Add map feature generation notify Lua API

12 files changed, 252 insertions, 151 deletions

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 28d8b9cc8..abfb8f94b 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -1289,6 +1289,10 @@ minetest.get_perlin(seeddiff, octaves, persistence, scale)
 ^ Return world-specific perlin noise (int(worldseed)+seeddiff)
 minetest.get_voxel_manip()
 ^ Return voxel manipulator object
+minetest.set_gen_notify(flags)
+^ Set the types of on-generate notifications that should be collected
+^ flags is a comma-delimited combination of:
+^ dungeon, temple, cave_begin, cave_end, large_cave_begin, large_cave_end
 minetest.get_mapgen_object(objectname)
 ^ Return requested mapgen object if available (see Mapgen objects)
 minetest.set_mapgen_params(MapgenParams)
@@ -1894,6 +1898,12 @@ the current mapgen.
     Returns an array containing the humidity values of nodes in the most recently generated chunk by the 
 current mapgen.
 
+- gennotify
+    Returns a table mapping requested generation notification types to arrays of positions at which the
+corresponding generated structures are located at within the current chunk.  To set the capture of positions
+of interest to be recorded on generate, use minetest.set_gen_notify().
+Possible fields of the table returned are:  dungeon, temple, cave_begin, cave_end, large_cave_begin, large_cave_end
+
 Registered entities
 --------------------
 - Functions receive a "luaentity" as self:
diff --git a/src/cavegen.cpp b/src/cavegen.cpp
index f04c02db9..b32e140f8 100644
--- a/src/cavegen.cpp
+++ b/src/cavegen.cpp
@@ -110,9 +110,21 @@ void CaveV6::makeCave(v3s16 nmin, v3s16 nmax, int max_stone_height) {
 		(float)(ps->next() % ar.Z) + 0.5
 	);
 
+	int notifytype = large_cave ? GENNOTIFY_LARGECAVE_BEGIN : GENNOTIFY_CAVE_BEGIN;
+	if (mg->gennotify & (1 << notifytype)) {
+		std::vector <v3s16> *nvec = mg->gen_notifications[notifytype];
+		nvec->push_back(v3s16(of.X + orp.X, of.Y + orp.Y, of.Z + orp.Z));
+	}
+
 	// Generate some tunnel starting from orp
 	for (u16 j = 0; j < tunnel_routepoints; j++)
 		makeTunnel(j % dswitchint == 0);
+
+	notifytype = large_cave ? GENNOTIFY_LARGECAVE_END : GENNOTIFY_CAVE_END;
+	if (mg->gennotify & (1 << notifytype)) {
+		std::vector <v3s16> *nvec = mg->gen_notifications[notifytype];
+		nvec->push_back(v3s16(of.X + orp.X, of.Y + orp.Y, of.Z + orp.Z));
+	}
 }
 
 
@@ -347,9 +359,21 @@ void CaveV7::makeCave(v3s16 nmin, v3s16 nmax, int max_stone_height) {
 		(float)(ps->next() % ar.Z) + 0.5
 	);
 
+	int notifytype = large_cave ? GENNOTIFY_LARGECAVE_BEGIN : GENNOTIFY_CAVE_BEGIN;
+	if (mg->gennotify & (1 << notifytype)) {
+		std::vector <v3s16> *nvec = mg->gen_notifications[notifytype];
+		nvec->push_back(v3s16(of.X + orp.X, of.Y + orp.Y, of.Z + orp.Z));
+	}
+
 	// Generate some tunnel starting from orp
 	for (u16 j = 0; j < tunnel_routepoints; j++)
 		makeTunnel(j % dswitchint == 0);
+
+	notifytype = large_cave ? GENNOTIFY_LARGECAVE_END : GENNOTIFY_CAVE_END;
+	if (mg->gennotify & (1 << notifytype)) {
+		std::vector <v3s16> *nvec = mg->gen_notifications[notifytype];
+		nvec->push_back(v3s16(of.X + orp.X, of.Y + orp.Y, of.Z + orp.Z));
+	}
 }
 
 
diff --git a/src/dungeongen.cpp b/src/dungeongen.cpp
index fee6f66c0..ff0a39e9e 100644
--- a/src/dungeongen.cpp
+++ b/src/dungeongen.cpp
@@ -42,11 +42,9 @@ NoiseParams nparams_dungeon_density =
 ///////////////////////////////////////////////////////////////////////////////
 
 
-DungeonGen::DungeonGen(INodeDefManager *ndef, u64 seed, s16 waterlevel,
-						DungeonParams *dparams) {
-	this->ndef        = ndef;
-	this->mapseed     = seed;
-	this->water_level = waterlevel;
+DungeonGen::DungeonGen(Mapgen *mapgen, DungeonParams *dparams) {
+	this->mg = mapgen;
+	this->vm = mapgen->vm;
 
 #ifdef DGEN_USE_TORCHES
 	c_torch  = ndef->getId("default:torch");
@@ -55,15 +53,16 @@ DungeonGen::DungeonGen(INodeDefManager *ndef, u64 seed, s16 waterlevel,
 	if (dparams) {
 		memcpy(&dp, dparams, sizeof(dp));
 	} else {
-		dp.c_water  = ndef->getId("mapgen_water_source");
-		dp.c_cobble = ndef->getId("mapgen_cobble");
-		dp.c_moss   = ndef->getId("mapgen_mossycobble");
-		dp.c_stair  = ndef->getId("mapgen_stair_cobble");
+		dp.c_water  = mg->ndef->getId("mapgen_water_source");
+		dp.c_cobble = mg->ndef->getId("mapgen_cobble");
+		dp.c_moss   = mg->ndef->getId("mapgen_mossycobble");
+		dp.c_stair  = mg->ndef->getId("mapgen_stair_cobble");
 
 		dp.diagonal_dirs = false;
-		dp.mossratio = 3.0;
-		dp.holesize  = v3s16(1, 2, 1);
-		dp.roomsize  = v3s16(0,0,0);
+		dp.mossratio  = 3.0;
+		dp.holesize   = v3s16(1, 2, 1);
+		dp.roomsize   = v3s16(0,0,0);
+		dp.notifytype = GENNOTIFY_DUNGEON;
 
 		dp.np_rarity  = nparams_dungeon_rarity;
 		dp.np_wetness = nparams_dungeon_wetness;
@@ -72,31 +71,29 @@ DungeonGen::DungeonGen(INodeDefManager *ndef, u64 seed, s16 waterlevel,
 }
 
 
-void DungeonGen::generate(ManualMapVoxelManipulator *vm, u32 bseed,
-						v3s16 nmin, v3s16 nmax) {
+void DungeonGen::generate(u32 bseed, v3s16 nmin, v3s16 nmax) {
 	//TimeTaker t("gen dungeons");
-	int approx_groundlevel = 10 + water_level;
+	int approx_groundlevel = 10 + mg->water_level;
 
 	if ((nmin.Y + nmax.Y) / 2 >= approx_groundlevel ||
-		NoisePerlin3D(&dp.np_rarity, nmin.X, nmin.Y, nmin.Z, mapseed) < 0.2)
+		NoisePerlin3D(&dp.np_rarity, nmin.X, nmin.Y, nmin.Z, mg->seed) < 0.2)
 		return;
-		
-	this->vmanip    = vm;
+
 	this->blockseed = bseed;
 	random.seed(bseed + 2);
 
 	// Dungeon generator doesn't modify places which have this set
-	vmanip->clearFlag(VMANIP_FLAG_DUNGEON_INSIDE | VMANIP_FLAG_DUNGEON_PRESERVE);
+	vm->clearFlag(VMANIP_FLAG_DUNGEON_INSIDE | VMANIP_FLAG_DUNGEON_PRESERVE);
 
 	// Set all air and water to be untouchable to make dungeons open
 	// to caves and open air
 	for (s16 z = nmin.Z; z <= nmax.Z; z++) {
 		for (s16 y = nmin.Y; y <= nmax.Y; y++) {
-			u32 i = vmanip->m_area.index(nmin.X, y, z);
+			u32 i = vm->m_area.index(nmin.X, y, z);
 			for (s16 x = nmin.X; x <= nmax.X; x++) {
-				content_t c = vmanip->m_data[i].getContent();
+				content_t c = vm->m_data[i].getContent();
 				if (c == CONTENT_AIR || c == dp.c_water)
-					vmanip->m_flags[i] |= VMANIP_FLAG_DUNGEON_PRESERVE;
+					vm->m_flags[i] |= VMANIP_FLAG_DUNGEON_PRESERVE;
 				i++;
 			}
 		}
@@ -109,13 +106,13 @@ void DungeonGen::generate(ManualMapVoxelManipulator *vm, u32 bseed,
 	if (dp.mossratio != 0.0) {
 		for (s16 z = nmin.Z; z <= nmax.Z; z++)
 		for (s16 y = nmin.Y; y <= nmax.Y; y++) {
-			u32 i = vmanip->m_area.index(nmin.X, y, z);
+			u32 i = vm->m_area.index(nmin.X, y, z);
 			for (s16 x = nmin.X; x <= nmax.X; x++) {
-				if (vmanip->m_data[i].getContent() == dp.c_cobble) {
-					float wetness = NoisePerlin3D(&dp.np_wetness, x, y, z, mapseed);
+				if (vm->m_data[i].getContent() == dp.c_cobble) {
+					float wetness = NoisePerlin3D(&dp.np_wetness, x, y, z, mg->seed);
 					float density = NoisePerlin3D(&dp.np_density, x, y, z, blockseed);
 					if (density < wetness / dp.mossratio)
-						vmanip->m_data[i].setContent(dp.c_moss);
+						vm->m_data[i].setContent(dp.c_moss);
 				}
 				i++;
 			}
@@ -128,7 +125,7 @@ void DungeonGen::generate(ManualMapVoxelManipulator *vm, u32 bseed,
 
 void DungeonGen::makeDungeon(v3s16 start_padding)
 {
-	v3s16 areasize = vmanip->m_area.getExtent();
+	v3s16 areasize = vm->m_area.getExtent();
 	v3s16 roomsize;
 	v3s16 roomplace;
 
@@ -136,7 +133,7 @@ void DungeonGen::makeDungeon(v3s16 start_padding)
 		Find place for first room
 	*/
 	bool fits = false;
-	for (u32 i = 0; i < 100; i++)
+	for (u32 i = 0; i < 100 && !fits; i++)
 	{
 		bool is_large_room = ((random.next() & 3) == 1);
 		roomsize = is_large_room ?
@@ -146,7 +143,7 @@ void DungeonGen::makeDungeon(v3s16 start_padding)
 
 		// start_padding is used to disallow starting the generation of
 		// a dungeon in a neighboring generation chunk
-		roomplace = vmanip->m_area.MinEdge + start_padding + v3s16(
+		roomplace = vm->m_area.MinEdge + start_padding + v3s16(
 			random.range(0,areasize.X-roomsize.X-1-start_padding.X),
 			random.range(0,areasize.Y-roomsize.Y-1-start_padding.Y),
 			random.range(0,areasize.Z-roomsize.Z-1-start_padding.Z));
@@ -161,20 +158,13 @@ void DungeonGen::makeDungeon(v3s16 start_padding)
 		for (s16 x = 1; x < roomsize.X - 1; x++)
 		{
 			v3s16 p = roomplace + v3s16(x, y, z);
-			u32 vi = vmanip->m_area.index(p);
-			if (vmanip->m_flags[vi] & VMANIP_FLAG_DUNGEON_INSIDE)
-			{
-				fits = false;
-				break;
-			}
-			if (vmanip->m_data[vi].getContent() == CONTENT_IGNORE)
-			{
+			u32 vi = vm->m_area.index(p);
+			if ((vm->m_flags[vi] & VMANIP_FLAG_DUNGEON_INSIDE) ||
+				vm->m_data[vi].getContent() == CONTENT_IGNORE) {
 				fits = false;
 				break;
 			}
 		}
-		if (fits)
-			break;
 	}
 	// No place found
 	if (fits == false)
@@ -194,10 +184,14 @@ void DungeonGen::makeDungeon(v3s16 start_padding)
 		makeRoom(roomsize, roomplace);
 
 		v3s16 room_center = roomplace + v3s16(roomsize.X / 2, 1, roomsize.Z / 2);
+		if (mg->gennotify & (1 << dp.notifytype)) {
+			std::vector <v3s16> *nvec = mg->gen_notifications[dp.notifytype];
+			nvec->push_back(room_center);
+		}
 
 #ifdef DGEN_USE_TORCHES
 		// Place torch at room center (for testing)
-		vmanip->m_data[vmanip->m_area.index(room_center)] = MapNode(c_torch);
+		vm->m_data[vm->m_area.index(room_center)] = MapNode(c_torch);
 #endif
 
 		// Quit if last room
@@ -210,12 +204,9 @@ void DungeonGen::makeDungeon(v3s16 start_padding)
 
 		v3s16 walker_start_place;
 
-		if(start_in_last_room)
-		{
+		if (start_in_last_room) {
 			walker_start_place = last_room_center;
-		}
-		else
-		{
+		} else {
 			walker_start_place = room_center;
 			// Store center of current room as the last one
 			last_room_center = room_center;
@@ -226,8 +217,7 @@ void DungeonGen::makeDungeon(v3s16 start_padding)
 		v3s16 doordir;
 		
 		m_pos = walker_start_place;
-		bool r = findPlaceForDoor(doorplace, doordir);
-		if (r == false)
+		if (!findPlaceForDoor(doorplace, doordir))
 			return;
 
 		if (random.range(0,1) == 0)
@@ -248,8 +238,7 @@ void DungeonGen::makeDungeon(v3s16 start_padding)
 
 		m_pos = corridor_end;
 		m_dir = corridor_end_dir;
-		r = findPlaceForRoomDoor(roomsize, doorplace, doordir, roomplace);
-		if (r == false)
+		if (!findPlaceForRoomDoor(roomsize, doorplace, doordir, roomplace))
 			return;
 
 		if (random.range(0,1) == 0)
@@ -274,21 +263,21 @@ void DungeonGen::makeRoom(v3s16 roomsize, v3s16 roomplace)
 	{
 		{
 			v3s16 p = roomplace + v3s16(0, y, z);
-			if (vmanip->m_area.contains(p) == false)
+			if (vm->m_area.contains(p) == false)
 				continue;
-			u32 vi = vmanip->m_area.index(p);
-			if (vmanip->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
+			u32 vi = vm->m_area.index(p);
+			if (vm->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
 				continue;
-			vmanip->m_data[vi] = n_cobble;
+			vm->m_data[vi] = n_cobble;
 		}
 		{
 			v3s16 p = roomplace + v3s16(roomsize.X - 1, y, z);
-			if (vmanip->m_area.contains(p) == false)
+			if (vm->m_area.contains(p) == false)
 				continue;
-			u32 vi = vmanip->m_area.index(p);
-			if (vmanip->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
+			u32 vi = vm->m_area.index(p);
+			if (vm->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
 				continue;
-			vmanip->m_data[vi] = n_cobble;
+			vm->m_data[vi] = n_cobble;
 		}
 	}
 
@@ -298,21 +287,21 @@ void DungeonGen::makeRoom(v3s16 roomsize, v3s16 roomplace)
 	{
 		{
 			v3s16 p = roomplace + v3s16(x, y, 0);
-			if (vmanip->m_area.contains(p) == false)
+			if (vm->m_area.contains(p) == false)
 				continue;
-			u32 vi = vmanip->m_area.index(p);
-			if (vmanip->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
+			u32 vi = vm->m_area.index(p);
+			if (vm->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
 				continue;
-			vmanip->m_data[vi] = n_cobble;
+			vm->m_data[vi] = n_cobble;
 		}
 		{
 			v3s16 p = roomplace + v3s16(x, y, roomsize.Z - 1);
-			if (vmanip->m_area.contains(p) == false)
+			if (vm->m_area.contains(p) == false)
 				continue;
-			u32 vi = vmanip->m_area.index(p);
-			if (vmanip->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
+			u32 vi = vm->m_area.index(p);
+			if (vm->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
 				continue;
-			vmanip->m_data[vi] = n_cobble;
+			vm->m_data[vi] = n_cobble;
 		}
 	}
 
@@ -322,21 +311,21 @@ void DungeonGen::makeRoom(v3s16 roomsize, v3s16 roomplace)
 	{
 		{
 			v3s16 p = roomplace + v3s16(x, 0, z);
-			if (vmanip->m_area.contains(p) == false)
+			if (vm->m_area.contains(p) == false)
 				continue;
-			u32 vi = vmanip->m_area.index(p);
-			if (vmanip->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
+			u32 vi = vm->m_area.index(p);
+			if (vm->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
 				continue;
-			vmanip->m_data[vi] = n_cobble;
+			vm->m_data[vi] = n_cobble;
 		}
 		{
 			v3s16 p = roomplace + v3s16(x,roomsize. Y - 1, z);
-			if (vmanip->m_area.contains(p) == false)
+			if (vm->m_area.contains(p) == false)
 				continue;
-			u32 vi = vmanip->m_area.index(p);
-			if (vmanip->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
+			u32 vi = vm->m_area.index(p);
+			if (vm->m_flags[vi] & VMANIP_FLAG_DUNGEON_UNTOUCHABLE)
 				continue;
-			vmanip->m_data[vi] = n_cobble;
+			vm->m_data[vi] = n_cobble;
 		}
 	}
 
@@ -346,11 +335,11 @@ void DungeonGen::makeRoom(v3s16 roomsize, v3s16 roomplace)
 	for (s16 x = 1; x < roomsize.X - 1; x++)
 	{
 		v3s16 p = roomplace + v3s16(x, y, z);
-		if (vmanip->m_area.contains(p) == false)
+		if (vm->m_area.contains(p) == false)
 			continue;
-		u32 vi = vmanip->m_area.index(p);
-		vmanip->m_flags[vi] |= VMANIP_FLAG_DUNGEON_UNTOUCHABLE;
-		vmanip->m_data[vi]   = n_air;
+		u32 vi = vm->m_area.index(p);
+		vm->m_flags[vi] |= VMANIP_FLAG_DUNGEON_UNTOUCHABLE;
+		vm->m_data[vi]   = n_air;
 	}
 }
 
@@ -363,13 +352,13 @@ void DungeonGen::makeFill(v3s16 place, v3s16 size,
 	for (s16 x = 0; x < size.X; x++)
 	{
 		v3s16 p = place + v3s16(x, y, z);
-		if (vmanip->m_area.contains(p) == false)
+		if (vm->m_area.contains(p) == false)
 			continue;
-		u32 vi = vmanip->m_area.index(p);
-		if (vmanip->m_flags[vi] & avoid_flags)
+		u32 vi = vm->m_area.index(p);
+		if (vm->m_flags[vi] & avoid_flags)
 			continue;
-		vmanip->m_flags[vi] |= or_flags;
-		vmanip->m_data[vi]   = n;
+		vm->m_flags[vi] |= or_flags;
+		vm->m_data[vi]   = n;
 	}
 }
 
@@ -387,7 +376,7 @@ void DungeonGen::makeDoor(v3s16 doorplace, v3s16 doordir)
 
 #ifdef DGEN_USE_TORCHES
 	// Place torch (for testing)
-	vmanip->m_data[vmanip->m_area.index(doorplace)] = MapNode(c_torch);
+	vm->m_data[vm->m_area.index(doorplace)] = MapNode(c_torch);
 #endif
 }
 
@@ -416,8 +405,8 @@ void DungeonGen::makeCorridor(v3s16 doorplace,
 		if (partcount != 0)
 			p.Y += make_stairs;
 
-		if (vmanip->m_area.contains(p) == true &&
-			vmanip->m_area.contains(p + v3s16(0, 1, 0)) == true) {
+		if (vm->m_area.contains(p) == true &&
+			vm->m_area.contains(p + v3s16(0, 1, 0)) == true) {
 			if (make_stairs) {
 				makeFill(p + v3s16(-1, -1, -1), dp.holesize + v3s16(2, 3, 2),
 						VMANIP_FLAG_DUNGEON_UNTOUCHABLE, MapNode(dp.c_cobble), 0);
@@ -434,13 +423,13 @@ void DungeonGen::makeCorridor(v3s16 doorplace,
 					// rotate face 180 deg if making stairs backwards
 					int facedir = dir_to_facedir(dir * make_stairs);
 					
-					u32 vi = vmanip->m_area.index(p.X - dir.X, p.Y - 1, p.Z - dir.Z);
-					if (vmanip->m_data[vi].getContent() == dp.c_cobble)
-						vmanip->m_data[vi] = MapNode(dp.c_stair, 0, facedir);
+					u32 vi = vm->m_area.index(p.X - dir.X, p.Y - 1, p.Z - dir.Z);
+					if (vm->m_data[vi].getContent() == dp.c_cobble)
+						vm->m_data[vi] = MapNode(dp.c_stair, 0, facedir);
 					
-					vi = vmanip->m_area.index(p.X, p.Y, p.Z);
-					if (vmanip->m_data[vi].getContent() == dp.c_cobble)
-						vmanip->m_data[vi] = MapNode(dp.c_stair, 0, facedir);
+					vi = vm->m_area.index(p.X, p.Y, p.Z);
+					if (vm->m_data[vi].getContent() == dp.c_cobble)
+						vm->m_data[vi] = MapNode(dp.c_stair, 0, facedir);
 				}
 			} else {
 				makeFill(p + v3s16(-1, -1, -1), dp.holesize + v3s16(2, 2, 2),
@@ -482,15 +471,15 @@ bool DungeonGen::findPlaceForDoor(v3s16 &result_place, v3s16 &result_dir)
 	{
 		v3s16 p = m_pos + m_dir;
 		v3s16 p1 = p + v3s16(0, 1, 0);
-		if (vmanip->m_area.contains(p) == false
-		 || vmanip->m_area.contains(p1) == false
+		if (vm->m_area.contains(p) == false
+		 || vm->m_area.contains(p1) == false
 		 || i % 4 == 0)
 		{
 			randomizeDir();
 			continue;
 		}
-		if (vmanip->getNodeNoExNoEmerge(p).getContent()  == dp.c_cobble
-		 && vmanip->getNodeNoExNoEmerge(p1).getContent() == dp.c_cobble)
+		if (vm->getNodeNoExNoEmerge(p).getContent()  == dp.c_cobble
+		 && vm->getNodeNoExNoEmerge(p1).getContent() == dp.c_cobble)
 		{
 			// Found wall, this is a good place!
 			result_place = p;
@@ -503,18 +492,18 @@ bool DungeonGen::findPlaceForDoor(v3s16 &result_place, v3s16 &result_dir)
 			Determine where to move next
 		*/
 		// Jump one up if the actual space is there
-		if (vmanip->getNodeNoExNoEmerge(p+v3s16(0,0,0)).getContent() == dp.c_cobble
-		 && vmanip->getNodeNoExNoEmerge(p+v3s16(0,1,0)).getContent() == CONTENT_AIR
-		 && vmanip->getNodeNoExNoEmerge(p+v3s16(0,2,0)).getContent() == CONTENT_AIR)
+		if (vm->getNodeNoExNoEmerge(p+v3s16(0,0,0)).getContent() == dp.c_cobble
+		 && vm->getNodeNoExNoEmerge(p+v3s16(0,1,0)).getContent() == CONTENT_AIR
+		 && vm->getNodeNoExNoEmerge(p+v3s16(0,2,0)).getContent() == CONTENT_AIR)
 			p += v3s16(0,1,0);
 		// Jump one down if the actual space is there
-		if (vmanip->getNodeNoExNoEmerge(p+v3s16(0,1,0)).getContent() == dp.c_cobble
-		 && vmanip->getNodeNoExNoEmerge(p+v3s16(0,0,0)).getContent() == CONTENT_AIR
-		 && vmanip->getNodeNoExNoEmerge(p+v3s16(0,-1,0)).getContent() == CONTENT_AIR)
+		if (vm->getNodeNoExNoEmerge(p+v3s16(0,1,0)).getContent() == dp.c_cobble
+		 && vm->getNodeNoExNoEmerge(p+v3s16(0,0,0)).getContent() == CONTENT_AIR
+		 && vm->getNodeNoExNoEmerge(p+v3s16(0,-1,0)).getContent() == CONTENT_AIR)
 			p += v3s16(0,-1,0);
 		// Check if walking is now possible
-		if (vmanip->getNodeNoExNoEmerge(p).getContent() != CONTENT_AIR
-		 || vmanip->getNodeNoExNoEmerge(p+v3s16(0,1,0)).getContent() != CONTENT_AIR)
+		if (vm->getNodeNoExNoEmerge(p).getContent() != CONTENT_AIR
+		 || vm->getNodeNoExNoEmerge(p+v3s16(0,1,0)).getContent() != CONTENT_AIR)
 		{
 			// Cannot continue walking here
 			randomizeDir();
@@ -571,12 +560,12 @@ bool DungeonGen::findPlaceForRoomDoor(v3s16 roomsize, v3s16 &result_doorplace,
 		for (s16 x = 1; x < roomsize.X - 1; x++)
 		{
 			v3s16 p = roomplace + v3s16(x, y, z);
-			if (vmanip->m_area.contains(p) == false)
+			if (vm->m_area.contains(p) == false)
 			{
 				fits = false;
 				break;
 			}
-			if (vmanip->m_flags[vmanip->m_area.index(p)]
+			if (vm->m_flags[vm->m_area.index(p)]
 					& VMANIP_FLAG_DUNGEON_INSIDE)
 			{
 				fits = false;
diff --git a/src/dungeongen.h b/src/dungeongen.h
index b2b28db3a..4a0bfcefd 100644
--- a/src/dungeongen.h
+++ b/src/dungeongen.h
@@ -30,7 +30,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 class ManualMapVoxelManipulator;
 class INodeDefManager;
-
+class Mapgen;
 
 v3s16 rand_ortho_dir(PseudoRandom &random, bool diagonal_dirs);
 v3s16 turn_xz(v3s16 olddir, int t);
@@ -44,6 +44,7 @@ struct DungeonParams {
 	content_t c_moss;
 	content_t c_stair;
 
+	int notifytype;
 	bool diagonal_dirs;
 	float mossratio;
 	v3s16 holesize;
@@ -56,13 +57,11 @@ struct DungeonParams {
 
 class DungeonGen {
 public:
+	ManualMapVoxelManipulator *vm;
+	Mapgen *mg;
 	u32 blockseed;
-	u64 mapseed;
-	ManualMapVoxelManipulator *vmanip;
-	INodeDefManager *ndef;
 	PseudoRandom random;
 	v3s16 csize;
-	s16 water_level;
 
 	content_t c_torch;
 	DungeonParams dp;
@@ -71,9 +70,8 @@ public:
 	v3s16 m_pos;
 	v3s16 m_dir;
 
-	DungeonGen(INodeDefManager *ndef, u64 seed, s16 waterlevel, DungeonParams *dparams);
-	void generate(ManualMapVoxelManipulator *vm, u32 bseed,
-		v3s16 full_node_min, v3s16 full_node_max);
+	DungeonGen(Mapgen *mg, DungeonParams *dparams);
+	void generate(u32 bseed, v3s16 full_node_min, v3s16 full_node_max);
 	
 	void makeDungeon(v3s16 start_padding);
 	void makeRoom(v3s16 roomsize, v3s16 roomplace);
diff --git a/src/emerge.cpp b/src/emerge.cpp
index 94b6464f6..f096bb874 100644
--- a/src/emerge.cpp
+++ b/src/emerge.cpp
@@ -105,8 +105,9 @@ EmergeManager::EmergeManager(IGameDef *gamedef) {
 	this->luaoverride_params_modified = 0;
 	this->luaoverride_flagmask        = 0;
 
-	mapgen_debug_info = g_settings->getBool("enable_mapgen_debug_info");
+	this->gennotify = 0;
 
+	mapgen_debug_info = g_settings->getBool("enable_mapgen_debug_info");
 
 	int nthreads;
 	if (g_settings->get("num_emerge_threads").empty()) {
diff --git a/src/emerge.h b/src/emerge.h
index ed982924b..d5bb72f85 100644
--- a/src/emerge.h
+++ b/src/emerge.h
@@ -94,6 +94,8 @@ public:
 	u16 qlimit_diskonly;
 	u16 qlimit_generate;
 
+	u32 gennotify;
+
 	MapgenParams *luaoverride_params;
 	u32 luaoverride_params_modified;
 	u32 luaoverride_flagmask;
diff --git a/src/mapgen.cpp b/src/mapgen.cpp
index 20fc4459b..3d5c7b3cc 100644
--- a/src/mapgen.cpp
+++ b/src/mapgen.cpp
@@ -64,6 +64,16 @@ FlagDesc flagdesc_deco_schematic[] = {
 	{NULL,             0}
 };
 
+FlagDesc flagdesc_gennotify[] = {
+	{"dungeon",          1 << GENNOTIFY_DUNGEON},
+	{"temple",           1 << GENNOTIFY_TEMPLE},
+	{"cave_begin",       1 << GENNOTIFY_CAVE_BEGIN},
+	{"cave_end",         1 << GENNOTIFY_CAVE_END},
+	{"large_cave_begin", 1 << GENNOTIFY_LARGECAVE_BEGIN},
+	{"large_cave_end",   1 << GENNOTIFY_LARGECAVE_END},
+	{NULL,               0}
+};
+
 ///////////////////////////////////////////////////////////////////////////////
 
 
@@ -896,6 +906,15 @@ Mapgen::Mapgen() {
 	ndef        = NULL;
 	heightmap   = NULL;
 	biomemap    = NULL;
+
+	for (unsigned int i = 0; i != NUM_GEN_NOTIFY; i++)
+		gen_notifications[i] = new std::vector<v3s16>;
+}
+
+
+Mapgen::~Mapgen() {
+	for (unsigned int i = 0; i != NUM_GEN_NOTIFY; i++)
+		delete gen_notifications[i];
 }
 
 
diff --git a/src/mapgen.h b/src/mapgen.h
index 47a7204bc..feec60e19 100644
--- a/src/mapgen.h
+++ b/src/mapgen.h
@@ -53,9 +53,16 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #define DECO_PLACE_CENTER_Y 2
 #define DECO_PLACE_CENTER_Z 4
 
+#define ORE_RANGE_ACTUAL 1
+#define ORE_RANGE_MIRROR 2
+
+#define NUM_GEN_NOTIFY 6
+
+
 extern FlagDesc flagdesc_mapgen[];
 extern FlagDesc flagdesc_ore[];
 extern FlagDesc flagdesc_deco_schematic[];
+extern FlagDesc flagdesc_gennotify[];
 
 class BiomeDefManager;
 class Biome;
@@ -67,6 +74,32 @@ struct BlockMakeData;
 class VoxelArea;
 class Map;
 
+
+enum MapgenObject {
+	MGOBJ_VMANIP,
+	MGOBJ_HEIGHTMAP,
+	MGOBJ_BIOMEMAP,
+	MGOBJ_HEATMAP,
+	MGOBJ_HUMIDMAP,
+	MGOBJ_GENNOTIFY
+};
+
+enum GenNotify {
+	GENNOTIFY_DUNGEON,
+	GENNOTIFY_TEMPLE,
+	GENNOTIFY_CAVE_BEGIN,
+	GENNOTIFY_CAVE_END,
+	GENNOTIFY_LARGECAVE_BEGIN,
+	GENNOTIFY_LARGECAVE_END
+};
+
+enum OreType {
+	ORE_SCATTER,
+	ORE_SHEET,
+	ORE_CLAYLIKE
+};
+
+
 struct MapgenParams {
 	std::string mg_name;
 	int chunksize;
@@ -100,8 +133,11 @@ public:
 	u8 *biomemap;
 	v3s16 csize;
 
+	u32 gennotify;
+	std::vector<v3s16> *gen_notifications[NUM_GEN_NOTIFY];
+
 	Mapgen();
-	virtual ~Mapgen() {}
+	virtual ~Mapgen();
 
 	s16 findGroundLevelFull(v2s16 p2d);
 	s16 findGroundLevel(v2s16 p2d, s16 ymin, s16 ymax);
@@ -123,23 +159,6 @@ struct MapgenFactory {
 	virtual ~MapgenFactory() {}
 };
 
-enum MapgenObject {
-	MGOBJ_VMANIP,
-	MGOBJ_HEIGHTMAP,
-	MGOBJ_BIOMEMAP,
-	MGOBJ_HEATMAP,
-	MGOBJ_HUMIDMAP
-};
-
-enum OreType {
-	ORE_SCATTER,
-	ORE_SHEET,
-	ORE_CLAYLIKE
-};
-
-#define ORE_RANGE_ACTUAL 1
-#define ORE_RANGE_MIRROR 2
-
 class Ore {
 public:
 	std::string ore_name;
diff --git a/src/mapgen_v6.cpp b/src/mapgen_v6.cpp
index 11491b6b6..3e152861c 100644
--- a/src/mapgen_v6.cpp
+++ b/src/mapgen_v6.cpp
@@ -74,6 +74,7 @@ MapgenV6::MapgenV6(int mapgenid, MapgenV6Params *params, EmergeManager *emerge)
 	this->water_level = params->water_level;
 	this->flags   = params->flags;
 	this->csize   = v3s16(1, 1, 1) * params->chunksize * MAP_BLOCKSIZE;
+	this->gennotify = emerge->gennotify;
 
 	this->freq_desert = params->freq_desert;
 	this->freq_beach  = params->freq_beach;
@@ -456,22 +457,24 @@ void MapgenV6::makeChunk(BlockMakeData *data) {
 			dp.c_stair   = c_stair_cobble;
 
 			dp.diagonal_dirs = false;
-			dp.mossratio = 3.0;
-			dp.holesize  = v3s16(1, 2, 1);
-			dp.roomsize  = v3s16(0, 0, 0);
+			dp.mossratio  = 3.0;
+			dp.holesize   = v3s16(1, 2, 1);
+			dp.roomsize   = v3s16(0, 0, 0);
+			dp.notifytype = GENNOTIFY_DUNGEON;
 		} else {
 			dp.c_cobble  = c_sandbrick;
 			dp.c_moss    = c_sandbrick; // should make this 'cracked sandstone' later
 			dp.c_stair   = c_stair_sandstone;
 
 			dp.diagonal_dirs = true;
-			dp.mossratio = 0.0;
-			dp.holesize  = v3s16(2, 3, 2);
-			dp.roomsize  = v3s16(2, 5, 2);
+			dp.mossratio  = 0.0;
+			dp.holesize   = v3s16(2, 3, 2);
+			dp.roomsize   = v3s16(2, 5, 2);
+			dp.notifytype = GENNOTIFY_TEMPLE;
 		}
 
-		DungeonGen dgen(ndef, data->seed, water_level, &dp);
-		dgen.generate(vm, blockseed, full_node_min, full_node_max);
+		DungeonGen dgen(this, &dp);
+		dgen.generate(blockseed, full_node_min, full_node_max);
 	}
 	
 	// Add top and bottom side of water to transforming_liquid queue
diff --git a/src/mapgen_v7.cpp b/src/mapgen_v7.cpp
index 88da4fcd2..6d5c04900 100644
--- a/src/mapgen_v7.cpp
+++ b/src/mapgen_v7.cpp
@@ -73,6 +73,7 @@ MapgenV7::MapgenV7(int mapgenid, MapgenV7Params *params, EmergeManager *emerge)
 	this->seed     = (int)params->seed;
 	this->water_level = params->water_level;
 	this->flags    = params->flags | MGV7_MOUNTAINS | MGV7_RIDGES;
+	this->gennotify = emerge->gennotify;
 
 	this->csize   = v3s16(1, 1, 1) * params->chunksize * MAP_BLOCKSIZE;
 
@@ -207,8 +208,8 @@ void MapgenV7::makeChunk(BlockMakeData *data) {
 		generateCaves(stone_surface_max_y);
 
 	if (flags & MG_DUNGEONS) {
-		DungeonGen dgen(ndef, data->seed, water_level, NULL);
-		dgen.generate(vm, blockseed, full_node_min, full_node_max);
+		DungeonGen dgen(this, NULL);
+		dgen.generate(blockseed, full_node_min, full_node_max);
 	}
 
 	for (size_t i = 0; i != emerge->decorations.size(); i++) {
diff --git a/src/script/lua_api/l_mapgen.cpp b/src/script/lua_api/l_mapgen.cpp
index fe7ac8dd6..5489531b6 100644
--- a/src/script/lua_api/l_mapgen.cpp
+++ b/src/script/lua_api/l_mapgen.cpp
@@ -54,6 +54,7 @@ struct EnumString ModApiMapgen::es_MapgenObject[] =
 	{MGOBJ_BIOMEMAP,  "biomemap"},
 	{MGOBJ_HEATMAP,   "heatmap"},
 	{MGOBJ_HUMIDMAP,  "humiditymap"},
+	{MGOBJ_GENNOTIFY, "gennotify"},
 	{0, NULL},
 };
 
@@ -95,8 +96,6 @@ int ModApiMapgen::l_get_mapgen_object(lua_State *L)
 
 	size_t maplen = mg->csize.X * mg->csize.Z;
 
-	int nargs = 1;
-
 	switch (mgobj) {
 		case MGOBJ_VMANIP: {
 			ManualMapVoxelManipulator *vm = mg->vm;
@@ -113,9 +112,7 @@ int ModApiMapgen::l_get_mapgen_object(lua_State *L)
 			// emerged max pos
 			push_v3s16(L, vm->m_area.MaxEdge);
 
-			nargs = 3;
-
-			break; }
+			return 3; }
 		case MGOBJ_HEIGHTMAP: {
 			if (!mg->heightmap)
 				return 0;
@@ -125,7 +122,8 @@ int ModApiMapgen::l_get_mapgen_object(lua_State *L)
 				lua_pushinteger(L, mg->heightmap[i]);
 				lua_rawseti(L, -2, i + 1);
 			}
-			break; }
+
+			return 1; }
 		case MGOBJ_BIOMEMAP: {
 			if (!mg->biomemap)
 				return 0;
@@ -135,7 +133,8 @@ int ModApiMapgen::l_get_mapgen_object(lua_State *L)
 				lua_pushinteger(L, mg->biomemap[i]);
 				lua_rawseti(L, -2, i + 1);
 			}
-			break; }
+
+			return 1; }
 		case MGOBJ_HEATMAP: { // Mapgen V7 specific objects
 		case MGOBJ_HUMIDMAP:
 			if (strcmp(emerge->params->mg_name.c_str(), "v7"))
@@ -153,10 +152,32 @@ int ModApiMapgen::l_get_mapgen_object(lua_State *L)
 				lua_pushnumber(L, arr[i]);
 				lua_rawseti(L, -2, i + 1);
 			}
-			break; }
+
+			return 1; }
+		case MGOBJ_GENNOTIFY: {
+			lua_newtable(L);
+			for (int i = 0; flagdesc_gennotify[i].name; i++) {
+				if (!(emerge->gennotify & flagdesc_gennotify[i].flag))
+					continue;
+
+				std::vector<v3s16> *posvec = mg->gen_notifications[i];
+				if (!posvec)
+					return 0;
+
+				lua_newtable(L);
+				for (unsigned int j = 0; j != posvec->size(); j++) {
+					push_v3s16(L, (*posvec)[j]);
+					lua_rawseti(L, -2, j + 1);
+				}
+				lua_setfield(L, -2, flagdesc_gennotify[i].name);
+
+				posvec->clear();
+			}
+
+			return 1; }
 	}
 
-	return nargs;
+	return 0;
 }
 
 // minetest.set_mapgen_params(params)
@@ -214,6 +235,16 @@ int ModApiMapgen::l_set_mapgen_params(lua_State *L)
 	return 0;
 }
 
+// set_gen_notify(string)
+int ModApiMapgen::l_set_gen_notify(lua_State *L)
+{
+	if (lua_isstring(L, 1)) {
+		EmergeManager *emerge = getServer(L)->getEmergeManager();
+		emerge->gennotify = readFlagString(lua_tostring(L, 1), flagdesc_gennotify);
+	}
+	return 0;
+}
+
 // register_biome({lots of stuff})
 int ModApiMapgen::l_register_biome(lua_State *L)
 {
@@ -581,6 +612,7 @@ void ModApiMapgen::Initialize(lua_State *L, int top)
 	API_FCT(get_mapgen_object);
 
 	API_FCT(set_mapgen_params);
+	API_FCT(set_gen_notify);
 
 	API_FCT(register_biome);
 	API_FCT(register_decoration);
diff --git a/src/script/lua_api/l_mapgen.h b/src/script/lua_api/l_mapgen.h
index d0da5bb13..43fd6a09f 100644
--- a/src/script/lua_api/l_mapgen.h
+++ b/src/script/lua_api/l_mapgen.h
@@ -32,6 +32,9 @@ private:
 	// set mapgen parameters
 	static int l_set_mapgen_params(lua_State *L);
 
+	// set_gen_notify(flagstring)
+	static int l_set_gen_notify(lua_State *L);
+
 	// register_biome({lots of stuff})
 	static int l_register_biome(lua_State *L);