Add core.find_nodes_with_meta() script API

doc/lua_api.txt

@@ -1871,6 +1871,8 @@ and `minetest.auth_reload` call the authetification handler.
 * `minetest.punch_node(pos)`
     * Punch node with the same effects that a player would cause
 
+* `minetest.find_nodes_with_meta(pos1, pos2)`
+    * Get a table of positions of nodes that have metadata within a region {pos1, pos2}
 * `minetest.get_meta(pos)`
     * Get a `NodeMetaRef` at that position
 * `minetest.get_node_timer(pos)`

src/map.cpp

@@ -1890,6 +1890,40 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
 	}
 }
 
+std::vector<v3s16> Map::findNodesWithMetadata(v3s16 p1, v3s16 p2)
+{
+	std::vector<v3s16> positions_with_meta;
+
+	sortBoxVerticies(p1, p2);
+	v3s16 bpmin = getNodeBlockPos(p1);
+	v3s16 bpmax = getNodeBlockPos(p2);
+
+	for (s16 z = bpmin.Z; z <= bpmax.Z; z++)
+	for (s16 y = bpmin.Y; y <= bpmax.Y; y++)
+	for (s16 x = bpmin.X; x <= bpmax.X; x++) {
+		v3s16 blockpos(x, y, z);
+
+		MapBlock *block = getBlockNoCreateNoEx(blockpos);
+		if (!block) {
+			verbosestream << "Map::getNodeMetadata(): Need to emerge "
+				<< PP(blockpos) << std::endl;
+			block = emergeBlock(blockpos, false);
+		}
+		if (!block) {
+			infostream << "WARNING: Map::getNodeMetadata(): Block not found"
+				<< std::endl;
+			continue;
+		}
+
+		v3s16 p_base = blockpos * MAP_BLOCKSIZE;
+		std::vector<v3s16> keys = block->m_node_metadata.getAllKeys();
+		for (size_t i = 0; i != keys.size(); i++)
+			positions_with_meta.push_back(keys[i] + p_base);
+	}
+
+	return positions_with_meta;
+}
+
 NodeMetadata *Map::getNodeMetadata(v3s16 p)
 {
 	v3s16 blockpos = getNodeBlockPos(p);

src/map.h

@@ -301,7 +301,8 @@ public:
 		These are basically coordinate wrappers to MapBlock
 	*/
 
-	NodeMetadata* getNodeMetadata(v3s16 p);
+	std::vector<v3s16> findNodesWithMetadata(v3s16 p1, v3s16 p2);
+	NodeMetadata *getNodeMetadata(v3s16 p);
 
 	/**
 	 * Sets metadata for a node.

src/nodemetadata.cpp

@@ -157,10 +157,21 @@ NodeMetadataList::~NodeMetadataList()
 	clear();
 }
 
-NodeMetadata* NodeMetadataList::get(v3s16 p)
+std::vector<v3s16> NodeMetadataList::getAllKeys()
 {
-	std::map<v3s16, NodeMetadata*>::const_iterator n = m_data.find(p);
-	if(n == m_data.end())
+	std::vector<v3s16> keys;
+
+	std::map<v3s16, NodeMetadata *>::const_iterator it;
+	for (it = m_data.begin(); it != m_data.end(); ++it)
+		keys.push_back(it->first);
+
+	return keys;
+}
+
+NodeMetadata *NodeMetadataList::get(v3s16 p)
+{
+	std::map<v3s16, NodeMetadata *>::const_iterator n = m_data.find(p);
+	if (n == m_data.end())
 		return NULL;
 	return n->second;
 }
@@ -168,8 +179,7 @@ NodeMetadata* NodeMetadataList::get(v3s16 p)
 void NodeMetadataList::remove(v3s16 p)
 {
 	NodeMetadata *olddata = get(p);
-	if(olddata)
-	{
+	if (olddata) {
 		delete olddata;
 		m_data.erase(p);
 	}
@@ -183,16 +193,15 @@ void NodeMetadataList::set(v3s16 p, NodeMetadata *d)
 
 void NodeMetadataList::clear()
 {
-	for(std::map<v3s16, NodeMetadata*>::iterator
-			i = m_data.begin();
-			i != m_data.end(); i++)
-	{
-		delete i->second;
+	std::map<v3s16, NodeMetadata*>::iterator it;
+	for (it = m_data.begin(); it != m_data.end(); ++it) {
+		delete it->second;
 	}
 	m_data.clear();
 }
 
-std::string NodeMetadata::getString(const std::string &name, unsigned short recursion) const
+std::string NodeMetadata::getString(const std::string &name,
+	unsigned short recursion) const
 {
 	std::map<std::string, std::string>::const_iterator it;
 	it = m_stringvars.find(name);
@@ -211,7 +220,8 @@ void NodeMetadata::setString(const std::string &name, const std::string &var)
 	}
 }
 
-std::string NodeMetadata::resolveString(const std::string &str, unsigned short recursion) const
+std::string NodeMetadata::resolveString(const std::string &str,
+	unsigned short recursion) const
 {
 	if (recursion > 1) {
 		return str;

src/nodemetadata.h

@@ -23,6 +23,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "irr_v3d.h"
 #include <string>
 #include <iostream>
+#include <vector>
 #include <map>
 
 /*
@@ -82,8 +83,10 @@ public:
 	void serialize(std::ostream &os) const;
 	void deSerialize(std::istream &is, IGameDef *gamedef);
 
+	// Add all keys in this list to the vector keys
+	std::vector<v3s16> getAllKeys();
 	// Get pointer to data
-	NodeMetadata* get(v3s16 p);
+	NodeMetadata *get(v3s16 p);
 	// Deletes data
 	void remove(v3s16 p);
 	// Deletes old data and sets a new one
@@ -92,7 +95,7 @@ public:
 	void clear();
 
 private:
-	std::map<v3s16, NodeMetadata*> m_data;
+	std::map<v3s16, NodeMetadata *> m_data;
 };
 
 #endif

src/script/lua_api/l_env.cpp

@@ -334,6 +334,22 @@ int ModApiEnvMod::l_add_node_level(lua_State *L)
 	return 1;
 }
 
+// find_nodes_with_meta(pos1, pos2)
+int ModApiEnvMod::l_find_nodes_with_meta(lua_State *L)
+{
+	GET_ENV_PTR;
+
+	std::vector<v3s16> positions = env->getMap().findNodesWithMetadata(
+		check_v3s16(L, 1), check_v3s16(L, 2));
+
+	lua_newtable(L);
+	for (size_t i = 0; i != positions.size(); i++) {
+		push_v3s16(L, positions[i]);
+		lua_rawseti(L, -2, i + 1);
+	}
+
+	return 1;
+}
 
 // get_meta(pos)
 int ModApiEnvMod::l_get_meta(lua_State *L)
@@ -912,6 +928,7 @@ void ModApiEnvMod::Initialize(lua_State *L, int top)
 	API_FCT(set_node_level);
 	API_FCT(add_node_level);
 	API_FCT(add_entity);
+	API_FCT(find_nodes_with_meta);
 	API_FCT(get_meta);
 	API_FCT(get_node_timer);
 	API_FCT(get_player_by_name);

src/script/lua_api/l_env.h

@@ -64,7 +64,6 @@ private:
 	// pos = {x=num, y=num, z=num}
 	static int l_punch_node(lua_State *L);
 
-
 	// get_node_max_level(pos)
 	// pos = {x=num, y=num, z=num}
 	static int l_get_node_max_level(lua_State *L);
@@ -81,6 +80,9 @@ private:
 	// pos = {x=num, y=num, z=num}
 	static int l_add_node_level(lua_State *L);
 
+	// find_nodes_with_meta(pos1, pos2)
+	static int l_find_nodes_with_meta(lua_State *L);
+
 	// get_meta(pos)
 	static int l_get_meta(lua_State *L);