Fractal mapgen: Add seabed and large pseudorandom caves

src/cavegen.cpp

@@ -23,6 +23,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mapgen_v5.h"
 #include "mapgen_v6.h"
 #include "mapgen_v7.h"
+#include "mapgen_fractal.h"
 #include "cavegen.h"
 
 NoiseParams nparams_caveliquids(0, 1, v3f(150.0, 150.0, 150.0), 776, 3, 0.6, 2.0);
@@ -807,3 +808,247 @@ void CaveV7::carveRoute(v3f vec, float f, bool randomize_xz)
 		}
 	}
 }
+
+
+///////////////////////////////////////// Caves Fractal
+
+
+CaveFractal::CaveFractal(MapgenFractal *mg, PseudoRandom *ps)
+{
+	this->mg             = mg;
+	this->vm             = mg->vm;
+	this->ndef           = mg->ndef;
+	this->water_level    = mg->water_level;
+	this->ps             = ps;
+	this->c_water_source = mg->c_water_source;
+	this->c_lava_source  = mg->c_lava_source;
+	this->c_ice          = mg->c_ice;
+	this->np_caveliquids = &nparams_caveliquids;
+
+	dswitchint = ps->range(1, 14);
+	flooded    = ps->range(1, 2) == 2;
+
+	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));
+
+	large_cave_is_flat = (ps->range(0, 1) == 0);
+}
+
+
+void CaveFractal::makeCave(v3s16 nmin, v3s16 nmax, int max_stone_height)
+{
+	node_min = nmin;
+	node_max = nmax;
+	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)
+	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);
+
+	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
+	orp = v3f(
+		(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
+	);
+
+	// Add generation notify begin event
+	v3s16 abs_pos(of.X + orp.X, of.Y + orp.Y, of.Z + orp.Z);
+	GenNotifyType notifytype = GENNOTIFY_LARGECAVE_BEGIN;
+	mg->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
+	abs_pos = v3s16(of.X + orp.X, of.Y + orp.Y, of.Z + orp.Z);
+	notifytype = GENNOTIFY_LARGECAVE_END;
+	mg->gennotify.addEvent(notifytype, abs_pos);
+}
+
+
+void CaveFractal::makeTunnel(bool dirswitch)
+{
+	// 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;
+	maxlen = v3s16(
+		rs_part_max_length_rs,
+		rs_part_max_length_rs / 2,
+		rs_part_max_length_rs
+	);
+
+	v3f vec;
+	// Jump downward sometimes
+	vec = v3f(
+		(float)(ps->next() % maxlen.X) - (float)maxlen.X / 2,
+		(float)(ps->next() % maxlen.Y) - (float)maxlen.Y / 2,
+		(float)(ps->next() % maxlen.Z) - (float)maxlen.Z / 2
+	);
+
+	// Do not make caves that are above ground.
+	// It is only necessary to check the startpoint and endpoint.
+	v3s16 orpi(orp.X, orp.Y, orp.Z);
+	v3s16 veci(vec.X, vec.Y, vec.Z);
+	v3s16 p;
+
+	p = orpi + veci + of + rs / 2;
+	if (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) * mg->ystride + (p.X - node_min.X);
+		s16 h = mg->heightmap[index];
+		if (h < p.Y)
+			return;
+	} else if (p.Y > water_level) {
+		return; // If it's not in our heightmap, use a simple heuristic
+	}
+
+	p = orpi + of + rs / 2;
+	if (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) * mg->ystride + (p.X - node_min.X);
+		s16 h = mg->heightmap[index];
+		if (h < p.Y)
+			return;
+	} else if (p.Y > water_level) {
+		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 < 0.05)
+		veclen = 1.0;
+
+	// Every second section is rough
+	bool randomize_xz = (ps->range(1, 2) == 1);
+
+	// Carve routes
+	for (float f = 0; f < 1.0; f += 1.0 / veclen)
+		carveRoute(vec, f, randomize_xz);
+
+	orp = rp;
+}
+
+
+void CaveFractal::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, mg->seed);
+	MapNode liquidnode = (nval < 0.40 && node_max.Y < MGFRACTAL_LAVA_DEPTH) ?
+		lavanode : waternode;
+
+	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++) {
+				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;
+
+				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;
+			}
+		}
+	}
+}

src/cavegen.h

@@ -22,10 +22,12 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #define VMANIP_FLAG_CAVE VOXELFLAG_CHECKED1
 #define MGV7_LAVA_DEPTH -256
+#define MGFRACTAL_LAVA_DEPTH -256
 
 class MapgenV5;
 class MapgenV6;
 class MapgenV7;
+class MapgenFractal;
 
 class CaveV5 {
 public:
@@ -161,4 +163,49 @@ class CaveV7 {
 	void carveRoute(v3f vec, float f, bool randomize_xz);
 };
 
+class CaveFractal {
+public:
+	MapgenFractal *mg;
+	MMVManip *vm;
+	INodeDefManager *ndef;
+
+	NoiseParams *np_caveliquids;
+
+	s16 min_tunnel_diameter;
+	s16 max_tunnel_diameter;
+	u16 tunnel_routepoints;
+	int dswitchint;
+	int part_max_length_rs;
+
+	bool large_cave_is_flat;
+	bool flooded;
+
+	s16 max_stone_y;
+	v3s16 node_min;
+	v3s16 node_max;
+
+	v3f orp;  // starting point, relative to caved space
+	v3s16 of; // absolute coordinates of caved space
+	v3s16 ar; // allowed route area
+	s16 rs;   // tunnel radius size
+	v3f main_direction;
+
+	s16 route_y_min;
+	s16 route_y_max;
+
+	PseudoRandom *ps;
+
+	content_t c_water_source;
+	content_t c_lava_source;
+	content_t c_ice;
+
+	int water_level;
+
+	CaveFractal() {}
+	CaveFractal(MapgenFractal *mg, PseudoRandom *ps);
+	void makeCave(v3s16 nmin, v3s16 nmax, int max_stone_height);
+	void makeTunnel(bool dirswitch);
+	void carveRoute(v3f vec, float f, bool randomize_xz);
+};
+
 #endif