Mgv6: Add heightmap. Do not make large caves that are entirely above ground

diff --git a/src/cavegen.cpp b/src/cavegen.cpp
index 6010780e94bf6a6945182050006dfe4277be6ac3..bac656511fc8daf045cd80e5152323c56b5d91be 100644 (file)
--- a/src/cavegen.cpp
+++ b/src/cavegen.cpp
@@ -173,6 +173,36 @@ void CaveV6::makeTunnel(bool dirswitch) {
                );
        }
 
+       // Do not make large caves that are entirely above ground.
+       // It is only necessary to check the startpoint and endpoint.
+       if (large_cave) {
+               v3s16 orpi(orp.X, orp.Y, orp.Z);
+               v3s16 veci(vec.X, vec.Y, vec.Z);
+               s16 h1;
+               s16 h2;
+
+               v3s16 p1 = orpi + veci + of + rs / 2;
+               if (p1.Z >= node_min.Z && p1.Z <= node_max.Z &&
+                               p1.X >= node_min.X && p1.X <= node_max.X) {
+                       u32 index1 = (p1.Z - node_min.Z) * mg->ystride + (p1.X - node_min.X);
+                       h1 = mg->heightmap[index1];
+               } else {
+                       h1 = water_level; // If not in heightmap
+               }
+
+               v3s16 p2 = orpi + of + rs / 2;
+               if (p2.Z >= node_min.Z && p2.Z <= node_max.Z &&
+                               p2.X >= node_min.X && p2.X <= node_max.X) {
+                       u32 index2 = (p2.Z - node_min.Z) * mg->ystride + (p2.X - node_min.X);
+                       h2 = mg->heightmap[index2];
+               } else {
+                       h2 = water_level;
+               }
+
+               if (p1.Y > h1 && p2.Y > h2) // If startpoint and endpoint are above ground
+                       return;
+       }
+
        vec += main_direction;
 
        v3f rp = orp + vec;

diff --git a/src/mapgen_v6.cpp b/src/mapgen_v6.cpp
index 95cdbd279693363befca0cd4d2623e9d27117439..4783e42857490315b4c035548581ca94f2da045c 100644 (file)
--- a/src/mapgen_v6.cpp
+++ b/src/mapgen_v6.cpp
@@ -55,6 +55,8 @@ MapgenV6::MapgenV6(int mapgenid, MapgenParams *params, EmergeManager *emerge)
        this->m_emerge = emerge;
        this->ystride = csize.X; //////fix this
 
+       this->heightmap = new s16[csize.X * csize.Z];
+
        MapgenV6Params *sp = (MapgenV6Params *)params->sparams;
        this->spflags     = sp->spflags;
        this->freq_desert = sp->freq_desert;
@@ -498,6 +500,9 @@ void MapgenV6::makeChunk(BlockMakeData *data)
 
        }
 
+       // Create heightmap after mudflow
+       updateHeightmap(node_min, node_max);
+
        // Add dungeons
        if ((flags & MG_DUNGEONS) && (stone_surface_max_y >= node_min.Y)) {
                DungeonParams dp;