GenElementManager: Pass opaque handles to Lua and rename to ObjDefManager

Add core.clear_registered_schematics() and refactor schematics somewhat

16 files changed, 363 insertions, 203 deletions

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 1431181f1..19d4f1672 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -419,6 +419,11 @@ the global `minetest.registered_*` tables.
 * `minetest.register_craftitem(name, item definition)`
     * added to `minetest.registered_items[name]`
 
+* `minetest.register_biome(biome definition)`
+    * returns an integer uniquely identifying the registered biome
+    * added to `minetest.registered_biome` with the key of `biome.name`
+    * if `biome.name` is nil, the key is the returned ID
+
 * `minetest.register_ore(ore definition)`
     * returns an integer uniquely identifying the registered ore
     * added to `minetest.registered_ores` with the key of `ore.name`
@@ -429,11 +434,23 @@ the global `minetest.registered_*` tables.
     * added to `minetest.registered_decorations` with the key of `decoration.name`
     * if `decoration.name` is nil, the key is the returned ID
 
+* `minetest.register_schematic(schematic definition)`
+    * returns an integer uniquely identifying the registered schematic
+    * added to `minetest.registered_schematic` with the key of `schematic.name`
+    * if `schematic.name` is nil, the key is the returned ID
+    * if the schematic is loaded from a file, schematic.name is set to the filename
+
+* `minetest.clear_registered_biomes()`
+    * clears all biomes currently registered
+
 * `minetest.clear_registered_ores()`
-   * clears all ores currently registered
+    * clears all ores currently registered
 
 * `minetest.clear_registered_decorations()`
-   * clears all decorations currently registered
+    * clears all decorations currently registered
+
+* `minetest.clear_registered_schematics()`
+    * clears all schematics currently registered
 
 Note that in some cases you will stumble upon things that are not contained
 in these tables (e.g. when a mod has been removed). Always check for
diff --git a/src/mapgen.cpp b/src/mapgen.cpp
index 851f018ee..fcde5bdb8 100644
--- a/src/mapgen.cpp
+++ b/src/mapgen.cpp
@@ -36,11 +36,10 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "treegen.h"
 #include "serialization.h"
 #include "util/serialize.h"
+#include "util/numeric.h"
 #include "filesys.h"
 #include "log.h"
 
-const char *GenElementManager::ELEMENT_TITLE = "element";
-
 FlagDesc flagdesc_mapgen[] = {
 	{"trees",    MG_TREES},
 	{"caves",    MG_CAVES},
@@ -64,6 +63,7 @@ FlagDesc flagdesc_gennotify[] = {
 
 ///////////////////////////////////////////////////////////////////////////////
 
+
 Mapgen::Mapgen()
 {
 	generating    = false;
@@ -431,85 +431,162 @@ void GenerateNotifier::getEvents(
 ///////////////////////////////////////////////////////////////////////////////
 
 
-GenElementManager::GenElementManager(IGameDef *gamedef)
+ObjDefManager::ObjDefManager(IGameDef *gamedef, ObjDefType type)
 {
+	m_objtype = type;
 	m_ndef = gamedef->getNodeDefManager();
 }
 
 
-GenElementManager::~GenElementManager()
+ObjDefManager::~ObjDefManager()
 {
-	for (size_t i = 0; i != m_elements.size(); i++)
-		delete m_elements[i];
+	for (size_t i = 0; i != m_objects.size(); i++)
+		delete m_objects[i];
 }
 
 
-u32 GenElementManager::add(GenElement *elem)
+ObjDefHandle ObjDefManager::add(ObjDef *obj)
 {
-	size_t nelem = m_elements.size();
+	assert(obj);
 
-	for (size_t i = 0; i != nelem; i++) {
-		if (m_elements[i] == NULL) {
-			elem->id = i;
-			m_elements[i] = elem;
-			return i;
-		}
-	}
+	if (obj->name.length() && getByName(obj->name))
+		return OBJDEF_INVALID_HANDLE;
+
+	u32 index = addRaw(obj);
+	if (index == OBJDEF_INVALID_INDEX)
+		return OBJDEF_INVALID_HANDLE;
 
-	if (nelem >= this->ELEMENT_LIMIT)
+	obj->handle = createHandle(index, m_objtype, obj->uid);
+	return obj->handle;
+}
+
+
+ObjDef *ObjDefManager::get(ObjDefHandle handle) const
+{
+	u32 index = validateHandle(handle);
+	return (index != OBJDEF_INVALID_INDEX) ? getRaw(index) : NULL;
+}
+
+
+ObjDef *ObjDefManager::set(ObjDefHandle handle, ObjDef *obj)
+{
+	u32 index = validateHandle(handle);
+	return (index != OBJDEF_INVALID_INDEX) ? setRaw(index, obj) : NULL;
+}
+
+
+u32 ObjDefManager::addRaw(ObjDef *obj)
+{
+	size_t nobjects = m_objects.size();
+	if (nobjects >= OBJDEF_MAX_ITEMS)
 		return -1;
 
-	elem->id = nelem;
-	m_elements.push_back(elem);
+	obj->index = nobjects;
+
+	// Ensure UID is nonzero so that a valid handle == OBJDEF_INVALID_HANDLE
+	// is not possible.  The slight randomness bias isn't very significant.
+	obj->uid = myrand() & OBJDEF_UID_MASK;
+	if (obj->uid == 0)
+		obj->uid = 1;
+
+	m_objects.push_back(obj);
 
-	verbosestream << "GenElementManager: added " << this->ELEMENT_TITLE
-		<< " element '" << elem->name << "'" << std::endl;
+	infostream << "ObjDefManager: added " << getObjectTitle()
+		<< ": name=\"" << obj->name
+		<< "\" index=" << obj->index
+		<< " uid="     << obj->uid
+		<< std::endl;
 
-	return nelem;
+	return nobjects;
 }
 
 
-GenElement *GenElementManager::get(u32 id)
+ObjDef *ObjDefManager::getRaw(u32 index) const
 {
-	return (id < m_elements.size()) ? m_elements[id] : NULL;
+	return m_objects[index];
 }
 
 
-GenElement *GenElementManager::getByName(const std::string &name)
+ObjDef *ObjDefManager::setRaw(u32 index, ObjDef *obj)
 {
-	for (size_t i = 0; i != m_elements.size(); i++) {
-		GenElement *elem = m_elements[i];
-		if (elem && name == elem->name)
-			return elem;
+	ObjDef *old_obj = m_objects[index];
+	m_objects[index] = obj;
+	return old_obj;
+}
+
+
+ObjDef *ObjDefManager::getByName(const std::string &name) const
+{
+	for (size_t i = 0; i != m_objects.size(); i++) {
+		ObjDef *obj = m_objects[i];
+		if (obj && !strcasecmp(name.c_str(), obj->name.c_str()))
+			return obj;
 	}
 
 	return NULL;
 }
 
 
-GenElement *GenElementManager::update(u32 id, GenElement *elem)
+void ObjDefManager::clear()
 {
-	if (id >= m_elements.size())
-		return NULL;
+	for (size_t i = 0; i != m_objects.size(); i++)
+		delete m_objects[i];
 
-	GenElement *old_elem = m_elements[id];
-	m_elements[id] = elem;
-	return old_elem;
+	m_objects.clear();
 }
 
 
-GenElement *GenElementManager::remove(u32 id)
+u32 ObjDefManager::validateHandle(ObjDefHandle handle) const
 {
-	return update(id, NULL);
+	ObjDefType type;
+	u32 index;
+	u32 uid;
+
+	bool is_valid =
+		(handle != OBJDEF_INVALID_HANDLE)         &&
+		decodeHandle(handle, &index, &type, &uid) &&
+		(type == m_objtype)                       &&
+		(index < m_objects.size())                &&
+		(m_objects[index]->uid == uid);
+
+	return is_valid ? index : -1;
 }
 
 
-void GenElementManager::clear()
+ObjDefHandle ObjDefManager::createHandle(u32 index, ObjDefType type, u32 uid)
 {
-	m_elements.clear();
+	ObjDefHandle handle = 0;
+	set_bits(&handle, 0, 18, index);
+	set_bits(&handle, 18, 6, type);
+	set_bits(&handle, 24, 7, uid);
+
+	u32 parity = calc_parity(handle);
+	set_bits(&handle, 31, 1, parity);
+
+	return handle ^ OBJDEF_HANDLE_SALT;
 }
 
 
+bool ObjDefManager::decodeHandle(ObjDefHandle handle, u32 *index,
+	ObjDefType *type, u32 *uid)
+{
+	handle ^= OBJDEF_HANDLE_SALT;
+
+	u32 parity = get_bits(handle, 31, 1);
+	set_bits(&handle, 31, 1, 0);
+	if (parity != calc_parity(handle))
+		return false;
+
+	*index = get_bits(handle, 0, 18);
+	*type  = (ObjDefType)get_bits(handle, 18, 6);
+	*uid   = get_bits(handle, 24, 7);
+	return true;
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+
+
 void MapgenParams::load(const Settings &settings)
 {
 	std::string seed_str;
diff --git a/src/mapgen.h b/src/mapgen.h
index 5b5ed19a2..59fe2fca7 100644
--- a/src/mapgen.h
+++ b/src/mapgen.h
@@ -179,36 +179,68 @@ struct MapgenFactory {
 	virtual ~MapgenFactory() {}
 };
 
-class GenElement {
+typedef std::map<std::string, std::string> StringMap;
+typedef u32 ObjDefHandle;
+
+#define OBJDEF_INVALID_INDEX ((u32)(-1))
+#define OBJDEF_INVALID_HANDLE 0
+#define OBJDEF_HANDLE_SALT 0x00585e6fu
+#define OBJDEF_MAX_ITEMS (1 << 18)
+#define OBJDEF_UID_MASK ((1 << 7) - 1)
+
+enum ObjDefType {
+	OBJDEF_GENERIC,
+	OBJDEF_BIOME,
+	OBJDEF_ORE,
+	OBJDEF_DECORATION,
+	OBJDEF_SCHEMATIC,
+};
+
+class ObjDef {
 public:
-	virtual ~GenElement() {}
-	u32 id;
+	virtual ~ObjDef() {}
+
+	u32 index;
+	u32 uid;
+	ObjDefHandle handle;
 	std::string name;
 };
 
-class GenElementManager {
+class ObjDefManager {
 public:
-	static const char *ELEMENT_TITLE;
-	static const size_t ELEMENT_LIMIT = -1;
+	ObjDefManager(IGameDef *gamedef, ObjDefType type);
+	virtual ~ObjDefManager();
 
-	GenElementManager(IGameDef *gamedef);
-	virtual ~GenElementManager();
+	virtual const char *getObjectTitle() const = 0;
 
-	virtual GenElement *create(int type) = 0;
-
-	virtual u32 add(GenElement *elem);
-	virtual GenElement *get(u32 id);
-	virtual GenElement *update(u32 id, GenElement *elem);
-	virtual GenElement *remove(u32 id);
+	virtual ObjDef *create(int type) = 0;
 	virtual void clear();
+	virtual ObjDef *getByName(const std::string &name) const;
+
+	//// Add new/get/set object definitions by handle
+	virtual ObjDefHandle add(ObjDef *obj);
+	virtual ObjDef *get(ObjDefHandle handle) const;
+	virtual ObjDef *set(ObjDefHandle handle, ObjDef *obj);
+
+	//// Raw variants that work on indexes
+	virtual u32 addRaw(ObjDef *obj);
+
+	// It is generally assumed that getRaw() will always return a valid object
+	// This won't be true if people do odd things such as call setRaw() with NULL
+	virtual ObjDef *getRaw(u32 index) const;
+	virtual ObjDef *setRaw(u32 index, ObjDef *obj);
 
-	virtual GenElement *getByName(const std::string &name);
+	INodeDefManager *getNodeDef() const { return m_ndef; }
 
-	INodeDefManager *getNodeDef() { return m_ndef; }
+	u32 validateHandle(ObjDefHandle handle) const;
+	static ObjDefHandle createHandle(u32 index, ObjDefType type, u32 uid);
+	static bool decodeHandle(ObjDefHandle handle, u32 *index,
+		ObjDefType *type, u32 *uid);
 
 protected:
 	INodeDefManager *m_ndef;
-	std::vector<GenElement *> m_elements;
+	std::vector<ObjDef *> m_objects;
+	ObjDefType m_objtype;
 };
 
 #endif
diff --git a/src/mapgen_v5.cpp b/src/mapgen_v5.cpp
index 240ae500a..7d74c80bd 100644
--- a/src/mapgen_v5.cpp
+++ b/src/mapgen_v5.cpp
@@ -479,7 +479,7 @@ void MapgenV5::generateCaves(int max_stone_y)
 		for (s16 y=node_min.Y - 1; y<=node_max.Y + 1; y++) {
 			u32 i = vm->m_area.index(node_min.X, y, z);
 			for (s16 x=node_min.X; x<=node_max.X; x++, i++, index++, index2d++) {
-				Biome *biome = (Biome *)bmgr->get(biomemap[index2d]);
+				Biome *biome = (Biome *)bmgr->getRaw(biomemap[index2d]);
 				content_t c = vm->m_data[i].getContent();
 				if (c == CONTENT_AIR
 						|| (y <= water_level
@@ -519,7 +519,7 @@ void MapgenV5::dustTopNodes()
 
 	for (s16 z = node_min.Z; z <= node_max.Z; z++)
 	for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
-		Biome *biome = (Biome *)bmgr->get(biomemap[index]);
+		Biome *biome = (Biome *)bmgr->getRaw(biomemap[index]);
 
 		if (biome->c_dust == CONTENT_IGNORE)
 			continue;
diff --git a/src/mapgen_v7.cpp b/src/mapgen_v7.cpp
index 44cb37f11..3e7188a2c 100644
--- a/src/mapgen_v7.cpp
+++ b/src/mapgen_v7.cpp
@@ -674,7 +674,7 @@ void MapgenV7::dustTopNodes()
 
 	for (s16 z = node_min.Z; z <= node_max.Z; z++)
 	for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
-		Biome *biome = (Biome *)bmgr->get(biomemap[index]);
+		Biome *biome = (Biome *)bmgr->getRaw(biomemap[index]);
 
 		if (biome->c_dust == CONTENT_IGNORE)
 			continue;
@@ -821,7 +821,7 @@ void MapgenV7::generateCaves(int max_stone_y)
 				u32 i = vm->m_area.index(node_min.X, y, z);
 				for (s16 x = node_min.X; x <= node_max.X;
 						x++, i++, index++, index2d++) {
-					Biome *biome = (Biome *)bmgr->get(biomemap[index2d]);
+					Biome *biome = (Biome *)bmgr->getRaw(biomemap[index2d]);
 					content_t c = vm->m_data[i].getContent();
 					if (c == CONTENT_AIR || (y <= water_level &&
 						c != biome->c_stone && c != c_stone))
diff --git a/src/mg_biome.cpp b/src/mg_biome.cpp
index e076d3092..a8b150e53 100644
--- a/src/mg_biome.cpp
+++ b/src/mg_biome.cpp
@@ -27,18 +27,16 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "util/mathconstants.h"
 #include "porting.h"
 
-const char *BiomeManager::ELEMENT_TITLE = "biome";
-
 
 ///////////////////////////////////////////////////////////////////////////////
 
+
 BiomeManager::BiomeManager(IGameDef *gamedef) :
-	GenElementManager(gamedef)
+	ObjDefManager(gamedef, OBJDEF_BIOME)
 {
 	// Create default biome to be used in case none exist
 	Biome *b = new Biome;
 
-	b->id              = 0;
 	b->name            = "Default";
 	b->flags           = 0;
 	b->depth_top       = 0;
@@ -75,8 +73,10 @@ BiomeManager::~BiomeManager()
 void BiomeManager::calcBiomes(s16 sx, s16 sy, float *heat_map,
 	float *humidity_map, s16 *height_map, u8 *biomeid_map)
 {
-	for (s32 i = 0; i != sx * sy; i++)
-		biomeid_map[i] = getBiome(heat_map[i], humidity_map[i], height_map[i])->id;
+	for (s32 i = 0; i != sx * sy; i++) {
+		Biome *biome = getBiome(heat_map[i], humidity_map[i], height_map[i]);
+		biomeid_map[i] = biome->index;
+	}
 }
 
 
@@ -85,8 +85,8 @@ Biome *BiomeManager::getBiome(float heat, float humidity, s16 y)
 	Biome *b, *biome_closest = NULL;
 	float dist_min = FLT_MAX;
 
-	for (size_t i = 1; i < m_elements.size(); i++) {
-		b = (Biome *)m_elements[i];
+	for (size_t i = 1; i < m_objects.size(); i++) {
+		b = (Biome *)m_objects[i];
 		if (!b || y > b->y_max || y < b->y_min)
 			continue;
 
@@ -100,18 +100,18 @@ Biome *BiomeManager::getBiome(float heat, float humidity, s16 y)
 		}
 	}
 
-	return biome_closest ? biome_closest : (Biome *)m_elements[0];
+	return biome_closest ? biome_closest : (Biome *)m_objects[0];
 }
 
 void BiomeManager::clear()
 {
 
-	for (size_t i = 1; i < m_elements.size(); i++) {
-		Biome *b = (Biome *)m_elements[i];
+	for (size_t i = 1; i < m_objects.size(); i++) {
+		Biome *b = (Biome *)m_objects[i];
 		delete b;
 	}
 
-	m_elements.resize(1);
+	m_objects.resize(1);
 }
 
 
diff --git a/src/mg_biome.h b/src/mg_biome.h
index 3648c085d..4e7e3fd7e 100644
--- a/src/mg_biome.h
+++ b/src/mg_biome.h
@@ -33,7 +33,7 @@ enum BiomeType
 	BIOME_TYPE_FLAT
 };
 
-class Biome : public GenElement, public NodeResolver {
+class Biome : public ObjDef, public NodeResolver {
 public:
 	u32 flags;
 
@@ -56,14 +56,18 @@ public:
 	virtual void resolveNodeNames(NodeResolveInfo *nri);
 };
 
-class BiomeManager : public GenElementManager {
+class BiomeManager : public ObjDefManager {
 public:
-	static const char *ELEMENT_TITLE;
-	static const size_t ELEMENT_LIMIT = 0x100;
+	static const char *OBJECT_TITLE;
 
 	BiomeManager(IGameDef *gamedef);
 	~BiomeManager();
 
+	const char *getObjectTitle() const
+	{
+		return "biome";
+	}
+
 	Biome *create(int btt)
 	{
 		return new Biome;
diff --git a/src/mg_decoration.cpp b/src/mg_decoration.cpp
index 23bbfa730..1858e346a 100644
--- a/src/mg_decoration.cpp
+++ b/src/mg_decoration.cpp
@@ -25,8 +25,6 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "log.h"
 #include "util/numeric.h"
 
-const char *DecorationManager::ELEMENT_TITLE = "decoration";
-
 FlagDesc flagdesc_deco[] = {
 	{"place_center_x", DECO_PLACE_CENTER_X},
 	{"place_center_y", DECO_PLACE_CENTER_Y},
@@ -40,7 +38,7 @@ FlagDesc flagdesc_deco[] = {
 
 
 DecorationManager::DecorationManager(IGameDef *gamedef) :
-	GenElementManager(gamedef)
+	ObjDefManager(gamedef, OBJDEF_DECORATION)
 {
 }
 
@@ -50,8 +48,8 @@ size_t DecorationManager::placeAllDecos(Mapgen *mg, u32 blockseed,
 {
 	size_t nplaced = 0;
 
-	for (size_t i = 0; i != m_elements.size(); i++) {
-		Decoration *deco = (Decoration *)m_elements[i];
+	for (size_t i = 0; i != m_objects.size(); i++) {
+		Decoration *deco = (Decoration *)m_objects[i];
 		if (!deco)
 			continue;
 
@@ -65,11 +63,11 @@ size_t DecorationManager::placeAllDecos(Mapgen *mg, u32 blockseed,
 
 void DecorationManager::clear()
 {
-	for (size_t i = 0; i < m_elements.size(); i++) {
-		Decoration *deco = (Decoration *)m_elements[i];
+	for (size_t i = 0; i < m_objects.size(); i++) {
+		Decoration *deco = (Decoration *)m_objects[i];
 		delete deco;
 	}
-	m_elements.clear();
+	m_objects.clear();
 }
 
 
@@ -169,7 +167,7 @@ size_t Decoration::placeDeco(Mapgen *mg, u32 blockseed, v3s16 nmin, v3s16 nmax)
 
 			v3s16 pos(x, y, z);
 			if (generate(mg->vm, &ps, pos))
-				mg->gennotify.addEvent(GENNOTIFY_DECORATION, pos, id);
+				mg->gennotify.addEvent(GENNOTIFY_DECORATION, pos, index);
 		}
 	}
 
diff --git a/src/mg_decoration.h b/src/mg_decoration.h
index 20a22d449..3b809b8d4 100644
--- a/src/mg_decoration.h
+++ b/src/mg_decoration.h
@@ -59,7 +59,7 @@ struct CutoffData {
 };
 #endif
 
-class Decoration : public GenElement, public NodeResolver {
+class Decoration : public ObjDef, public NodeResolver {
 public:
 	INodeDefManager *ndef;
 
@@ -121,14 +121,16 @@ public:
 };
 */
 
-class DecorationManager : public GenElementManager {
+class DecorationManager : public ObjDefManager {
 public:
-	static const char *ELEMENT_TITLE;
-	static const size_t ELEMENT_LIMIT = 0x10000;
-
 	DecorationManager(IGameDef *gamedef);
 	~DecorationManager() {}
 
+	const char *getObjectTitle() const
+	{
+		return "decoration";
+	}
+
 	Decoration *create(int type)
 	{
 		switch (type) {
diff --git a/src/mg_ore.cpp b/src/mg_ore.cpp
index 850f25516..e7e062c69 100644
--- a/src/mg_ore.cpp
+++ b/src/mg_ore.cpp
@@ -24,8 +24,6 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "map.h"
 #include "log.h"
 
-const char *OreManager::ELEMENT_TITLE = "ore";
-
 FlagDesc flagdesc_ore[] = {
 	{"absheight", OREFLAG_ABSHEIGHT},
 	{NULL,        0}
@@ -36,7 +34,7 @@ FlagDesc flagdesc_ore[] = {
 
 
 OreManager::OreManager(IGameDef *gamedef) :
-	GenElementManager(gamedef)
+	ObjDefManager(gamedef, OBJDEF_ORE)
 {
 }
 
@@ -45,8 +43,8 @@ size_t OreManager::placeAllOres(Mapgen *mg, u32 blockseed, v3s16 nmin, v3s16 nma
 {
 	size_t nplaced = 0;
 
-	for (size_t i = 0; i != m_elements.size(); i++) {
-		Ore *ore = (Ore *)m_elements[i];
+	for (size_t i = 0; i != m_objects.size(); i++) {
+		Ore *ore = (Ore *)m_objects[i];
 		if (!ore)
 			continue;
 
@@ -60,11 +58,11 @@ size_t OreManager::placeAllOres(Mapgen *mg, u32 blockseed, v3s16 nmin, v3s16 nma
 
 void OreManager::clear()
 {
-	for (size_t i = 0; i < m_elements.size(); i++) {
-		Ore *ore = (Ore *)m_elements[i];
+	for (size_t i = 0; i < m_objects.size(); i++) {
+		Ore *ore = (Ore *)m_objects[i];
 		delete ore;
 	}
-	m_elements.clear();
+	m_objects.clear();
 }
 
 
diff --git a/src/mg_ore.h b/src/mg_ore.h
index 67ca9a849..978b8ae3d 100644
--- a/src/mg_ore.h
+++ b/src/mg_ore.h
@@ -47,7 +47,7 @@ enum OreType {
 
 extern FlagDesc flagdesc_ore[];
 
-class Ore : public GenElement, public NodeResolver {
+class Ore : public ObjDef, public NodeResolver {
 public:
 	static const bool NEEDS_NOISE = false;
 
@@ -112,14 +112,16 @@ public:
 		v3s16 nmin, v3s16 nmax);
 };
 
-class OreManager : public GenElementManager {
+class OreManager : public ObjDefManager {
 public:
-	static const char *ELEMENT_TITLE;
-	static const size_t ELEMENT_LIMIT = 0x10000;
-
 	OreManager(IGameDef *gamedef);
 	~OreManager() {}
 
+	const char *getObjectTitle() const
+	{
+		return "ore";
+	}
+
 	Ore *create(int type)
 	{
 		switch (type) {
diff --git a/src/mg_schematic.cpp b/src/mg_schematic.cpp
index 23b62115f..f154f4fda 100644
--- a/src/mg_schematic.cpp
+++ b/src/mg_schematic.cpp
@@ -28,13 +28,11 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "serialization.h"
 #include "filesys.h"
 
-const char *SchematicManager::ELEMENT_TITLE = "schematic";
-
 ///////////////////////////////////////////////////////////////////////////////
 
 
 SchematicManager::SchematicManager(IGameDef *gamedef) :
-	GenElementManager(gamedef)
+	ObjDefManager(gamedef, OBJDEF_SCHEMATIC)
 {
 }
 
@@ -201,7 +199,7 @@ void Schematic::placeStructure(Map *map, v3s16 p, u32 flags, Rotation rot,
 
 
 bool Schematic::loadSchematicFromFile(const char *filename, INodeDefManager *ndef,
-	std::map<std::string, std::string> &replace_names)
+	StringMap *replace_names)
 {
 	content_t cignore = CONTENT_IGNORE;
 	bool have_cignore = false;
@@ -246,8 +244,8 @@ bool Schematic::loadSchematicFromFile(const char *filename, INodeDefManager *nde
 		}
 
 		std::map<std::string, std::string>::iterator it;
-		it = replace_names.find(name);
-		if (it != replace_names.end())
+		it = replace_names->find(name);
+		if (it != replace_names->end())
 			name = it->second;
 
 		nri->nodenames.push_back(name);
diff --git a/src/mg_schematic.h b/src/mg_schematic.h
index ad5afb15f..4a85f69a6 100644
--- a/src/mg_schematic.h
+++ b/src/mg_schematic.h
@@ -42,7 +42,7 @@ class NodeResolver;
 #define MTSCHEM_PROB_ALWAYS 0xFF
 
 
-class Schematic : public GenElement, public NodeResolver {
+class Schematic : public ObjDef, public NodeResolver {
 public:
 	std::vector<content_t> c_nodes;
 
@@ -62,7 +62,7 @@ public:
 		Rotation rot, bool force_placement, INodeDefManager *ndef);
 
 	bool loadSchematicFromFile(const char *filename, INodeDefManager *ndef,
-		std::map<std::string, std::string> &replace_names);
+		StringMap *replace_names);
 	void saveSchematicToFile(const char *filename, INodeDefManager *ndef);
 	bool getSchematicFromMap(Map *map, v3s16 p1, v3s16 p2);
 
@@ -73,14 +73,16 @@ public:
 		std::vector<std::pair<s16, u8> > *splist);
 };
 
-class SchematicManager : public GenElementManager {
+class SchematicManager : public ObjDefManager {
 public:
-	static const char *ELEMENT_TITLE;
-	static const size_t ELEMENT_LIMIT = 0x10000;
-
 	SchematicManager(IGameDef *gamedef);
 	~SchematicManager() {}
 
+	const char *getObjectTitle() const
+	{
+		return "schematic";
+	}
+
 	Schematic *create(int type)
 	{
 		return new Schematic;
diff --git a/src/script/lua_api/l_mapgen.cpp b/src/script/lua_api/l_mapgen.cpp
index 172f2b5cc..5af6cf457 100644
--- a/src/script/lua_api/l_mapgen.cpp
+++ b/src/script/lua_api/l_mapgen.cpp
@@ -86,11 +86,56 @@ struct EnumString ModApiMapgen::es_Rotation[] =
 };
 
 
+bool read_schematic_def(lua_State *L, int index, Schematic *schem,
+	INodeDefManager *ndef, StringMap *replace_names);
+
 ///////////////////////////////////////////////////////////////////////////////
 
 
+Schematic *get_schematic(lua_State *L, int index,
+	SchematicManager *schemmgr, StringMap *replace_names)
+{
+	if (index < 0)
+		index = lua_gettop(L) + 1 + index;
+
+	Schematic *schem;
+
+	if (lua_isnumber(L, index)) {
+		return (Schematic *)schemmgr->get(lua_tointeger(L, index));
+	} else if (lua_istable(L, index)) {
+		schem = new Schematic;
+		if (!read_schematic_def(L, index, schem,
+				schemmgr->getNodeDef(), replace_names)) {
+			delete schem;
+			return NULL;
+		}
+	} else  if (lua_isstring(L, index)) {
+		const char *filename = lua_tostring(L, index);
+		schem = (Schematic *)schemmgr->getByName(filename);
+		if (schem)
+			return schem;
+
+		schem = new Schematic;
+		if (!schem->loadSchematicFromFile(filename,
+				schemmgr->getNodeDef(), replace_names)) {
+			delete schem;
+			return NULL;
+		}
+	} else {
+		return NULL;
+	}
+
+	if (schemmgr->add(schem) == OBJDEF_INVALID_HANDLE) {
+		delete schem;
+		return NULL;
+	}
+
+	return schem;
+}
+
+
 bool read_schematic_def(lua_State *L, int index, Schematic *schem,
-	INodeDefManager *ndef, std::map<std::string, std::string> &replace_names)
+	INodeDefManager *ndef, StringMap *replace_names)
 {
 	//// Get schematic size
 	lua_getfield(L, index, "size");
@@ -128,9 +173,8 @@ bool read_schematic_def(lua_State *L, int index, Schematic *schem,
 		param2 = !lua_isnil(L, -1) ? lua_tonumber(L, -1) : 0;
 		lua_pop(L, 1);
 
-		std::map<std::string, std::string>::iterator it;
-		it = replace_names.find(name);
-		if (it != replace_names.end())
+		StringMap::iterator it = replace_names->find(name);
+		if (it != replace_names->end())
 			name = it->second;
 
 		schemdata[i] = MapNode(ndef, name, param1, param2);
@@ -175,51 +219,12 @@ bool read_schematic_def(lua_State *L, int index, Schematic *schem,
 }
 
 
-Schematic *get_schematic(lua_State *L, int index, SchematicManager *schemmgr,
-	std::map<std::string, std::string> &replace_names)
+
+void read_schematic_replacements(lua_State *L, int index, StringMap *replace_names)
 {
 	if (index < 0)
 		index = lua_gettop(L) + 1 + index;
 
-	Schematic *schem;
-
-	if (lua_isnumber(L, index)) {
-		return (Schematic *)schemmgr->get(lua_tointeger(L, index));
-	} else if (lua_istable(L, index)) {
-		schem = new Schematic;
-		if (!read_schematic_def(L, index, schem,
-				schemmgr->getNodeDef(), replace_names)) {
-			delete schem;
-			return NULL;
-		}
-	} else  if (lua_isstring(L, index)) {
-		const char *filename = lua_tostring(L, index);
-		schem = (Schematic *)schemmgr->getByName(filename);
-		if (schem)
-			return schem;
-
-		schem = new Schematic;
-		if (!schem->loadSchematicFromFile(filename,
-				schemmgr->getNodeDef(), replace_names)) {
-			delete schem;
-			return NULL;
-		}
-	} else {
-		return NULL;
-	}
-
-	if (schemmgr->add(schem) == (u32)-1) {
-		delete schem;
-		return 0;
-	}
-
-	return schem;
-}
-
-
-void read_schematic_replacements(lua_State *L,
-	std::map<std::string, std::string> &replace_names, int index)
-{
 	lua_pushnil(L);
 	while (lua_next(L, index)) {
 		std::string replace_from;
@@ -238,7 +243,7 @@ void read_schematic_replacements(lua_State *L,
 			replace_to = lua_tostring(L, -1);
 		}
 
-		replace_names[replace_from] = replace_to;
+		replace_names->insert(std::make_pair(replace_from, replace_to));
 		lua_pop(L, 1);
 	}
 }
@@ -477,24 +482,23 @@ int ModApiMapgen::l_register_biome(lua_State *L)
 	b->humidity_point  = getfloatfield_default(L, index, "humidity_point", 0.f);
 	b->flags           = 0; //reserved
 
-	u32 id = bmgr->add(b);
-	if (id == (u32)-1) {
+	ObjDefHandle handle = bmgr->add(b);
+	if (handle == OBJDEF_INVALID_HANDLE) {
 		delete b;
 		return 0;
 	}
 
 	NodeResolveInfo *nri = new NodeResolveInfo(b);
 	std::list<std::string> &nnames = nri->nodenames;
-	nnames.push_back(getstringfield_default(L, index, "node_top",          ""));
-	nnames.push_back(getstringfield_default(L, index, "node_filler",       ""));
-	nnames.push_back(getstringfield_default(L, index, "node_stone",        ""));
-	nnames.push_back(getstringfield_default(L, index, "node_water_top",    ""));
-	nnames.push_back(getstringfield_default(L, index, "node_water",        ""));
-	nnames.push_back(getstringfield_default(L, index, "node_dust",         ""));
+	nnames.push_back(getstringfield_default(L, index, "node_top",       ""));
+	nnames.push_back(getstringfield_default(L, index, "node_filler",    ""));
+	nnames.push_back(getstringfield_default(L, index, "node_stone",     ""));
+	nnames.push_back(getstringfield_default(L, index, "node_water_top", ""));
+	nnames.push_back(getstringfield_default(L, index, "node_water",     ""));
+	nnames.push_back(getstringfield_default(L, index, "node_dust",      ""));
 	ndef->pendNodeResolve(nri);
 
-	verbosestream << "register_biome: " << b->name << std::endl;
-	lua_pushinteger(L, id);
+	lua_pushinteger(L, handle);
 	return 1;
 }
 
@@ -556,20 +560,20 @@ int ModApiMapgen::l_register_decoration(lua_State *L)
 		if (!b)
 			continue;
 
-		deco->biomes.insert(b->id);
+		deco->biomes.insert(b->index);
 	}
 
 	//// Handle decoration type-specific parameters
 	bool success = false;
 	switch (decotype) {
-		case DECO_SIMPLE:
-			success = regDecoSimple(L, nri, (DecoSimple *)deco);
-			break;
-		case DECO_SCHEMATIC:
-			success = regDecoSchematic(L, schemmgr, (DecoSchematic *)deco);
-			break;
-		case DECO_LSYSTEM:
-			break;
+	case DECO_SIMPLE:
+		success = regDecoSimple(L, nri, (DecoSimple *)deco);
+		break;
+	case DECO_SCHEMATIC:
+		success = regDecoSchematic(L, schemmgr, (DecoSchematic *)deco);
+		break;
+	case DECO_LSYSTEM:
+		break;
 	}
 
 	ndef->pendNodeResolve(nri);
@@ -579,14 +583,13 @@ int ModApiMapgen::l_register_decoration(lua_State *L)
 		return 0;
 	}
 
-	u32 id = decomgr->add(deco);
-	if (id == (u32)-1) {
+	ObjDefHandle handle = decomgr->add(deco);
+	if (handle == OBJDEF_INVALID_HANDLE) {
 		delete deco;
 		return 0;
 	}
 
-	verbosestream << "register_decoration: " << deco->name << std::endl;
-	lua_pushinteger(L, id);
+	lua_pushinteger(L, handle);
 	return 1;
 }
 
@@ -638,14 +641,14 @@ bool ModApiMapgen::regDecoSchematic(lua_State *L,
 	deco->rotation = (Rotation)getenumfield(L, index, "rotation",
 		es_Rotation, ROTATE_0);
 
-	std::map<std::string, std::string> replace_names;
+	StringMap replace_names;
 	lua_getfield(L, index, "replacements");
 	if (lua_istable(L, -1))
-		read_schematic_replacements(L, replace_names, lua_gettop(L));
+		read_schematic_replacements(L, -1, &replace_names);
 	lua_pop(L, 1);
 
 	lua_getfield(L, index, "schematic");
-	Schematic *schem = get_schematic(L, -1, schemmgr, replace_names);
+	Schematic *schem = get_schematic(L, -1, schemmgr, &replace_names);
 	lua_pop(L, 1);
 
 	deco->schematic = schem;
@@ -719,8 +722,8 @@ int ModApiMapgen::l_register_ore(lua_State *L)
 			"random_factor", 1.f);
 	}
 
-	u32 id = oremgr->add(ore);
-	if (id == (u32)-1) {
+	ObjDefHandle handle = oremgr->add(ore);
+	if (handle == OBJDEF_INVALID_HANDLE) {
 		delete ore;
 		return 0;
 	}
@@ -736,8 +739,7 @@ int ModApiMapgen::l_register_ore(lua_State *L)
 
 	ndef->pendNodeResolve(nri);
 
-	verbosestream << "register_ore: " << ore->name << std::endl;
-	lua_pushinteger(L, id);
+	lua_pushinteger(L, handle);
 	return 1;
 }
 
@@ -746,16 +748,21 @@ int ModApiMapgen::l_register_schematic(lua_State *L)
 {
 	SchematicManager *schemmgr = getServer(L)->getEmergeManager()->schemmgr;
 
-	std::map<std::string, std::string> replace_names;
+	StringMap replace_names;
 	if (lua_istable(L, 2))
-		read_schematic_replacements(L, replace_names, 2);
+		read_schematic_replacements(L, 2, &replace_names);
 
-	Schematic *schem = get_schematic(L, 1, schemmgr, replace_names);
+	Schematic *schem = get_schematic(L, 1, schemmgr, &replace_names);
 	if (!schem)
 		return 0;
-	printf("register_schematic!\n");
-	verbosestream << "register_schematic: " << schem->name << std::endl;
-	lua_pushinteger(L, schem->id);
+
+	ObjDefHandle handle = schemmgr->add(schem);
+	if (handle == OBJDEF_INVALID_HANDLE) {
+		delete schem;
+		return 0;
+	}
+
+	lua_pushinteger(L, handle);
 	return 1;
 }
 
@@ -837,7 +844,7 @@ int ModApiMapgen::l_generate_decorations(lua_State *L)
 	return 0;
 }
 
-// create_schematic(p1, p2, probability_list, filename)
+// create_schematic(p1, p2, probability_list, filename, y_slice_prob_list)
 int ModApiMapgen::l_create_schematic(lua_State *L)
 {
 	Schematic schem;
@@ -894,6 +901,7 @@ int ModApiMapgen::l_create_schematic(lua_State *L)
 	actionstream << "create_schematic: saved schematic file '"
 		<< filename << "'." << std::endl;
 
+	lua_pushboolean(L, true);
 	return 1;
 }
 
@@ -917,12 +925,12 @@ int ModApiMapgen::l_place_schematic(lua_State *L)
 		force_placement = lua_toboolean(L, 5);
 
 	//// Read node replacements
-	std::map<std::string, std::string> replace_names;
+	StringMap replace_names;
 	if (lua_istable(L, 4))
-		read_schematic_replacements(L, replace_names, 4);
+		read_schematic_replacements(L, 4, &replace_names);
 
 	//// Read schematic
-	Schematic *schem = get_schematic(L, 2, schemmgr, replace_names);
+	Schematic *schem = get_schematic(L, 2, schemmgr, &replace_names);
 	if (!schem) {
 		errorstream << "place_schematic: failed to get schematic" << std::endl;
 		return 0;
@@ -931,6 +939,7 @@ int ModApiMapgen::l_place_schematic(lua_State *L)
 	schem->placeStructure(map, p, 0, (Rotation)rot, force_placement,
 		schemmgr->getNodeDef());
 
+	lua_pushboolean(L, true);
 	return 1;
 }
 
diff --git a/src/util/numeric.cpp b/src/util/numeric.cpp
index a1f1fd0ab..2306976ec 100644
--- a/src/util/numeric.cpp
+++ b/src/util/numeric.cpp
@@ -183,7 +183,6 @@ u64 murmur_hash_64_ua(const void *key, int len, unsigned int seed)
 	return h;
 }
 
-
 /*
 	blockpos: position of block in block coordinates
 	camera_pos: position of camera in nodes
diff --git a/src/util/numeric.h b/src/util/numeric.h
index ccc9fbee4..74c1dfea6 100644
--- a/src/util/numeric.h
+++ b/src/util/numeric.h
@@ -249,6 +249,28 @@ int myrand_range(int min, int max);
 	Miscellaneous functions
 */
 
+inline u32 get_bits(u32 x, u32 pos, u32 len)
+{
+	u32 mask = (1 << len) - 1;
+	return (x >> pos) & mask;
+}
+
+inline void set_bits(u32 *x, u32 pos, u32 len, u32 val)
+{
+	u32 mask = (1 << len) - 1;
+	*x &= ~(mask << len);
+	*x |= (val & mask) << pos;
+}
+
+inline u32 calc_parity(u32 v)
+{
+	v ^= v >> 16;
+	v ^= v >> 8;
+	v ^= v >> 4;
+	v &= 0xf;
+	return (0x6996 >> v) & 1;
+}
+
 u64 murmur_hash_64_ua(const void *key, int len, unsigned int seed);
 
 bool isBlockInSight(v3s16 blockpos_b, v3f camera_pos, v3f camera_dir,