Tunnels: Completely disable generation when 'cave width' >= 10.0 (#9093)

Previously, the only way to disable the 3D noise tunnels was to set
'cave width' > 1.0, however doing so did not disable the very intensive
noise calculations or the generation loop.
All the other types of cave generation (randomwalk caves, caverns)
can already be independently and completely disabled.
This feature is now needed more because the small randomwalk caves are
now available for use as an alternative to the 3D noise tunnels.

diff --git a/builtin/settingtypes.txt b/builtin/settingtypes.txt
index b6e5de599ed12cd5704b5adb737d4b5d6b5eae3a..3334926e7c7de74184051c1129a1aa85f1461f76 100644 (file)
--- a/builtin/settingtypes.txt
+++ b/builtin/settingtypes.txt
@@ -1470,6 +1470,8 @@ mg_biome_np_humidity_blend (Humidity blend noise) noise_params_2d 0, 1.5, (8, 8,
 mgv5_spflags (Mapgen V5 specific flags) flags caverns caverns,nocaverns
 
 #    Controls width of tunnels, a smaller value creates wider tunnels.
+#    Value >= 10.0 completely disables generation of tunnels and avoids the
+#    intensive noise calculations.
 mgv5_cave_width (Cave width) float 0.09
 
 #    Y of upper limit of large caves.
@@ -1602,6 +1604,8 @@ mgv7_spflags (Mapgen V7 specific flags) flags mountains,ridges,nofloatlands,cave
 mgv7_mount_zero_level (Mountain zero level) int 0
 
 #    Controls width of tunnels, a smaller value creates wider tunnels.
+#    Value >= 10.0 completely disables generation of tunnels and avoids the
+#    intensive noise calculations.
 mgv7_cave_width (Cave width) float 0.09
 
 #    Y of upper limit of large caves.
@@ -1725,6 +1729,8 @@ mgcarpathian_river_depth (River channel depth) float 24.0
 mgcarpathian_valley_width (River valley width) float 0.25
 
 #    Controls width of tunnels, a smaller value creates wider tunnels.
+#    Value >= 10.0 completely disables generation of tunnels and avoids the
+#    intensive noise calculations.
 mgcarpathian_cave_width (Cave width) float 0.09
 
 #    Y of upper limit of large caves.
@@ -1849,6 +1855,8 @@ mgflat_large_cave_num_max (Large cave maximum number) int 2 0 64
 mgflat_large_cave_flooded (Large cave proportion flooded) float 0.5 0.0 1.0
 
 #    Controls width of tunnels, a smaller value creates wider tunnels.
+#    Value >= 10.0 completely disables generation of tunnels and avoids the
+#    intensive noise calculations.
 mgflat_cave_width (Cave width) float 0.09
 
 #    Terrain noise threshold for lakes.
@@ -1898,6 +1906,8 @@ mgflat_np_dungeons (Dungeon noise) noise_params_3d 0.9, 0.5, (500, 500, 500), 0,
 mgfractal_spflags (Mapgen Fractal specific flags) flags terrain terrain,noterrain
 
 #    Controls width of tunnels, a smaller value creates wider tunnels.
+#    Value >= 10.0 completely disables generation of tunnels and avoids the
+#    intensive noise calculations.
 mgfractal_cave_width (Cave width) float 0.09
 
 #    Y of upper limit of large caves.
@@ -2076,6 +2086,8 @@ mgvalleys_river_depth (River depth) int 4
 mgvalleys_river_size (River size) int 5
 
 #    Controls width of tunnels, a smaller value creates wider tunnels.
+#    Value >= 10.0 completely disables generation of tunnels and avoids the
+#    intensive noise calculations.
 mgvalleys_cave_width (Cave width) float 0.09
 
 #    Lower Y limit of dungeons.

diff --git a/src/mapgen/mapgen.cpp b/src/mapgen/mapgen.cpp
index a1ac7a5ca7fc33622233b5f4793a60bb6326b35e..bd074d1580d7febc4d33bc028365d41f0ed19421 100644 (file)
--- a/src/mapgen/mapgen.cpp
+++ b/src/mapgen/mapgen.cpp
@@ -831,7 +831,9 @@ void MapgenBasic::dustTopNodes()
 
 void MapgenBasic::generateCavesNoiseIntersection(s16 max_stone_y)
 {
-       if (node_min.Y > max_stone_y)
+       // cave_width >= 10 is used to disable generation and avoid the intensive
+       // 3D noise calculations. Tunnels already have zero width when cave_width > 1.
+       if (node_min.Y > max_stone_y || cave_width >= 10.0f)
                return;
 
        CavesNoiseIntersection caves_noise(ndef, m_bmgr, csize,