1 files changed, 223 insertions, 177 deletions

diff --git a/src/mapgen_v7.cpp b/src/mapgen_v7.cpp
index 9f612de81..9fb65f577 100644
--- a/src/mapgen_v7.cpp
+++ b/src/mapgen_v7.cpp
@@ -1,6 +1,7 @@
 /*
 Minetest
-Copyright (C) 2010-2013 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
+Copyright (C) 2010-2015 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
+Copyright (C) 2010-2015 paramat, Matt Gregory
 
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU Lesser General Public License as published by
@@ -27,6 +28,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "content_sao.h"
 #include "nodedef.h"
 #include "voxelalgorithms.h"
+//#include "profiler.h" // For TimeTaker
 #include "settings.h" // For g_settings
 #include "emerge.h"
 #include "dungeongen.h"
@@ -44,6 +46,7 @@ FlagDesc flagdesc_mapgen_v7[] = {
 	{NULL,        0}
 };
 
+
 ///////////////////////////////////////////////////////////////////////////////
 
 
@@ -56,7 +59,10 @@ MapgenV7::MapgenV7(int mapgenid, MapgenParams *params, EmergeManager *emerge)
 	//// amount of elements to skip for the next index
 	//// for noise/height/biome maps (not vmanip)
 	this->ystride = csize.X;
-	this->zstride = csize.X * (csize.Y + 2);
+	// 1-up 1-down overgeneration
+	this->zstride_1u1d = csize.X * (csize.Y + 2);
+	// 1-down overgeneration
+	this->zstride_1d = csize.X * (csize.Y + 1);
 
 	this->biomemap        = new u8[csize.X * csize.Z];
 	this->heightmap       = new s16[csize.X * csize.Z];
@@ -65,7 +71,9 @@ MapgenV7::MapgenV7(int mapgenid, MapgenParams *params, EmergeManager *emerge)
 	this->ridge_heightmap = new s16[csize.X * csize.Z];
 
 	MapgenV7Params *sp = (MapgenV7Params *)params->sparams;
-	this->spflags = sp->spflags;
+
+	this->spflags    = sp->spflags;
+	this->cave_width = sp->cave_width;
 
 	//// Terrain noise
 	noise_terrain_base    = new Noise(&sp->np_terrain_base,    seed, csize.X, csize.Z);
@@ -77,10 +85,12 @@ MapgenV7::MapgenV7(int mapgenid, MapgenParams *params, EmergeManager *emerge)
 	noise_ridge_uwater    = new Noise(&sp->np_ridge_uwater,    seed, csize.X, csize.Z);
 
 	//// 3d terrain noise
+	// 1-up 1-down overgeneration
 	noise_mountain = new Noise(&sp->np_mountain, seed, csize.X, csize.Y + 2, csize.Z);
 	noise_ridge    = new Noise(&sp->np_ridge,    seed, csize.X, csize.Y + 2, csize.Z);
-	noise_cave1    = new Noise(&sp->np_cave1,    seed, csize.X, csize.Y + 2, csize.Z);
-	noise_cave2    = new Noise(&sp->np_cave2,    seed, csize.X, csize.Y + 2, csize.Z);
+	// 1-down overgeneraion
+	noise_cave1    = new Noise(&sp->np_cave1,    seed, csize.X, csize.Y + 1, csize.Z);
+	noise_cave2    = new Noise(&sp->np_cave2,    seed, csize.X, csize.Y + 1, csize.Z);
 
 	//// Biome noise
 	noise_heat           = new Noise(&params->np_biome_heat,           seed, csize.X, csize.Z);
@@ -144,25 +154,27 @@ MapgenV7::~MapgenV7()
 
 MapgenV7Params::MapgenV7Params()
 {
-	spflags = MGV7_MOUNTAINS | MGV7_RIDGES;
+	spflags    = MGV7_MOUNTAINS | MGV7_RIDGES;
+	cave_width = 0.3;
 
 	np_terrain_base    = NoiseParams(4,    70,  v3f(600,  600,  600),  82341, 5, 0.6,  2.0);
 	np_terrain_alt     = NoiseParams(4,    25,  v3f(600,  600,  600),  5934,  5, 0.6,  2.0);
 	np_terrain_persist = NoiseParams(0.6,  0.1, v3f(2000, 2000, 2000), 539,   3, 0.6,  2.0);
-	np_height_select   = NoiseParams(-12,  24,  v3f(500,  500,  500),  4213,  6, 0.7,  2.0);
+	np_height_select   = NoiseParams(-8,   16,  v3f(500,  500,  500),  4213,  6, 0.7,  2.0);
 	np_filler_depth    = NoiseParams(0,    1.2, v3f(150,  150,  150),  261,   3, 0.7,  2.0);
 	np_mount_height    = NoiseParams(256,  112, v3f(1000, 1000, 1000), 72449, 3, 0.6,  2.0);
 	np_ridge_uwater    = NoiseParams(0,    1,   v3f(1000, 1000, 1000), 85039, 5, 0.6,  2.0);
 	np_mountain        = NoiseParams(-0.6, 1,   v3f(250,  350,  250),  5333,  5, 0.63, 2.0);
 	np_ridge           = NoiseParams(0,    1,   v3f(100,  100,  100),  6467,  4, 0.75, 2.0);
-	np_cave1           = NoiseParams(0,    12,  v3f(100,  100,  100),  52534, 4, 0.5,  2.0);
-	np_cave2           = NoiseParams(0,    12,  v3f(100,  100,  100),  10325, 4, 0.5,  2.0);
+	np_cave1           = NoiseParams(0,    12,  v3f(96,   96,   96),   52534, 4, 0.5,  2.0);
+	np_cave2           = NoiseParams(0,    12,  v3f(96,   96,   96),   10325, 4, 0.5,  2.0);
 }
 
 
 void MapgenV7Params::readParams(const Settings *settings)
 {
-	settings->getFlagStrNoEx("mgv7_spflags", spflags, flagdesc_mapgen_v7);
+	settings->getFlagStrNoEx("mgv7_spflags",  spflags, flagdesc_mapgen_v7);
+	settings->getFloatNoEx("mgv7_cave_width", cave_width);
 
 	settings->getNoiseParams("mgv7_np_terrain_base",    np_terrain_base);
 	settings->getNoiseParams("mgv7_np_terrain_alt",     np_terrain_alt);
@@ -180,7 +192,8 @@ void MapgenV7Params::readParams(const Settings *settings)
 
 void MapgenV7Params::writeParams(Settings *settings) const
 {
-	settings->setFlagStr("mgv7_spflags", spflags, flagdesc_mapgen_v7, (u32)-1);
+	settings->setFlagStr("mgv7_spflags",  spflags, flagdesc_mapgen_v7, U32_MAX);
+	settings->setFloat("mgv7_cave_width", cave_width);
 
 	settings->setNoiseParams("mgv7_np_terrain_base",    np_terrain_base);
 	settings->setNoiseParams("mgv7_np_terrain_alt",     np_terrain_alt);
@@ -196,10 +209,10 @@ void MapgenV7Params::writeParams(Settings *settings) const
 }
 
 
-///////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////////
 
 
-int MapgenV7::getGroundLevelAtPoint(v2s16 p)
+int MapgenV7::getSpawnLevelAtPoint(v2s16 p)
 {
 	// Base terrain calculation
 	s16 y = baseTerrainLevelAtPoint(p.X, p.Y);
@@ -207,22 +220,24 @@ int MapgenV7::getGroundLevelAtPoint(v2s16 p)
 	// Ridge/river terrain calculation
 	float width = 0.2;
 	float uwatern = NoisePerlin2D(&noise_ridge_uwater->np, p.X, p.Y, seed) * 2;
-	// actually computing the depth of the ridge is much more expensive;
-	// if inside a river, simply guess
+	// if inside a river this is an unsuitable spawn point
 	if (fabs(uwatern) <= width)
-		return water_level - 10;
+		return MAX_MAP_GENERATION_LIMIT;
 
 	// Mountain terrain calculation
-	int iters = 128; // don't even bother iterating more than 128 times..
+	int iters = 128;
 	while (iters--) {
-		//current point would have been air
-		if (!getMountainTerrainAtPoint(p.X, y, p.Y))
-			return y;
-
+		if (!getMountainTerrainAtPoint(p.X, y + 1, p.Y)) {  // Air, y is ground level
+			if (y <= water_level || y > water_level + 16)
+				return MAX_MAP_GENERATION_LIMIT;  // Unsuitable spawn point
+			else
+				return y;
+		}
 		y++;
 	}
 
-	return y;
+	// Unsuitable spawn point, no ground surface found
+	return MAX_MAP_GENERATION_LIMIT;
 }
 
 
@@ -255,10 +270,13 @@ void MapgenV7::makeChunk(BlockMakeData *data)
 	// Make some noise
 	calculateNoise();
 
-	// Generate base terrain, mountains, and ridges with initial heightmaps
+	// Generate terrain and ridges with initial heightmaps
 	s16 stone_surface_max_y = generateTerrain();
 
-	// Create heightmap
+	if (spflags & MGV7_RIDGES)
+		generateRidgeTerrain();
+
+	// Update heightmap to include mountain terrain
 	updateHeightmap(node_min, node_max);
 
 	// Create biomemap at heightmap surface
@@ -315,7 +333,8 @@ void MapgenV7::makeChunk(BlockMakeData *data)
 	}
 
 	// Generate the registered decorations
-	m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);
+	if (flags & MG_DECORATIONS)
+		m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);
 
 	// Generate the registered ores
 	m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);
@@ -341,9 +360,9 @@ void MapgenV7::makeChunk(BlockMakeData *data)
 void MapgenV7::calculateNoise()
 {
 	//TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
-	int x = node_min.X;
-	int y = node_min.Y - 1;
-	int z = node_min.Z;
+	s16 x = node_min.X;
+	s16 y = node_min.Y - 1;
+	s16 z = node_min.Z;
 
 	noise_terrain_persist->perlinMap2D(x, z);
 	float *persistmap = noise_terrain_persist->result;
@@ -352,9 +371,9 @@ void MapgenV7::calculateNoise()
 	noise_terrain_alt->perlinMap2D(x, z, persistmap);
 	noise_height_select->perlinMap2D(x, z);
 
-	if (flags & MG_CAVES) {
-		noise_cave1->perlinMap3D(x, y, z);
-		noise_cave2->perlinMap3D(x, y, z);
+	if (spflags & MGV7_MOUNTAINS) {
+		noise_mountain->perlinMap3D(x, y, z);
+		noise_mount_height->perlinMap2D(x, z);
 	}
 
 	if ((spflags & MGV7_RIDGES) && node_max.Y >= water_level) {
@@ -362,7 +381,8 @@ void MapgenV7::calculateNoise()
 		noise_ridge_uwater->perlinMap2D(x, z);
 	}
 
-	// Mountain noises are calculated in generateMountainTerrain()
+	// Cave noises are calculated in generateCaves()
+	// only if solid terrain is present in mapchunk
 
 	noise_filler_depth->perlinMap2D(x, z);
 	noise_heat->perlinMap2D(x, z);
@@ -392,7 +412,7 @@ Biome *MapgenV7::getBiomeAtPoint(v3s16 p)
 	return bmgr->getBiome(heat, humidity, groundlevel);
 }
 
-//needs to be updated
+
 float MapgenV7::baseTerrainLevelAtPoint(s16 x, s16 z)
 {
 	float hselect = NoisePerlin2D(&noise_height_select->np, x, z, seed);
@@ -446,142 +466,62 @@ bool MapgenV7::getMountainTerrainFromMap(int idx_xyz, int idx_xz, s16 y)
 }
 
 
-#if 0
-void MapgenV7::carveRivers() {
-	MapNode n_air(CONTENT_AIR), n_water_source(c_water_source);
-	MapNode n_stone(c_stone);
-	u32 index = 0;
-
-	int river_depth = 4;
-
-	for (s16 z = node_min.Z; z <= node_max.Z; z++)
-	for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
-		float terrain_mod  = noise_terrain_mod->result[index];
-		NoiseParams *np = noise_terrain_river->np;
-		np.persist = noise_terrain_persist->result[index];
-		float terrain_river = NoisePerlin2DNoTxfm(np, x, z, seed);
-		float height = terrain_river * (1 - abs(terrain_mod)) *
-						noise_terrain_river->np.scale;
-		height = log(height * height); //log(h^3) is pretty interesting for terrain
-
-		s16 y = heightmap[index];
-		if (height < 1.0 && y > river_depth &&
-			y - river_depth >= node_min.Y && y <= node_max.Y) {
-
-			for (s16 ry = y; ry != y - river_depth; ry--) {
-				u32 vi = vm->m_area.index(x, ry, z);
-				vm->m_data[vi] = n_air;
-			}
-
-			u32 vi = vm->m_area.index(x, y - river_depth, z);
-			vm->m_data[vi] = n_water_source;
-		}
-	}
-}
-#endif
-
-
 int MapgenV7::generateTerrain()
 {
-	s16 stone_surface_min_y;
-	s16 stone_surface_max_y;
-
-	generateBaseTerrain(&stone_surface_min_y, &stone_surface_max_y);
-
-	if ((spflags & MGV7_MOUNTAINS) && stone_surface_min_y < node_max.Y)
-		stone_surface_max_y = generateMountainTerrain(stone_surface_max_y);
-
-	if (spflags & MGV7_RIDGES)
-		generateRidgeTerrain();
-
-	return stone_surface_max_y;
-}
-
-
-void MapgenV7::generateBaseTerrain(s16 *stone_surface_min_y, s16 *stone_surface_max_y)
-{
 	MapNode n_air(CONTENT_AIR);
 	MapNode n_stone(c_stone);
 	MapNode n_water(c_water_source);
 
 	v3s16 em = vm->m_area.getExtent();
-	s16 surface_min_y = MAX_MAP_GENERATION_LIMIT;
-	s16 surface_max_y = -MAX_MAP_GENERATION_LIMIT;
-	u32 index = 0;
+	s16 stone_surface_max_y = -MAX_MAP_GENERATION_LIMIT;
+	u32 index2d = 0;
+	bool mountain_flag = spflags & MGV7_MOUNTAINS;
 
 	for (s16 z = node_min.Z; z <= node_max.Z; z++)
-	for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
-		float surface_height = baseTerrainLevelFromMap(index);
-		s16 surface_y = (s16)surface_height;
-
-		heightmap[index]       = surface_y;
-		ridge_heightmap[index] = surface_y;
+	for (s16 x = node_min.X; x <= node_max.X; x++, index2d++) {
+		s16 surface_y = baseTerrainLevelFromMap(index2d);
+		heightmap[index2d]       = surface_y;  // Create base terrain heightmap
+		ridge_heightmap[index2d] = surface_y;
 
-		if (surface_y < surface_min_y)
-			surface_min_y = surface_y;
+		if (surface_y > stone_surface_max_y)
+			stone_surface_max_y = surface_y;
 
-		if (surface_y > surface_max_y)
-			surface_max_y = surface_y;
+		u32 vi = vm->m_area.index(x, node_min.Y - 1, z);
+		u32 index3d = (z - node_min.Z) * zstride_1u1d + (x - node_min.X);
 
-		u32 i = vm->m_area.index(x, node_min.Y - 1, z);
 		for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
-			if (vm->m_data[i].getContent() == CONTENT_IGNORE) {
-				if (y <= surface_y)
-					vm->m_data[i] = n_stone;
-				else if (y <= water_level)
-					vm->m_data[i] = n_water;
-				else
-					vm->m_data[i] = n_air;
-			}
-			vm->m_area.add_y(em, i, 1);
-		}
-	}
-
-	*stone_surface_min_y = surface_min_y;
-	*stone_surface_max_y = surface_max_y;
-}
-
-
-int MapgenV7::generateMountainTerrain(s16 ymax)
-{
-	noise_mountain->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
-	noise_mount_height->perlinMap2D(node_min.X, node_min.Z);
-
-	MapNode n_stone(c_stone);
-	u32 j = 0;
-
-	for (s16 z = node_min.Z; z <= node_max.Z; z++)
-	for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
-		u32 vi = vm->m_area.index(node_min.X, y, z);
-		for (s16 x = node_min.X; x <= node_max.X; x++) {
-			int index = (z - node_min.Z) * csize.X + (x - node_min.X);
-			content_t c = vm->m_data[vi].getContent();
-
-			if (getMountainTerrainFromMap(j, index, y)
-					&& (c == CONTENT_AIR || c == c_water_source)) {
-				vm->m_data[vi] = n_stone;
-				if (y > ymax)
-					ymax = y;
+			if (vm->m_data[vi].getContent() == CONTENT_IGNORE) {
+				if (y <= surface_y) {
+					vm->m_data[vi] = n_stone;  // Base terrain
+				} else if (mountain_flag &&
+						getMountainTerrainFromMap(index3d, index2d, y)) {
+					vm->m_data[vi] = n_stone;  // Mountain terrain
+					if (y > stone_surface_max_y)
+						stone_surface_max_y = y;
+				} else if (y <= water_level) {
+					vm->m_data[vi] = n_water;
+				} else {
+					vm->m_data[vi] = n_air;
+				}
 			}
-
-			vi++;
-			j++;
+			vm->m_area.add_y(em, vi, 1);
+			index3d += ystride;
 		}
 	}
 
-	return ymax;
+	return stone_surface_max_y;
 }
 
 
 void MapgenV7::generateRidgeTerrain()
 {
-	if (node_max.Y < water_level)
+	if (node_max.Y < water_level - 16)
 		return;
 
 	MapNode n_water(c_water_source);
 	MapNode n_air(CONTENT_AIR);
 	u32 index = 0;
-	float width = 0.2; // TODO: figure out acceptable perlin noise values
+	float width = 0.2;
 
 	for (s16 z = node_min.Z; z <= node_max.Z; z++)
 	for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
@@ -589,7 +529,7 @@ void MapgenV7::generateRidgeTerrain()
 		for (s16 x = node_min.X; x <= node_max.X; x++, index++, vi++) {
 			int j = (z - node_min.Z) * csize.X + (x - node_min.X);
 
-			if (heightmap[j] < water_level - 16)
+			if (heightmap[j] < water_level - 16)  // Use base terrain heightmap
 				continue;
 
 			float uwatern = noise_ridge_uwater->result[j] * 2;
@@ -635,7 +575,7 @@ MgStoneType MapgenV7::generateBiomes(float *heat_map, float *humidity_map)
 
 		// If there is air or water above enable top/filler placement, otherwise force
 		// nplaced to stone level by setting a number exceeding any possible filler depth.
-		u16 nplaced = (air_above || water_above) ? 0 : (u16)-1;
+		u16 nplaced = (air_above || water_above) ? 0 : U16_MAX;
 
 		for (s16 y = node_max.Y; y >= node_min.Y; y--) {
 			content_t c = vm->m_data[vi].getContent();
@@ -672,7 +612,7 @@ MgStoneType MapgenV7::generateBiomes(float *heat_map, float *humidity_map)
 				// This is done by aborting the cycle of top/filler placement
 				// immediately by forcing nplaced to stone level.
 				if (c_below == CONTENT_AIR || c_below == c_water_source)
-					nplaced = (u16)-1;
+					nplaced = U16_MAX;
 
 				if (nplaced < depth_top) {
 					vm->m_data[vi] = MapNode(biome->c_top);
@@ -697,7 +637,7 @@ MgStoneType MapgenV7::generateBiomes(float *heat_map, float *humidity_map)
 				air_above = true;
 				water_above = false;
 			} else {  // Possible various nodes overgenerated from neighbouring mapchunks
-				nplaced = (u16)-1;  // Disable top/filler placement
+				nplaced = U16_MAX;  // Disable top/filler placement
 				air_above = false;
 				water_above = false;
 			}
@@ -760,6 +700,143 @@ void MapgenV7::dustTopNodes()
 }
 
 
+void MapgenV7::generateCaves(s16 max_stone_y)
+{
+	if (max_stone_y < node_min.Y)
+		return;
+
+	noise_cave1->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
+	noise_cave2->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
+
+	v3s16 em = vm->m_area.getExtent();
+	u32 index2d = 0;
+
+	for (s16 z = node_min.Z; z <= node_max.Z; z++)
+	for (s16 x = node_min.X; x <= node_max.X; x++, index2d++) {
+		bool column_is_open = false;  // Is column open to overground
+		bool is_tunnel = false;  // Is tunnel or tunnel floor
+		// Indexes at column top (node_max.Y)
+		u32 vi = vm->m_area.index(x, node_max.Y, z);
+		u32 index3d = (z - node_min.Z) * zstride_1d + csize.Y * ystride +
+			(x - node_min.X);
+		// Biome of column
+		Biome *biome = (Biome *)bmgr->getRaw(biomemap[index2d]);
+
+		// Don't excavate the overgenerated stone at node_max.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 = node_max.Y; y >= node_min.Y - 1; y--,
+				index3d -= 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;
+			}
+			// Ground
+			float d1 = contour(noise_cave1->result[index3d]);
+			float d2 = contour(noise_cave2->result[index3d]);
+
+			if (d1 * d2 > cave_width && ndef->get(c).is_ground_content) {
+				// In tunnel and ground content, excavate
+				vm->m_data[vi] = MapNode(CONTENT_AIR);
+				is_tunnel = true;
+			} else {
+				// Not in tunnel or not ground content
+				if (is_tunnel && column_is_open &&
+						(c == biome->c_filler || c == biome->c_stone))
+					// Tunnel entrance floor
+					vm->m_data[vi] = MapNode(biome->c_top);
+
+				column_is_open = false;
+				is_tunnel = false;
+			}
+		}
+	}
+
+	if (node_min.Y >= water_level)
+		return;
+
+	PseudoRandom ps(blockseed + 21343);
+	u32 bruises_count = ps.range(0, 2);
+	for (u32 i = 0; i < bruises_count; i++) {
+		CaveV7 cave(this, &ps);
+		cave.makeCave(node_min, node_max, max_stone_y);
+	}
+}
+
+
+///////////////////////////////////////////////////////////////
+
+
+#if 0
+int MapgenV7::generateMountainTerrain(s16 ymax)
+{
+	MapNode n_stone(c_stone);
+	u32 j = 0;
+
+	for (s16 z = node_min.Z; z <= node_max.Z; z++)
+	for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
+		u32 vi = vm->m_area.index(node_min.X, y, z);
+		for (s16 x = node_min.X; x <= node_max.X; x++) {
+			int index = (z - node_min.Z) * csize.X + (x - node_min.X);
+			content_t c = vm->m_data[vi].getContent();
+
+			if (getMountainTerrainFromMap(j, index, y)
+					&& (c == CONTENT_AIR || c == c_water_source)) {
+				vm->m_data[vi] = n_stone;
+				if (y > ymax)
+					ymax = y;
+			}
+
+			vi++;
+			j++;
+		}
+	}
+
+	return ymax;
+}
+#endif
+
+
+#if 0
+void MapgenV7::carveRivers() {
+	MapNode n_air(CONTENT_AIR), n_water_source(c_water_source);
+	MapNode n_stone(c_stone);
+	u32 index = 0;
+
+	int river_depth = 4;
+
+	for (s16 z = node_min.Z; z <= node_max.Z; z++)
+	for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
+		float terrain_mod  = noise_terrain_mod->result[index];
+		NoiseParams *np = noise_terrain_river->np;
+		np.persist = noise_terrain_persist->result[index];
+		float terrain_river = NoisePerlin2DNoTxfm(np, x, z, seed);
+		float height = terrain_river * (1 - abs(terrain_mod)) *
+						noise_terrain_river->np.scale;
+		height = log(height * height); //log(h^3) is pretty interesting for terrain
+
+		s16 y = heightmap[index];
+		if (height < 1.0 && y > river_depth &&
+			y - river_depth >= node_min.Y && y <= node_max.Y) {
+
+			for (s16 ry = y; ry != y - river_depth; ry--) {
+				u32 vi = vm->m_area.index(x, ry, z);
+				vm->m_data[vi] = n_air;
+			}
+
+			u32 vi = vm->m_area.index(x, y - river_depth, z);
+			vm->m_data[vi] = n_water_source;
+		}
+	}
+}
+#endif
+
+
 #if 0
 void MapgenV7::addTopNodes()
 {
@@ -854,34 +931,3 @@ void MapgenV7::addTopNodes()
 	}
 }
 #endif
-
-
-void MapgenV7::generateCaves(s16 max_stone_y)
-{
-	if (max_stone_y >= node_min.Y) {
-		u32 index   = 0;
-
-		for (s16 z = node_min.Z; z <= node_max.Z; z++)
-		for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
-			u32 i = vm->m_area.index(node_min.X, y, z);
-			for (s16 x = node_min.X; x <= node_max.X; x++, i++, index++) {
-				float d1 = contour(noise_cave1->result[index]);
-				float d2 = contour(noise_cave2->result[index]);
-				if (d1 * d2 > 0.3) {
-					content_t c = vm->m_data[i].getContent();
-					if (!ndef->get(c).is_ground_content || c == CONTENT_AIR)
-						continue;
-
-					vm->m_data[i] = MapNode(CONTENT_AIR);
-				}
-			}
-		}
-	}
-
-	PseudoRandom ps(blockseed + 21343);
-	u32 bruises_count = (ps.range(1, 4) == 1) ? ps.range(1, 2) : 0;
-	for (u32 i = 0; i < bruises_count; i++) {
-		CaveV7 cave(this, &ps);
-		cave.makeCave(node_min, node_max, max_stone_y);
-	}
-}