Replace //homogenize with //replaceinverse (//homogenize x is equivalent to //replaceinverse air x), add documentation for it.

Chat Commands.md

@@ -51,13 +51,22 @@ Set the current WorldEdit region to <node>.
 
 ### //replace <search node> <replace node>
 
-Replace all instances of <search node> with <place node> in the current WorldEdit region.
+Replace all instances of <search node> with <replace node> in the current WorldEdit region.
 
     //replace cobble stone
     //replace default:steelblock glass
     //replace dirt flowers:flower_waterlily
     //replace flowers:flower_rose flowers:flower_tulip
 
+### //replaceinverse <search node> <replace node>
+
+Replace all nodes other than <search node> with <replace node> in the current WorldEdit region.
+
+    //replaceinverse air stone
+    //replaceinverse water_source default:dirt
+    //replaceinverse mesecons:mesecon air
+    //replaceinverse default:steelblock default:glass
+
 ### //hollowsphere <radius> <node>
 
 Add hollow sphere at WorldEdit position 1 with radius <radius>, composed of <node>.

WorldEdit API.md

@@ -20,6 +20,12 @@ Replaces all instances of `searchnode` with `replacenode` in a region defined by
 
 Returns the number of nodes replaced.
 
+### count = worldedit.replaceinverse(pos1, pos2, searchnode, replacenode)
+
+Replaces all nodes other than `searchnode` with `replacenode` in a region defined by positions `pos1` and `pos2`.
+
+Returns the number of nodes replaced.
+
 ### count = worldedit.copy(pos1, pos2, axis, amount)
 
 Copies the region defined by positions `pos1` and `pos2` along the `axis` axis ("x" or "y" or "z") by `amount` nodes.

worldedit/manipulations.lua

@@ -74,6 +74,37 @@ worldedit.replace = function(pos1, pos2, searchnode, replacenode)
 	return count
 end
 
+--replaces all nodes other than `searchnode` with `replacenode` in a region defined by positions `pos1` and `pos2`, returning the number of nodes replaced
+worldedit.replaceinverse = function(pos1, pos2, searchnode, replacenode)
+	local pos1, pos2 = worldedit.sort_pos(pos1, pos2)
+	local env = minetest.env
+
+	if minetest.registered_nodes[searchnode] == nil then
+		searchnode = "default:" .. searchnode
+	end
+
+	local pos = {x=pos1.x, y=0, z=0}
+	local node = {name=replacenode}
+	local count = 0
+	while pos.x <= pos2.x do
+		pos.y = pos1.y
+		while pos.y <= pos2.y do
+			pos.z = pos1.z
+			while pos.z <= pos2.z do
+				local name = env:get_node(pos).name
+				if name ~= "ignore" and name ~= searchnode then
+					env:add_node(pos, node)
+					count = count + 1
+				end
+				pos.z = pos.z + 1
+			end
+			pos.y = pos.y + 1
+		end
+		pos.x = pos.x + 1
+	end
+	return count
+end
+
 --copies the region defined by positions `pos1` and `pos2` along the `axis` axis ("x" or "y" or "z") by `amount` nodes, returning the number of nodes copied
 worldedit.copy = function(pos1, pos2, axis, amount)
 	local pos1, pos2 = worldedit.sort_pos(pos1, pos2)

worldedit_commands/init.lua

@@ -197,9 +197,9 @@ minetest.register_chatcommand("/replace", {
 	end,
 })
 
-minetest.register_chatcommand("/homogenize", {
+minetest.register_chatcommand("/replaceinverse", {
-	params = "<node>",
+	params = "<search node> <replace node>",
-	description = "Replace all non-air nodes with <node> in the current WorldEdit region",
+	description = "Replace all nodes other than <search node> with <replace node> in the current WorldEdit region",
 	privs = {worldedit=true},
 	func = function(name, param)
 		local pos1, pos2 = worldedit.pos1[name], worldedit.pos2[name]
@@ -208,13 +208,22 @@ minetest.register_chatcommand("/homogenize", {
 			return
 		end
 
-		if not worldedit.node_is_valid(param) then
+		local found, _, searchnode, replacenode = param:find("^([^%s]+)%s+([^%s]+)$")
-			minetest.chat_send_player(name, "Invalid node name: " .. param)
+		if found == nil then
+			minetest.chat_send_player(name, "Invalid usage: " .. param)
+			return
+		end
+		if not worldedit.node_is_valid(searchnode) then
+			minetest.chat_send_player(name, "Invalid search node name: " .. searchnode)
+			return
+		end
+		if not worldedit.node_is_valid(replacenode) then
+			minetest.chat_send_player(name, "Invalid replace node name: " .. replacenode)
 			return
 		end
 
-		local count = worldedit.homogenize(pos1, pos2, param)
+		local count = worldedit.replaceinverse(pos1, pos2, searchnode, replacenode)
-		minetest.chat_send_player(name, count .. " nodes homogenized")
+		minetest.chat_send_player(name, count .. " nodes replaced")
 	end,
 })