fix Voxel usage

README.md

@@ -45,6 +45,7 @@ License: LGPLv2
   - plan_obj:do_add_chunk_voxel(plan_pos)   - Place all nodes for chunk in real world using voxelmanip (TODO)
   - plan_obj:get_status()          - get the plan status. Returns values are "new", "build" and "finished"
   - plan_obj:set_status(status)    - set the plan status. Created plan is new, allowed new stati are "build" and "finished"
+  - plan_obj:load_region(min_world_pos[, max_world_pos]) - Load a Voxel-Manip for faster lookups to the real world
 
 ### Hooks
   - plan_obj:on_status()           - if defined, is called from get_plan_status() to get custom updates
@@ -59,7 +60,6 @@ License: LGPLv2
   - plan_obj.data.groundnode_count - count of nodes found for ground_y determination (internal)
   - plan_obj.data.min_pos        - minimal {x,y,z} vector
   - plan_obj.data.max_pos        - maximal {x,y,z} vector
-  - plan_obj:load_region(min_world_pos, max_world_pos) - Load a Voxel-Manip for faster lookups to the real world
 
 ## Node object
 ### class-methods

npc_ai.lua

@@ -48,18 +48,12 @@ function npc_ai_class:get_if_buildable(node)
 	local node_index
 	local world_content_id
 
-	if self.plan.vm_area then
-		node_index = self.plan.vm_area:indexp(world_pos)
-		world_content_id = self.plan.vm_data[node_index]
-	end
-	if not world_content_id then
-		self.plan:load_region(world_pos, world_pos)
-		node_index = self.plan.vm_area:indexp(world_pos)
-		world_content_id = self.plan.vm_data[node_index]
-	end
-	if not world_content_id then
-		return nil --something wrong
+	if not self.plan.vm_area or not self.plan.vm_area:contains(world_pos.x, world_pos.y, world_pos.z) then
+		self.plan:load_region(world_pos)
 	end
+	node_index = self.plan.vm_area:indexp(world_pos)
+	world_content_id = self.plan.vm_data[node_index]
+
 	node.world_node_name = minetest.get_name_from_content_id(world_content_id)
 	if world_content_id == mapped.content_id then
 		-- right node is at the place. there are no costs to touch them. Check if a touch needed