Move files to subdirectories (#6599)

* Move files around

1 files changed, 882 insertions, 0 deletions

diff --git a/src/mapgen/cavegen.cpp b/src/mapgen/cavegen.cpp
new file mode 100644
index 000000000..e66634517
--- /dev/null
+++ b/src/mapgen/cavegen.cpp
@@ -0,0 +1,882 @@
+/*
+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);
+
+	const 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
+		bool is_top_filler_above = false;  // Is top or filler above node
+		// 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;
+				is_top_filler_above = false;
+				continue;
+			}
+
+			if (c == biome->c_river_water) {
+				column_is_open = true;
+				is_under_river = true;
+				is_top_filler_above = false;
+				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;
+				// If tunnel roof is top or filler, replace with stone
+				if (is_top_filler_above)
+					vm->m_data[vi + em.X] = MapNode(biome->c_stone);
+				is_top_filler_above = false;
+			} 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);
+						is_top_filler_above = true;
+						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);
+					is_top_filler_above = true;
+					nplaced++;
+				} else if (nplaced < base_filler) {
+					vm->m_data[vi] = MapNode(biome->c_filler);
+					is_top_filler_above = true;
+					nplaced++;
+				} else {
+					// Disable top/filler placement
+					column_is_open = false;
+					is_under_tunnel = false;
+				}
+			} else {
+				// Not tunnel or tunnel entrance floor
+				// Check node for possible replacing with stone for tunnel roof
+				if (c == biome->c_top || c == biome->c_filler)
+					is_top_filler_above = true;
+
+				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 near_cavern = false;
+	const 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 n_absamp_cavern = fabs(noise_cavern->result[index3d]) *
+				cavern_amp[cavern_amp_index];
+			// Disable CavesRandomWalk at a safe distance from caverns
+			// to avoid excessively spreading liquids in caverns.
+			if (n_absamp_cavern > m_cavern_threshold - 0.1f) {
+				near_cavern = true;
+				if (n_absamp_cavern > m_cavern_threshold &&
+						m_ndef->get(c).is_ground_content)
+					vm->m_data[vi] = MapNode(CONTENT_AIR);
+			}
+		}
+	}
+
+	delete[] cavern_amp;
+
+	return near_cavern;
+}
+
+
+////
+//// CavesRandomWalk
+////
+
+CavesRandomWalk::CavesRandomWalk(
+	INodeDefManager *ndef,
+	GenerateNotifier *gennotify,
+	s32 seed,
+	int water_level,
+	content_t water_source,
+	content_t lava_source,
+	int lava_depth)
+{
+	assert(ndef);
+
+	this->ndef           = ndef;
+	this->gennotify      = gennotify;
+	this->seed           = seed;
+	this->water_level    = water_level;
+	this->np_caveliquids = &nparams_caveliquids;
+	this->lava_depth     = 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))
+					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))
+					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];
+	}
+
+	return water_level;
+
+}