refactor: Remove cave generation from mineral ore generation odds (#24783)

* Remove cave generation from mineral ore generation odds

* use clearer vars

code/modules/lavaland/lavaland_theme.dm

@@ -1,3 +1,8 @@
+/// Approximate lower bound of the walkable land area on Lavaland, north of the southern lava border.
+#define LAVALAND_MIN_CAVE_Y 10
+/// Approximate upper bound of the walkable land area on Lavaland, south of the Legion entrance.
+#define LAVALAND_MAX_CAVE_Y 222
+
 /datum/lavaland_theme
 	/// Name of lavaland theme
 	var/name = "Not Specified"
@@ -12,6 +17,20 @@
 	else if(!ispath(primary_turf_type))
 		stack_trace("Wrong turf type `[primary_turf_type.type]` in `[type]` lavaland theme")
 
+/datum/lavaland_theme/proc/setup_caves()
+	var/max_attempts = 100
+	var/max_cave_spawns = 40
+	var/z = level_name_to_num(MINING)
+	while(max_attempts > 0 && max_cave_spawns > 0)
+		var/x = rand(1, world.maxx)
+		var/y = rand(LAVALAND_MIN_CAVE_Y, LAVALAND_MAX_CAVE_Y)
+		var/turf/next_turf = locate(x, y, z)
+		var/area/next_area = get_area(next_turf)
+		if(istype(next_turf, /turf/simulated/mineral/random/volcanic) && istype(next_area, /area/lavaland/surface/outdoors/unexplored/danger))
+			next_turf.ChangeTurf(/turf/simulated/floor/plating/asteroid/airless/cave/volcanic, FALSE, TRUE, TRUE)
+			max_cave_spawns--
+		max_attempts--
+
 /**
  * This proc should do all theme specific thing.
  * Now it only generates rivers, but it can do all stuff you desire.
@@ -46,3 +65,6 @@
 /datum/lavaland_theme/chasm/setup()
 	var/datum/river_spawner/spawner = new(level_name_to_num(MINING), spread_prob_ = 10, spread_prob_loss_ = 5)
 	spawner.generate(nodes = 6, min_x = 50, min_y = 7, max_x = 250, max_y = 225)
+
+#undef LAVALAND_MIN_CAVE_Y
+#undef LAVALAND_MAX_CAVE_Y