//replacemix: add command

README.md

@@ -18,8 +18,9 @@ If you can dream of it, it probably belongs here!
  - [`//maze3d <replace_node> [<path_length> [<path_width> [<path_depth> [<seed>]]]]`](#maze3d-replace_node-seed)
  - [`//bonemeal [<strength> [<chance>]]`](#bonemeal-strength-chance)
  - [`//walls <replace_node>`](#walls-replace_node)
+ - [`//replacemix <target_node> [<chance>] <replace_node_a> [<chance_a>] [<replace_node_b> [<chance_b>]] [<replace_node_N> [<chance_N>]] ....`]
  - [`//count`](#count)
- - [`//multi <command_a> <command_b> .....`](#multi-command_a-command_b-command_c-)
+ - [`//multi <command_a> <command_b> ....`](#multi-command_a-command_b-command_c-)
  - [`//y`](#y)
  - [`//n`](#n)
 
@@ -141,6 +142,55 @@ Creates vertical walls of `<replace_node>` around the inside edges of the define
 //walls goldblock
 ```
 
+### `//replacemix <target_node> [<chance>] <replace_node_a> [<chance_a>] [<replace_node_b> [<chance_b>]] [<replace_node_N> [<chance_N>]] ...`
+Replaces a given node with a random mix of other nodes. Functions like `//mix`.
+
+This command is best explained with examples:
+
+```
+//replacemix dirt stone
+```
+
+The above functions just like `//replace` - nothing special going on here. It replaces all `dirt` nodes with `stone`.
+
+Let's make it more interesting:
+
+```
+//replacemix dirt 5 stone
+```
+
+The above replaces 1 in every 5 `dirt` nodes with `stone`. Let's get even fancier:
+
+```
+//replacemix stone stone_with_diamond stone_with_gold
+```
+
+The above replaces `stone` nodes with a random mix of `stone_with_diamond` and `stone_with_gold` nodes. But wait - there's more!
+
+```
+//replacemix stone stone_with_diamond stone_with_gold 4
+```
+
+The above replaces `stone` nodes with a random mix of `stone_with_diamond` and `stone_with_gold` nodes as before, but this time in the ratio 1:4 (i.e. for every `stone_with_diamond` node there will be 4 `stone_with_gold` nodes). Note that the `1` for `stone_with_diamond` is implicit there.
+
+If we wanted to put all of the above features together into a single command, then we might do this:
+
+```
+//replacemix dirt 3 sandstone 10 dry_dirt cobble 2
+```
+
+The above replaces 1 in 3 `dirt` nodes with a mix of `sandstone`, `dry_dirt`, and `cobble` nodes in the ratio 10:1:2. Awesome!
+
+Here are all the above examples together:
+
+```
+//replacemix dirt stone
+//replacemix dirt 5 stone
+//replacemix stone stone_with_diamond stone_with_gold
+//replacemix stone stone_with_diamond stone_with_gold 4
+//replacemix dirt 3 sandstone 10 dry_dirt cobble 2
+```
+
 ### `//count`
 Counts all the nodes in the defined region and returns the result along with calculated percentages (note that if the chat window used a monospace font, the returned result would be a perfect table. If someone has a ~~hack~~ solution to make the columns line up neatly, please [open an issue](https://github.com/sbrl/Minetest-WorldEditAdditions/issues/new) :D)
 

worldeditadditions/init.lua

@@ -16,6 +16,7 @@ dofile(worldeditadditions.modpath.."/lib/overlay.lua")
 dofile(worldeditadditions.modpath.."/lib/ellipsoid.lua")
 dofile(worldeditadditions.modpath.."/lib/torus.lua")
 dofile(worldeditadditions.modpath.."/lib/walls.lua")
+dofile(worldeditadditions.modpath.."/lib/replacemix.lua")
 dofile(worldeditadditions.modpath.."/lib/maze2d.lua")
 dofile(worldeditadditions.modpath.."/lib/maze3d.lua")
 

worldeditadditions/lib/replacemix.lua

@@ -0,0 +1,56 @@
+--- Like //mix, but replaces a given node instead.
+-- @module worldeditadditions.replacemix
+
+-- ██████  ███████ ██████  ██       █████   ██████ ███████ ███    ███ ██ ██   ██
+-- ██   ██ ██      ██   ██ ██      ██   ██ ██      ██      ████  ████ ██  ██ ██
+-- ██████  █████   ██████  ██      ███████ ██      █████   ██ ████ ██ ██   ███
+-- ██   ██ ██      ██      ██      ██   ██ ██      ██      ██  ██  ██ ██  ██ ██
+-- ██   ██ ███████ ██      ███████ ██   ██  ██████ ███████ ██      ██ ██ ██   ██
+function worldeditadditions.replacemix(pos1, pos2, target_node, target_node_chance, replacements)
+	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_target = minetest.get_content_id(target_node)
+	
+	-- Initialise statistics
+	local changed = 0
+	local candidates = 0
+	local distribution = {}
+	
+	-- Generate the list of node ids
+	local node_ids_replace = {}
+	for node_name, weight in pairs(replacements) do
+		local next_id = minetest.get_content_id(node_name)
+		for i = 1, weight do
+			table.insert(
+				node_ids_replace,
+				next_id
+			)
+		end
+		distribution[next_id] = 0
+	end
+	local node_ids_replace_count = #node_ids_replace
+	
+	for i in area:iterp(pos1, pos2) do
+		
+		if data[i] == node_id_target then
+			candidates = candidates + 1
+			if math.random(target_node_chance) == 1 then
+				local next_id = node_ids_replace[math.random(node_ids_replace_count)]
+				data[i] = next_id
+				changed = changed + 1
+				-- We initialised this above
+				distribution[next_id] = distribution[next_id] + 1
+			end
+		end
+	end
+	
+	-- Save the modified nodes back to disk & return
+	worldedit.manip_helpers.finish(manip, data)
+	
+	return true, changed, candidates, distribution
+end

worldeditadditions/utils/strings.lua

@@ -73,7 +73,27 @@ function worldeditadditions.str_padstart(str, len, char)
     return string.rep(char, len - #str) .. str
 end
 
-function worldeditadditions.make_ascii_table(data)
+--- Turns an associative node_id → count table into a human-readable list.
+-- Works well with worldeditadditions.make_ascii_table().
+function worldeditadditions.node_distribution_to_list(distribution, nodes_total)
+	local distribution_data = {}
+	for node_id, count in pairs(distribution) do
+		table.insert(distribution_data, {
+			count,
+			tostring(worldeditadditions.round((count / nodes_total) * 100, 2)).."%",
+			minetest.get_name_from_content_id(node_id)
+		})
+	end
+	return distribution_data
+end
+
+--- Makes a human-readable table of data.
+-- Data should be a 2D array - i.e. a table of tables. The nested tables should
+-- contain a list of items for a single row.
+-- If total is specified, then a grand total is printed at the bottom - this is
+-- useful when you want to print a node list - works well with
+-- worldeditadditions.node_distribution_to_list().
+function worldeditadditions.make_ascii_table(data, total)
 	local extra_padding = 2
 	local result = {}
 	local max_lengths = {}
@@ -94,6 +114,11 @@ function worldeditadditions.make_ascii_table(data)
 		result[#result+1] = table.concat(row_result, "")
 	end
 	
+	if total then
+		result[#result+1] = string.rep("=", 6 + #tostring(total) + 6).."\n"..
+		"Total "..total.." nodes\n"
+	end
+	
 	-- TODO: Add multi-column support here
 	return table.concat(result, "\n")
 end

worldeditadditions_commands/commands/replacemix.lua

@@ -0,0 +1,93 @@
+local we_c = worldeditadditions_commands
+
+-- ██████  ███████ ██████  ██       █████   ██████ ███████ ███    ███ ██ ██   ██
+-- ██   ██ ██      ██   ██ ██      ██   ██ ██      ██      ████  ████ ██  ██ ██
+-- ██████  █████   ██████  ██      ███████ ██      █████   ██ ████ ██ ██   ███
+-- ██   ██ ██      ██      ██      ██   ██ ██      ██      ██  ██  ██ ██  ██ ██
+-- ██   ██ ███████ ██      ███████ ██   ██  ██████ ███████ ██      ██ ██ ██   ██
+worldedit.register_command("replacemix", {
+	params = "<target_node> [<chance>] <replace_node_a> [<chance_a>] [<replace_node_b> [<chance_b>]] [<replace_node_N> [<chance_N>]] ...",
+	description = "Replaces target_node with a mix of other nodes. Functions simmilarly to //mix. <chance> is optional and the chance to replace the target node at all. replace_node_a is the node to replace target_node with. If multiple nodes are specified in a space separated list, then when replacing an instance of target_node one is randomly chosen from the list. Just like with //mix, if a positive integer is present after a replace_node, that adds a weighting to that particular node making it more common.",
+	privs = { worldedit = true },
+	require_pos = 2,
+	parse = function(params_text)
+		if not params_text or params_text == "" then
+			return false, "Error: No arguments specified"
+		end
+		
+		local parts = worldeditadditions.split(params_text, "%s+", false)
+		
+		local target_node = nil
+		local target_node_chance = 1
+		local replace_nodes = {}
+		
+		local mode = "target_node"
+		local last_node_name = nil
+		for i, part in ipairs(parts) do
+			if mode == "target_node" then
+				target_node = worldedit.normalize_nodename(part)
+				if not target_node then
+					return false, "Error: Invalid target_node name"
+				end
+				mode = "target_chance"
+			elseif mode == "target_chance" and tonumber(part) then
+				target_node_chance = tonumber(part)
+				mode = "replace_node"
+			elseif (mode == "target_chance" and not tonumber(part)) or mode == "replace_node" then
+				mode = "replace_node"
+				if tonumber(part) then
+					if not last_node_name then
+						return false, "Error: No previous node name was found (this is a probably a bug)."
+					end
+					replace_nodes[last_node_name] = math.floor(tonumber(part))
+				else
+					if last_node_name and not replace_nodes[last_node_name] then
+						replace_nodes[last_node_name] = 1
+					end
+					
+					local node_name = worldedit.normalize_nodename(part)
+					if not node_name then
+						return false, "Error: Invalid replace node name '"..part.."'."
+					end
+					last_node_name = node_name
+				end
+			end
+		end
+		if not replace_nodes[last_node_name] then
+			replace_nodes[last_node_name] = 1
+		end
+		
+		-- We unconditionally math.floor here because when we tried to test for it directly it was unreliable
+		return true, target_node, target_node_chance, replace_nodes
+	end,
+	nodes_needed = function(name) -- target_node, target_node_chance, replace_nodes
+		return worldedit.volume(worldedit.pos1[name], worldedit.pos2[name])
+	end,
+	func = function(name, target_node, target_node_chance, replace_nodes)
+		local start_time = os.clock()
+		
+		local success, changed, candidates, distribution = worldeditadditions.replacemix(
+			worldedit.pos1[name], worldedit.pos2[name],
+			target_node,
+			target_node_chance,
+			replace_nodes
+		)
+		if not success then
+			return success, changed
+		end
+		
+		local nodes_total = worldedit.volume(worldedit.pos1[name], worldedit.pos2[name])
+		local percentage_replaced = worldeditadditions.round((changed / candidates)*100, 2)
+		local distribution_table = worldeditadditions.make_ascii_table(
+			worldeditadditions.node_distribution_to_list(distribution, changed),
+			changed
+		)
+		
+		local time_taken = os.clock() - start_time
+		
+		
+		minetest.log("action", name .. " used //replacemix at "..worldeditadditions.vector.tostring(worldedit.pos1[name]).." - "..worldeditadditions.vector.tostring(worldedit.pos2[name])..", replacing " .. changed.." nodes (out of "..nodes_total.." nodes) in "..time_taken.."s")
+		
+		return true, distribution_table..changed.." out of "..candidates.." (~"..percentage_replaced.."%) candidates replaced in "..time_taken.."s"
+	end
+})

worldeditadditions_commands/init.lua

@@ -23,6 +23,7 @@ dofile(we_c.modpath.."/commands/ellipsoid.lua")
 dofile(we_c.modpath.."/commands/torus.lua")
 dofile(we_c.modpath.."/commands/walls.lua")
 dofile(we_c.modpath.."/commands/maze.lua")
+dofile(we_c.modpath.."/commands/replacemix.lua")
 
 dofile(we_c.modpath.."/commands/count.lua")