Mgv7: Add option to repeat surface biomes in floatlands

builtin/settingtypes.txt

@@ -1151,11 +1151,11 @@ mgv6_np_apple_trees (Apple trees noise) noise_params 0, 1, (100, 100, 100), 3429
 [***Mapgen v7]
 
 #    Map generation attributes specific to Mapgen v7.
-#    The 'ridges' flag enables the rivers.
-#    Floatlands are currently experimental and subject to change.
+#    'ridges' enables the rivers.
+#    'biomerepeat' causes surface biomes to repeat in the floatlands.
 #    Flags that are not specified in the flag string are not modified from the default.
 #    Flags starting with 'no' are used to explicitly disable them.
-mgv7_spflags (Mapgen v7 specific flags) flags mountains,ridges,nofloatlands,caverns mountains,ridges,floatlands,caverns,nomountains,noridges,nofloatlands,nocaverns
+mgv7_spflags (Mapgen v7 specific flags) flags mountains,ridges,nofloatlands,caverns,biomerepeat mountains,ridges,floatlands,caverns,biomerepeat,nomountains,noridges,nofloatlands,nocaverns,nobiomerepeat
 
 #    Controls width of tunnels, a smaller value creates wider tunnels.
 mgv7_cave_width (Cave width) float 0.09

minetest.conf.example

@@ -1390,12 +1390,12 @@
 #### Mapgen v7
 
 #    Map generation attributes specific to Mapgen v7.
-#    The 'ridges' flag enables the rivers.
-#    Floatlands are currently experimental and subject to change.
+#    'ridges' enables the rivers.
+#    'biomerepeat' causes surface biomes to repeat in the floatlands.
 #    Flags that are not specified in the flag string are not modified from the default.
 #    Flags starting with 'no' are used to explicitly disable them.
-#    type: flags possible values: mountains, ridges, floatlands, caverns, nomountains, noridges, nofloatlands, nocaverns
-# mgv7_spflags = mountains,ridges,nofloatlands,caverns
+#    type: flags possible values: mountains, ridges, floatlands, caverns, biomerepeat, nomountains, noridges, nofloatlands, nocaverns, nobiomerepeat
+# mgv7_spflags = mountains,ridges,nofloatlands,caverns,biomerepeat
 
 #    Controls width of tunnels, a smaller value creates wider tunnels.
 #    type: float

src/mapgen_v7.cpp

@@ -40,11 +40,12 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 
 FlagDesc flagdesc_mapgen_v7[] = {
-	{"mountains",  MGV7_MOUNTAINS},
-	{"ridges",     MGV7_RIDGES},
-	{"floatlands", MGV7_FLOATLANDS},
-	{"caverns",    MGV7_CAVERNS},
-	{NULL,         0}
+	{"mountains",   MGV7_MOUNTAINS},
+	{"ridges",      MGV7_RIDGES},
+	{"floatlands",  MGV7_FLOATLANDS},
+	{"caverns",     MGV7_CAVERNS},
+	{"biomerepeat", MGV7_BIOMEREPEAT},
+	{NULL,          0}
 };
 
 
@@ -285,6 +286,12 @@ void MapgenV7::makeChunk(BlockMakeData *data)
 
 	blockseed = getBlockSeed2(full_node_min, seed);
 
+	// Get zero level for biomes and decorations
+	// Optionally repeat surface biomes in floatlands
+	s16 biome_zero_level = ((spflags & MGV7_FLOATLANDS) &&
+		(spflags & MGV7_BIOMEREPEAT) && node_max.Y >= shadow_limit) ?
+		floatland_level - 1 : water_level - 1;
+
 	// Generate base and mountain terrain
 	// An initial heightmap is no longer created here for use in generateRidgeTerrain()
 	s16 stone_surface_max_y = generateTerrain();
@@ -298,7 +305,7 @@ void MapgenV7::makeChunk(BlockMakeData *data)
 
 	// Init biome generator, place biome-specific nodes, and build biomemap
 	biomegen->calcBiomeNoise(node_min);
-	MgStoneType stone_type = generateBiomes(water_level - 1);
+	MgStoneType stone_type = generateBiomes(biome_zero_level);
 
 	// Generate caverns, tunnels and classic caves
 	if (flags & MG_CAVES) {
@@ -323,7 +330,7 @@ void MapgenV7::makeChunk(BlockMakeData *data)
 	// Generate the registered decorations
 	if (flags & MG_DECORATIONS)
 		m_emerge->decomgr->placeAllDecos(this, blockseed,
-			node_min, node_max, water_level - 1);
+			node_min, node_max, biome_zero_level);
 
 	// Generate the registered ores
 	m_emerge->oremgr->placeAllOres(this, blockseed,

src/mapgen_v7.h

@@ -23,19 +23,21 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #include "mapgen.h"
 
-//////////// Mapgen V7 flags
-#define MGV7_MOUNTAINS  0x01
-#define MGV7_RIDGES     0x02
-#define MGV7_FLOATLANDS 0x04
-#define MGV7_CAVERNS    0x08
+/////////////// Mapgen V7 flags
+#define MGV7_MOUNTAINS   0x01
+#define MGV7_RIDGES      0x02
+#define MGV7_FLOATLANDS  0x04
+#define MGV7_CAVERNS     0x08
+#define MGV7_BIOMEREPEAT 0x10
 
 class BiomeManager;
 
 extern FlagDesc flagdesc_mapgen_v7[];
 
 
 struct MapgenV7Params : public MapgenParams {
-	u32 spflags = MGV7_MOUNTAINS | MGV7_RIDGES | MGV7_CAVERNS;
+	u32 spflags = MGV7_MOUNTAINS | MGV7_RIDGES |
+		MGV7_CAVERNS | MGV7_BIOMEREPEAT;
 	float cave_width = 0.09f;
 	s16 large_cave_depth = -33;
 	s16 lava_depth = -256;