Mapgen: Add 4D fractal mapgen
authorparamat <mat.gregory@virginmedia.com>
Tue, 14 Apr 2015 03:38:01 +0000 (04:38 +0100)
committerparamat <mat.gregory@virginmedia.com>
Tue, 6 Oct 2015 05:43:04 +0000 (06:43 +0100)
src/CMakeLists.txt
src/emerge.cpp
src/mapgen_fractal.cpp [new file with mode: 0644]
src/mapgen_fractal.h [new file with mode: 0644]

index 32e25c3bd00639bb7043724d26ecbf4c55355942..72b52436ce45f237f226474b3d9408c2e7c0d98c 100644 (file)
@@ -352,6 +352,7 @@ set(common_SRCS
        map.cpp
        mapblock.cpp
        mapgen.cpp
+       mapgen_fractal.cpp
        mapgen_singlenode.cpp
        mapgen_v5.cpp
        mapgen_v6.cpp
index 92edd2007b03121531d6d8b36c7e0d0e5c6e0d90..3532ca29dea40f79feecf14049c127a43c68086c 100644 (file)
@@ -34,6 +34,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "log.h"
 #include "map.h"
 #include "mapblock.h"
+#include "mapgen_fractal.h"
 #include "mapgen_v5.h"
 #include "mapgen_v6.h"
 #include "mapgen_v7.h"
@@ -104,6 +105,7 @@ MapgenDesc g_reg_mapgens[] = {
        {"v5",         new MapgenFactoryV5,         true},
        {"v6",         new MapgenFactoryV6,         true},
        {"v7",         new MapgenFactoryV7,         true},
+       {"fractal",    new MapgenFactoryFractal,    false},
        {"singlenode", new MapgenFactorySinglenode, false},
 };
 
diff --git a/src/mapgen_fractal.cpp b/src/mapgen_fractal.cpp
new file mode 100644 (file)
index 0000000..144fa29
--- /dev/null
@@ -0,0 +1,597 @@
+/*
+Minetest
+Copyright (C) 2010-2013 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
+Additional development and fractal code by paramat
+
+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 "content_sao.h"
+#include "nodedef.h"
+#include "voxelalgorithms.h"
+#include "settings.h" // For g_settings
+#include "emerge.h"
+#include "dungeongen.h"
+#include "cavegen.h"
+#include "treegen.h"
+#include "mg_biome.h"
+#include "mg_ore.h"
+#include "mg_decoration.h"
+#include "mapgen_fractal.h"
+
+
+FlagDesc flagdesc_mapgen_fractal[] = {
+       {"julia", MGFRACTAL_JULIA},
+       {NULL,    0}
+};
+
+///////////////////////////////////////////////////////////////////////////////////////
+
+
+MapgenFractal::MapgenFractal(int mapgenid, MapgenParams *params, EmergeManager *emerge)
+       : Mapgen(mapgenid, params, emerge)
+{
+       this->m_emerge = emerge;
+       this->bmgr     = emerge->biomemgr;
+
+       //// 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);
+
+       this->biomemap        = new u8[csize.X * csize.Z];
+       this->heightmap       = new s16[csize.X * csize.Z];
+       this->heatmap         = NULL;
+       this->humidmap        = NULL;
+
+       MapgenFractalParams *sp = (MapgenFractalParams *)params->sparams;
+       this->spflags = sp->spflags;
+       this->iterations = sp->iterations;
+       this->scale_x = sp->scale_x;
+       this->scale_y = sp->scale_y;
+       this->scale_z = sp->scale_z;
+       this->offset_x = sp->offset_x;
+       this->offset_y = sp->offset_y;
+       this->offset_z = sp->offset_z;
+
+       //// 3d terrain noise
+       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);
+
+       //// Biome noise
+       noise_heat           = new Noise(&params->np_biome_heat,           seed, csize.X, csize.Z);
+       noise_humidity       = new Noise(&params->np_biome_humidity,       seed, csize.X, csize.Z);
+       noise_heat_blend     = new Noise(&params->np_biome_heat_blend,     seed, csize.X, csize.Z);
+       noise_humidity_blend = new Noise(&params->np_biome_humidity_blend, seed, csize.X, csize.Z);
+
+       //// Resolve nodes to be used
+       INodeDefManager *ndef = emerge->ndef;
+
+       c_stone                = ndef->getId("mapgen_stone");
+       c_water_source         = ndef->getId("mapgen_water_source");
+       c_lava_source          = ndef->getId("mapgen_lava_source");
+       c_desert_stone         = ndef->getId("mapgen_desert_stone");
+       c_ice                  = ndef->getId("mapgen_ice");
+       c_sandstone            = ndef->getId("mapgen_sandstone");
+
+       c_cobble               = ndef->getId("mapgen_cobble");
+       c_stair_cobble         = ndef->getId("mapgen_stair_cobble");
+       c_mossycobble          = ndef->getId("mapgen_mossycobble");
+       c_sandstonebrick       = ndef->getId("mapgen_sandstonebrick");
+       c_stair_sandstonebrick = ndef->getId("mapgen_stair_sandstonebrick");
+
+       if (c_ice == CONTENT_IGNORE)
+               c_ice = CONTENT_AIR;
+       if (c_mossycobble == CONTENT_IGNORE)
+               c_mossycobble = c_cobble;
+       if (c_stair_cobble == CONTENT_IGNORE)
+               c_stair_cobble = c_cobble;
+       if (c_sandstonebrick == CONTENT_IGNORE)
+               c_sandstonebrick = c_sandstone;
+       if (c_stair_sandstonebrick == CONTENT_IGNORE)
+               c_stair_sandstonebrick = c_sandstone;
+}
+
+
+MapgenFractal::~MapgenFractal()
+{
+       delete noise_cave1;
+       delete noise_cave2;
+
+       delete noise_heat;
+       delete noise_humidity;
+       delete noise_heat_blend;
+       delete noise_humidity_blend;
+
+       delete[] heightmap;
+       delete[] biomemap;
+}
+
+
+MapgenFractalParams::MapgenFractalParams()
+{
+       spflags = 0;
+
+       iterations = 9;
+       scale_x = 1024;
+       scale_y = 256;
+       scale_z = 1024;
+       offset_x = -1.75;
+       offset_y = 0;
+       offset_z = 0;
+       slice_w = 0.5;
+       julia_x = 0.33;
+       julia_y = 0.33;
+       julia_z = 0.33;
+       julia_w = 0.33;
+
+       np_cave1 = NoiseParams(0, 12, v3f(128, 128, 128), 52534, 4, 0.5, 2.0);
+       np_cave2 = NoiseParams(0, 12, v3f(128, 128, 128), 10325, 4, 0.5, 2.0);
+}
+
+
+void MapgenFractalParams::readParams(const Settings *settings)
+{
+       settings->getFlagStrNoEx("mgfractal_spflags", spflags, flagdesc_mapgen_fractal);
+
+       settings->getU16NoEx("mgfractal_iterations", iterations);
+       settings->getFloatNoEx("mgfractal_scale_x", scale_x);
+       settings->getFloatNoEx("mgfractal_scale_y", scale_y);
+       settings->getFloatNoEx("mgfractal_scale_z", scale_z);
+       settings->getFloatNoEx("mgfractal_offset_x", offset_x);
+       settings->getFloatNoEx("mgfractal_offset_y", offset_y);
+       settings->getFloatNoEx("mgfractal_offset_z", offset_z);
+       settings->getFloatNoEx("mgfractal_slice_w", slice_w);
+       settings->getFloatNoEx("mgfractal_julia_x", julia_x);
+       settings->getFloatNoEx("mgfractal_julia_y", julia_y);
+       settings->getFloatNoEx("mgfractal_julia_z", julia_z);
+       settings->getFloatNoEx("mgfractal_julia_w", julia_w);
+
+       settings->getNoiseParams("mgfractal_np_cave1", np_cave1);
+       settings->getNoiseParams("mgfractal_np_cave2", np_cave2);
+}
+
+
+void MapgenFractalParams::writeParams(Settings *settings) const
+{
+       settings->setFlagStr("mgfractal_spflags", spflags, flagdesc_mapgen_fractal, U32_MAX);
+
+       settings->setU16("mgfractal_iterations", iterations);
+       settings->setFloat("mgfractal_scale_x", scale_x);
+       settings->setFloat("mgfractal_scale_y", scale_y);
+       settings->setFloat("mgfractal_scale_z", scale_z);
+       settings->setFloat("mgfractal_offset_x", offset_x);
+       settings->setFloat("mgfractal_offset_y", offset_y);
+       settings->setFloat("mgfractal_offset_z", offset_z);
+       settings->setFloat("mgfractal_slice_w", slice_w);
+       settings->setFloat("mgfractal_julia_x", julia_x);
+       settings->setFloat("mgfractal_julia_y", julia_y);
+       settings->setFloat("mgfractal_julia_z", julia_z);
+       settings->setFloat("mgfractal_julia_w", julia_w);
+
+       settings->setNoiseParams("mgfractal_np_cave1", np_cave1);
+       settings->setNoiseParams("mgfractal_np_cave2", np_cave2);
+}
+
+
+/////////////////////////////////////////////////////////////////
+
+
+int MapgenFractal::getGroundLevelAtPoint(v2s16 p)
+{
+       s16 search_top = water_level + 128;
+       s16 search_base = water_level;
+       s16 level = -MAX_MAP_GENERATION_LIMIT;
+       for (s16 y = search_top; y >= search_base; y--) {
+               if (getTerrainAtPoint(p.X, y, p.Y))
+                       return y;
+       }
+
+       return level;
+}
+
+
+void MapgenFractal::makeChunk(BlockMakeData *data)
+{
+       // Pre-conditions
+       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);
+
+       this->generating = true;
+       this->vm   = data->vmanip;
+       this->ndef = data->nodedef;
+       //TimeTaker t("makeChunk");
+
+       v3s16 blockpos_min = data->blockpos_min;
+       v3s16 blockpos_max = data->blockpos_max;
+       node_min = blockpos_min * MAP_BLOCKSIZE;
+       node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
+       full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
+       full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
+
+       blockseed = getBlockSeed2(full_node_min, seed);
+
+       // Make some noise
+       calculateNoise();
+
+       // Generate base terrain, mountains, and ridges with initial heightmaps
+       s16 stone_surface_max_y = generateTerrain();
+
+       // Create heightmap
+       updateHeightmap(node_min, node_max);
+
+       // Create biomemap at heightmap surface
+       bmgr->calcBiomes(csize.X, csize.Z, noise_heat->result,
+               noise_humidity->result, heightmap, biomemap);
+
+       // Actually place the biome-specific nodes
+       MgStoneType stone_type = generateBiomes(noise_heat->result, noise_humidity->result);
+
+       if (flags & MG_CAVES)
+               generateCaves(stone_surface_max_y);
+
+       if ((flags & MG_DUNGEONS) && (stone_surface_max_y >= node_min.Y)) {
+               DungeonParams dp;
+
+               dp.np_rarity  = nparams_dungeon_rarity;
+               dp.np_density = nparams_dungeon_density;
+               dp.np_wetness = nparams_dungeon_wetness;
+               dp.c_water    = c_water_source;
+               if (stone_type == STONE) {
+                       dp.c_cobble = c_cobble;
+                       dp.c_moss   = c_mossycobble;
+                       dp.c_stair  = c_stair_cobble;
+
+                       dp.diagonal_dirs = false;
+                       dp.mossratio     = 3.0;
+                       dp.holesize      = v3s16(1, 2, 1);
+                       dp.roomsize      = v3s16(0, 0, 0);
+                       dp.notifytype    = GENNOTIFY_DUNGEON;
+               } else if (stone_type == DESERT_STONE) {
+                       dp.c_cobble = c_desert_stone;
+                       dp.c_moss   = c_desert_stone;
+                       dp.c_stair  = c_desert_stone;
+
+                       dp.diagonal_dirs = true;
+                       dp.mossratio     = 0.0;
+                       dp.holesize      = v3s16(2, 3, 2);
+                       dp.roomsize      = v3s16(2, 5, 2);
+                       dp.notifytype    = GENNOTIFY_TEMPLE;
+               } else if (stone_type == SANDSTONE) {
+                       dp.c_cobble = c_sandstonebrick;
+                       dp.c_moss   = c_sandstonebrick;
+                       dp.c_stair  = c_sandstonebrick;
+
+                       dp.diagonal_dirs = false;
+                       dp.mossratio     = 0.0;
+                       dp.holesize      = v3s16(2, 2, 2);
+                       dp.roomsize      = v3s16(2, 0, 2);
+                       dp.notifytype    = GENNOTIFY_DUNGEON;
+               }
+
+               DungeonGen dgen(this, &dp);
+               dgen.generate(blockseed, full_node_min, full_node_max);
+       }
+
+       // Generate the registered 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);
+
+       // Sprinkle some dust on top after everything else was generated
+       dustTopNodes();
+
+       //printf("makeChunk: %dms\n", t.stop());
+
+       updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
+
+       if (flags & MG_LIGHT)
+               calcLighting(node_min - v3s16(0, 1, 0), node_max + v3s16(0, 1, 0),
+                       full_node_min, full_node_max);
+
+       //setLighting(node_min - v3s16(1, 0, 1) * MAP_BLOCKSIZE,
+       //                      node_max + v3s16(1, 0, 1) * MAP_BLOCKSIZE, 0xFF);
+
+       this->generating = false;
+}
+
+
+void MapgenFractal::calculateNoise()
+{
+       //TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
+       int x = node_min.X;
+       int y = node_min.Y - 1;
+       int z = node_min.Z;
+
+       if (flags & MG_CAVES) {
+               noise_cave1->perlinMap3D(x, y, z);
+               noise_cave2->perlinMap3D(x, y, z);
+       }
+
+       noise_heat->perlinMap2D(x, z);
+       noise_humidity->perlinMap2D(x, z);
+       noise_heat_blend->perlinMap2D(x, z);
+       noise_humidity_blend->perlinMap2D(x, z);
+
+       for (s32 i = 0; i < csize.X * csize.Z; i++) {
+               noise_heat->result[i] += noise_heat_blend->result[i];
+               noise_humidity->result[i] += noise_humidity_blend->result[i];
+       }
+
+       heatmap = noise_heat->result;
+       humidmap = noise_humidity->result;
+       //printf("calculateNoise: %dus\n", t.stop());
+}
+
+
+bool MapgenFractal::getTerrainAtPoint(s16 x, s16 y, s16 z)
+{
+       float cx, cy, cz, cw, ox, oy, oz, ow;
+
+       if (spflags & MGFRACTAL_JULIA) {  // Julia set
+               cx = julia_x;
+               cy = julia_y;
+               cz = julia_z;
+               cw = julia_w;
+               ox = (float)x / scale_x + offset_x;
+               oy = (float)y / scale_y + offset_y;
+               oz = (float)z / scale_z + offset_z;
+               ow = slice_w;
+       } else {  // Mandelbrot set
+               cx = (float)x / scale_x + offset_x;
+               cy = (float)y / scale_y + offset_y;
+               cz = (float)z / scale_z + offset_z;
+               cw = slice_w;
+               ox = 0.0;
+               oy = 0.0;
+               oz = 0.0;
+               ow = 0.0;
+       }
+
+       for (u16 iter = 0; iter < iterations; iter++) {
+               // 4D "Roundy" Mandelbrot set
+               float nx = ox * ox - oy * oy - oz * oz - ow * ow + cx;
+               float ny = 2.0 * (ox * oy + oz * ow) + cy;
+               float nz = 2.0 * (ox * oz + oy * ow) + cz;
+               float nw = 2.0 * (ox * ow + oy * oz) + cw;
+
+               if (nx * nx + ny * ny + nz * nz + nw * nw > 4.0) {
+                       return false;
+               }
+
+               ox = nx;
+               oy = ny;
+               oz = nz;
+               ow = nw;
+       }
+
+       return true;
+}
+
+
+s16 MapgenFractal::generateTerrain()
+{
+       MapNode n_air(CONTENT_AIR);
+       MapNode n_stone(c_stone);
+       MapNode n_water(c_water_source);
+
+       s16 stone_surface_max_y = -MAX_MAP_GENERATION_LIMIT;
+
+       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++) {
+                       if (vm->m_data[i].getContent() == CONTENT_IGNORE) {
+                               if (getTerrainAtPoint(x, y, z)) {
+                                       vm->m_data[i] = n_stone;
+                                       if (y > stone_surface_max_y)
+                                               stone_surface_max_y = y;
+                               } else if (y <= water_level) {
+                                       vm->m_data[i] = n_water;
+                               } else {
+                                       vm->m_data[i] = n_air;
+                               }
+                       }
+               }
+       }
+
+       return stone_surface_max_y;
+}
+
+
+MgStoneType MapgenFractal::generateBiomes(float *heat_map, float *humidity_map)
+{
+       v3s16 em = vm->m_area.getExtent();
+       u32 index = 0;
+       MgStoneType stone_type = STONE;
+
+       for (s16 z = node_min.Z; z <= node_max.Z; z++)
+       for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
+               Biome *biome = NULL;
+               u16 depth_top = 0;
+               u16 base_filler = 0;
+               u16 depth_water_top = 0;
+               u32 vi = vm->m_area.index(x, node_max.Y, z);
+
+               // Check node at base of mapchunk above, either a node of a previously
+               // generated mapchunk or if not, a node of overgenerated base terrain.
+               content_t c_above = vm->m_data[vi + em.X].getContent();
+               bool air_above = c_above == CONTENT_AIR;
+               bool water_above = c_above == c_water_source;
+
+               // 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_MAX;
+
+
+               for (s16 y = node_max.Y; y >= node_min.Y; y--) {
+                       content_t c = vm->m_data[vi].getContent();
+
+                       // Biome is recalculated each time an upper surface is detected while
+                       // working down a column. The selected biome then remains in effect for
+                       // all nodes below until the next surface and biome recalculation.
+                       // Biome is recalculated:
+                       // 1. At the surface of stone below air or water.
+                       // 2. At the surface of water below air.
+                       // 3. When stone or water is detected but biome has not yet been calculated.
+                       if ((c == c_stone && (air_above || water_above || !biome)) ||
+                                       (c == c_water_source && (air_above || !biome))) {
+                               biome = bmgr->getBiome(heat_map[index], humidity_map[index], y);
+                               depth_top = biome->depth_top;
+                               base_filler = depth_top + biome->depth_filler;
+                               depth_water_top = biome->depth_water_top;
+
+                               // Detect stone type for dungeons during every biome calculation.
+                               // This is more efficient than detecting per-node and will not
+                               // miss any desert stone or sandstone biomes.
+                               if (biome->c_stone == c_desert_stone)
+                                       stone_type = DESERT_STONE;
+                               else if (biome->c_stone == c_sandstone)
+                                       stone_type = SANDSTONE;
+                       }
+
+                       if (c == c_stone) {
+                               content_t c_below = vm->m_data[vi - em.X].getContent();
+
+                               // If the node below isn't solid, make this node stone, so that
+                               // any top/filler nodes above are structurally supported.
+                               // 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_MAX;
+
+                               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 {
+                                       vm->m_data[vi] = MapNode(biome->c_stone);
+                               }
+
+                               air_above = false;
+                               water_above = false;
+                       } else if (c == c_water_source) {
+                               vm->m_data[vi] = MapNode((y > (s32)(water_level - depth_water_top)) ?
+                                               biome->c_water_top : biome->c_water);
+                               nplaced = 0;  // Enable top/filler placement for next surface
+                               air_above = false;
+                               water_above = true;
+                       } else if (c == CONTENT_AIR) {
+                               nplaced = 0;  // Enable top/filler placement for next surface
+                               air_above = true;
+                               water_above = false;
+                       } else {  // Possible various nodes overgenerated from neighbouring mapchunks
+                               nplaced = U16_MAX;  // Disable top/filler placement
+                               air_above = false;
+                               water_above = false;
+                       }
+
+                       vm->m_area.add_y(em, vi, -1);
+               }
+       }
+
+       return stone_type;
+}
+
+
+void MapgenFractal::dustTopNodes()
+{
+       if (node_max.Y < water_level)
+               return;
+
+       v3s16 em = vm->m_area.getExtent();
+       u32 index = 0;
+
+       for (s16 z = node_min.Z; z <= node_max.Z; z++)
+       for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
+               Biome *biome = (Biome *)bmgr->getRaw(biomemap[index]);
+
+               if (biome->c_dust == CONTENT_IGNORE)
+                       continue;
+
+               u32 vi = vm->m_area.index(x, full_node_max.Y, z);
+               content_t c_full_max = vm->m_data[vi].getContent();
+               s16 y_start;
+
+               if (c_full_max == CONTENT_AIR) {
+                       y_start = full_node_max.Y - 1;
+               } else if (c_full_max == CONTENT_IGNORE) {
+                       vi = vm->m_area.index(x, node_max.Y + 1, z);
+                       content_t c_max = vm->m_data[vi].getContent();
+
+                       if (c_max == CONTENT_AIR)
+                               y_start = node_max.Y;
+                       else
+                               continue;
+               } else {
+                       continue;
+               }
+
+               vi = vm->m_area.index(x, y_start, z);
+               for (s16 y = y_start; y >= node_min.Y - 1; y--) {
+                       if (vm->m_data[vi].getContent() != CONTENT_AIR)
+                               break;
+
+                       vm->m_area.add_y(em, vi, -1);
+               }
+
+               content_t c = vm->m_data[vi].getContent();
+               if (!ndef->get(c).buildable_to && c != CONTENT_IGNORE && c != biome->c_dust) {
+                       vm->m_area.add_y(em, vi, 1);
+                       vm->m_data[vi] = MapNode(biome->c_dust);
+               }
+       }
+}
+
+
+void MapgenFractal::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);
+                               }
+                       }
+               }
+       }
+}
+
diff --git a/src/mapgen_fractal.h b/src/mapgen_fractal.h
new file mode 100644 (file)
index 0000000..71729cb
--- /dev/null
@@ -0,0 +1,133 @@
+/*
+Minetest
+Copyright (C) 2010-2013 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
+Additional development and fractal code by paramat
+
+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.
+*/
+
+#ifndef MAPGEN_FRACTAL_HEADER
+#define MAPGEN_FRACTAL_HEADER
+
+#include "mapgen.h"
+
+/////////////////// Mapgen Fractal flags
+#define MGFRACTAL_JULIA 0x01
+
+class BiomeManager;
+
+extern FlagDesc flagdesc_mapgen_fractal[];
+
+
+struct MapgenFractalParams : public MapgenSpecificParams {
+       u32 spflags;
+
+       u16 iterations;
+       float scale_x;
+       float scale_y;
+       float scale_z;
+       float offset_x;
+       float offset_y;
+       float offset_z;
+       float slice_w;
+       float julia_x;
+       float julia_y;
+       float julia_z;
+       float julia_w;
+
+       NoiseParams np_cave1;
+       NoiseParams np_cave2;
+
+       MapgenFractalParams();
+       ~MapgenFractalParams() {}
+
+       void readParams(const Settings *settings);
+       void writeParams(Settings *settings) const;
+};
+
+class MapgenFractal : public Mapgen {
+public:
+       EmergeManager *m_emerge;
+       BiomeManager *bmgr;
+
+       int ystride;
+       int zstride;
+       u32 spflags;
+
+       v3s16 node_min;
+       v3s16 node_max;
+       v3s16 full_node_min;
+       v3s16 full_node_max;
+
+       u16 iterations;
+       float scale_x;
+       float scale_y;
+       float scale_z;
+       float offset_x;
+       float offset_y;
+       float offset_z;
+       float slice_w;
+       float julia_x;
+       float julia_y;
+       float julia_z;
+       float julia_w;
+
+       Noise *noise_cave1;
+       Noise *noise_cave2;
+
+       Noise *noise_heat;
+       Noise *noise_humidity;
+       Noise *noise_heat_blend;
+       Noise *noise_humidity_blend;
+
+       content_t c_stone;
+       content_t c_water_source;
+       content_t c_lava_source;
+       content_t c_desert_stone;
+       content_t c_ice;
+       content_t c_sandstone;
+
+       content_t c_cobble;
+       content_t c_stair_cobble;
+       content_t c_mossycobble;
+       content_t c_sandstonebrick;
+       content_t c_stair_sandstonebrick;
+
+       MapgenFractal(int mapgenid, MapgenParams *params, EmergeManager *emerge);
+       ~MapgenFractal();
+
+       virtual void makeChunk(BlockMakeData *data);
+       int getGroundLevelAtPoint(v2s16 p);
+       void calculateNoise();
+       bool getTerrainAtPoint(s16 x, s16 y, s16 z);
+       s16 generateTerrain();
+       MgStoneType generateBiomes(float *heat_map, float *humidity_map);
+       void dustTopNodes();
+       void generateCaves(s16 max_stone_y);
+};
+
+struct MapgenFactoryFractal : public MapgenFactory {
+       Mapgen *createMapgen(int mgid, MapgenParams *params, EmergeManager *emerge)
+       {
+               return new MapgenFractal(mgid, params, emerge);
+       };
+
+       MapgenSpecificParams *createMapgenParams()
+       {
+               return new MapgenFractalParams();
+       };
+};
+
+#endif