Randomwalk caves: Add parameters for number, proportion flooded. Allow small caves (#8928)

Add mapgen parameters to set the range of the random number of
randomwalk caves per mapchunk, and to set the proportion that are
flooded with liquids.
Default values are, for now, unchanged from the previous hardcoded
values.

Add parameters to allow small randomwalk caves
Disabled by default for now as they have never been present in the
non-mgv6 mapgens.

1 files changed, 10 insertions, 8 deletions

diff --git a/src/mapgen/cavegen.cpp b/src/mapgen/cavegen.cpp
index 21540d7ce..2e2a1bbe3 100644
--- a/src/mapgen/cavegen.cpp
+++ b/src/mapgen/cavegen.cpp
@@ -280,18 +280,20 @@ CavesRandomWalk::CavesRandomWalk(
 	int water_level,
 	content_t water_source,
 	content_t lava_source,
+	float large_cave_flooded,
 	int lava_depth,
 	BiomeGen *biomegen)
 {
 	assert(ndef);
 
-	this->ndef           = ndef;
-	this->gennotify      = gennotify;
-	this->seed           = seed;
-	this->water_level    = water_level;
-	this->np_caveliquids = &nparams_caveliquids;
-	this->lava_depth     = lava_depth;
-	this->bmgn           = biomegen;
+	this->ndef               = ndef;
+	this->gennotify          = gennotify;
+	this->seed               = seed;
+	this->water_level        = water_level;
+	this->np_caveliquids     = &nparams_caveliquids;
+	this->large_cave_flooded = large_cave_flooded;
+	this->lava_depth         = lava_depth;
+	this->bmgn               = biomegen;
 
 	c_water_source = water_source;
 	if (c_water_source == CONTENT_IGNORE)
@@ -322,7 +324,7 @@ void CavesRandomWalk::makeCave(MMVManip *vm, v3s16 nmin, v3s16 nmax,
 
 	this->ystride = nmax.X - nmin.X + 1;
 
-	flooded = ps->range(1, 2) == 2;
+	flooded = ps->range(1, 1000) <= large_cave_flooded * 1000.0f;
 
 	// If flooded:
 	// Get biome at mapchunk midpoint. If cave liquid defined for biome, use it.