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path: root/src/voxel.cpp
Commit message (Collapse)AuthorAge
* Remove some old dead code. Fix some Clang warnings in SRP (ng->N... willLoic Blot2015-07-24
| | | | always evaluate to true.
* Optimise MapBlockMesh related functionsgregorycu2015-02-23
| | | | | | | | | Directely or indirectly optimises the following functions: * MapBlockMesh::MapBlockMesh * MapBlockMesh::getTileInfo * MapBlockMesh::makeFastFace * MapBlockMesh::getSmoothLightCombined
* Create empty default constructor for MapNodeCraig Robbins2015-01-18
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* Add VoxelArea::hasEmptyExtentunknown2015-01-13
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* VoxelManipulator: Remove unnecessary deallocation stepskwolekr2014-12-27
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* Large increase in performanceCraig Robbins2014-12-24
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* Use std::string::empty() instead of size() where applicableAnton2014-12-12
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* Optimise VoxelManipulator::copyFromCraig Robbins2014-12-04
| | | | | | ~3-4x faster This indirectly optimises MapBlock:copyTo() which in turn improves performance of MeshMakeData::fill()
* Optimise functions from CNodeDefManager and VoxelManipulatorCraig Robbins2014-11-21
| | | | | CNodeDefManager::get() VoxelManipulator::addArea()
* Remove emerge and speedup addArea by using memcopy instead of one by one ↵sapier2014-06-23
| | | | assignment
* Use memset for flag initialization (compiler optimization is way better)sapier2014-06-23
| | | | use temp variables instead of recalculating array index
* Omnicleanup: header cleanup, add ModApiUtil shared between game and mainmenuKahrl2013-08-14
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* Fix nearly all warningskwolekr2013-05-19
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* Migrate to STL containers/algorithms.Ilya Zhuravlev2013-03-11
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* Fix most walled-off caveskwolekr2013-02-25
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* Update Copyright YearsSfan52013-02-24
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* Change Minetest-c55 to MinetestPilzAdam2013-02-24
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* Properly and efficiently use split utility headersPerttu Ahola2012-06-17
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* Switch the license to be LGPLv2/later, with small parts still remaining as ↵Perttu Ahola2012-06-05
| | | | GPLv2/later, by agreement of major contributors
* Implement propagateSunlight for VoxelManipulatorPerttu Ahola2012-03-27
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* Optimize lighting by a tiny bitPerttu Ahola2011-11-29
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* GameDef compilesPerttu Ahola2011-11-29
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* extended content-type rangePerttu Ahola2011-07-23
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* Moved some mapnode content stuff from mapnode.{h,cpp} and digging property ↵Perttu Ahola2011-06-17
| | | | stuff from material.cpp to content_mapnode.{h,cpp}
* partly working chunk-based map generator (doesn't save properly, spawn is ↵Perttu Ahola2011-02-01
| | | | pretty random)
* map generation framework under development... not quite operational at this ↵Perttu Ahola2011-01-30
| | | | point.
* Reworked texture, material, mineral and whatever handlingPerttu Ahola2011-01-26
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* removed alternative name "pressure" from param2Perttu Ahola2011-01-25
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* Faster lighting at map generation timePerttu Ahola2011-01-24
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* commented out old water stuffPerttu Ahola2011-01-24
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* old water removed, some fixes here and therePerttu Ahola2011-01-17
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* working goodPerttu Ahola2010-12-26
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* some work-in-progressPerttu Ahola2010-12-22
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* organizing stuff.Perttu Ahola2010-12-21
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* framework for modifying texturesPerttu Ahola2010-12-20
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* day/night working client sidePerttu Ahola2010-12-19
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* before daynight mesh cachePerttu Ahola2010-12-18
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* little fixesPerttu Ahola2010-12-14
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* working nicelyPerttu Ahola2010-12-13
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* starting to separate "material" to "content" and "tile"Perttu Ahola2010-12-12
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* removed accidental double flowWaterPerttu Ahola2010-12-11
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* commit before some radicallish changes to water behaviorPerttu Ahola2010-12-11
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* some work-in-progress water stuffPerttu Ahola2010-12-01
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* license stuffPerttu Ahola2010-11-29
| | | | | --HG-- rename : src/licensecomment.txt => licensecomment.txt
* vokselijuttu lisättyPerttu Ahola2010-11-29
'#n689'>689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861
/*
Minetest
Copyright (C) 2010-2013 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 "util/numeric.h"
#include "map.h"
#include "mapgen.h"
#include "mapgen_v5.h"
#include "mapgen_v6.h"
#include "mapgen_v7.h"
#include "mg_biome.h"
#include "cavegen.h"

static NoiseParams nparams_caveliquids(0, 1, v3f(150.0, 150.0, 150.0), 776, 3, 0.6, 2.0);


////
//// CavesNoiseIntersection
////

CavesNoiseIntersection::CavesNoiseIntersection(
	INodeDefManager *nodedef, BiomeManager *biomemgr, v3s16 chunksize,
	NoiseParams *np_cave1, NoiseParams *np_cave2, s32 seed, float cave_width)
{
	assert(nodedef);
	assert(biomemgr);

	m_ndef = nodedef;
	m_bmgr = biomemgr;

	m_csize = chunksize;
	m_cave_width = cave_width;

	m_ystride    = m_csize.X;
	m_zstride_1d = m_csize.X * (m_csize.Y + 1);

	// Noises are created using 1-down overgeneration
	// A Nx-by-1-by-Nz-sized plane is at the bottom of the desired for
	// re-carving the solid overtop placed for blocking sunlight
	noise_cave1 = new Noise(np_cave1, seed, m_csize.X, m_csize.Y + 1, m_csize.Z);
	noise_cave2 = new Noise(np_cave2, seed, m_csize.X, m_csize.Y + 1, m_csize.Z);
}


CavesNoiseIntersection::~CavesNoiseIntersection()
{
	delete noise_cave1;
	delete noise_cave2;
}


void CavesNoiseIntersection::generateCaves(MMVManip *vm,
	v3s16 nmin, v3s16 nmax, u8 *biomemap)
{
	assert(vm);
	assert(biomemap);

	noise_cave1->perlinMap3D(nmin.X, nmin.Y - 1, nmin.Z);
	noise_cave2->perlinMap3D(nmin.X, nmin.Y - 1, nmin.Z);

	v3s16 em = vm->m_area.getExtent();
	u32 index2d = 0;  // Biomemap index

	for (s16 z = nmin.Z; z <= nmax.Z; z++)
	for (s16 x = nmin.X; x <= nmax.X; x++, index2d++) {
		bool column_is_open = false;  // Is column open to overground
		bool is_under_river = false;  // Is column under river water
		bool is_under_tunnel = false;  // Is tunnel or is under tunnel
		// Indexes at column top
		u32 vi = vm->m_area.index(x, nmax.Y, z);
		u32 index3d = (z - nmin.Z) * m_zstride_1d + m_csize.Y * m_ystride +
			(x - nmin.X);  // 3D noise index
		// Biome of column
		Biome *biome = (Biome *)m_bmgr->getRaw(biomemap[index2d]);
		u16 depth_top = biome->depth_top;
		u16 base_filler = depth_top + biome->depth_filler;
		u16 depth_riverbed = biome->depth_riverbed;
		u16 nplaced = 0;
		// Don't excavate the overgenerated stone at nmax.Y + 1,
		// this creates a 'roof' over the tunnel, preventing light in
		// tunnels at mapchunk borders when generating mapchunks upwards.
		// This 'roof' is removed when the mapchunk above is generated.
		for (s16 y = nmax.Y; y >= nmin.Y - 1; y--,
				index3d -= m_ystride,
				vm->m_area.add_y(em, vi, -1)) {

			content_t c = vm->m_data[vi].getContent();
			if (c == CONTENT_AIR || c == biome->c_water_top ||
					c == biome->c_water) {
				column_is_open = true;
				continue;
			} else if (c == biome->c_river_water) {
				column_is_open = true;
				is_under_river = true;
				continue;
			}
			// Ground
			float d1 = contour(noise_cave1->result[index3d]);
			float d2 = contour(noise_cave2->result[index3d]);

			if (d1 * d2 > m_cave_width && m_ndef->get(c).is_ground_content) {
				// In tunnel and ground content, excavate
				vm->m_data[vi] = MapNode(CONTENT_AIR);
				is_under_tunnel = true;
			} else if (column_is_open && is_under_tunnel &&
					(c == biome->c_stone || c == biome->c_filler)) {
				// Tunnel entrance floor, place biome surface nodes
				if (is_under_river) {
					if (nplaced < depth_riverbed) {
						vm->m_data[vi] = MapNode(biome->c_riverbed);
						nplaced++;
					} else {
						// Disable top/filler placement
						column_is_open = false;
						is_under_river = false;
						is_under_tunnel = false;
					}
				} else if (nplaced < depth_top) {
					vm->m_data[vi] = MapNode(biome->c_top);
					nplaced++;
				} else if (nplaced < base_filler) {
					vm->m_data[vi] = MapNode(biome->c_filler);
					nplaced++;
				} else {
					// Disable top/filler placement
					column_is_open = false;
					is_under_tunnel = false;
				}
			} else {
				// Not tunnel or tunnel entrance floor
				column_is_open = false;
			}
		}
	}
}


////
//// CavernsNoise
////

CavernsNoise::CavernsNoise(
	INodeDefManager *nodedef, v3s16 chunksize, NoiseParams *np_cavern,
	s32 seed, float cavern_limit, float cavern_taper, float cavern_threshold)
{
	assert(nodedef);

	m_ndef = nodedef;

	m_csize = chunksize;
	m_cavern_limit     = cavern_limit;
	m_cavern_taper     = cavern_taper;
	m_cavern_threshold = cavern_threshold;

	m_ystride = m_csize.X;
	m_zstride_1d = m_csize.X * (m_csize.Y + 1);

	// Noise is created using 1-down overgeneration
	// A Nx-by-1-by-Nz-sized plane is at the bottom of the desired for
	// re-carving the solid overtop placed for blocking sunlight
	noise_cavern = new Noise(np_cavern, seed, m_csize.X, m_csize.Y + 1, m_csize.Z);

	c_water_source = m_ndef->getId("mapgen_water_source");
	if (c_water_source == CONTENT_IGNORE)
		c_water_source = CONTENT_AIR;

	c_lava_source = m_ndef->getId("mapgen_lava_source");
	if (c_lava_source == CONTENT_IGNORE)
		c_lava_source = CONTENT_AIR;
}


CavernsNoise::~CavernsNoise()
{
	delete noise_cavern;
}


bool CavernsNoise::generateCaverns(MMVManip *vm, v3s16 nmin, v3s16 nmax)
{
	assert(vm);

	// Calculate noise
	noise_cavern->perlinMap3D(nmin.X, nmin.Y - 1, nmin.Z);

	// Cache cavern_amp values
	float *cavern_amp = new float[m_csize.Y + 1];
	u8 cavern_amp_index = 0;  // Index zero at column top
	for (s16 y = nmax.Y; y >= nmin.Y - 1; y--, cavern_amp_index++) {
		cavern_amp[cavern_amp_index] =
			MYMIN((m_cavern_limit - y) / (float)m_cavern_taper, 1.0f);
	}

	//// Place nodes
	bool has_cavern = false;
	v3s16 em = vm->m_area.getExtent();
	u32 index2d = 0;

	for (s16 z = nmin.Z; z <= nmax.Z; z++)
	for (s16 x = nmin.X; x <= nmax.X; x++, index2d++) {
		// Reset cave_amp index to column top
		cavern_amp_index = 0;
		// Initial voxelmanip index at column top
		u32 vi = vm->m_area.index(x, nmax.Y, z);
		// Initial 3D noise index at column top
		u32 index3d = (z - nmin.Z) * m_zstride_1d + m_csize.Y * m_ystride +
			(x - nmin.X);
		// Don't excavate the overgenerated stone at node_max.Y + 1,
		// this creates a 'roof' over the cavern, preventing light in
		// caverns at mapchunk borders when generating mapchunks upwards.
		// This 'roof' is excavated when the mapchunk above is generated.
		for (s16 y = nmax.Y; y >= nmin.Y - 1; y--,
				index3d -= m_ystride,
				vm->m_area.add_y(em, vi, -1),
				cavern_amp_index++) {
			content_t c = vm->m_data[vi].getContent();
			float nabs_cavern = fabs(noise_cavern->result[index3d]);
			// Caverns generate first but still remove lava and water in case
			// of overgenerated classic caves.
			if (nabs_cavern * cavern_amp[cavern_amp_index] > m_cavern_threshold &&
					(m_ndef->get(c).is_ground_content ||
					c == c_lava_source || c == c_water_source)) {
				vm->m_data[vi] = MapNode(CONTENT_AIR);
				has_cavern = true;
			}
		}
	}

	delete[] cavern_amp;
	return has_cavern;
}


////
//// CavesRandomWalk
////

CavesRandomWalk::CavesRandomWalk(
	INodeDefManager *ndef,
	GenerateNotifier *gennotify,
	s32 seed,
	int water_level,
	content_t water_source,
	content_t lava_source)
{
	assert(ndef);

	this->ndef           = ndef;
	this->gennotify      = gennotify;
	this->seed           = seed;
	this->water_level    = water_level;
	this->np_caveliquids = &nparams_caveliquids;
	this->lava_depth     = DEFAULT_LAVA_DEPTH;

	c_water_source = water_source;
	if (c_water_source == CONTENT_IGNORE)
		c_water_source = ndef->getId("mapgen_water_source");
	if (c_water_source == CONTENT_IGNORE)
		c_water_source = CONTENT_AIR;

	c_lava_source = lava_source;
	if (c_lava_source == CONTENT_IGNORE)
		c_lava_source = ndef->getId("mapgen_lava_source");
	if (c_lava_source == CONTENT_IGNORE)
		c_lava_source = CONTENT_AIR;
}


void CavesRandomWalk::makeCave(MMVManip *vm, v3s16 nmin, v3s16 nmax,
	PseudoRandom *ps, bool is_large_cave, int max_stone_height, s16 *heightmap)
{
	assert(vm);
	assert(ps);

	this->vm         = vm;
	this->ps         = ps;
	this->node_min   = nmin;
	this->node_max   = nmax;
	this->heightmap  = heightmap;
	this->large_cave = is_large_cave;

	this->ystride = nmax.X - nmin.X + 1;

	// Set initial parameters from randomness
	int dswitchint = ps->range(1, 14);
	flooded = ps->range(1, 2) == 2;

	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));
		min_tunnel_diameter = 2;
		max_tunnel_diameter = ps->range(2, 6);
	}

	large_cave_is_flat = (ps->range(0, 1) == 0);

	main_direction = v3f(0, 0, 0);

	// Allowed route area size in nodes
	ar = node_max - node_min + v3s16(1, 1, 1);
	// Area starting point in nodes
	of = node_min;

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

	route_y_min = 0;
	// Allow half a diameter + 7 over stone surface
	route_y_max = -of.Y + max_stone_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 minpos = 0;
		if (node_min.Y < water_level && node_max.Y > water_level) {
			minpos = water_level - max_tunnel_diameter / 3 - of.Y;
			route_y_max = water_level + max_tunnel_diameter / 3 - of.Y;
		}
		route_y_min = ps->range(minpos, minpos + 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
	orp.Z = (float)(ps->next() % ar.Z) + 0.5f;
	orp.Y = (float)(ps->range(route_start_y_min, route_start_y_max)) + 0.5f;
	orp.X = (float)(ps->next() % ar.X) + 0.5f;

	// Add generation notify begin event
	if (gennotify) {
		v3s16 abs_pos(of.X + orp.X, of.Y + orp.Y, of.Z + orp.Z);
		GenNotifyType notifytype = large_cave ?
			GENNOTIFY_LARGECAVE_BEGIN : GENNOTIFY_CAVE_BEGIN;
		gennotify->addEvent(notifytype, abs_pos);
	}

	// Generate some tunnel starting from orp
	for (u16 j = 0; j < tunnel_routepoints; j++)
		makeTunnel(j % dswitchint == 0);

	// Add generation notify end event
	if (gennotify) {
		v3s16 abs_pos(of.X + orp.X, of.Y + orp.Y, of.Z + orp.Z);
		GenNotifyType notifytype = large_cave ?
			GENNOTIFY_LARGECAVE_END : GENNOTIFY_CAVE_END;
		gennotify->addEvent(notifytype, abs_pos);
	}
}


void CavesRandomWalk::makeTunnel(bool dirswitch)
{
	if (dirswitch && !large_cave) {
		main_direction.Z = ((float)(ps->next() % 20) - (float)10) / 10;
		main_direction.Y = ((float)(ps->next() % 20) - (float)10) / 30;
		main_direction.X = ((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;
	rs = ps->range(min_d, max_d);
	s16 rs_part_max_length_rs = rs * part_max_length_rs;

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

	// Do not make caves that are above ground.
	// It is only necessary to check the startpoint and endpoint.
	v3s16 p1 = v3s16(orp.X, orp.Y, orp.Z) + of + rs / 2;
	v3s16 p2 = v3s16(vec.X, vec.Y, vec.Z) + p1;
	if (isPosAboveSurface(p1) || isPosAboveSurface(p2))
		return;

	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;

	float veclen = vec.getLength();
	if (veclen < 0.05f)
		veclen = 1.0f;

	// Every second section is rough
	bool randomize_xz = (ps->range(1, 2) == 1);

	// Carve routes
	for (float f = 0.f; f < 1.0f; f += 1.0f / veclen)
		carveRoute(vec, f, randomize_xz);

	orp = rp;
}


void CavesRandomWalk::carveRoute(v3f vec, float f, bool randomize_xz)
{
	MapNode airnode(CONTENT_AIR);
	MapNode waternode(c_water_source);
	MapNode lavanode(c_lava_source);

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

	float nval = NoisePerlin3D(np_caveliquids, startp.X,
		startp.Y, startp.Z, seed);
	MapNode liquidnode = (nval < 0.40f && node_max.Y < lava_depth) ?
		lavanode : waternode;

	v3f fp = orp + vec * f;
	fp.X += 0.1f * ps->range(-10, 10);
	fp.Z += 0.1f * 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);
	}

	bool flat_cave_floor = !large_cave && ps->range(0, 2) == 2;

	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 (flat_cave_floor && 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;
				}

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

				if (vm->m_area.contains(p) == false)
					continue;

				u32 i = vm->m_area.index(p);
				content_t c = vm->m_data[i].getContent();
				if (!ndef->get(c).is_ground_content)
					continue;

				if (large_cave) {
					int full_ymin = node_min.Y - MAP_BLOCKSIZE;
					int full_ymax = node_max.Y + MAP_BLOCKSIZE;

					if (flooded && full_ymin < water_level && full_ymax > water_level)
						vm->m_data[i] = (p.Y <= water_level) ? waternode : airnode;
					else if (flooded && full_ymax < water_level)
						vm->m_data[i] = (p.Y < startp.Y - 4) ? liquidnode : airnode;
					else
						vm->m_data[i] = airnode;
				} else {
					if (c == CONTENT_IGNORE)
						continue;

					vm->m_data[i] = airnode;
					vm->m_flags[i] |= VMANIP_FLAG_CAVE;
				}
			}
		}
	}
}


inline bool CavesRandomWalk::isPosAboveSurface(v3s16 p)
{
	if (heightmap != NULL &&
			p.Z >= node_min.Z && p.Z <= node_max.Z &&
			p.X >= node_min.X && p.X <= node_max.X) {
		u32 index = (p.Z - node_min.Z) * ystride + (p.X - node_min.X);
		if (heightmap[index] < p.Y)
			return true;
	} else if (p.Y > water_level) {
		return true;
	}

	return false;
}


////
//// CavesV6
////

CavesV6::CavesV6(INodeDefManager *ndef, GenerateNotifier *gennotify,
	int water_level, content_t water_source, content_t lava_source)
{
	assert(ndef);

	this->ndef        = ndef;
	this->gennotify   = gennotify;
	this->water_level = water_level;

	c_water_source = water_source;
	if (c_water_source == CONTENT_IGNORE)
		c_water_source = ndef->getId("mapgen_water_source");
	if (c_water_source == CONTENT_IGNORE)
		c_water_source = CONTENT_AIR;

	c_lava_source = lava_source;
	if (c_lava_source == CONTENT_IGNORE)
		c_lava_source = ndef->getId("mapgen_lava_source");
	if (c_lava_source == CONTENT_IGNORE)
		c_lava_source = CONTENT_AIR;
}


void CavesV6::makeCave(MMVManip *vm, v3s16 nmin, v3s16 nmax,
	PseudoRandom *ps, PseudoRandom *ps2,
	bool is_large_cave, int max_stone_height, s16 *heightmap)
{
	assert(vm);
	assert(ps);
	assert(ps2);

	this->vm         = vm;
	this->ps         = ps;
	this->ps2        = ps2;
	this->node_min   = nmin;
	this->node_max   = nmax;
	this->heightmap  = heightmap;
	this->large_cave = is_large_cave;

	this->ystride = nmax.X - nmin.X + 1;

	// Set initial parameters from randomness
	min_tunnel_diameter = 2;
	max_tunnel_diameter = ps->range(2, 6);
	int dswitchint      = ps->range(1, 14);
	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));
	}
	large_cave_is_flat = (ps->range(0, 1) == 0);

	main_direction = v3f(0, 0, 0);

	// Allowed route area size in nodes
	ar = node_max - node_min + v3s16(1, 1, 1);
	// Area starting point in nodes
	of = node_min;

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

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

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

	if (large_cave) {
		s16 minpos = 0;
		if (node_min.Y < water_level && node_max.Y > water_level) {
			minpos = water_level - max_tunnel_diameter / 3 - of.Y;
			route_y_max = water_level + max_tunnel_diameter / 3 - of.Y;
		}
		route_y_min = ps->range(minpos, minpos + 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
	orp.Z = (float)(ps->next() % ar.Z) + 0.5f;
	orp.Y = (float)(ps->range(route_start_y_min, route_start_y_max)) + 0.5f;
	orp.X = (float)(ps->next() % ar.X) + 0.5f;

	// Add generation notify begin event
	if (gennotify != NULL) {
		v3s16 abs_pos(of.X + orp.X, of.Y + orp.Y, of.Z + orp.Z);
		GenNotifyType notifytype = large_cave ?
			GENNOTIFY_LARGECAVE_BEGIN : GENNOTIFY_CAVE_BEGIN;
		gennotify->addEvent(notifytype, abs_pos);
	}

	// Generate some tunnel starting from orp
	for (u16 j = 0; j < tunnel_routepoints; j++)
		makeTunnel(j % dswitchint == 0);

	// Add generation notify end event
	if (gennotify != NULL) {
		v3s16 abs_pos(of.X + orp.X, of.Y + orp.Y, of.Z + orp.Z);
		GenNotifyType notifytype = large_cave ?
			GENNOTIFY_LARGECAVE_END : GENNOTIFY_CAVE_END;
		gennotify->addEvent(notifytype, abs_pos);
	}
}


void CavesV6::makeTunnel(bool dirswitch)
{
	if (dirswitch && !large_cave) {
		main_direction.Z = ((float)(ps->next() % 20) - (float)10) / 10;
		main_direction.Y = ((float)(ps->next() % 20) - (float)10) / 30;
		main_direction.X = ((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;
	rs = ps->range(min_d, max_d);
	s16 rs_part_max_length_rs = rs * part_max_length_rs;

	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.Z = (float)(ps->next() % maxlen.Z) - (float)maxlen.Z / 2;
	vec.Y = (float)(ps->next() % maxlen.Y) - (float)maxlen.Y / 2;
	vec.X = (float)(ps->next() % maxlen.X) - (float)maxlen.X / 2;

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

	// Do not make caves that are entirely above ground, to fix shadow bugs
	// caused by overgenerated large caves.
	// It is only necessary to check the startpoint and endpoint.
	v3s16 p1 = v3s16(orp.X, orp.Y, orp.Z) + of + rs / 2;
	v3s16 p2 = v3s16(vec.X, vec.Y, vec.Z) + p1;

	// If startpoint and endpoint are above ground, disable placement of nodes
	// in carveRoute while still running all PseudoRandom calls to ensure caves
	// are consistent with existing worlds.
	bool tunnel_above_ground =
		p1.Y > getSurfaceFromHeightmap(p1) &&
		p2.Y > getSurfaceFromHeightmap(p2);

	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;

	float veclen = vec.getLength();
	// As odd as it sounds, veclen is *exactly* 0.0 sometimes, causing a FPE
	if (veclen < 0.05f)
		veclen = 1.0f;

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

	// Carve routes
	for (float f = 0.f; f < 1.0f; f += 1.0f / veclen)
		carveRoute(vec, f, randomize_xz, tunnel_above_ground);

	orp = rp;
}


void CavesV6::carveRoute(v3f vec, float f, bool randomize_xz,
	bool tunnel_above_ground)
{
	MapNode airnode(CONTENT_AIR);
	MapNode waternode(c_water_source);
	MapNode lavanode(c_lava_source);

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

	v3f fp = orp + vec * f;
	fp.X += 0.1f * ps->range(-10, 10);
	fp.Z += 0.1f * 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++) {
			if (tunnel_above_ground)
				continue;

			s16 maxabsxz = MYMAX(abs(x0), abs(z0));
			s16 si2 = rs / 2 - MYMAX(0, maxabsxz - rs / 7 - 1);
			for (s16 y0 = -si2; y0 <= si2; y0++) {
				if (large_cave_is_flat) {
					// Make large caves not so tall
					if (rs > 7 && abs(y0) >= rs / 3)
						continue;
				}

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

				if (vm->m_area.contains(p) == false)
					continue;

				u32 i = vm->m_area.index(p);
				content_t c = vm->m_data[i].getContent();
				if (!ndef->get(c).is_ground_content)
					continue;

				if (large_cave) {
					int full_ymin = node_min.Y - MAP_BLOCKSIZE;
					int full_ymax = node_max.Y + MAP_BLOCKSIZE;

					if (full_ymin < water_level && full_ymax > water_level) {
						vm->m_data[i] = (p.Y <= water_level) ? waternode : airnode;
					} else if (full_ymax < water_level) {
						vm->m_data[i] = (p.Y < startp.Y - 2) ? lavanode : airnode;
					} else {
						vm->m_data[i] = airnode;
					}
				} else {
					if (c == CONTENT_IGNORE || c == CONTENT_AIR)
						continue;

					vm->m_data[i] = airnode;
					vm->m_flags[i] |= VMANIP_FLAG_CAVE;
				}
			}
		}
	}
}


inline s16 CavesV6::getSurfaceFromHeightmap(v3s16 p)
{
	if (heightmap != NULL &&
			p.Z >= node_min.Z && p.Z <= node_max.Z &&
			p.X >= node_min.X && p.X <= node_max.X) {
		u32 index = (p.Z - node_min.Z) * ystride + (p.X - node_min.X);
		return heightmap[index];
	} else {
		return water_level;
	}
}