Mgvalleys: Use shared tunnel / cavern code instead of internal

Caverns first appeared in mgvalleys and were later added to other
mapgens as shared code. Now this shared code can replace mgvalley's
internal cavern code.
Also use shared tunnel code instead of internal code.

Changes to mapgen that will affect existing worlds (mgvalleys is not
stable):

Single lava and water sources not added in tunnels.
Previous caverns are unchanged but an equal number of new ones are
added at a distance from the previous.
From y = -256 to 192 nodes below, where the caverns taper at their
upper limit, they will have a slightly different shape as the taper
is now linear.

1 files changed, 14 insertions, 23 deletions

diff --git a/src/mapgen/mapgen_valleys.h b/src/mapgen/mapgen_valleys.h
index b44439030..c4d92239c 100644
--- a/src/mapgen/mapgen_valleys.h
+++ b/src/mapgen/mapgen_valleys.h
@@ -46,28 +46,31 @@ class BiomeGenOriginal;
 
 struct MapgenValleysParams : public MapgenParams {
 	u32 spflags = MGVALLEYS_HUMID_RIVERS | MGVALLEYS_ALT_CHILL;
-	s16 large_cave_depth = -33;
-	s16 massive_cave_depth = -256; // highest altitude of massive caves
 	u16 altitude_chill = 90; // The altitude at which temperature drops by 20C.
-	u16 lava_features = 0; // How often water will occur in caves.
 	u16 river_depth = 4; // How deep to carve river channels.
 	u16 river_size = 5; // How wide to make rivers.
-	u16 water_features = 0; // How often water will occur in caves.
+
 	float cave_width = 0.09f;
+	s16 large_cave_depth = -33;
+	s16 lava_depth = 1;
+	s16 cavern_limit = -256;
+	s16 cavern_taper = 192;
+	float cavern_threshold = 0.6f;
 	s16 dungeon_ymin = -31000;
 	s16 dungeon_ymax = 63; // No higher than surface mapchunks
 
-	NoiseParams np_cave1;
-	NoiseParams np_cave2;
 	NoiseParams np_filler_depth;
 	NoiseParams np_inter_valley_fill;
 	NoiseParams np_inter_valley_slope;
 	NoiseParams np_rivers;
-	NoiseParams np_massive_caves;
 	NoiseParams np_terrain_height;
 	NoiseParams np_valley_depth;
 	NoiseParams np_valley_profile;
 
+	NoiseParams np_cave1;
+	NoiseParams np_cave2;
+	NoiseParams np_cavern;
+
 	MapgenValleysParams();
 	~MapgenValleysParams() = default;
 
@@ -97,33 +100,23 @@ public:
 	virtual void makeChunk(BlockMakeData *data);
 	int getSpawnLevelAtPoint(v2s16 p);
 
-	s16 large_cave_depth;
-
 private:
 	BiomeGenOriginal *m_bgen;
 
 	float altitude_chill;
-	s16 massive_cave_depth;
-	s16 dungeon_ymin;
-	s16 dungeon_ymax;
-
 	bool humid_rivers;
 	bool use_altitude_chill;
 	float humidity_adjust;
-	s16 cave_water_max_height;
-	s16 lava_max_height;
-	s16 lava_features_lim;
 	float river_depth_bed;
 	float river_size_factor;
-	float *tcave_cache;
-	s16 water_features_lim;
+
+	s16 large_cave_depth;
+	s16 dungeon_ymin;
+	s16 dungeon_ymax;
 
 	Noise *noise_inter_valley_fill;
 	Noise *noise_inter_valley_slope;
 	Noise *noise_rivers;
-	Noise *noise_cave1;
-	Noise *noise_cave2;
-	Noise *noise_massive_caves;
 	Noise *noise_terrain_height;
 	Noise *noise_valley_depth;
 	Noise *noise_valley_profile;
@@ -135,6 +128,4 @@ private:
 	virtual int generateTerrain();
 	float terrainLevelFromNoise(TerrainNoise *tn);
 	float adjustedTerrainLevelFromNoise(TerrainNoise *tn);
-
-	virtual void generateCaves(s16 max_stone_y, s16 large_cave_depth);
 };