make glow worms slowly grow when placed by player, and die in bright light

config.lua

@@ -42,6 +42,8 @@ local plants = {
 	{name="sweet_pod", delay_multiplier=2},
 }
 
+--Trees
+
 setting("int", "tree_min_growth_delay", 2400, "Minimum sapling growth delay")
 setting("int", "tree_max_growth_delay", 4800, "Maximum sapling growth delay")
 
@@ -52,14 +54,19 @@ end
 setting("int", "blood_thorn_growth_interval", 12, "blood_thorn growth ABM interval")
 setting("int", "blood_thorn_growth_chance", 83, "blood_thorn growth ABM chance")
 
+--Plants
+
 setting("int", "plant_growth_time", 500, "Base plant growth time")
 
 for _, plant in pairs(plants) do
 	setting("float", plant.name.."_delay_multiplier", plant.delay_multiplier, plant.name.." growth delay multiplier")
 end
 
+setting("float", "glow_worm_delay_multiplier", 10.0, "glow worm growth delay multiplier")
 setting("bool", "light_kills_fungus", true, "Light kills fungus")
 
+--Caverns
+
 setting("float", "vertical_cavern_scale", 256, "Vertical cavern dimension scale")
 setting("float", "horizontal_cavern_scale", 256, "Horizontal cavern dimension scale")
 

glow_worms.lua

@@ -8,17 +8,32 @@ minetest.register_node("dfcaverns:glow_worm", {
 	inventory_image = "dfcaverns_glow_worm.png",
 	wield_image = "dfcaverns_glow_worm.png",
 	is_ground_content = true,
-	groups = {oddly_breakable_by_hand=3},
+	groups = {oddly_breakable_by_hand=3, light_sensitive_fungus = 12},
+	_dfcaverns_dead_node = "air",
 	light_source = 9,
 	paramtype = "light",
 	drawtype = "plantlike",
 	walkable = false,
 	buildable_to = true,
 	visual_scale = 1.0,
-	selection_box = {
+	after_place_node = function(pos, placer) 
-		type = "fixed",
+		if dfcaverns.config.glow_worm_delay_multiplier > 0 then
-		fixed = {-0.5, -0.5, -0.5, 0.5, -0.5, 0.5},
+			minetest.get_node_timer(pos):start(math.random(
-	},
+				dfcaverns.config.glow_worm_delay_multiplier * dfcaverns.config.plant_growth_time * 0.75,
+				dfcaverns.config.glow_worm_delay_multiplier * dfcaverns.config.plant_growth_time * 1.25))
+		end
+	end,
+	on_timer = function(pos, elapsed)
+		local below = {x=pos.x, y=pos.y-1, z=pos.z}
+		if minetest.get_node(below).name == "air" then
+			minetest.set_node(below, {name="dfcaverns:glow_worm"})
+			if math.random() > 0.5 then
+				minetest.get_node_timer(below):start(math.random(
+				dfcaverns.config.glow_worm_delay_multiplier * dfcaverns.config.plant_growth_time * 0.75,
+				dfcaverns.config.glow_worm_delay_multiplier * dfcaverns.config.plant_growth_time * 1.25))			
+			end
+		end
+	end,
 })
 
 local c_air = minetest.get_content_id("air")
@@ -56,3 +71,4 @@ minetest.register_abm({
 		minetest.set_node(pos, {name="air"})
 	end,	
 })
+

settingtypes.txt

@@ -12,13 +12,15 @@ dfcaverns_blood_thorn_growth_interval (blood_thorn growth ABM interval) int 12
 dfcaverns_blood_thorn_growth_chance (blood_thorn growth ABM chance) int 83
 
 [Plant growth]
-dfcaverns_plant_growth_timer (Base plant growth timer interval) int 100
+dfcaverns_plant_growth_time (Base plant growth timer interval) int 100
 dfcaverns_cave_wheat_delay_multiplier (cave_wheat growth delay multiplier) float 1
 dfcaverns_dimple_cup_delay_multiplier (dimple_cup growth delay multiplier) float 3
 dfcaverns_pig_tail_delay_multiplier (pig_tail growth delay multiplier) float 1
 dfcaverns_plump_helmet_delay_multiplier (plump_helmet growth delay multiplier) float 3
 dfcaverns_quarry_bush_delay_multiplier (quarry_bush growth delay multiplier) float 2
 dfcaverns_sweet_pod_delay_multiplier (sweet_pod growth delay multiplier) float 2
+#To disable glow worm growth, set this to 0.
+dfcaverns_glow_worm_delay_multiplier (glow worm growth delay multiplier) float 10
 dfcaverns_light_kills_fungus (Light kills fungus) bool true
 
 [Cavern dimensions]