Biomes: Add 'get heat', 'get humidity', 'get biome data' APIs

'get biome data' returns biome id, heat and humidity.
Clean up nearby lines in lua_api.txt.

src/mapgen/mg_biome.cpp

@@ -84,8 +84,66 @@ void BiomeManager::clear()
 	m_objects.resize(1);
 }
 
-////////////////////////////////////////////////////////////////////////////////
 
+// For BiomeGen type 'BiomeGenOriginal'
+float BiomeManager::getHeatAtPosOriginal(v3s16 pos, NoiseParams &np_heat,
+	NoiseParams &np_heat_blend, u64 seed)
+{
+	return
+		NoisePerlin2D(&np_heat,       pos.X, pos.Z, seed) +
+		NoisePerlin2D(&np_heat_blend, pos.X, pos.Z, seed);
+}
+
+
+// For BiomeGen type 'BiomeGenOriginal'
+float BiomeManager::getHumidityAtPosOriginal(v3s16 pos, NoiseParams &np_humidity,
+	NoiseParams &np_humidity_blend, u64 seed)
+{
+	return
+		NoisePerlin2D(&np_humidity,       pos.X, pos.Z, seed) +
+		NoisePerlin2D(&np_humidity_blend, pos.X, pos.Z, seed);
+}
+
+
+// For BiomeGen type 'BiomeGenOriginal'
+Biome *BiomeManager::getBiomeFromNoiseOriginal(float heat, float humidity, s16 y)
+{
+	Biome *biome_closest = nullptr;
+	Biome *biome_closest_blend = nullptr;
+	float dist_min = FLT_MAX;
+	float dist_min_blend = FLT_MAX;
+
+	for (size_t i = 1; i < getNumObjects(); i++) {
+		Biome *b = (Biome *)getRaw(i);
+		if (!b || y > b->y_max + b->vertical_blend || y < b->y_min)
+			continue;
+
+		float d_heat = heat - b->heat_point;
+		float d_humidity = humidity - b->humidity_point;
+		float dist = (d_heat * d_heat) + (d_humidity * d_humidity);
+
+		if (y <= b->y_max) { // Within y limits of biome b
+			if (dist < dist_min) {
+				dist_min = dist;
+				biome_closest = b;
+			}
+		} else if (dist < dist_min_blend) { // Blend area above biome b
+			dist_min_blend = dist;
+			biome_closest_blend = b;
+		}
+	}
+
+	mysrand(y + (heat - humidity) * 2);
+	if (biome_closest_blend &&
+			myrand_range(0, biome_closest_blend->vertical_blend) >=
+			y - biome_closest_blend->y_max)
+		return biome_closest_blend;
+
+	return (biome_closest) ? biome_closest : (Biome *)getRaw(BIOME_NONE);
+}
+
+
+////////////////////////////////////////////////////////////////////////////////
 
 void BiomeParamsOriginal::readParams(const Settings *settings)
 {

src/mapgen/mg_biome.h

@@ -225,6 +225,13 @@ public:
 
 	virtual void clear();
 
+	// For BiomeGen type 'BiomeGenOriginal'
+	float getHeatAtPosOriginal(v3s16 pos, NoiseParams &np_heat,
+		NoiseParams &np_heat_blend, u64 seed);
+	float getHumidityAtPosOriginal(v3s16 pos, NoiseParams &np_humidity,
+		NoiseParams &np_humidity_blend, u64 seed);
+	Biome *getBiomeFromNoiseOriginal(float heat, float humidity, s16 y);
+
 private:
 	Server *m_server;
 

src/script/lua_api/l_mapgen.cpp

@@ -463,7 +463,7 @@ size_t get_biome_list(lua_State *L, int index,
 ///////////////////////////////////////////////////////////////////////////////
 
 // get_biome_id(biomename)
-// returns the biome id used in biomemap
+// returns the biome id as used in biomemap and returned by 'get_biome_data()'
 int ModApiMapgen::l_get_biome_id(lua_State *L)
 {
 	NO_MAP_LOCK_REQUIRED;
@@ -488,6 +488,154 @@ int ModApiMapgen::l_get_biome_id(lua_State *L)
 }
 
 
+// get_heat(pos)
+// returns the heat at the position
+int ModApiMapgen::l_get_heat(lua_State *L)
+{
+	NO_MAP_LOCK_REQUIRED;
+
+	v3s16 pos = read_v3s16(L, 1);
+
+	NoiseParams np_heat;
+	NoiseParams np_heat_blend;
+
+	MapSettingsManager *settingsmgr =
+		getServer(L)->getEmergeManager()->map_settings_mgr;
+
+	if (!settingsmgr->getMapSettingNoiseParams("mg_biome_np_heat",
+			&np_heat) ||
+			!settingsmgr->getMapSettingNoiseParams("mg_biome_np_heat_blend",
+			&np_heat_blend))
+		return 0;
+
+	std::string value;
+	if (!settingsmgr->getMapSetting("seed", &value))
+		return 0;
+	std::istringstream ss(value);
+	u64 seed;
+	ss >> seed;
+
+	BiomeManager *bmgr = getServer(L)->getEmergeManager()->biomemgr;
+	if (!bmgr)
+		return 0;
+
+	float heat = bmgr->getHeatAtPosOriginal(pos, np_heat, np_heat_blend, seed);
+	if (!heat)
+		return 0;
+
+	lua_pushnumber(L, heat);
+
+	return 1;
+}
+
+
+// get_humidity(pos)
+// returns the humidity at the position
+int ModApiMapgen::l_get_humidity(lua_State *L)
+{
+	NO_MAP_LOCK_REQUIRED;
+
+	v3s16 pos = read_v3s16(L, 1);
+
+	NoiseParams np_humidity;
+	NoiseParams np_humidity_blend;
+
+	MapSettingsManager *settingsmgr =
+		getServer(L)->getEmergeManager()->map_settings_mgr;
+
+	if (!settingsmgr->getMapSettingNoiseParams("mg_biome_np_humidity",
+			&np_humidity) ||
+			!settingsmgr->getMapSettingNoiseParams("mg_biome_np_humidity_blend",
+			&np_humidity_blend))
+		return 0;
+
+	std::string value;
+	if (!settingsmgr->getMapSetting("seed", &value))
+		return 0;
+	std::istringstream ss(value);
+	u64 seed;
+	ss >> seed;
+
+	BiomeManager *bmgr = getServer(L)->getEmergeManager()->biomemgr;
+	if (!bmgr)
+		return 0;
+
+	float humidity = bmgr->getHumidityAtPosOriginal(pos, np_humidity,
+		np_humidity_blend, seed);
+	if (!humidity)
+		return 0;
+
+	lua_pushnumber(L, humidity);
+
+	return 1;
+}
+
+
+// get_biome_data(pos)
+// returns a table containing the biome id, heat and humidity at the position
+int ModApiMapgen::l_get_biome_data(lua_State *L)
+{
+	NO_MAP_LOCK_REQUIRED;
+
+	v3s16 pos = read_v3s16(L, 1);
+
+	NoiseParams np_heat;
+	NoiseParams np_heat_blend;
+	NoiseParams np_humidity;
+	NoiseParams np_humidity_blend;
+
+	MapSettingsManager *settingsmgr =
+		getServer(L)->getEmergeManager()->map_settings_mgr;
+
+	if (!settingsmgr->getMapSettingNoiseParams("mg_biome_np_heat",
+			&np_heat) ||
+			!settingsmgr->getMapSettingNoiseParams("mg_biome_np_heat_blend",
+			&np_heat_blend) ||
+			!settingsmgr->getMapSettingNoiseParams("mg_biome_np_humidity",
+			&np_humidity) ||
+			!settingsmgr->getMapSettingNoiseParams("mg_biome_np_humidity_blend",
+			&np_humidity_blend))
+		return 0;
+
+	std::string value;
+	if (!settingsmgr->getMapSetting("seed", &value))
+		return 0;
+	std::istringstream ss(value);
+	u64 seed;
+	ss >> seed;
+
+	BiomeManager *bmgr = getServer(L)->getEmergeManager()->biomemgr;
+	if (!bmgr)
+		return 0;
+
+	float heat = bmgr->getHeatAtPosOriginal(pos, np_heat, np_heat_blend, seed);
+	if (!heat)
+		return 0;
+
+	float humidity = bmgr->getHumidityAtPosOriginal(pos, np_humidity,
+		np_humidity_blend, seed);
+	if (!humidity)
+		return 0;
+
+	Biome *biome = (Biome *)bmgr->getBiomeFromNoiseOriginal(heat, humidity, pos.Y);
+	if (!biome || biome->index == OBJDEF_INVALID_INDEX)
+		return 0;
+
+	lua_newtable(L);
+
+	lua_pushinteger(L, biome->index);
+	lua_setfield(L, -2, "biome");
+
+	lua_pushnumber(L, heat);
+	lua_setfield(L, -2, "heat");
+
+	lua_pushnumber(L, humidity);
+	lua_setfield(L, -2, "humidity");
+
+	return 1;
+}
+
+
 // get_mapgen_object(objectname)
 // returns the requested object used during map generation
 int ModApiMapgen::l_get_mapgen_object(lua_State *L)
@@ -1520,6 +1668,9 @@ int ModApiMapgen::l_serialize_schematic(lua_State *L)
 void ModApiMapgen::Initialize(lua_State *L, int top)
 {
 	API_FCT(get_biome_id);
+	API_FCT(get_heat);
+	API_FCT(get_humidity);
+	API_FCT(get_biome_data);
 	API_FCT(get_mapgen_object);
 
 	API_FCT(get_mapgen_params);

src/script/lua_api/l_mapgen.h

@@ -25,9 +25,21 @@ class ModApiMapgen : public ModApiBase
 {
 private:
 	// get_biome_id(biomename)
-	// returns the biome id used in biomemap
+	// returns the biome id as used in biomemap and returned by 'get_biome_data()'
 	static int l_get_biome_id(lua_State *L);
 
+	// get_heat(pos)
+	// returns the heat at the position
+	static int l_get_heat(lua_State *L);
+
+	// get_humidity(pos)
+	// returns the humidity at the position
+	static int l_get_humidity(lua_State *L);
+
+	// get_biome_data(pos)
+	// returns a table containing the biome id, heat and humidity at the position
+	static int l_get_biome_data(lua_State *L);
+
 	// get_mapgen_object(objectname)
 	// returns the requested object used during map generation
 	static int l_get_mapgen_object(lua_State *L);