Dungeons: Make multiple large rooms possible (#8678)

Re-add the random size range for large rooms.
Remove 'first_room_large' bool.
Add 'large_room_chance' parameter that can disable large rooms,
specify 1 large room, or specify a chance for large rooms.
If 1 or a chance is specified, the first generated room is large,
to take advantage of the intersection checks that are done for the
1st room only.

src/mapgen/dungeongen.cpp

@@ -64,9 +64,10 @@ DungeonGen::DungeonGen(const NodeDefManager *ndef,
 		dp.corridor_len_max    = 13;
 		dp.room_size_min       = v3s16(4, 4, 4);
 		dp.room_size_max       = v3s16(8, 6, 8);
-		dp.room_size_large     = v3s16(16, 16, 16);
-		dp.first_room_large    = true;
-		dp.num_rooms           = 16;
+		dp.room_size_large_min = v3s16(8, 8, 8);
+		dp.room_size_large_max = v3s16(16, 16, 16);
+		dp.large_room_chance   = 1;
+		dp.num_rooms           = 8;
 		dp.num_dungeons        = 1;
 		dp.notifytype          = GENNOTIFY_DUNGEON;
 
@@ -152,11 +153,10 @@ void DungeonGen::makeDungeon(v3s16 start_padding)
 	*/
 	bool fits = false;
 	for (u32 i = 0; i < 100 && !fits; i++) {
-		// Only the first room can be 'large'
-		if (dp.first_room_large) {
-			roomsize.Z = dp.room_size_large.Z;
-			roomsize.Y = dp.room_size_large.Y;
-			roomsize.X = dp.room_size_large.X;
+		if (dp.large_room_chance >= 1) {
+			roomsize.Z = random.range(dp.room_size_large_min.Z, dp.room_size_large_max.Z);
+			roomsize.Y = random.range(dp.room_size_large_min.Y, dp.room_size_large_max.Y);
+			roomsize.X = random.range(dp.room_size_large_min.X, dp.room_size_large_max.X);
 		} else {
 			roomsize.Z = random.range(dp.room_size_min.Z, dp.room_size_max.Z);
 			roomsize.Y = random.range(dp.room_size_min.Y, dp.room_size_max.Y);
@@ -250,9 +250,16 @@ void DungeonGen::makeDungeon(v3s16 start_padding)
 		makeCorridor(doorplace, doordir, corridor_end, corridor_end_dir);
 
 		// Find a place for a random sized room
-		roomsize.Z = random.range(dp.room_size_min.Z, dp.room_size_max.Z);
-		roomsize.Y = random.range(dp.room_size_min.Y, dp.room_size_max.Y);
-		roomsize.X = random.range(dp.room_size_min.X, dp.room_size_max.X);
+		if (dp.large_room_chance > 1 && random.range(1, dp.large_room_chance) == 1) {
+			// Large room
+			roomsize.Z = random.range(dp.room_size_large_min.Z, dp.room_size_large_max.Z);
+			roomsize.Y = random.range(dp.room_size_large_min.Y, dp.room_size_large_max.Y);
+			roomsize.X = random.range(dp.room_size_large_min.X, dp.room_size_large_max.X);
+		} else {
+			roomsize.Z = random.range(dp.room_size_min.Z, dp.room_size_max.Z);
+			roomsize.Y = random.range(dp.room_size_min.Y, dp.room_size_max.Y);
+			roomsize.X = random.range(dp.room_size_min.X, dp.room_size_max.X);
+		}
 
 		m_pos = corridor_end;
 		m_dir = corridor_end_dir;
@@ -265,7 +272,6 @@ void DungeonGen::makeDungeon(v3s16 start_padding)
 		else
 			// Don't actually make a door
 			roomplace -= doordir;
-
 	}
 }
 

src/mapgen/dungeongen.h

@@ -58,10 +58,14 @@ struct DungeonParams {
 	// Room size random range. Includes walls / floor / ceilng
 	v3s16 room_size_min;
 	v3s16 room_size_max;
-	// Large room size
-	v3s16 room_size_large;
-	// First generated room is large
-	bool first_room_large;
+	// Large room size random range. Includes walls / floor / ceilng
+	v3s16 room_size_large_min;
+	v3s16 room_size_large_max;
+	// Value 0 disables large rooms.
+	// Value 1 results in 1 large room, the first generated room.
+	// Value > 1 makes the first generated room large, all other rooms have a
+	// '1 in value' chance of being large.
+	u16 large_room_chance;
 	// Dimensions of 3D 'brush' that creates corridors.
 	// Dimensions are of the empty space, not including walls / floor / ceilng.
 	v3s16 holesize;

src/mapgen/mapgen.cpp

@@ -877,20 +877,20 @@ void MapgenBasic::generateDungeons(s16 max_stone_y)
 	dp.np_alt_wall =
 		NoiseParams(-0.4, 1.0, v3f(40.0, 40.0, 40.0), 32474, 6, 1.1, 2.0);
 
-	dp.seed             = seed;
-	dp.num_dungeons     = num_dungeons;
-	dp.only_in_ground   = true;
-	dp.num_rooms        = ps.range(2, 16);
-	dp.room_size_min    = v3s16(6, 5, 6);
-	dp.room_size_max    = v3s16(10, 6, 10);
-	dp.room_size_large  = v3s16(
-		ps.range(10, 18), ps.range(8, 16), ps.range(10, 18));
-	dp.first_room_large = ps.range(1, 4) == 1;
-	dp.holesize         = v3s16(2, 3, 2);
-	dp.corridor_len_min = 1;
-	dp.corridor_len_max = 13;
-	dp.diagonal_dirs    = ps.range(1, 12) == 1;
-	dp.notifytype       = GENNOTIFY_DUNGEON;
+	dp.seed                = seed;
+	dp.num_dungeons        = num_dungeons;
+	dp.only_in_ground      = true;
+	dp.num_rooms           = ps.range(2, 16);
+	dp.room_size_min       = v3s16(6, 5, 6);
+	dp.room_size_max       = v3s16(10, 6, 10);
+	dp.room_size_large_min = v3s16(10, 8, 10);
+	dp.room_size_large_max = v3s16(18, 16, 18);
+	dp.large_room_chance   = (ps.range(1, 4) == 1) ? 1 : 0;
+	dp.holesize            = v3s16(2, 3, 2);
+	dp.corridor_len_min    = 1;
+	dp.corridor_len_max    = 13;
+	dp.diagonal_dirs       = ps.range(1, 12) == 1;
+	dp.notifytype          = GENNOTIFY_DUNGEON;
 
 	// Get biome at mapchunk midpoint
 	v3s16 chunk_mid = node_min + (node_max - node_min) / v3s16(2, 2, 2);

src/mapgen/mapgen_v6.cpp

@@ -572,13 +572,13 @@ void MapgenV6::makeChunk(BlockMakeData *data)
 
 			DungeonParams dp;
 
-			dp.seed             = seed;
-			dp.num_dungeons     = num_dungeons;
-			dp.only_in_ground   = true;
-			dp.corridor_len_min = 1;
-			dp.corridor_len_max = 13;
-			dp.num_rooms        = ps.range(2, 16);
-			dp.first_room_large = ps.range(1, 4) == 1;
+			dp.seed              = seed;
+			dp.num_dungeons      = num_dungeons;
+			dp.only_in_ground    = true;
+			dp.corridor_len_min  = 1;
+			dp.corridor_len_max  = 13;
+			dp.num_rooms         = ps.range(2, 16);
+			dp.large_room_chance = (ps.range(1, 4) == 1) ? 1 : 0;
 
 			dp.np_alt_wall
 				= NoiseParams(-0.4, 1.0, v3f(40.0, 40.0, 40.0), 32474, 6, 1.1, 2.0);
@@ -592,8 +592,8 @@ void MapgenV6::makeChunk(BlockMakeData *data)
 				dp.holesize            = v3s16(2, 3, 2);
 				dp.room_size_min       = v3s16(6, 9, 6);
 				dp.room_size_max       = v3s16(10, 11, 10);
-				dp.room_size_large     = v3s16(
-					ps.range(10, 18), ps.range(13, 21), ps.range(10, 18));
+				dp.room_size_large_min = v3s16(10, 13, 10);
+				dp.room_size_large_max = v3s16(18, 21, 18);
 				dp.notifytype          = GENNOTIFY_TEMPLE;
 			} else {
 				dp.c_wall              = c_cobble;
@@ -604,8 +604,8 @@ void MapgenV6::makeChunk(BlockMakeData *data)
 				dp.holesize            = v3s16(1, 2, 1);
 				dp.room_size_min       = v3s16(4, 4, 4);
 				dp.room_size_max       = v3s16(8, 6, 8);
-				dp.room_size_large     = v3s16(
-					ps.range(8, 16), ps.range(8, 16), ps.range(8, 16));
+				dp.room_size_large_min = v3s16(8, 8, 8);
+				dp.room_size_large_max = v3s16(16, 16, 16);
 				dp.notifytype          = GENNOTIFY_DUNGEON;
 			}