Add functionality for inverting door swing

TODO.txt

@@ -1,4 +1,3 @@
 
 TODO:
-- add methods for opening doors in opposite directions
 - save meta data when swapping outward opening doors

init.lua

@@ -72,19 +72,35 @@ if not core.global_exists("smodel") then
 end
 
 
+
+--- API Methods
+--
+--  @section methods
+
+
 --- Helper method for inward opening door-like nodes.
 --
 --  @function simple_models:door_inward_open
 --  @tparam vector pos Position of node.
 --  @tparam string new_node Technical name of node replacement.
-simple_models.door_inward_open = function(self, pos, new_node)
+--  @tparam bool invert If `true`, door swings in opposite direction (right instead of left).
+simple_models.door_inward_open = function(self, pos, new_node, invert)
 	local node = core.get_node_or_nil(pos)
 	if not node then return end
 
-	local rot = node.param2-1
-	if rot < 0 then
-		rot = 3
+	local rot
+	if not invert then
+		rot = node.param2-1
+		if rot < 0 then
+			rot = 3
+		end
+	else
+		rot = node.param2+1
+		if rot > 3 then
+			rot = 0
+		end
 	end
+
 	core.swap_node(pos, {
 		name = new_node,
 		param1 = node.param1,
@@ -97,14 +113,24 @@ end
 --  @function simple_models:door_inward_close
 --  @tparam vector pos Position of node.
 --  @tparam string new_node Technical name of node replacement.
-simple_models.door_inward_close = function(self, pos, new_node)
+--  @tparam bool invert If `true`, door swings in opposite direction (right instead of left).
+simple_models.door_inward_close = function(self, pos, new_node, invert)
 	local node = core.get_node_or_nil(pos)
 	if not node then return end
 
-	local rot = node.param2+1
-	if rot > 3 then
-		rot = 0
+	local rot
+	if not invert then
+		rot = node.param2+1
+		if rot > 3 then
+			rot = 0
+		end
+	else
+		rot = node.param2-1
+		if rot < 0 then
+			rot = 3
+		end
 	end
+
 	core.swap_node(pos, {
 		name = new_node,
 		param1 = node.param1,
@@ -128,17 +154,22 @@ local get_pos_front = function(pos, param2)
 	return new_pos
 end
 
-local get_pos_behind = function(pos, param2)
+local get_pos_behind = function(pos, param2, invert)
 	local new_pos = table.copy(pos)
 
+	local addto = 1
+	if invert then
+		addto = -addto
+	end
+
 	if param2 == 0 then
-		new_pos.x = new_pos.x-1
+		new_pos.x = new_pos.x - addto
 	elseif param2 == 2 then
-		new_pos.x = new_pos.x+1
+		new_pos.x = new_pos.x + addto
 	elseif param2 == 1 then
-		new_pos.z = new_pos.z+1
+		new_pos.z = new_pos.z + addto
 	elseif param2 == 3 then
-		new_pos.z = new_pos.z-1
+		new_pos.z = new_pos.z - addto
 	end
 
 	return new_pos
@@ -149,7 +180,8 @@ end
 --  @function simple_models:door_outward_open
 --  @tparam vector pos Position of node.
 --  @tparam string new_node Technical name of node replacement.
-simple_models.door_outward_open = function(self, pos, new_node)
+--  @tparam bool invert If `true`, door swings in opposite direction (right instead of left).
+simple_models.door_outward_open = function(self, pos, new_node, invert)
 	local node = core.get_node_or_nil(pos)
 	if not node then return end
 
@@ -159,10 +191,19 @@ simple_models.door_outward_open = function(self, pos, new_node)
 	-- something is blocking door or new_pos is same as old
 	if blocker and blocker.name ~= "air" then return end
 
-	local rot = node.param2+1
-	if rot > 3 then
-		rot = 0
+	local rot
+	if not invert then
+		rot = node.param2+1
+		if rot > 3 then
+			rot = 0
+		end
+	else
+		rot = node.param2-1
+		if rot < 0 then
+			rot = 3
+		end
 	end
+
 	core.remove_node(pos)
 	core.set_node(new_pos, {
 		name = new_node,
@@ -176,20 +217,30 @@ end
 --  @function simple_models:door_outward_close
 --  @tparam vector pos Position of node.
 --  @tparam string new_node Technical name of node replacement.
-simple_models.door_outward_close = function(self, pos, new_node)
+--  @tparam bool invert If `true`, door swings in opposite direction (right instead of left).
+simple_models.door_outward_close = function(self, pos, new_node, invert)
 	local node = core.get_node_or_nil(pos)
 	if not node then return end
 
-	local new_pos = get_pos_behind(pos, node.param2)
+	local new_pos = get_pos_behind(pos, node.param2, invert)
 
 	local blocker = core.get_node(new_pos)
 	-- something is blocking door or new_pos is same as old
 	if blocker and blocker.name ~= "air" then return end
 
-	local rot = node.param2-1
-	if rot < 0 then
-		rot = 3
+	local rot
+	if not invert then
+		rot = node.param2-1
+		if rot < 0 then
+			rot = 3
+		end
+	else
+		rot = node.param2+1
+		if rot > 3 then
+			rot = 0
+		end
 	end
+
 	core.remove_node(pos)
 	core.set_node(new_pos, {
 		name = new_node,