Rework metaballs backend

We need a way of defining metaballs per-player. Our solution to this is 
a custom in-memory per-player storage system. The reason for this is 
because just a position (e.g. that provided by pos1/pos2) is not enough 
- we need a radius as well.

worldeditadditions/init.lua

@@ -59,11 +59,11 @@ dofile(wea.modpath.."/lib/scale.lua")
 dofile(wea.modpath.."/lib/spiral_square.lua")
 dofile(wea.modpath.."/lib/spiral_circle.lua")
 dofile(wea.modpath.."/lib/dome.lua")
-dofile(wea.modpath.."/lib/metaballs.lua")
 dofile(wea.modpath.."/lib/conv/conv.lua")
 dofile(wea.modpath.."/lib/erode/erode.lua")
 dofile(wea.modpath.."/lib/noise/init.lua")
 wea.sculpt		= dofile(wea.modpath.."/lib/sculpt/init.lua")
+wea.metaballs	= dofile(wea.modpath.."/lib/metaballs.lua")
 
 dofile(wea.modpath.."/lib/copy.lua")
 dofile(wea.modpath.."/lib/move.lua")

worldeditadditions/lib/metaballs/init.lua

@@ -0,0 +1,15 @@
+local wea = worldeditadditions
+local wea_m = wea.modpath .. "/lib/metaballs/"
+
+local playerdata = dofile(wea_m.."playerdata.lua")
+
+local metaballs_ns = {
+	render = dofile(wea_m.."render.lua"),
+	add = playerdata.add,
+	remove = playerdata.remove,
+	list = playerdata.list,
+	list_pretty = playerdata.list_pretty,
+	clear = playerdata.clear
+}
+
+return metaballs_ns

worldeditadditions/lib/metaballs/playerdata.lua

@@ -0,0 +1,104 @@
+local wea = worldeditadditions
+local Vector3 = wea.Vector3
+
+local metaballdata = {}
+
+--- Adds a new metaball for a given player at the specified position with a specified radius.
+-- @param	player_name	string	The name of the player.
+-- @param	pos			Vector3	The position of the metaball.
+-- @param	radius		number	The radius of the metaball.
+-- @returns	bool,number	The number of metaballs now defined for the given player.
+local function add(player_name, pos, radius)
+	local pos = Vector3.clone(pos)
+	
+	if type(player_name) ~= "string" then
+		return false, "Error: Invalid player name specified."
+	end
+	if type(radius) ~= "number" then
+		return false, "Error: Expected the radius to be of type number, but got value of type "..type(radius).." instead."
+	end
+	if radius < 1 then
+		return false, "The minimum radius of a metaball is 1, but got a radius of "..tostring(radius).."."
+	end
+	
+	if not metaballdata[player_name] then
+		metaballdata[player_name] = {}
+	end
+	
+	-- TODO: Limit the number of metaballs that can be defined?
+	table.insert(metaballdata[player_name], {
+		pos = pos,
+		radius = radius
+	})
+	
+	return true, #metaballdata[player_name]
+end
+
+--- Returns a list of all metaballs defined for the given player.
+-- @param	player_name	string	The name of the player.
+-- @returns	bool,[{ pos: Vector3, radius: number }, ...]	A list of metaballs for the given player.
+local function list(player_name)
+	if type(player_name) ~= "string" then
+		return false, "Error: Invalid player name specified."
+	end
+	
+	if not metaballdata[player_name] then return {} end
+	
+	return true, metaballdata[player_name]
+end
+
+--- Returns a pretty-printed list of metaballs for the given player.
+-- @param	player_name	string	The name of the player.
+-- @returns	bool,string		A pretty-printed list of metaballs for the given player.
+local function list_pretty(player_name)
+	local success, metaball_list = list(player_name)
+	if not success then return success, metaball_list end
+	
+	local rows = { { "Index", "Position", "Radius" } }
+	for i,metaball in ipairs(metaball_list) do
+		table.insert(rows, {
+			i,
+			metaball.pos,
+			metaball.radius
+		})
+	end
+	
+	return true, wea.format.make_ascii_table(rows).."\n---------------------------\nTotal "..tostring(#metaball_list).." metaballs"
+end
+
+--- Removes the metaball with the specified index for a given player.
+-- @param	player_name	string	The name of the player.
+-- @param	index		number	The index of the metaball to remove.
+-- @returns	bool,number	The number of metaballs now defined for the given player.
+local function remove(player_name, index)
+	local success, metaball_list = list(player_name)
+	if not success then return success, metaball_list end
+	
+	if #metaball_list > index then
+		return false, "Error: Requested the removal of metaball "..tostring(index)..", but there are "..tostring(#metaball_list).." metaballs defined."
+	end
+	
+	table.remove(metaball_list, index)
+	
+	return #metaball_list
+end
+
+--- Removes all the currently defined metaballs for the given player.
+-- @param	player_name	string	The name of the player.
+-- @returns	bool,number	The number of metaballs that WERE defined for the given player.
+local function clear(player_name)
+	local success, metaball_list = list(player_name)
+	if not success then return success, metaball_list end
+	
+	metaballdata[player_name] = {}
+	
+	return #metaball_list
+end
+
+return {
+	add = add,
+	list = list,
+	list_pretty = list_pretty,
+	remove = remove,
+	clear = clear
+}

worldeditadditions/lib/metaballs/render.lua

@@ -10,7 +10,7 @@ local Vector3 = wea.Vector3
 -- direction the point should point.
 -- @param	metaballs		[{pos: Vector3, radius: number}]	Aa list of metaballs to render. Each metaball should be a table with 2 properties: pos - the position of the centre of the metaball as a Vector3, and radius - the radius of the metaball.
 -- @param	replace_node	string		The fully qualified name of the node to use to make the dome with.
-function worldeditadditions.metaballs(metaballs, replace_node, threshold)
+local function render(metaballs, replace_node, threshold)
 	local pos1, pos2
 	if not threshold then threshold = 1 end
 	
@@ -61,3 +61,6 @@ function worldeditadditions.metaballs(metaballs, replace_node, threshold)
 	
 	return true, replaced
 end
+
+
+return render

worldeditadditions_commands/commands/metaballs.lua

@@ -0,0 +1,71 @@
+local wea = worldeditadditions
+local Vector3 = wea.Vector3
+
+-- ██████   ██████  ███    ███ ███████
+-- ██   ██ ██    ██ ████  ████ ██
+-- ██   ██ ██    ██ ██ ████ ██ █████
+-- ██   ██ ██    ██ ██  ██  ██ ██
+-- ██████   ██████  ██      ██ ███████
+worldedit.register_command("metaballs", {
+	params = "add <radius> | remove <index> | list | render <replace_node> | clear",
+	description = "Defines and creates metaballs. After using the add subcommand to define 1 or more metaballs (uses pos1), the render subcommand can then be used to create the metaballs as nodes.",
+	privs = { worldedit = true },
+	require_pos = 1,
+	parse = function(params_text)
+		if not params_text then params_text = "" end
+		
+		local parts = wea.split_shell(params_text)
+		
+		if #parts < 1 then
+			return false, "Error: Not enough arguments (see /help /dome for usage information)."
+		end
+		local subcommand = parts[1]
+		local subargs = {}
+		if subcommand == "add" then
+			local radius = tonumber(parts[2])
+			if not radius then
+				return false, "Error: Invalid radius '"..parts[1].."'. The radius must be a positive integer."
+			end
+			if radius < 1 then
+				return false, "Error: The minimum radius size is 1, but you entered "..tostring(radius).."."
+			end
+			table.insert(subargs, radius)
+		elseif subcommand == "remove" then
+			local index = tonumber(parts[2])
+			if not index then
+				return false, "Error: Invalid index '"..parts[1].."'. The index to remove must be a positive integer."
+			end
+			if index < 1 then
+				return false, "Error: The minimum index size is 1, but you entered "..tostring(index).."."
+			end
+			table.insert(subargs, index)
+		elseif subcommand == "render" then
+			local replace_node = worldedit.normalize_nodename(parts[2])
+			if not replace_node then
+				return false, "Error: Invalid replace_node '"..parts[2].."'."
+			end
+			table.insert(subargs, replace_node)
+		end
+		
+		return true, subcommand, subargs
+	end,
+	nodes_needed = function(name, subcommand)
+		if subcommand == "render" then
+			return worldedit.volume(worldedit.pos1[name], worldedit.pos2[name])
+		else
+			return 0
+		end
+	end,
+	func = function(name, radius, replace_node, axes, hollow)
+		local start_time = wea.get_ms_time()
+		
+		
+		
+		
+		local time_taken = wea.get_ms_time() - start_time
+		
+		
+		minetest.log("action", name.." used //dome+ at "..pos.." with a radius of "..tostring(radius)..", modifying "..nodes_replaced.." nodes in "..wea.format.human_time(time_taken))
+		return true, nodes_replaced.." nodes replaced "..wea.format.human_time(time_taken)
+	end
+})