/*
Minetest-c55
Copyright (C) 2010-2011 celeron55, Perttu Ahola <celeron55@gmail.com>

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 "serverobject.h"
#include "content_sao.h"
#include "nodedef.h"
#include "content_mapnode.h" // For content_mapnode_get_new_name
#include "voxelalgorithms.h"
#include "profiler.h"
#include "settings.h" // For g_settings
#include "main.h" // For g_profiler
#include "mapgen_v6.h"

/////////////////// Mapgen V6 perlin noise default values
NoiseParams nparams_v6_def_terrain_base =
	{-AVERAGE_MUD_AMOUNT, 20.0, v3f(250.0, 250.0, 250.0), 82341, 5, 0.6};
NoiseParams nparams_v6_def_terrain_higher =
	{20.0, 16.0, v3f(500.0, 500.0, 500.0), 85039, 5, 0.6};
NoiseParams nparams_v6_def_steepness =
	{0.85, 0.5, v3f(125.0, 125.0, 125.0), -932, 5, 0.7};
NoiseParams nparams_v6_def_height_select =
	{0.5, 1.0, v3f(250.0, 250.0, 250.0), 4213, 5, 0.69};
NoiseParams nparams_v6_def_trees =
	{0.0, 1.0, v3f(125.0, 125.0, 125.0), 2, 4, 0.66};
NoiseParams nparams_v6_def_mud =
	{AVERAGE_MUD_AMOUNT, 2.0, v3f(200.0, 200.0, 200.0), 91013, 3, 0.55};
NoiseParams nparams_v6_def_beach =
	{0.0, 1.0, v3f(250.0, 250.0, 250.0), 59420, 3, 0.50};
NoiseParams nparams_v6_def_biome =
	{0.0, 1.0, v3f(250.0, 250.0, 250.0), 9130, 3, 0.50};
NoiseParams nparams_v6_def_cave =
	{6.0, 6.0, v3f(250.0, 250.0, 250.0), 34329, 3, 0.50};


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


MapgenV6::MapgenV6(int mapgenid, MapgenV6Params *params) {
	this->generating  = false;
	this->id       = mapgenid;

	this->seed     = (int)params->seed;
	this->water_level = params->water_level;
	this->flags   = params->flags;
	this->csize   = v3s16(1, 1, 1) * params->chunksize * MAP_BLOCKSIZE;

	this->freq_desert = params->freq_desert;
	this->freq_beach  = params->freq_beach;

	this->ystride = csize.X; //////fix this

	np_cave = params->np_cave;

	noise_terrain_base   = new Noise(params->np_terrain_base,   seed, csize.X, csize.Y);
	noise_terrain_higher = new Noise(params->np_terrain_higher, seed, csize.X, csize.Y);
	noise_steepness      = new Noise(params->np_steepness,      seed, csize.X, csize.Y);
	noise_height_select  = new Noise(params->np_height_select,  seed, csize.X, csize.Y);
	noise_trees          = new Noise(params->np_trees,          seed, csize.X, csize.Y);
	noise_mud            = new Noise(params->np_mud,            seed, csize.X, csize.Y);
	noise_beach          = new Noise(params->np_beach,          seed, csize.X, csize.Y);
	noise_biome          = new Noise(params->np_biome,          seed, csize.X, csize.Y);

	map_terrain_base   = noise_terrain_base->result;
	map_terrain_higher = noise_terrain_higher->result;
	map_steepness      = noise_steepness->result;
	map_height_select  = noise_height_select->result;
	map_trees          = noise_trees->result;
	map_mud            = noise_mud->result;
	map_beach          = noise_beach->result;
	map_biome          = noise_biome->result;
}


MapgenV6::~MapgenV6() {
	delete noise_terrain_base;
	delete noise_terrain_higher;
	delete noise_steepness;
	delete noise_height_select;
	delete noise_trees;
	delete noise_mud;
	delete noise_beach;
	delete noise_biome;
}


/*
	Some helper functions for the map generator
*/

#if 1
// Returns Y one under area minimum if not found
s16 MapgenV6::find_ground_level(VoxelManipulator &vmanip, v2s16 p2d,
		INodeDefManager *ndef)
{
	v3s16 em = vmanip.m_area.getExtent();
	s16 y_nodes_max = vmanip.m_area.MaxEdge.Y;
	s16 y_nodes_min = vmanip.m_area.MinEdge.Y;
	u32 i = vmanip.m_area.index(v3s16(p2d.X, y_nodes_max, p2d.Y));
	s16 y;
	for(y=y_nodes_max; y>=y_nodes_min; y--)
	{
		MapNode &n = vmanip.m_data[i];
		if(ndef->get(n).walkable)
			break;

		vmanip.m_area.add_y(em, i, -1);
	}
	if(y >= y_nodes_min)
		return y;
	else
		return y_nodes_min - 1;
}

// Returns Y one under area minimum if not found
s16 MapgenV6::find_stone_level(VoxelManipulator &vmanip, v2s16 p2d,
		INodeDefManager *ndef)
{
	v3s16 em = vmanip.m_area.getExtent();
	s16 y_nodes_max = vmanip.m_area.MaxEdge.Y;
	s16 y_nodes_min = vmanip.m_area.MinEdge.Y;
	u32 i = vmanip.m_area.index(v3s16(p2d.X, y_nodes_max, p2d.Y));
	s16 y;
	content_t c_stone = ndef->getId("mapgen_stone");
	content_t c_desert_stone = ndef->getId("mapgen_desert_stone");
	for(y=y_nodes_max; y>=y_nodes_min; y--)
	{
		MapNode &n = vmanip.m_data[i];
		content_t c = n.getContent();
		if(c != CONTENT_IGNORE && (
				c == c_stone || c == c_desert_stone))
			break;

		vmanip.m_area.add_y(em, i, -1);
	}
	if(y >= y_nodes_min)
		return y;
	else
		return y_nodes_min - 1;
}
#endif

void MapgenV6::make_tree(ManualMapVoxelManipulator &vmanip, v3s16 p0,
		bool is_apple_tree, INodeDefManager *ndef)
{
	MapNode treenode(ndef->getId("mapgen_tree"));
	MapNode leavesnode(ndef->getId("mapgen_leaves"));
	MapNode applenode(ndef->getId("mapgen_apple"));

	s16 trunk_h = myrand_range(4, 5);
	v3s16 p1 = p0;
	for(s16 ii=0; ii<trunk_h; ii++)
	{
		if(vmanip.m_area.contains(p1))
			vmanip.m_data[vmanip.m_area.index(p1)] = treenode;
		p1.Y++;
	}

	// p1 is now the last piece of the trunk
	p1.Y -= 1;

	VoxelArea leaves_a(v3s16(-2,-1,-2), v3s16(2,2,2));
	//SharedPtr<u8> leaves_d(new u8[leaves_a.getVolume()]);
	Buffer<u8> leaves_d(leaves_a.getVolume());
	for(s32 i=0; i<leaves_a.getVolume(); i++)
		leaves_d[i] = 0;

	// Force leaves at near the end of the trunk
	{
		s16 d = 1;
		for(s16 z=-d; z<=d; z++)
		for(s16 y=-d; y<=d; y++)
		for(s16 x=-d; x<=d; x++)
		{
			leaves_d[leaves_a.index(v3s16(x,y,z))] = 1;
		}
	}

	// Add leaves randomly
	for(u32 iii=0; iii<7; iii++)
	{
		s16 d = 1;

		v3s16 p(
			myrand_range(leaves_a.MinEdge.X, leaves_a.MaxEdge.X-d),
			myrand_range(leaves_a.MinEdge.Y, leaves_a.MaxEdge.Y-d),
			myrand_range(leaves_a.MinEdge.Z, leaves_a.MaxEdge.Z-d)
		);

		for(s16 z=0; z<=d; z++)
		for(s16 y=0; y<=d; y++)
		for(s16 x=0; x<=d; x++)
		{
			leaves_d[leaves_a.index(p+v3s16(x,y,z))] = 1;
		}
	}

	// Blit leaves to vmanip
	for(s16 z=leaves_a.MinEdge.Z; z<=leaves_a.MaxEdge.Z; z++)
	for(s16 y=leaves_a.MinEdge.Y; y<=leaves_a.MaxEdge.Y; y++)
	for(s16 x=leaves_a.MinEdge.X; x<=leaves_a.MaxEdge.X; x++)
	{
		v3s16 p(x,y,z);
		p += p1;
		if(vmanip.m_area.contains(p) == false)
			continue;
		u32 vi = vmanip.m_area.index(p);
		if(vmanip.m_data[vi].getContent() != CONTENT_AIR
				&& vmanip.m_data[vi].getContent() != CONTENT_IGNORE)
			continue;
		u32 i = leaves_a.index(x,y,z);
		if(leaves_d[i] == 1) {
			bool is_apple = myrand_range(0,99) < 10;
			if(is_apple_tree && is_apple) {
				vmanip.m_data[vi] = applenode;
			} else {
				vmanip.m_data[vi] = leavesnode;
			}
		}
	}
}


/*
	Noise functions. Make sure seed is mangled differently in each one.
*/


// Amount of trees per area in nodes
double MapgenV6::tree_amount_2d(u64 seed, v2s16 p)
{
	/*double noise = noise2d_perlin(
			0.5+(float)p.X/125, 0.5+(float)p.Y/125,
			seed+2, 4, 0.66);*/
	double noise = map_trees[(p.Y - node_min.Z) * ystride + (p.X - node_min.X)];
	double zeroval = -0.39;
	if(noise < zeroval)
		return 0;
	else
		return 0.04 * (noise-zeroval) / (1.0-zeroval);
}

// Required by mapgen.h
bool MapgenV6::block_is_underground(u64 seed, v3s16 blockpos)
{
	/*s16 minimum_groundlevel = (s16)get_sector_minimum_ground_level(
			seed, v2s16(blockpos.X, blockpos.Z));*/
	// Nah, this is just a heuristic, just return something
	s16 minimum_groundlevel = water_level;

	if(blockpos.Y*MAP_BLOCKSIZE + MAP_BLOCKSIZE <= minimum_groundlevel)
		return true;
	else
		return false;
}


double MapgenV6::base_rock_level_2d(u64 seed, v2s16 p)
{
	int index = (p.Y - node_min.Z) * ystride + (p.X - node_min.X);

	// The base ground level
	/*double base = (double)WATER_LEVEL - (double)AVERAGE_MUD_AMOUNT
			+ 20. * noise2d_perlin(
			0.5+(float)p.X/250., 0.5+(float)p.Y/250.,
			seed+82341, 5, 0.6);*/
	double base = water_level + map_terrain_base[index];

	// Higher ground level
	/*double higher = (double)WATER_LEVEL + 20. + 16. * noise2d_perlin(
			0.5+(float)p.X/500., 0.5+(float)p.Y/500.,
			seed+85039, 5, 0.6);*/
	double higher = water_level + map_terrain_higher[index];

	// Limit higher to at least base
	if(higher < base)
		higher = base;

	// Steepness factor of cliffs
	/*double b = 0.85 + 0.5 * noise2d_perlin(
			0.5+(float)p.X/125., 0.5+(float)p.Y/125.,
			seed-932, 5, 0.7);*/
	double b = map_steepness[index];
	b = rangelim(b, 0.0, 1000.0);
	b = pow(b, 7);
	b *= 5;
	b = rangelim(b, 0.5, 1000.0);

	// Values 1.5...100 give quite horrible looking slopes
	if(b > 1.5 && b < 100.0){
		if(b < 10.0)
			b = 1.5;
		else
			b = 100.0;
	}

	// Offset to more low
	double a_off = -0.20;

	// High/low selector
	/*double a = (double)0.5 + b * (a_off + noise2d_perlin(
			0.5+(float)p.X/250., 0.5+(float)p.Y/250.,
			seed+4213, 5, 0.69));*/
	double a = 0.5 + b * (a_off + map_height_select[index]);

	// Limit
	a = rangelim(a, 0.0, 1.0);

	double h = base*(1.0-a) + higher*a;

	return h;
}

double MapgenV6::baseRockLevelFromNoise(v2s16 p) {
	double base = water_level + 
		NoisePerlin2DPosOffset(noise_terrain_base->np, p.X, 0.5, p.Y, 0.5, seed);
	double higher = water_level +
		NoisePerlin2DPosOffset(noise_terrain_higher->np, p.X, 0.5, p.Y, 0.5, seed);

	if (higher < base)
		higher = base;

	double b = NoisePerlin2DPosOffset(noise_steepness->np, p.X, 0.5, p.Y, 0.5, seed);
	b = rangelim(b, 0.0, 1000.0);
	b = b*b*b*b*b*b*b;
	b *= 5;
	b = rangelim(b, 0.5, 1000.0);

	if(b > 1.5 && b < 100.0){
		if(b < 10.0)
			b = 1.5;
		else
			b = 100.0;
	}
	
	double a_off = -0.20;
	double a = 0.5 + b * (a_off + NoisePerlin2DNoTxfmPosOffset(
			noise_height_select->np, p.X, 0.5, p.Y, 0.5, seed));
	a = rangelim(a, 0.0, 1.0);

	return base * (1.0 - a) + higher * a;
}


s16 MapgenV6::find_ground_level_from_noise(u64 seed, v2s16 p2d, s16 precision)
{
	return baseRockLevelFromNoise(p2d) + AVERAGE_MUD_AMOUNT;
}

double MapgenV6::get_mud_add_amount(u64 seed, v2s16 p)
{
	/*return ((float)AVERAGE_MUD_AMOUNT + 2.0 * noise2d_perlin(
			0.5+(float)p.X/200, 0.5+(float)p.Y/200,
			seed+91013, 3, 0.55));*/
	int index = (p.Y - node_min.Z) * ystride + (p.X - node_min.X);
	return map_mud[index];
}

bool MapgenV6::get_have_beach(u64 seed, v2s16 p2d)
{
	// Determine whether to have sand here
	/*double sandnoise = noise2d_perlin(
			0.2+(float)p2d.X/250, 0.7+(float)p2d.Y/250,
			seed+59420, 3, 0.50);*/
	int index = (p2d.Y - node_min.Z) * ystride + (p2d.X - node_min.X);
	double sandnoise = map_beach[index];

	return (sandnoise > freq_beach);
}

BiomeType MapgenV6::get_biome(u64 seed, v2s16 p2d)
{
	// Just do something very simple as for now
	/*double d = noise2d_perlin(
			0.6+(float)p2d.X/250, 0.2+(float)p2d.Y/250,
			seed+9130, 3, 0.50);*/
	int index = (p2d.Y - node_min.Z) * ystride + (p2d.X - node_min.X);
	double d = map_biome[index];
	if(d > freq_desert)
		return BT_DESERT;
	if (flags & MGV6_BIOME_BLEND) {
		if(d > freq_desert - 0.10 &&
			 (noise2d(p2d.X, p2d.Y, seed) + 1.0) > (freq_desert - d) * 20.0)
			return BT_DESERT;
	}
	return BT_NORMAL;
};

u32 MapgenV6::get_blockseed(u64 seed, v3s16 p)
{
	s32 x=p.X, y=p.Y, z=p.Z;
	return (u32)(seed%0x100000000ULL) + z*38134234 + y*42123 + x*23;
}


int MapgenV6::getGroundLevelAtPoint(v2s16 p) {
	return baseRockLevelFromNoise(p) + AVERAGE_MUD_AMOUNT;
}

#define VMANIP_FLAG_CAVE VOXELFLAG_CHECKED1

void MapgenV6::makeChunk(BlockMakeData *data)
{
	if(data->no_op)
	{
		//dstream<<"makeBlock: no-op"<<std::endl;
		return;
	}

	this->generating = true;

	assert(data->vmanip);
	assert(data->nodedef);
	assert(data->blockpos_requested.X >= data->blockpos_min.X &&
			data->blockpos_requested.Y >= data->blockpos_min.Y &&
			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);

	INodeDefManager *ndef = data->nodedef;

	// Hack: use minimum block coordinates for old code that assumes
	// a single block
	v3s16 blockpos = data->blockpos_requested;

	/*dstream<<"makeBlock(): ("<<blockpos.X<<","<<blockpos.Y<<","
			<<blockpos.Z<<")"<<std::endl;*/

	v3s16 blockpos_min = data->blockpos_min;
	v3s16 blockpos_max = data->blockpos_max;
	v3s16 blockpos_full_min = blockpos_min - v3s16(1,1,1);
	v3s16 blockpos_full_max = blockpos_max + v3s16(1,1,1);

	ManualMapVoxelManipulator &vmanip = *(data->vmanip);
	// Area of central chunk
	node_min = blockpos_min*MAP_BLOCKSIZE;
	node_max = (blockpos_max+v3s16(1,1,1))*MAP_BLOCKSIZE-v3s16(1,1,1);
	// Full allocated area
	v3s16 full_node_min = (blockpos_min-1)*MAP_BLOCKSIZE;
	v3s16 full_node_max = (blockpos_max+2)*MAP_BLOCKSIZE-v3s16(1,1,1);

	v3s16 central_area_size = node_max - node_min + v3s16(1,1,1);

	const s16 max_spread_amount = MAP_BLOCKSIZE;

	int volume_blocks = (blockpos_max.X - blockpos_min.X + 1)
			* (blockpos_max.Y - blockpos_min.Y + 1)
			* (blockpos_max.Z - blockpos_max.Z + 1);

	int volume_nodes = volume_blocks *
			MAP_BLOCKSIZE*MAP_BLOCKSIZE*MAP_BLOCKSIZE;

	// Generated surface area
	//double gen_area_nodes = MAP_BLOCKSIZE*MAP_BLOCKSIZE * rel_volume;

	// Horribly wrong heuristic, but better than nothing
	bool block_is_underground = (water_level > node_max.Y);

	/*
		Create a block-specific seed
	*/
	u32 blockseed = get_blockseed(data->seed, full_node_min);

	/*
		Make some noise
	*/
	{
		int x = node_min.X;
		int z = node_min.Z;

		// Need to adjust for the original implementation's +.5 offset...
		noise_terrain_base->perlinMap2D(
			x + 0.5 * noise_terrain_base->np->spread.X,
			z + 0.5 * noise_terrain_base->np->spread.Z);
		noise_terrain_base->transformNoiseMap();

		noise_terrain_higher->perlinMap2D(
			x + 0.5 * noise_terrain_higher->np->spread.X,
			z + 0.5 * noise_terrain_higher->np->spread.Z);
		noise_terrain_higher->transformNoiseMap();

		noise_steepness->perlinMap2D(
			x + 0.5 * noise_steepness->np->spread.X,
			z + 0.5 * noise_steepness->np->spread.Z);
		noise_steepness->transformNoiseMap();

		noise_height_select->perlinMap2D(
			x + 0.5 * noise_height_select->np->spread.X,
			z + 0.5 * noise_height_select->np->spread.Z);

		noise_trees->perlinMap2D(
			x + 0.5 * noise_trees->np->spread.X,
			z + 0.5 * noise_trees->np->spread.Z);

		noise_mud->perlinMap2D(
			x + 0.5 * noise_mud->np->spread.X,
			z + 0.5 * noise_mud->np->spread.Z);
		noise_mud->transformNoiseMap();

		noise_beach->perlinMap2D(
			x + 0.2 * noise_beach->np->spread.X,
			z + 0.7 * noise_beach->np->spread.Z);

		noise_biome->perlinMap2D(
			x + 0.6 * noise_biome->np->spread.X,
			z + 0.2 * noise_biome->np->spread.Z);
	}


	/*
		Cache some ground type values for speed
	*/

// Creates variables c_name=id and n_name=node
#define CONTENT_VARIABLE(ndef, name)\
	content_t c_##name = ndef->getId("mapgen_" #name);\
	MapNode n_##name(c_##name);
// Default to something else if was CONTENT_IGNORE
#define CONTENT_VARIABLE_FALLBACK(name, dname)\
	if(c_##name == CONTENT_IGNORE){\
		c_##name = c_##dname;\
		n_##name = n_##dname;\
	}

	CONTENT_VARIABLE(ndef, stone);
	CONTENT_VARIABLE(ndef, air);
	CONTENT_VARIABLE(ndef, water_source);
	CONTENT_VARIABLE(ndef, dirt);
	CONTENT_VARIABLE(ndef, sand);
	CONTENT_VARIABLE(ndef, gravel);
	CONTENT_VARIABLE(ndef, clay);
	CONTENT_VARIABLE(ndef, lava_source);
	CONTENT_VARIABLE(ndef, cobble);
	CONTENT_VARIABLE(ndef, mossycobble);
	CONTENT_VARIABLE(ndef, dirt_with_grass);
	CONTENT_VARIABLE(ndef, junglegrass);
	CONTENT_VARIABLE(ndef, stone_with_coal);
	CONTENT_VARIABLE(ndef, stone_with_iron);
	CONTENT_VARIABLE(ndef, mese);
	CONTENT_VARIABLE(ndef, desert_sand);
	CONTENT_VARIABLE_FALLBACK(desert_sand, sand);
	CONTENT_VARIABLE(ndef, desert_stone);
	CONTENT_VARIABLE_FALLBACK(desert_stone, stone);

	// Maximum height of the stone surface and obstacles.
	// This is used to guide the cave generation
	s16 stone_surface_max_y = 0;

	/*
		Generate general ground level to full area
	*/
	{
#if 1
	TimeTaker timer1("Generating ground level");

	for(s16 x=node_min.X; x<=node_max.X; x++)
	for(s16 z=node_min.Z; z<=node_max.Z; z++)
	{
		// Node position
		v2s16 p2d = v2s16(x,z);

		/*
			Skip of already generated
		*/
		/*{
			v3s16 p(p2d.X, node_min.Y, p2d.Y);
			if(vmanip.m_data[vmanip.m_area.index(p)].d != CONTENT_AIR)
				continue;
		}*/

		// Ground height at this point
		float surface_y_f = 0.0;

		// Use perlin noise for ground height
		surface_y_f = base_rock_level_2d(data->seed, p2d);

		/*// Experimental stuff
		{
			float a = highlands_level_2d(data->seed, p2d);
			if(a > surface_y_f)
				surface_y_f = a;
		}*/

		// Convert to integer
		s16 surface_y = (s16)surface_y_f;

		// Log it
		if(surface_y > stone_surface_max_y)
			stone_surface_max_y = surface_y;

		BiomeType bt = get_biome(data->seed, p2d);
		/*
			Fill ground with stone
		*/
		{
			// Use fast index incrementing
			v3s16 em = vmanip.m_area.getExtent();
			u32 i = vmanip.m_area.index(v3s16(p2d.X, node_min.Y, p2d.Y));
			for(s16 y=node_min.Y; y<=node_max.Y; y++)
			{
				if(vmanip.m_data[i].getContent() == CONTENT_IGNORE){
					if(y <= surface_y){
						if(y > water_level && bt == BT_DESERT)
							vmanip.m_data[i] = n_desert_stone;
						else
							vmanip.m_data[i] = n_stone;
					} else if(y <= water_level){
						vmanip.m_data[i] = MapNode(c_water_source);
					} else {
						vmanip.m_data[i] = MapNode(c_air);
					}
				}
				vmanip.m_area.add_y(em, i, 1);
			}
		}
	}
#endif

	}//timer1

	// Limit dirt flow area by 1 because mud is flown into neighbors.
	assert(central_area_size.X == central_area_size.Z);
	s16 mudflow_minpos = 0-max_spread_amount+1;
	s16 mudflow_maxpos = central_area_size.X+max_spread_amount-2;

	/*
		Loop this part, it will make stuff look older and newer nicely
	*/

	/*double cave_amount = 6.0 + 6.0 * noise2d_perlin(
			0.5+(double)node_min.X/250, 0.5+(double)node_min.Y/250,
			data->seed+34329, 3, 0.50);*/

	double cave_amount = NoisePerlin2D(np_cave, node_min.X, node_min.Y, data->seed);

	const u32 age_loops = 2;
	for(u32 i_age=0; i_age<age_loops; i_age++)
	{ // Aging loop
	/******************************
		BEGINNING OF AGING LOOP
	******************************/

#if 1
	{
	// 24ms @cs=8
	//TimeTaker timer1("caves");

	/*
		Make caves (this code is relatively horrible)
	*/
	cave_amount = MYMAX(0.0, cave_amount);
	u32 caves_count = cave_amount * volume_nodes / 50000;
	u32 bruises_count = 1;
	PseudoRandom ps(blockseed+21343);
	PseudoRandom ps2(blockseed+1032);
	if(ps.range(1, 6) == 1)
		bruises_count = ps.range(0, ps.range(0, 2));
	if(get_biome(data->seed, v2s16(node_min.X, node_min.Z)) == BT_DESERT){
		caves_count /= 3;
		bruises_count /= 3;
	}
	for(u32 jj=0; jj<caves_count+bruises_count; jj++)
	{
		if (!(flags & MG_CAVES))
			continue;

		/*int avg_height = (int)
			  ((base_rock_level_2d(data->seed, v2s16(node_min.X, node_min.Z)) +
				base_rock_level_2d(data->seed, v2s16(node_max.X, node_max.Z))) / 2);
		if ((node_max.Y + node_min.Y) / 2 > avg_height)
			break;*/

		bool large_cave = (jj >= caves_count);
		s16 min_tunnel_diameter = 2;
		s16 max_tunnel_diameter = ps.range(2,6);
		int dswitchint = ps.range(1,14);
		u16 tunnel_routepoints = 0;
		int part_max_length_rs = 0;
		if(large_cave){
			part_max_length_rs = ps.range(2,4);
			tunnel_routepoints = ps.range(5, ps.range(15,30));
			min_tunnel_diameter = 5;
			max_tunnel_diameter = ps.range(7, ps.range(8,24));
		} else {
			part_max_length_rs = ps.range(2,9);
			tunnel_routepoints = ps.range(10, ps.range(15,30));
		}
		bool large_cave_is_flat = (ps.range(0,1) == 0);

		v3f main_direction(0,0,0);

		// Allowed route area size in nodes
		v3s16 ar = central_area_size;

		// Area starting point in nodes
		v3s16 of = node_min;

		// Allow a bit more
		//(this should be more than the maximum radius of the tunnel)
		s16 insure = 10;
		s16 more = max_spread_amount - max_tunnel_diameter/2 - insure;
		ar += v3s16(1,0,1) * more * 2;
		of -= v3s16(1,0,1) * more;

		s16 route_y_min = 0;
		// Allow half a diameter + 7 over stone surface
		s16 route_y_max = -of.Y + stone_surface_max_y + max_tunnel_diameter/2 + 7;

		// Limit maximum to area
		route_y_max = rangelim(route_y_max, 0, ar.Y-1);

		if(large_cave)
		{
			s16 min = 0;
			if(node_min.Y < water_level && node_max.Y > water_level)
			{
				min = water_level - max_tunnel_diameter/3 - of.Y;
				route_y_max = water_level + max_tunnel_diameter/3 - of.Y;
			}
			route_y_min = ps.range(min, min + max_tunnel_diameter);
			route_y_min = rangelim(route_y_min, 0, route_y_max);
		}

		s16 route_start_y_min = route_y_min;
		s16 route_start_y_max = route_y_max;

		route_start_y_min = rangelim(route_start_y_min, 0, ar.Y-1);
		route_start_y_max = rangelim(route_start_y_max, route_start_y_min, ar.Y-1);

		// Randomize starting position
		v3f orp(
			(float)(ps.next()%ar.X)+0.5,
			(float)(ps.range(route_start_y_min, route_start_y_max))+0.5,
			(float)(ps.next()%ar.Z)+0.5
		);

		v3s16 startp(orp.X, orp.Y, orp.Z);
		startp += of;

		MapNode airnode(CONTENT_AIR);
		MapNode waternode(c_water_source);
		MapNode lavanode(c_lava_source);

		/*
			Generate some tunnel starting from orp
		*/

		for(u16 j=0; j<tunnel_routepoints; j++)
		{
			if(j%dswitchint==0 && large_cave == false)
			{
				main_direction = v3f(
					((float)(ps.next()%20)-(float)10)/10,
					((float)(ps.next()%20)-(float)10)/30,
					((float)(ps.next()%20)-(float)10)/10
				);
				main_direction *= (float)ps.range(0, 10)/10;
			}

			// Randomize size
			s16 min_d = min_tunnel_diameter;
			s16 max_d = max_tunnel_diameter;
			s16 rs = ps.range(min_d, max_d);

			// Every second section is rough
			bool randomize_xz = (ps2.range(1,2) == 1);

			v3s16 maxlen;
			if(large_cave)
			{
				maxlen = v3s16(
					rs*part_max_length_rs,
					rs*part_max_length_rs/2,
					rs*part_max_length_rs
				);
			}
			else
			{
				maxlen = v3s16(
					rs*part_max_length_rs,
					ps.range(1, rs*part_max_length_rs),
					rs*part_max_length_rs
				);
			}

			v3f vec;

			vec = v3f(
				(float)(ps.next()%(maxlen.X*1))-(float)maxlen.X/2,
				(float)(ps.next()%(maxlen.Y*1))-(float)maxlen.Y/2,
				(float)(ps.next()%(maxlen.Z*1))-(float)maxlen.Z/2
			);

			// Jump downward sometimes
			if(!large_cave && ps.range(0,12) == 0)
			{
				vec = v3f(
					(float)(ps.next()%(maxlen.X*1))-(float)maxlen.X/2,
					(float)(ps.next()%(maxlen.Y*2))-(float)maxlen.Y*2/2,
					(float)(ps.next()%(maxlen.Z*1))-(float)maxlen.Z/2
				);
			}

			/*if(large_cave){
				v3f p = orp + vec;
				s16 h = find_ground_level_clever(vmanip,
						v2s16(p.X, p.Z), ndef);
				route_y_min = h - rs/3;
				route_y_max = h + rs;
			}*/

			vec += main_direction;

			v3f rp = orp + vec;
			if(rp.X < 0)
				rp.X = 0;
			else if(rp.X >= ar.X)
				rp.X = ar.X-1;
			if(rp.Y < route_y_min)
				rp.Y = route_y_min;
			else if(rp.Y >= route_y_max)
				rp.Y = route_y_max-1;
			if(rp.Z < 0)
				rp.Z = 0;
			else if(rp.Z >= ar.Z)
				rp.Z = ar.Z-1;
			vec = rp - orp;

			for(float f=0; f<1.0; f+=1.0/vec.getLength())
			{
				v3f fp = orp + vec * f;
				fp.X += 0.1*ps.range(-10,10);
				fp.Z += 0.1*ps.range(-10,10);
				v3s16 cp(fp.X, fp.Y, fp.Z);

				s16 d0 = -rs/2;
				s16 d1 = d0 + rs;
				if(randomize_xz){
					d0 += ps.range(-1,1);
					d1 += ps.range(-1,1);
				}
				for(s16 z0=d0; z0<=d1; z0++)
				{
					s16 si = rs/2 - MYMAX(0, abs(z0)-rs/7-1);
					for(s16 x0=-si-ps.range(0,1); x0<=si-1+ps.range(0,1); x0++)
					{
						s16 maxabsxz = MYMAX(abs(x0), abs(z0));
						s16 si2 = rs/2 - MYMAX(0, maxabsxz-rs/7-1);
						for(s16 y0=-si2; y0<=si2; y0++)
						{
							/*// Make better floors in small caves
							if(y0 <= -rs/2 && rs<=7)
								continue;*/
							if(large_cave_is_flat){
								// Make large caves not so tall
								if(rs > 7 && abs(y0) >= rs/3)
									continue;
							}

							s16 z = cp.Z + z0;
							s16 y = cp.Y + y0;
							s16 x = cp.X + x0;
							v3s16 p(x,y,z);
							p += of;

							if(vmanip.m_area.contains(p) == false)
								continue;

							u32 i = vmanip.m_area.index(p);

							if(large_cave)
							{
								if(full_node_min.Y < water_level &&
									full_node_max.Y > water_level){
									if(p.Y <= water_level)
										vmanip.m_data[i] = waternode;
									else
										vmanip.m_data[i] = airnode;
								} else if(full_node_max.Y < water_level){
									if(p.Y < startp.Y - 2)
										vmanip.m_data[i] = lavanode;
									else
										vmanip.m_data[i] = airnode;
								} else {
									vmanip.m_data[i] = airnode;
								}
							} else {
								// Don't replace air or water or lava or ignore
								if(vmanip.m_data[i].getContent() == CONTENT_IGNORE ||
								vmanip.m_data[i].getContent() == CONTENT_AIR ||
								vmanip.m_data[i].getContent() == c_water_source ||
								vmanip.m_data[i].getContent() == c_lava_source)
									continue;

								vmanip.m_data[i] = airnode;

								// Set tunnel flag
								vmanip.m_flags[i] |= VMANIP_FLAG_CAVE;
							}
						}
					}
				}
			}

			orp = rp;
		}

	}

	}//timer1
#endif

#if 1
	{
	// 15ms @cs=8
	TimeTaker timer1("add mud");

	/*
		Add mud to the central chunk
	*/

	for(s16 x=node_min.X; x<=node_max.X; x++)
	for(s16 z=node_min.Z; z<=node_max.Z; z++)
	{
		// Node position in 2d
		v2s16 p2d = v2s16(x,z);

		// Randomize mud amount
		s16 mud_add_amount = get_mud_add_amount(data->seed, p2d) / 2.0 + 0.5;

		// Find ground level
		s16 surface_y = find_stone_level(vmanip, p2d, ndef);
		// Handle area not found
		if(surface_y == vmanip.m_area.MinEdge.Y - 1)
			continue;

		MapNode addnode(c_dirt);
		BiomeType bt = get_biome(data->seed, p2d);

		if(bt == BT_DESERT)
			addnode = MapNode(c_desert_sand);

		if(bt == BT_DESERT && surface_y + mud_add_amount <= water_level+1){
			addnode = MapNode(c_sand);
		} else if(mud_add_amount <= 0){
			mud_add_amount = 1 - mud_add_amount;
			addnode = MapNode(c_gravel);
		} else if(bt == BT_NORMAL && get_have_beach(data->seed, p2d) &&
				surface_y + mud_add_amount <= water_level+2){
			addnode = MapNode(c_sand);
		}

		if(bt == BT_DESERT){
			if(surface_y > 20){
				mud_add_amount = MYMAX(0, mud_add_amount - (surface_y - 20)/5);
			}
		}

		/*
			If topmost node is grass, change it to mud.
			It might be if it was flown to there from a neighboring
			chunk and then converted.
		*/
		{
			u32 i = vmanip.m_area.index(v3s16(p2d.X, surface_y, p2d.Y));
			MapNode *n = &vmanip.m_data[i];
			if(n->getContent() == c_dirt_with_grass)
				*n = MapNode(c_dirt);
		}

		/*
			Add mud on ground
		*/
		{
			s16 mudcount = 0;
			v3s16 em = vmanip.m_area.getExtent();
			s16 y_start = surface_y+1;
			u32 i = vmanip.m_area.index(v3s16(p2d.X, y_start, p2d.Y));
			for(s16 y=y_start; y<=node_max.Y; y++)
			{
				if(mudcount >= mud_add_amount)
					break;

				MapNode &n = vmanip.m_data[i];
				n = addnode;
				mudcount++;

				vmanip.m_area.add_y(em, i, 1);
			}
		}

	}

	}//timer1
#endif

	/*
		Add blobs of dirt and gravel underground
	*/
	if(get_biome(data->seed, v2s16(node_min.X, node_min.Z)) == BT_NORMAL)
	{
	PseudoRandom pr(blockseed+983);
	for(int i=0; i<volume_nodes/10/10/10; i++)
	{
		bool only_fill_cave = (myrand_range(0,1) != 0);
		v3s16 size(
			pr.range(1, 8),
			pr.range(1, 8),
			pr.range(1, 8)
		);
		v3s16 p0(
			pr.range(node_min.X, node_max.X)-size.X/2,
			pr.range(node_min.Y, node_max.Y)-size.Y/2,
			pr.range(node_min.Z, node_max.Z)-size.Z/2
		);
		MapNode n1;
		if(p0.Y > -32 && pr.range(0,1) == 0)
			n1 = MapNode(c_dirt);
		else
			n1 = MapNode(c_gravel);
		for(int x1=0; x1<size.X; x1++)
		for(int y1=0; y1<size.Y; y1++)
		for(int z1=0; z1<size.Z; z1++)
		{
			v3s16 p = p0 + v3s16(x1,y1,z1);
			u32 i = vmanip.m_area.index(p);
			if(!vmanip.m_area.contains(i))
				continue;
			// Cancel if not stone and not cave air
			if(vmanip.m_data[i].getContent() != c_stone &&
					!(vmanip.m_flags[i] & VMANIP_FLAG_CAVE))
				continue;
			if(only_fill_cave && !(vmanip.m_flags[i] & VMANIP_FLAG_CAVE))
				continue;
			vmanip.m_data[i] = n1;
		}
	}
	}

#if 1
	{
	// 340ms @cs=8
	TimeTaker timer1("flow mud");

	/*
		Flow mud away from steep edges
	*/

	// Iterate a few times
	for(s16 k=0; k<3; k++)
	{

	for(s16 x=mudflow_minpos; x<=mudflow_maxpos; x++)
	for(s16 z=mudflow_minpos; z<=mudflow_maxpos; z++)
	{
		// Invert coordinates every 2nd iteration
		if(k%2 == 0)
		{
			x = mudflow_maxpos - (x-mudflow_minpos);
			z = mudflow_maxpos - (z-mudflow_minpos);
		}

		// Node position in 2d
		v2s16 p2d = v2s16(node_min.X, node_min.Z) + v2s16(x,z);

		v3s16 em = vmanip.m_area.getExtent();
		u32 i = vmanip.m_area.index(v3s16(p2d.X, node_max.Y, p2d.Y));
		s16 y=node_max.Y;

		while(y >= node_min.Y)
		{

		for(;; y--)
		{
			MapNode *n = NULL;
			// Find mud
			for(; y>=node_min.Y; y--)
			{
				n = &vmanip.m_data[i];
				//if(content_walkable(n->d))
				//	break;
				if(n->getContent() == c_dirt ||
						n->getContent() == c_dirt_with_grass ||
						n->getContent() == c_gravel)
					break;

				vmanip.m_area.add_y(em, i, -1);
			}

			// Stop if out of area
			//if(vmanip.m_area.contains(i) == false)
			if(y < node_min.Y)
				break;

			/*// If not mud, do nothing to it
			MapNode *n = &vmanip.m_data[i];
			if(n->d != CONTENT_MUD && n->d != CONTENT_GRASS)
				continue;*/

			if(n->getContent() == c_dirt ||
					n->getContent() == c_dirt_with_grass)
			{
				// Make it exactly mud
				n->setContent(c_dirt);

				/*
					Don't flow it if the stuff under it is not mud
				*/
				{
					u32 i2 = i;
					vmanip.m_area.add_y(em, i2, -1);
					// Cancel if out of area
					if(vmanip.m_area.contains(i2) == false)
						continue;
					MapNode *n2 = &vmanip.m_data[i2];
					if(n2->getContent() != c_dirt &&
							n2->getContent() != c_dirt_with_grass)
						continue;
				}
			}

			/*s16 recurse_count = 0;
	mudflow_recurse:*/

			v3s16 dirs4[4] = {
				v3s16(0,0,1), // back
				v3s16(1,0,0), // right
				v3s16(0,0,-1), // front
				v3s16(-1,0,0), // left
			};

			// Theck that upper is air or doesn't exist.
			// Cancel dropping if upper keeps it in place
			u32 i3 = i;
			vmanip.m_area.add_y(em, i3, 1);
			if(vmanip.m_area.contains(i3) == true
					&& ndef->get(vmanip.m_data[i3]).walkable)
			{
				continue;
			}

			// Drop mud on side

			for(u32 di=0; di<4; di++)
			{
				v3s16 dirp = dirs4[di];
				u32 i2 = i;
				// Move to side
				vmanip.m_area.add_p(em, i2, dirp);
				// Fail if out of area
				if(vmanip.m_area.contains(i2) == false)
					continue;
				// Check that side is air
				MapNode *n2 = &vmanip.m_data[i2];
				if(ndef->get(*n2).walkable)
					continue;
				// Check that under side is air
				vmanip.m_area.add_y(em, i2, -1);
				if(vmanip.m_area.contains(i2) == false)
					continue;
				n2 = &vmanip.m_data[i2];
				if(ndef->get(*n2).walkable)
					continue;
				/*// Check that under that is air (need a drop of 2)
				vmanip.m_area.add_y(em, i2, -1);
				if(vmanip.m_area.contains(i2) == false)
					continue;
				n2 = &vmanip.m_data[i2];
				if(content_walkable(n2->d))
					continue;*/
				// Loop further down until not air
				bool dropped_to_unknown = false;
				do{
					vmanip.m_area.add_y(em, i2, -1);
					n2 = &vmanip.m_data[i2];
					// if out of known area
					if(vmanip.m_area.contains(i2) == false
							|| n2->getContent() == CONTENT_IGNORE){
						dropped_to_unknown = true;
						break;
					}
				}while(ndef->get(*n2).walkable == false);
				// Loop one up so that we're in air
				vmanip.m_area.add_y(em, i2, 1);
				n2 = &vmanip.m_data[i2];

				bool old_is_water = (n->getContent() == c_water_source);
				// Move mud to new place
				if(!dropped_to_unknown) {
					*n2 = *n;
					// Set old place to be air (or water)
					if(old_is_water)
						*n = MapNode(c_water_source);
					else
						*n = MapNode(CONTENT_AIR);
				}

				// Done
				break;
			}
		}
		}
	}

	}

	}//timer1
#endif

	} // Aging loop
	/***********************
		END OF AGING LOOP
	************************/

	/*
		Add top and bottom side of water to transforming_liquid queue
	*/

	for(s16 x=full_node_min.X; x<=full_node_max.X; x++)
	for(s16 z=full_node_min.Z; z<=full_node_max.Z; z++)
	{
		// Node position
		v2s16 p2d(x,z);
		{
			bool water_found = false;
			// Use fast index incrementing
			v3s16 em = vmanip.m_area.getExtent();
			u32 i = vmanip.m_area.index(v3s16(p2d.X, full_node_max.Y, p2d.Y));
			for(s16 y=full_node_max.Y; y>=full_node_min.Y; y--)
			{
				if(y == full_node_max.Y){
					water_found =
						(vmanip.m_data[i].getContent() == c_water_source ||
						vmanip.m_data[i].getContent() == c_lava_source);
				}
				else if(water_found == false)
				{
					if(vmanip.m_data[i].getContent() == c_water_source ||
							vmanip.m_data[i].getContent() == c_lava_source)
					{
						v3s16 p = v3s16(p2d.X, y, p2d.Y);
						data->transforming_liquid.push_back(p);
						water_found = true;
					}
				}
				else
				{
					// This can be done because water_found can only
					// turn to true and end up here after going through
					// a single block.
					if(vmanip.m_data[i+1].getContent() != c_water_source ||
							vmanip.m_data[i+1].getContent() != c_lava_source)
					{
						v3s16 p = v3s16(p2d.X, y+1, p2d.Y);
						data->transforming_liquid.push_back(p);
						water_found = false;
					}
				}

				vmanip.m_area.add_y(em, i, -1);
			}
		}
	}

	/*
		Grow grass
	*/

	for(s16 x=full_node_min.X; x<=full_node_max.X; x++)
	for(s16 z=full_node_min.Z; z<=full_node_max.Z; z++)
	{
		// Node position in 2d
		v2s16 p2d = v2s16(x,z);

		/*
			Find the lowest surface to which enough light ends up
			to make grass grow.

			Basically just wait until not air and not leaves.
		*/
		s16 surface_y = 0;
		{
			v3s16 em = vmanip.m_area.getExtent();
			u32 i = vmanip.m_area.index(v3s16(p2d.X, node_max.Y, p2d.Y));
			s16 y;
			// Go to ground level
			for(y=node_max.Y; y>=full_node_min.Y; y--)
			{
				MapNode &n = vmanip.m_data[i];
				if(ndef->get(n).param_type != CPT_LIGHT
						|| ndef->get(n).liquid_type != LIQUID_NONE)
					break;
				vmanip.m_area.add_y(em, i, -1);
			}
			if(y >= full_node_min.Y)
				surface_y = y;
			else
				surface_y = full_node_min.Y;
		}

		u32 i = vmanip.m_area.index(p2d.X, surface_y, p2d.Y);
		MapNode *n = &vmanip.m_data[i];
		if(n->getContent() == c_dirt){
			// Well yeah, this can't be overground...
			if(surface_y < water_level - 20)
				continue;
			n->setContent(c_dirt_with_grass);
		}
	}

	/*
		Generate some trees
	*/
	assert(central_area_size.X == central_area_size.Z);
	if (flags & MG_TREES) {
		// Divide area into parts
		s16 div = 8;
		s16 sidelen = central_area_size.X / div;
		double area = sidelen * sidelen;
		for(s16 x0=0; x0<div; x0++)
		for(s16 z0=0; z0<div; z0++)
		{
			// Center position of part of division
			v2s16 p2d_center(
				node_min.X + sidelen/2 + sidelen*x0,
				node_min.Z + sidelen/2 + sidelen*z0
			);
			// Minimum edge of part of division
			v2s16 p2d_min(
				node_min.X + sidelen*x0,
				node_min.Z + sidelen*z0
			);
			// Maximum edge of part of division
			v2s16 p2d_max(
				node_min.X + sidelen + sidelen*x0 - 1,
				node_min.Z + sidelen + sidelen*z0 - 1
			);
			// Amount of trees
			u32 tree_count = area * tree_amount_2d(data->seed, p2d_center);
			// Put trees in random places on part of division
			for(u32 i=0; i<tree_count; i++)
			{
				s16 x = myrand_range(p2d_min.X, p2d_max.X);
				s16 z = myrand_range(p2d_min.Y, p2d_max.Y);
				s16 y = find_ground_level(vmanip, v2s16(x,z), ndef);
				// Don't make a tree under water level
				if(y < water_level)
					continue;
				// Don't make a tree so high that it doesn't fit
				if(y > node_max.Y - 6)
					continue;
				v3s16 p(x,y,z);
				/*
					Trees grow only on mud and grass
				*/
				{
					u32 i = vmanip.m_area.index(v3s16(p));
					MapNode *n = &vmanip.m_data[i];
					if(n->getContent() != c_dirt
							&& n->getContent() != c_dirt_with_grass)
						continue;
				}
				p.Y++;
				// Make a tree
				make_tree(vmanip, p, false, ndef);
			}
		}
	}


	/*
		Calculate lighting
	*/
	{
	ScopeProfiler sp(g_profiler, "EmergeThread: mapgen lighting update",
			SPT_AVG);
	//VoxelArea a(node_min, node_max);
	VoxelArea a(node_min-v3s16(1,0,1)*MAP_BLOCKSIZE,
			node_max+v3s16(1,0,1)*MAP_BLOCKSIZE);
	/*VoxelArea a(node_min-v3s16(1,0,1)*MAP_BLOCKSIZE/2,
			node_max+v3s16(1,0,1)*MAP_BLOCKSIZE/2);*/
	enum LightBank banks[2] = {LIGHTBANK_DAY, LIGHTBANK_NIGHT};
	for(int i=0; i<2; i++)
	{
		enum LightBank bank = banks[i];

		core::map<v3s16, bool> light_sources;
		core::map<v3s16, u8> unlight_from;

		voxalgo::clearLightAndCollectSources(vmanip, a, bank, ndef,
				light_sources, unlight_from);

		bool inexistent_top_provides_sunlight = !block_is_underground;
		voxalgo::SunlightPropagateResult res = voxalgo::propagateSunlight(
				vmanip, a, inexistent_top_provides_sunlight,
				light_sources, ndef);
		// TODO: Do stuff according to bottom_sunlight_valid

		vmanip.unspreadLight(bank, unlight_from, light_sources, ndef);

		vmanip.spreadLight(bank, light_sources, ndef);
	}
	}
}