389/*
Minetest
Copyright (C) 2010-2015 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
Copyright (C) 2010-2015 paramat, Matt Gregory

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/


#include "mapgen.h"
#include "voxel.h"
#include "noise.h"
#include "mapblock.h"
#include "mapnode.h"
#include "map.h"
#include "content_sao.h"
#include "nodedef.h"
#include "voxelalgorithms.h"
//#include "profiler.h" // For TimeTaker
#include "settings.h" // For g_settings
#include "emerge.h"
#include "dungeongen.h"
#include "cavegen.h"
#include "mg_biome.h"
#include "mg_ore.h"
#include "mg_decoration.h"
#include "mapgen_fractal.h"


FlagDesc flagdesc_mapgen_fractal[] = {
	{NULL,    0}
};

///////////////////////////////////////////////////////////////////////////////////////


MapgenFractal::MapgenFractal(int mapgenid, MapgenFractalParams *params, EmergeManager *emerge)
	: MapgenBasic(mapgenid, params, emerge)
{
	this->spflags    = params->spflags;
	this->cave_width = params->cave_width;
	this->fractal    = params->fractal;
	this->iterations = params->iterations;
	this->scale      = params->scale;
	this->offset     = params->offset;
	this->slice_w    = params->slice_w;
	this->julia_x    = params->julia_x;
	this->julia_y    = params->julia_y;
	this->julia_z    = params->julia_z;
	this->julia_w    = params->julia_w;

	//// 2D terrain noise
	noise_seabed       = new Noise(&params->np_seabed, seed, csize.X, csize.Z);
	noise_filler_depth = new Noise(&params->np_filler_depth, seed, csize.X, csize.Z);

	MapgenBasic::np_cave1 = params->np_cave1;
	MapgenBasic::np_cave2 = params->np_cave2;

	this->formula = fractal / 2 + fractal % 2;
	this->julia   = fractal % 2 == 0;
}


MapgenFractal::~MapgenFractal()
{
	delete noise_seabed;
	delete noise_filler_depth;
}


MapgenFractalParams::MapgenFractalParams()
{
	spflags    = 0;
	cave_width = 0.09;
	fractal    = 1;
	iterations = 11;
	scale      = v3f(4096.0, 1024.0, 4096.0);
	offset     = v3f(1.79, 0.0, 0.0);
	slice_w    = 0.0;
	julia_x    = 0.33;
	julia_y    = 0.33;
	julia_z    = 0.33;
	julia_w    = 0.33;

	np_seabed       = NoiseParams(-14, 9,   v3f(600, 600, 600), 41900, 5, 0.6, 2.0);
	np_filler_depth = NoiseParams(0,   1.2, v3f(150, 150, 150), 261,   3, 0.7, 2.0);
	np_cave1        = NoiseParams(0,   12,  v3f(61,  61,  61),  52534, 3, 0.5, 2.0);
	np_cave2        = NoiseParams(0,   12,  v3f(67,  67,  67),  10325, 3, 0.5, 2.0);
}


void MapgenFractalParams::readParams(const Settings *settings)
{
	settings->getFlagStrNoEx("mgfractal_spflags",  spflags, flagdesc_mapgen_fractal);
	settings->getFloatNoEx("mgfractal_cave_width", cave_width);
	settings->getU16NoEx("mgfractal_fractal",      fractal);
	settings->getU16NoEx("mgfractal_iterations",   iterations);
	settings->getV3FNoEx("mgfractal_scale",        scale);
	settings->getV3FNoEx("mgfractal_offset",       offset);
	settings->getFloatNoEx("mgfractal_slice_w",    slice_w);
	settings->getFloatNoEx("mgfractal_julia_x",    julia_x);
	settings->getFloatNoEx("mgfractal_julia_y",    julia_y);
	settings->getFloatNoEx("mgfractal_julia_z",    julia_z);
	settings->getFloatNoEx("mgfractal_julia_w",    julia_w);

	settings->getNoiseParams("mgfractal_np_seabed",       np_seabed);
	settings->getNoiseParams("mgfractal_np_filler_depth", np_filler_depth);
	settings->getNoiseParams("mgfractal_np_cave1",        np_cave1);
	settings->getNoiseParams("mgfractal_np_cave2",        np_cave2);
}


void MapgenFractalParams::writeParams(Settings *settings) const
{
	settings->setFlagStr("mgfractal_spflags",  spflags, flagdesc_mapgen_fractal, U32_MAX);
	settings->setFloat("mgfractal_cave_width", cave_width);
	settings->setU16("mgfractal_fractal",      fractal);
	settings->setU16("mgfractal_iterations",   iterations);
	settings->setV3F("mgfractal_scale",        scale);
	settings->setV3F("mgfractal_offset",       offset);
	settings->setFloat("mgfractal_slice_w",    slice_w);
	settings->setFloat("mgfractal_julia_x",    julia_x);
	settings->setFloat("mgfractal_julia_y",    julia_y);
	settings->setFloat("mgfractal_julia_z",    julia_z);
	settings->setFloat("mgfractal_julia_w",    julia_w);

	settings->setNoiseParams("mgfractal_np_seabed",       np_seabed);
	settings->setNoiseParams("mgfractal_np_filler_depth", np_filler_depth);
	settings->setNoiseParams("mgfractal_np_cave1",        np_cave1);
	settings->setNoiseParams("mgfractal_np_cave2",        np_cave2);
}


/////////////////////////////////////////////////////////////////


int MapgenFractal::getSpawnLevelAtPoint(v2s16 p)
{
	bool solid_below = false;  // Dry solid node is present below to spawn on
	u8 air_count = 0;  // Consecutive air nodes above the dry solid node
	s16 seabed_level = NoisePerlin2D(&noise_seabed->np, p.X, p.Y, seed);
	// Seabed can rise above water_level or might be raised to create dry land
	s16 search_start = MYMAX(seabed_level, water_level + 1);
	if (seabed_level > water_level)
		solid_below = true;

	for (s16 y = search_start; y <= search_start + 128; y++) {
		if (getFractalAtPoint(p.X, y, p.Y)) {  // Fractal node
			solid_below = true;
			air_count = 0;
		} else if (solid_below) {  // Air above solid node
			air_count++;
			if (air_count == 2)
				return y - 2;
		}
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include "lua_api/l_env.h"
#include "lua_api/l_internal.h"
#include "lua_api/l_nodemeta.h"
#include "lua_api/l_nodetimer.h"
#include "lua_api/l_noise.h"

		data->blockpos_requested.Z >= data->blockpos_min.Z);
	assert(data->blockpos_requested.X <= data->blockpos_max.X &&
		data->blockpos_requested.Y <= data->blockpos_max.Y &&
		data->blockpos_requested.Z <= data->blockpos_max.Z);

	this->generating = true;
	this->vm   = data->vmanip;
	this->ndef = data->nodedef;
	//TimeTaker t("makeChunk");

	v3s16 blockpos_min = data->blockpos_min;
	v3s16 blockpos_max = data->blockpos_max;
	node_min = blockpos_min * MAP_BLOCKSIZE;
	node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
	full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
	full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);

	blockseed = getBlockSeed2(full_node_min, seed);

	// Generate base terrain, mountains, and ridges with initial heightmaps
	s16 stone_surface_max_y = generateTerrain();

	// Create heightmap
	updateHeightmap(node_min, node_max);

	// Init biome generator, place biome-specific nodes, and build biomemap
	biomegen->calcBiomeNoise(node_min);
	MgStoneType stone_type = generateBiomes();

	if (flags & MG_CAVES)
		generateCaves(stone_surface_max_y, MGFRACTAL_LARGE_CAVE_DEPTH);

	if (flags & MG_DUNGEONS)
		generateDungeons(stone_surface_max_y, stone_type);

	// Generate the registered decorations
	if (flags & MG_DECORATIONS)
		m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);

	// Generate the registered ores
	m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);

	// Sprinkle some dust on top after everything else was generated
	dustTopNodes();

	//printf("makeChunk: %dms\n", t.stop());

	updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);

	if (flags & MG_LIGHT)
		calcLighting(node_min - v3s16(0, 1, 0), node_max + v3s16(0, 1, 0),
			full_node_min, full_node_max);

	//setLighting(node_min - v3s16(1, 0, 1) * MAP_BLOCKSIZE,
	//			node_max + v3s16(1, 0, 1) * MAP_BLOCKSIZE, 0xFF);

	this->generating = false;
}


bool MapgenFractal::getFractalAtPoint(s16 x, s16 y, s16 z)
{
	float cx, cy, cz, cw, ox, oy, oz, ow;

	if (julia) {  // Julia set
		cx = julia_x;
		cy = julia_y;
		cz = julia_z;
		cw = julia_w;
		ox = (float)x / scale.X - offset.X;
		oy = (float)y / scale.Y - offset.Y;
		oz = (float)z / scale.Z - offset.Z;
		ow = slice_w;
	} else {  // Mandelbrot set
		cx = (float)x / scale.X - offset.X;
		cy = (float)y / scale.Y - offset.Y;
		cz = (float)z / scale.Z - offset.Z;
		cw = slice_w;
		ox = 0.0f;
		oy = 0.0f;
		oz = 0.0f;
		ow = 0.0f;
	}

	float nx = 0.0f;
	float ny = 0.0f;
	float nz = 0.0f;
	float nw = 0.0f;

	for (u16 iter = 0; iter < iterations; iter++) {

		if (formula == 1) {  // 4D "Roundy"
			nx = ox * ox - oy * oy - oz * oz - ow * ow + cx;
			ny = 2.0f * (ox * oy + oz * ow) + cy;
			nz = 2.0f * (ox * oz + oy * ow) + cz;
			nw = 2.0f * (ox * ow + oy * oz) + cw;
		} else if (formula == 2) {  // 4D "Squarry"
			nx = ox * ox - oy * oy - oz * oz - ow * ow + cx;
			ny = 2.0f * (ox * oy + oz * ow) + cy;
			nz = 2.0f * (ox * oz + oy * ow) + cz;
			nw = 2.0f * (ox * ow - oy * oz) + cw;
		} else if (formula == 3) {  // 4D "Mandy Cousin"
			nx = ox * ox - oy * oy - oz * oz + ow * ow + cx;
			ny = 2.0f ->refcount--;

	state->script->on_emerge_area_completion(blockpos, action, state);

	if (state->refcount == 0)
		delete state;
}

// Exported functions

// set_node(pos, node)
// pos = {x=num, y=num, z=num}
int ModApiEnvMod::l_set_node
			nx = ox * ox - oy * oy - oz * oz - ow * ow + cx;
			ny = 2.0f * (ox * oy + oz * ow) + cy;
			nz = 2.0f * (ox * oz - oy * ow) + cz;
			nw = 2.0f * (ox * ow + oy * oz) + cw;
		} else if (formula == 5) {  // 3D "Mandelbrot/Mandelbar"
			nx = ox * ox - oy * oy - oz * oz + cx;
			ny = 2.0f * ox * oy + cy;
			nz = -2.0f * ox * oz + cz;
		} else if (formula == 6) {  // 3D "Christmas Tree"
			// Altering the formula here is necessary to avoid division by zero
			if (fabs(oz) < 0.000000001f) {
				nx = ox * ox - oy * oy - oz * oz + cx;
				ny = 2.0f * oy * ox + cy;
				nz = 4.0f * oz * ox + cz;
			} else {
				float a = (2.0f * ox) / (sqrt(oy * oy + oz * oz));
				nx = ox * ox - oy * oy - oz * oz + cx;
				ny = a * (oy * oy - oz * oz) + cy;
				nz = a * 2.0f * oy * oz + cz;
			}
		} else if (formula == 7) {  // 3D "Mandelbulb"
			if (fabs(oy) < 0.000000001f) {
				nx = ox * ox - oz * oz + cx;
				ny = cy;
				nz = -2.0f * oz * sqrt(ox * ox) + cz;
			} else {
				float a = 1.0f - (oz * oz) / (ox * ox + oy * oy);
				nx = (ox * ox - oy * oy) * a + cx;
				ny = 2.0f * ox * oy * a + cy;
				nz = -2.0f * oz * sqrt(ox * ox + oy * oy) + cz;
			}
		} else if (formula == 8) {  // 3D "Cosine Mandelbulb"
			if (fabs(oy) < 0.000000001f) {
				nx = 2.0f * ox * oz + cx;
				ny = 4.0f * oy * oz + cy;
				nz = oz * oz - ox * ox - oy * oy + cz// get_node_light(pos, timeofday)
// pos = {x=num, y=num, z=num}
// timeofday: nil = current time, 0 = night, 0.5 = day
int ModApiEnvMod::l_get_node_light(lua_State *L)
{
	GET_ENV_PTR;

	// Do it
	v3s16 pos = read_v3s16(L, 1);
	u32 time_of_day = env->getTimeOfDay();
	if(lua_isnumber(L, 2))
		time_of_day = 24000.0 * lua_tonumber(L, 2);
	time_of_day %= 24000;
	u32 dnr = time_to_daynight_ratio(time_of_day, true);

	bool is_position_ok;
	MapNode n = env->getMap().getNodeNoEx(pos, &is_position_ok);
	if (is_position_ok) {
		INodeDefManager *ndef = env->getGameDef()->ndef();
		lua_pushinteger(L, n.getLightBlend(dnr, ndef));
	} else {
		lua_pushnil(L);
	}
	return 1;
}<
				nw = 2.0f * rxyz * ow + cw;
			} else {
				float a = 1.0f - (ow * ow) / (rxyz * rxyz);
				float b = a * (1.0f - (oz * oz) / (rxy * rxy));
				nx = (ox * ox - oy * oy) * b + cx;
				ny = 2.0f * ox * oy * b + cy;
				nz = -2.0f * rxy * oz * a + cz;
				nw = 2.0f * rxyz * ow + cw;
			}
		}

		if (nx * nx + ny * ny + nz * nz + nw * nw > 4.0f)
			return false;

		ox = nx;
		oy = ny;
		oz = nz;
		ow = nw;
	}

	return true;
}


s16 MapgenFractal::generateTerrain()
{
	MapNode n_air(CONTENT_AIR);
	MapNode n_stone(c_stone);
	MapNode n_water(c_water_source);

	s16 stone_surface_max_y = -MAX_MAP_GENERATION_LIMIT;
	u32 index2d = 0;

	noise_seabed->perlinMap2D(node_min.X, node_min.Z);

	for (s16 z = node_min.Z; z <= node_max.Z; z++) {
		for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
			u32 vi = vm->m_area.index(node_min.X, y, z);
			for (s16 x = node_min.X; x <= node_max.X; x++, vi++, index2d++) {
				if (vm->m_data[vi].getContent() == CONTENT_IGNORE) {
					s16 seabed_height = noise_seabed->result[index2d];

					if (y <= seabed_height || getFractalAtPoint(x, y, z)) {
						vm->m_data[vi] = n_stone;
						if (y > stone_surface_max_y)
							stone_surface_max_y = y;
					} else if (y <= water_level) {
						vm->m_data[vi] = n_water;
					} else {
						vm->
// punch_node(pos)
// pos = {x=num, y=num, z=num}
int ModApiEnvMod::l_punch_node(lua_State *L)
{
	GET_ENV_PTR;

	ScriptApiNode *scriptIfaceNode = getScriptApi<ScriptApiNode>(L);

	v3s16 pos = read_v3s16(L, 1);

	// Don't attempt to load non-loaded area as of now
	MapNode n = env->getMap().getNodeNoEx(pos);
	if(n.getContent() == CONTENT_IGNORE){
		lua_pushboolean(L, false);
		return 1;
	}
	// Punch it with a NULL puncher (appears in Lua as a non-functional
	// ObjectRef)
	bool success = scriptIfaceNode->node_on_punch(pos, n, NULL, PointedThing());
	lua_pushboolean(L, success);
	return 1;
}

// get_node_max_level(pos)
// pos = {x=num, y=num, z=num}
int ModApiEnvMod::l_get_node_max_level(lua_State *L)
{
	GET_ENV_PTR;

	v3s16 pos = read_v3s16(L, 1);
	MapNode n = env->getMap().getNodeNoEx(pos);
	lua_pushnumber(L, n.getMaxLevel(env->getGameDef()->ndef()));
	return 1;
}

// get_node_level(pos)
// pos = {x=num, y=num, z=num}
int ModApiEnvMod::l_get_node_level(lua_State *L)
{
	GET_ENV_PTR;

	v3s16 pos = read_v3s16(L, 1);
	MapNode n = env->getMap().getNodeNoEx(pos);
	lua_pushnumber(L, n.getLevel(env->getGameDef()->ndef()));
	return 1;
}

// set_node_level(pos, level)
// pos = {x=num, y=num, z=num}
// level: 0..63
int ModApiEnvMod::l_set_node_level(lua_State *L)
{
	GET_ENV_PTR;

	v3s16 pos = read_v3s16(L, 1);
	u8 level = 1;
	if(lua_isnumber(L, 2))
		level = lua_tonumber(L, 2);
	MapNode n = env->getMap().getNodeNoEx(pos);
	lua_pushnumber(L, n.setLevel(env->getGameDef()->ndef(), level));
	env->setNode(pos, n);
	return 1;
}

// add_node_level(pos, level)
// pos = {x=num, y=num, z=num}
// level: 0..63
int ModApiEnvMod::l_add_node_level(lua_State *L)
{
	GET_ENV_PTR;

	v3s16 pos = read_v3s16(L, 1);
	u8 level = 1;
	if(lua_isnumber(L, 2))
		level = lua_tonumber(L, 2);
	MapNode n = env->getMap().getNodeNoEx(pos);
	lua_pushnumber(L, n.addLevel(env->getGameDef()->ndef(), level));
	env->setNode(pos, n);
	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)
{
	GET_ENV_PTR;

	// Do it
	v3s16 p = read_v3s16(L, 1);
	NodeMetaRef::create(L, p, env);
	return 1;
}

// get_node_timer(pos)
int ModApiEnvMod::l_get_node_timer(lua_State *L)
{
	GET_ENV_PTR;

	// Do it
	v3s16 p = read_v3s16(L, 1);
	NodeTimerRef::create(L, p, env);
	return 1;
}

// add_entity(pos, entityname) -> ObjectRef or nil
// pos = {x=num, y=num, z=num}
int ModApiEnvMod::l_add_entity(lua_State *L)
{
	GET_ENV_PTR;

	// pos
	v3f pos = checkFloatPos(L, 1);
	// content
	const char *name = luaL_checkstring(L, 2);
	// Do it
	ServerActiveObject *obj = new LuaEntitySAO(env, pos, name, "");
	int objectid = env->addActiveObject(obj);
	// If failed to add, return nothing (reads as nil)
	if(objectid == 0)
		return 0;
	// Return ObjectRef
	getScriptApiBase(L)->objectrefGetOrCreate(L, obj);
	return 1;
}

// add_item(pos, itemstack or itemstring or table) -> ObjectRef or nil
// pos = {x=num, y=num, z=num}
int ModApiEnvMod::l_add_item(lua_State *L)
{
	GET_ENV_PTR;

	// pos
	//v3f pos = checkFloatPos(L, 1);
	// item
	ItemStack item = read_item(L, 2,getServer(L));
	if(item.empty() || !item.isKnown(getServer(L)->idef()))
		return 0;

	int error_handler = PUSH_ERROR_HANDLER(L);

	// Use spawn_item to spawn a __builtin:item
	lua_getglobal(L, "core");
	lua_getfield(L, -1, "spawn_item");
	lua_remove(L, -2); // Remove core
	if(lua_isnil(L, -1))
		return 0;
	lua_pushvalue(L, 1);
	lua_pushstring(L, item.getItemString().c_str());

	PCALL_RESL(L, lua_pcall(L, 2, 1, error_handler));

	lua_remove(L, error_handler);
	return 1;
}

// get_player_by_name(name)
int ModApiEnvMod::l_get_player_by_name(lua_State *L)
{
	GET_ENV_PTR;

	// Do it
	const char *name = luaL_checkstring(L, 1);
	Player *player = env->getPlayer(name);
	if(player == NULL){
		lua_pushnil(L);
		return 1;
	}
	PlayerSAO *sao = player->getPlayerSAO();
	if(sao == NULL){
		lua_pushnil(L);
		return 1;
	}
	// Put player on stack
	getScriptApiBase(L)->objectrefGetOrCreate(L, sao);
	return 1;
}

// get_objects_inside_radius(pos, radius)
int ModApiEnvMod::l_get_objects_inside_radius(lua_State *L)
{
	GET_ENV_PTR;

	// Do it
	v3f pos = checkFloatPos(L, 1);
	float radius = luaL_checknumber(L, 2) * BS;
	std::vector<u16> ids;
	env->getObjectsInsideRadius(ids, pos, radius);
	ScriptApiBase *script = getScriptApiBase(L);
	lua_createtable(L, ids.size(), 0);
	std::vector<u16>::const_iterator iter = ids.begin();
	for(u32 i = 0; iter != ids.end(); iter++) {
		ServerActiveObject *obj = env->getActiveObject(*iter);
		// Insert object reference into table
		script->objectrefGetOrCreate(L, obj);
		lua_rawseti(L, -2, ++i);
	}
	return 1;
}

// set_timeofday(val)
// val = 0...1
int ModApiEnvMod::l_set_timeofday(lua_State *L)
{
	GET_ENV_PTR;

	// Do it
	float timeofday_f = luaL_checknumber(L, 1);
	sanity_check(timeofday_f >= 0.0 && timeofday_f <= 1.0);
	int timeofday_mh = (int)(timeofday_f * 24000.0);
	// This should be set directly in the environment but currently
	// such changes aren't immediately sent to the clients, so call
	// the server instead.
	//env->setTimeOfDay(timeofday_mh);
	getServer(L)->setTimeOfDay(timeofday_mh);
	return 0;
}

// get_timeofday() -> 0...1
int ModApiEnvMod::l_get_timeofday(lua_State *L)
{
	GET_ENV_PTR;

	// Do it
	int timeofday_mh = env->getTimeOfDay();
	float timeofday_f = (float)timeofday_mh / 24000.0;
	lua_pushnumber(L, timeofday_f);
	return 1;
}

// get_day_count() -> int
int ModApiEnvMod::l_get_day_count(lua_State *L)
{
	GET_ENV_PTR;

	lua_pushnumber(L, env->getDayCount());
	return 1;
}

// get_gametime()
int ModApiEnvMod::l_get_gametime(lua_State *L)
{
	GET_ENV_PTR;

	int game_time = env->getGameTime();
	lua_pushnumber(L, game_time);
	return 1;
}


// find_node_near(pos, radius, nodenames) -> pos or nil
// nodenames: eg. {"ignore", "group:tree"} or "default:dirt"
int ModApiEnvMod::l_find_node_near(lua_State *L)
{
	GET_ENV_PTR;

	INodeDefManager *ndef = getServer(L)->ndef();
	v3s16 pos = read_v3s16(L, 1);
	int radius = luaL_checkinteger(L, 2);
	std::set<content_t> filter;
	if(lua_istable(L, 3)){
		int table = 3;
		lua_pushnil(L);
		while(lua_next(L, table) != 0){
			// key at index -2 and value at index -1
			luaL_checktype(L, -1, LUA_TSTRING);
			ndef->getIds(lua_tostring(L, -1), filter);
			// removes value, keeps key for next iteration
			lua_pop(L, 1);
		}
	} else if(lua_isstring(L, 3)){
		ndef->getIds(lua_tostring(L, 3), filter);
	}

	for(int d=1; d<=radius; d++){
		std::vector<v3s16> list = FacePositionCache::getFacePositions(d);
		for(std::vector<v3s16>::iterator i = list.begin();
				i != list.end(); ++i){
			v3s16 p = pos + (*i);
			content_t c = env->getMap().getNodeNoEx(p).getContent();
			if(filter.count(c) != 0){
				push_v3s16(L, p);
				return 1;
			}
		}
	}
	return 0;
}

// find_nodes_in_area(minp, maxp, nodenames) -> list of positions
// nodenames: eg. {"ignore", "group:tree"} or "default:dirt"
int ModApiEnvMod::l_find_nodes_in_area(lua_State *L)
{
	GET_ENV_PTR;

	INodeDefManager *ndef = getServer(L)->ndef();
	v3s16 minp = read_v3s16(L, 1);
	v3s16 maxp = read_v3s16(L, 2);
	std::set<content_t> filter;
	if(lua_istable(L, 3)) {
		int table = 3;
		lua_pushnil(L);
		while(lua_next(L, table) != 0) {
			// key at index -2 and value at index -1
			luaL_checktype(L, -1, LUA_TSTRING);
			ndef->getIds(lua_tostring(L, -1), filter);
			// removes value, keeps key for next iteration
			lua_pop(L, 1);
		}
	} else if(lua_isstring(L, 3)) {
		ndef->getIds(lua_tostring(L, 3), filter);
	}

	std::map<content_t, u16> individual_count;

	lua_newtable(L);
	u64 i = 0;
	for (s16 x = minp.X; x <= maxp.X; x++)
		for (s16 y = minp.Y; y <= maxp.Y; y++)
			for (s16 z = minp.Z; z <= maxp.Z; z++) {
				v3s16 p(x, y, z);
				content_t c = env->getMap().getNodeNoEx(p).getContent();
				if (filter.count(c) != 0) {
					push_v3s16(L, p);
					lua_rawseti(L, -2, ++i);
					individual_count[c]++;
				}
	}
	lua_newtable(L);
	for (std::set<content_t>::iterator it = filter.begin();
			it != filter.end(); ++it) {
		lua_pushnumber(L, individual_count[*it]);
		lua_setfield(L, -2, ndef->get(*it).name.c_str());
	}
	return 2;
}

// find_nodes_in_area_under_air(minp, maxp, nodenames) -> list of positions
// nodenames: e.g. {"ignore", "group:tree"} or "default:dirt"
int ModApiEnvMod::l_find_nodes_in_area_under_air(lua_State *L)
{
	/* Note: A similar but generalized (and therefore slower) version of this
	 * function could be created -- e.g. find_nodes_in_area_under -- which
	 * would accept a node name (or ID?) or list of names that the "above node"
	 * should be.
	 * TODO
	 */

	GET_ENV_PTR;

	INodeDefManager *ndef = getServer(L)->ndef();
	v3s16 minp = read_v3s16(L, 1);
	v3s16 maxp = read_v3s16(L, 2);
	std::set<content_t> filter;

	if (lua_istable(L, 3)) {
		int table = 3;
		lua_pushnil(L);
		while(lua_next(L, table) != 0) {
			// key at index -2 and value at index -1
			luaL_checktype(L, -1, LUA_TSTRING);
			ndef->getIds(lua_tostring(L, -1), filter);
			// removes value, keeps key for next iteration
			lua_pop(L, 1);
		}
	} else if (lua_isstring(L, 3)) {
		ndef->getIds(lua_tostring(L, 3), filter);
	}

	lua_newtable(L);
	u64 i = 0;
	for (s16 x = minp.X; x <= maxp.X; x++)
	for (s16 z = minp.Z; z <= maxp.Z; z++) {
		s16 y = minp.Y;
		v3s16 p(x, y, z);
		content_t c = env->getMap().getNodeNoEx(p).getContent();
		for (; y <= maxp.Y; y++) {
			v3s16 psurf(x, y + 1, z);
			content_t csurf = env->getMap().getNodeNoEx(psurf).getContent();
			if(c != CONTENT_AIR && csurf == CONTENT_AIR &&
					filter.count(c) != 0) {
				push_v3s16(L, v3s16(x, y, z));
				lua_rawseti(L, -2, ++i);
			}
			c = csurf;
		}
	}
	return 1;
}

// get_perlin(seeddiff, octaves, persistence, scale)
// returns world-specific PerlinNoise
int ModApiEnvMod::l_get_perlin(lua_State *L)
{
	GET_ENV_PTR_NO_MAP_LOCK;

	NoiseParams params;

	if (lua_istable(L, 1)) {
		read_noiseparams(L, 1, &params);
	} else {
		params.seed    = luaL_checkint(L, 1);
		params.octaves = luaL_checkint(L, 2);
		params.persist = luaL_checknumber(L, 3);
		params.spread  = v3f(1, 1, 1) * luaL_checknumber(L, 4);
	}

	params.seed += (int)env->getServerMap().getSeed();

	LuaPerlinNoise *n = new LuaPerlinNoise(&params);
	*(void **)(lua_newuserdata(L, sizeof(void *))) = n;
	luaL_getmetatable(L, "PerlinNoise");
	lua_setmetatable(L, -2);
	return 1;
}

// get_perlin_map(noiseparams, size)
// returns world-specific PerlinNoiseMap
int ModApiEnvMod::l_get_perlin_map(lua_State *L)
{
	GET_ENV_PTR_NO_MAP_LOCK;

	NoiseParams np;
	if (!read_noiseparams(L, 1, &np))
		return 0;
	v3s16 size = read_v3s16(L, 2);

	int seed = (int)(env->getServerMap().getSeed());
	LuaPerlinNoiseMap *n = new LuaPerlinNoiseMap(&np, seed, size);
	*(void **)(lua_newuserdata(L, sizeof(void *))) = n;
	luaL_getmetatable(L, "PerlinNoiseMap");
	lua_setmetatable(L, -2);
	return 1;
}

// get_voxel_manip()
// returns voxel manipulator
int ModApiEnvMod::l_get_voxel_manip(lua_State *L)
{
	GET_ENV_PTR;

	Map *map = &(env->getMap());
	LuaVoxelManip *o = (lua_istable(L, 1) && lua_istable(L, 2)) ?
		new LuaVoxelManip(map, read_v3s16(L, 1), read_v3s16(L, 2)) :
		new LuaVoxelManip(map);

	*(void **)(lua_newuserdata(L, sizeof(void *))) = o;
	luaL_getmetatable(L, "VoxelManip");
	lua_setmetatable(L, -2);
	return 1;
}

// clear_objects([options])
// clear all objects in the environment
// where options = {mode = "full" or "quick"}
int ModApiEnvMod::l_clear_objects(lua_State *L)
{
	GET_ENV_PTR;

	ClearObjectsMode mode = CLEAR_OBJECTS_MODE_FULL;
	if (lua_istable(L, 1)) {
		mode = (ClearObjectsMode)getenumfield(L, 1, "mode",
			ModApiEnvMod::es_ClearObjectsMode, mode);
	}

	env->clearObjects(mode);
	return 0;
}

// line_of_sight(pos1, pos2, stepsize) -> true/false, pos
int ModApiEnvMod::l_line_of_sight(lua_State *L)
{
	float stepsize = 1.0;

	GET_ENV_PTR;

	// read position 1 from lua
	v3f pos1 = checkFloatPos(L, 1);
	// read position 2 from lua
	v3f pos2 = checkFloatPos(L, 2);
	//read step size from lua
	if (lua_isnumber(L, 3)) {
		stepsize = lua_tonumber(L, 3);
	}

	v3s16 p;
	bool success = env->line_of_sight(pos1, pos2, stepsize, &p);
	lua_pushboolean(L, success);
	if (!success) {
		push_v3s16(L, p);
		return 2;
	}
	return 1;
}

// emerge_area(p1, p2, [callback, context])
// emerge mapblocks in area p1..p2, calls callback with context upon completion
int ModApiEnvMod::l_emerge_area(lua_State *L)
{
	GET_ENV_PTR;

	EmergeCompletionCallback callback = NULL;
	ScriptCallbackState *state = NULL;

	EmergeManager *emerge = getServer(L)->getEmergeManager();

	v3s16 bpmin = getNodeBlockPos(read_v3s16(L, 1));
	v3s16 bpmax = getNodeBlockPos(read_v3s16(L, 2));
	sortBoxVerticies(bpmin, bpmax);

	size_t num_blocks = VoxelArea(bpmin, bpmax).getVolume();
	assert(num_blocks != 0);

	if (lua_isfunction(L, 3)) {
		callback = LuaEmergeAreaCallback;

		lua_pushvalue(L, 3);
		int callback_ref = luaL_ref(L, LUA_REGISTRYINDEX);

		lua_pushvalue(L, 4);
		int args_ref = luaL_ref(L, LUA_REGISTRYINDEX);

		state = new ScriptCallbackState;
		state->script       = getServer(L)->getScriptIface();
		state->callback_ref = callback_ref;
		state->args_ref     = args_ref;
		state->refcount     = num_blocks;
		state->origin       = getScriptApiBase(L)->getOrigin();
	}

	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++) {
		emerge->enqueueBlockEmergeEx(v3s16(x, y, z), PEER_ID_INEXISTENT,
			BLOCK_EMERGE_ALLOW_GEN | BLOCK_EMERGE_FORCE_QUEUE, callback, state);
	}

	return 0;
}

// delete_area(p1, p2)
// delete mapblocks in area p1..p2
int ModApiEnvMod::l_delete_area(lua_State *L)
{
	GET_ENV_PTR;

	v3s16 bpmin = getNodeBlockPos(read_v3s16(L, 1));
	v3s16 bpmax = getNodeBlockPos(read_v3s16(L, 2));
	sortBoxVerticies(bpmin, bpmax);

	ServerMap &map = env->getServerMap();

	MapEditEvent event;
	event.type = MEET_OTHER;

	bool success = true;
	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 bp(x, y, z);
		if (map.deleteBlock(bp)) {
			env->setStaticForActiveObjectsInBlock(bp, false);
			event.modified_blocks.insert(bp);
		} else {
			success = false;
		}
	}

	map.dispatchEvent(&event);
	lua_pushboolean(L, success);
	return 1;
}

// find_path(pos1, pos2, searchdistance,
//     max_jump, max_drop, algorithm) -> table containing path
int ModApiEnvMod::l_find_path(lua_State *L)
{
	GET_ENV_PTR;

	v3s16 pos1                  = read_v3s16(L, 1);
	v3s16 pos2                  = read_v3s16(L, 2);
	unsigned int searchdistance = luaL_checkint(L, 3);
	unsigned int max_jump       = luaL_checkint(L, 4);
	unsigned int max_drop       = luaL_checkint(L, 5);
	PathAlgorithm algo          = PA_PLAIN_NP;
	if (!lua_isnil(L, 6)) {
		std::string algorithm = luaL_checkstring(L,6);

		if (algorithm == "A*")
			algo = PA_PLAIN;

		if (algorithm == "Dijkstra")
			algo = PA_DIJKSTRA;
	}

	std::vector<v3s16> path = get_path(env, pos1, pos2,
		searchdistance, max_jump, max_drop, algo);

	if (path.size() > 0)
	{
		lua_newtable(L);
		int top = lua_gettop(L);
		unsigned int index = 1;
		for (std::vector<v3s16>::iterator i = path.begin(); i != path.end();i++)
		{
			lua_pushnumber(L,index);
			push_v3s16(L, *i);
			lua_settable(L, top);
			index++;
		}
		return 1;
	}

	return 0;
}

// spawn_tree(pos, treedef)
int ModApiEnvMod::l_spawn_tree(lua_State *L)
{
	GET_ENV_PTR;

	v3s16 p0 = read_v3s16(L, 1);

	treegen::TreeDef tree_def;
	std::string trunk,leaves,fruit;
	INodeDefManager *ndef = env->getGameDef()->ndef();

	if(lua_istable(L, 2))
	{
		getstringfield(L, 2, "axiom", tree_def.initial_axiom);
		getstringfield(L, 2, "rules_a", tree_def.rules_a);
		getstringfield(L, 2, "rules_b", tree_def.rules_b);
		getstringfield(L, 2, "rules_c", tree_def.rules_c);
		getstringfield(L, 2, "rules_d", tree_def.rules_d);
		getstringfield(L, 2, "trunk", trunk);
		tree_def.trunknode=ndef->getId(trunk);
		getstringfield(L, 2, "leaves", leaves);
		tree_def.leavesnode=ndef->getId(leaves);
		tree_def.leaves2_chance=0;
		getstringfield(L, 2, "leaves2", leaves);
		if (leaves !="")
		{
			tree_def.leaves2node=ndef->getId(leaves);
			getintfield(L, 2, "leaves2_chance", tree_def.leaves2_chance);
		}
		getintfield(L, 2, "angle", tree_def.angle);
		getintfield(L, 2, "iterations", tree_def.iterations);
		if (!getintfield(L, 2, "random_level", tree_def.iterations_random_level))
			tree_def.iterations_random_level = 0;
		getstringfield(L, 2, "trunk_type", tree_def.trunk_type);
		getboolfield(L, 2, "thin_branches", tree_def.thin_branches);
		tree_def.fruit_chance=0;
		getstringfield(L, 2, "fruit", fruit);
		if (fruit != "")
		{
			tree_def.fruitnode=ndef->getId(fruit);
			getintfield(L, 2, "fruit_chance",tree_def.fruit_chance);
		}
		tree_def.explicit_seed = getintfield(L, 2, "seed", tree_def.seed);
	}
	else
		return 0;

	treegen::error e;
	if ((e = treegen::spawn_ltree (env, p0, ndef, tree_def)) != treegen::SUCCESS) {
		if (e == treegen::UNBALANCED_BRACKETS) {
			luaL_error(L, "spawn_tree(): closing ']' has no matching opening bracket");
		} else {
			luaL_error(L, "spawn_tree(): unknown error");
		}
	}

	return 1;
}

// transforming_liquid_add(pos)
int ModApiEnvMod::l_transforming_liquid_add(lua_State *L)
{
	GET_ENV_PTR;

	v3s16 p0 = read_v3s16(L, 1);
	env->getMap().transforming_liquid_add(p0);
	return 1;
}

// forceload_block(blockpos)
// blockpos = {x=num, y=num, z=num}
int ModApiEnvMod::l_forceload_block(lua_State *L)
{
	GET_ENV_PTR;

	v3s16 blockpos = read_v3s16(L, 1);
	env->getForceloadedBlocks()->insert(blockpos);
	return 0;
}

// forceload_free_block(blockpos)
// blockpos = {x=num, y=num, z=num}
int ModApiEnvMod::l_forceload_free_block(lua_State *L)
{
	GET_ENV_PTR;

	v3s16 blockpos = read_v3s16(L, 1);
	env->getForceloadedBlocks()->erase(blockpos);
	return 0;
}

void ModApiEnvMod::Initialize(lua_State *L, int top)
{
	API_FCT(set_node);
	API_FCT(add_node);
	API_FCT(swap_node);
	API_FCT(add_item);
	API_FCT(remove_node);
	API_FCT(get_node);
	API_FCT(get_node_or_nil);
	API_FCT(get_node_light);
	API_FCT(place_node);
	API_FCT(dig_node);
	API_FCT(punch_node);
	API_FCT(get_node_max_level);
	API_FCT(get_node_level);
	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);
	API_FCT(get_objects_inside_radius);
	API_FCT(set_timeofday);
	API_FCT(get_timeofday);
	API_FCT(get_gametime);
	API_FCT(get_day_count);
	API_FCT(find_node_near);
	API_FCT(find_nodes_in_area);
	API_FCT(find_nodes_in_area_under_air);
	API_FCT(emerge_area);
	API_FCT(delete_area);
	API_FCT(get_perlin);
	API_FCT(get_perlin_map);
	API_FCT(get_voxel_manip);
	API_FCT(clear_objects);
	API_FCT(spawn_tree);
	API_FCT(find_path);
	API_FCT(line_of_sight);
	API_FCT(transforming_liquid_add);
	API_FCT(forceload_block);
	API_FCT(forceload_free_block);
}