Guarantee 1 chest with treasures

init.lua

@@ -40,12 +40,16 @@ else
 	table.insert(chest_stuff, {name="farming:apple", max = 3})
 end
 
-function tsm_pyramids.fill_chest(pos, stype, flood_sand)
+function tsm_pyramids.fill_chest(pos, stype, flood_sand, treasure_chance)
 	local sand = "default:sand"
+	if not treasure_chance then
+		treasure_chance = 100
+	end
 	if stype == "desert_sandstone" or stype == "desert_stone" then
 		sand = "default:desert_sand"
 	end
 	local n = minetest.get_node(pos)
+	local treasure_added = false
 	if n and n.name and n.name == "default:chest" then
 		local meta = minetest.get_meta(pos)
 		local inv = meta:get_inventory()
@@ -56,13 +60,14 @@ function tsm_pyramids.fill_chest(pos, stype, flood_sand)
 			table.insert(stacks, {name=sand, count = math.random(1,32)})
 		end
 		-- Add treasures
-		if math.random(1,10) >= 7 then
+		if math.random(1,100) <= treasure_chance then
 			if minetest.get_modpath("treasurer") ~= nil then
 				stacks = treasurer.select_random_treasures(3,7,9,{"minetool", "food", "crafting_component"})
 			else
 				for i=0,2,1 do
 					local stuff = chest_stuff[math.random(1,#chest_stuff)]
 					table.insert(stacks, {name=stuff.name, count = math.random(1,stuff.max)})
+					treasure_added = true
 				end
 			end
 		end
@@ -72,6 +77,7 @@ function tsm_pyramids.fill_chest(pos, stype, flood_sand)
 			end
 		end
 	end
+	return treasure_added
 end
 
 local function add_spawner(pos, mummy_offset)

room.lua

@@ -1054,12 +1054,20 @@ function tsm_pyramids.make_room(pos, stype, room_id, rotations)
 	if #chests > 0 then
 		-- Make at least 8 attempts to fill chests
 		local filled = 0
+		local chests_with_treasure = 0
 		while filled < 8 do
 			for c=1, #chests do
-				tsm_pyramids.fill_chest(chests[c], stype, sanded)
+				local has_treasure = tsm_pyramids.fill_chest(chests[c], stype, sanded, 30)
+				if has_treasure then
+					chests_with_treasure = chests_with_treasure + 1
+				end
 				filled = filled + 1
 			end
 		end
+		-- If no chests were filled with treasure so far, fill a random chest guaranteed
+		if chests_with_treasure == 0 then
+			tsm_pyramids.fill_chests(chests[math.random(1, #chests)], stype, sanded, 100)
+		end
 	end
 	if room.traps and math.random(1,4) then
 		tsm_pyramids.make_traps(pos, stype, rotations, layout)