ██       ██████  ██     ██
+-- ██   ██ ██    ██ ██      ██      ██    ██ ██     ██
+-- ███████ ██    ██ ██      ██      ██    ██ ██  █  ██
+-- ██   ██ ██    ██ ██      ██      ██    ██ ██ ███ ██
+-- ██   ██  ██████  ███████ ███████  ██████   ███ ███
+--- Hollows out the defined region, leaving a given number of nodes on the
+-- outside.
+-- (think of the bits of the outermost parts of the defined region as the
+-- 'walls' to a box)
+function worldeditadditions.hollow(pos1, pos2, wall_thickness)
+	pos1, pos2 = worldedit.sort_pos(pos1, pos2)
+	-- pos2 will always have the highest co-ordinates now
+	
+	-- Fetch the nodes in the specified area
+	local manip, area = worldedit.manip_helpers.init(pos1, pos2)
+	local data = manip:get_data()
+	
+	local node_id_ignore = minetest.get_content_id("air")
+	
+	-- minetest.log("action", "pos1: " .. worldeditadditions.vector.tostring(pos1))
+	-- minetest.log("action", "pos2: " .. worldeditadditions.vector.tostring(pos2))
+	
+	local changes = { replaced = 0 }
+	for z = pos2.z - wall_thickness, pos1.z + wall_thickness, -1 do
+		for y = pos2.y - wall_thickness, pos1.y + wall_thickness, -1 do
+			for x = pos2.x - wall_thickness, pos1.x + wall_thickness, -1 do
+				local i = area:index(x, y, z)
+				
+				local is_air = worldeditadditions.is_airlike(data[i])
+				local is_ignore = data[i] == node_id_ignore
+				
+				if not is_ignore and not is_air then
+					data[i] = node_id_air
+					changes.replaced = changes.replaced + 1
+				end
+			end
+		end
+	end
+	
+	-- Save the modified nodes back to disk & return
+	worldedit.manip_helpers.finish(manip, data)
+	
+	return true, changes
+end

worldeditadditions_commands/commands/hollow.lua

@@ -0,0 +1,48 @@
+-- ██   ██  ██████  ██      ██       ██████  ██     ██
+-- ██   ██ ██    ██ ██      ██      ██    ██ ██     ██
+-- ███████ ██    ██ ██      ██      ██    ██ ██  █  ██
+-- ██   ██ ██    ██ ██      ██      ██    ██ ██ ███ ██
+-- ██   ██  ██████  ███████ ███████  ██████   ███ ███
+worldedit.register_command("hollow", {
+	params = "[<wall_thickness>]",
+	description = "Replaces nodes inside the defined region with air, but leaving a given number of nodes near the outermost edges alone. In other words, it makes the defined region hollow leaving walls of a given thickness (default: 1)",
+	privs = { worldedit = true },
+	require_pos = 2,
+	parse = function(params_text)
+		if not params_text or #params_text == 0 then params_text = "1" end
+		
+		local wall_thickness = tonumber(params_text)
+		
+		if not wall_thickness then
+			return false, "Error: Unrecognised number '"..params_text.."'."
+		end
+		
+		return success, wall_thickness
+	end,
+	nodes_needed = function(name, wall_thickness)
+		-- //overlay only modifies up to 1 node per column in the selected region
+		local pos1, pos2 = worldedit.sort_pos(worldedit.pos1[name], worldedit.pos2[name])
+		return worldedit.volume(
+			{
+				x = pos2.x - wall_thickness,
+				y = pos2.y - wall_thickness,
+				z = pos2.z - wall_thickness
+			},
+			{
+				x = pos2.x + wall_thickness,
+				y = pos2.y + wall_thickness,
+				z = pos2.z + wall_thickness
+			}
+		)
+	end,
+	func = function(name, wall_thickness)
+		local start_time = worldeditadditions.get_ms_time()
+		local success, changes = worldeditadditions.hollow(worldedit.pos1[name], worldedit.pos2[name], wall_thickness)
+		local time_taken = worldeditadditions.get_ms_time() - start_time
+		
+		if not success then return success, changes end
+		
+		minetest.log("action", name .. " used //hollow at " .. worldeditadditions.vector.tostring(worldedit.pos1[name]) .. ", replacing " .. changes.replaced .. " nodes in " .. time_taken .. "s")
+		return true, changes.replaced .. " nodes replaced in " .. worldeditadditions.human_time(time_taken)
+	end
+})

worldeditadditions_commands/init.lua

@@ -31,6 +31,7 @@ dofile(we_c.modpath.."/commands/maze.lua")
 dofile(we_c.modpath.."/commands/replacemix.lua")
 dofile(we_c.modpath.."/commands/convolve.lua")
 dofile(we_c.modpath.."/commands/erode.lua")
+dofile(we_c.modpath.."/commands/hollow.lua")
 
 dofile(we_c.modpath.."/commands/count.lua")
 dofile(we_c.modpath.."/commands/saplingaliases.lua")