add lava and water alerts, and an option for setting lava impassible (true by default)

README.txt

@@ -136,6 +136,10 @@ A ringing bell indicates that there are insufficient materials in inventory to s
 
 A short high-pitched honk means that one or more of the builder heads don't have an item set. A common oversight, especially with large and elaborate digging machines, that might be hard to notice and annoying to fix if not noticed right away.
 
+Splooshing water sounds means your Digtron is digging adjacent to (or through) water-containing nodes. Digtrons are waterproof, but this might be a useful indication that you should take care when installing doors in the tunnel walls you've placed here.
+
+A triple "voop voop voop!" alarm indicates that there is lava adjacent to your Digtron. Digtrons can't penetrate lava by default, and although they are not destroyed by lava this alarm indicates that a non-lava-proof Digtron operator may wish to exercise caution when backing up.
+
 Crafting recipes
 ================
 

init.lua

@@ -7,8 +7,9 @@ dofile( minetest.get_modpath( "digtron" ) .. "/node_builders.lua" ) -- contains
 dofile( minetest.get_modpath( "digtron" ) .. "/node_controllers.lua" ) -- controllers
 dofile( minetest.get_modpath( "digtron" ) .."/recipes.lua" )
 
-digtron.creative_mode = false
-digtron.particle_effects = true
+digtron.creative_mode = false -- this causes digtrons to operate without consuming fuel or building materials.
+digtron.particle_effects = true -- Enables the spray of particles out the back of a digger head
+digtron.lava_impassible = true -- when true, lava counts as protected nodes.
 
 digtron.cycle_time = 1 -- How many seconds a digtron waits between cycles. Auto-controllers can make this wait longer, but cannot make it shorter.
 digtron.traction_factor = 3.0 -- How many digtron nodes can be moved for each adjacent solid node that the digtron has traction against

node_controllers.lua

@@ -32,6 +32,12 @@ local execute_cycle = function(pos, clicker)
 		return pos, "Digtron is adjacent to unloaded nodes.\n" .. status_text
 	end
 	
+	if layout.water_touching == true then
+		minetest.sound_play("sploosh", {gain=1.0, pos=pos})
+	end
+	if layout.lava_touching == true then
+		minetest.sound_play("woopwoopwoop", {gain=1.0, pos=pos})
+	end	
 	if layout.traction * digtron.traction_factor < table.getn(layout.all) then
 		-- digtrons can't fly
 		minetest.sound_play("squeal", {gain=1.0, pos=pos})

sounds/license.txt

@@ -6,6 +6,8 @@ dingding.ogg - https://www.freesound.org/people/JohnsonBrandEditing/sounds/17393
 squeal.ogg - https://www.freesound.org/people/RutgerMuller/sounds/104026/ public domain via CC 1.0 by RutgerMuller
 honk.ogg - https://freesound.org/people/bigmanjoe/sounds/349922/ public domain via CC 1.0 by bigmanjoe
 truck.ogg - https://www.freesound.org/people/jberkuta14/sounds/134898/ public domain via CC 1.0 by jberkuta14
+sploosh.ogg - https://www.freesound.org/people/mr_marcello/sounds/257609/ public domain via CC 1.0 by mr_marcello
+woopwoopwoop.ogg - https://www.freesound.org/people/gregconquest/sounds/188012/ public domain via CC 1.0 by gregconquest
 
 
 Creative Commons Attribution 3.0 license:

util.lua

@@ -138,6 +138,8 @@ digtron.get_all_digtron_neighbours = function(pos, player)
 	layout.diggers = {}
 	layout.builders = {}
 	layout.extents = {}
+	layout.water_touching = false
+	layout.lava_touching = false
 	layout.protected = Pointset.create() -- if any nodes we look at are protected, make note of that. That way we don't need to keep re-testing protection state later.
 	layout.controller = {x=pos.x, y=pos.y, z=pos.z} 	--Make a deep copy of the pos parameter just in case the calling code wants to play silly buggers with it
 
@@ -182,6 +184,15 @@ digtron.get_all_digtron_neighbours = function(pos, player)
 			layout.protected:set(testpos.x, testpos.y, testpos.z, true)
 		end
 		
+		if minetest.get_item_group(node.name, "water") ~= 0 then
+			layout.water_touching = true
+		elseif minetest.get_item_group(node.name, "lava") ~= 0 then
+			layout.lava_touching = true
+			if digtron.lava_impassible == true then
+				layout.protected:set(testpos.x, testpos.y, testpos.z, true)
+			end
+		end
+		
 		local group_number = minetest.get_item_group(node.name, "digtron")
 		if group_number > 0 then
 			--found one. Add it to the digtrons output