implement y_min and y_max, make netherite rarer

mods/MAPGEN/mcl_secret_ores/init.lua

@@ -21,6 +21,7 @@ local function is_occluded(pos,dp)
 end
 
 function mcl_secret_ores.on_dig(pos, oldnode,def)
+	if (def.y_min and pos.y < def.y_min) or ( def.y_max and pos.y > def.y_max ) then return end
 	for k,v in pairs(adjacents) do
 		local p=vector.add(pos,v)
 		local n=minetest.get_node_or_nil(p)
@@ -53,11 +54,13 @@ minetest.register_on_mods_loaded(function()
 end)
 
 mcl_secret_ores.register_ore({
-	wherein = {"mcl_nether:netherrack"},
+	wherein = {"mcl_nether:netherrack","mcl_blackstone:blackstone","mcl_blackstone:basalt"},
 	ore = "mcl_nether:ancient_debris",
+	y_min = mcl_vars.mg_nether_min,
+	y_max = mcl_vars.mg_nether_lava_max,
 	randomfunc = function(p)
 		p = vector.round(p)
 		local pr = PseudoRandom(p.x*p.y*p.z)
-		if pr:next(1,1000) == 1 then return true end
+		if pr:next(1,5000) == 1 then return true end
 	end,
 })

mods/MAPGEN/mcl_secret_ores/mod.conf

@@ -1,2 +1,3 @@
 name = mcl_secret_ores
 author = cora
+depends = mcl_init