Add debug setting to simplify editing the tutorial map

Set "tutorial_debug_map_editing = true" in minetest.conf

Disables grass layer and other stuff not part of the schematic

mods/tutorial/mapgen.lua

@@ -1,4 +1,11 @@
+-- TUTORIAL MAP GENERATION
 
+-- == DEBUG SETTINGS ==
+-- If true, the generated tutorial map is in "map editing" mode, only generating
+-- the raw castle, no grass layer or other random decorations will be generated
+local map_editing = minetest.settings:get_bool("tutorial_debug_map_editing")
+
+-- == END OF DEBUG SETTINGS ==
 
 -- Directory where the map data will be stored
 tutorial.map_directory = minetest.get_modpath("tutorial").."/mapdata/"
@@ -333,14 +340,14 @@ minetest.register_on_generated(function(minp, maxp, seed)
 		end
 	end
 
-	-- Make grass
+	-- Generate a layer of grass for the outside area
+	if map_editing ~= true then
 		local grasslev = 0
 		if minp.y <= grasslev and maxp.y >= grasslev then
 			local vdata = vm:get_data(vbuffer)
 			local area = VoxelArea:new({MinEdge=emin, MaxEdge=emax})
 			local c_dirt_with_grass = minetest.get_content_id("default:dirt_with_grass")
 			local c_grass = minetest.get_content_id("default:grass_5")
-		local c_dirt = minetest.get_content_id("default:dirt_with_grass")
 			for x = minp.x, maxp.x do
 				for z = minp.z, maxp.z do
 					local p_pos = area:index(x, grasslev, z)
@@ -364,7 +371,7 @@ minetest.register_on_generated(function(minp, maxp, seed)
 			vm:set_data(vdata)
 			state_changed = true
 		end
-
+	end
 
 	if(state_changed) then
 		vm:calc_lighting(nil, nil, false)