Mgv5/v7/flat/fractal: Move tunnel noise calculation into generateCaves
[oweals/minetest.git] / src / mapgen_v5.cpp
1 /*
2 Minetest
3 Copyright (C) 2010-2015 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
4 Copyright (C) 2010-2015 paramat, Matt Gregory
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 GNU Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public License along
17 with this program; if not, write to the Free Software Foundation, Inc.,
18 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20
21
22 #include "mapgen.h"
23 #include "voxel.h"
24 #include "noise.h"
25 #include "mapblock.h"
26 #include "mapnode.h"
27 #include "map.h"
28 #include "content_sao.h"
29 #include "nodedef.h"
30 #include "voxelalgorithms.h"
31 //#include "profiler.h" // For TimeTaker
32 #include "settings.h" // For g_settings
33 #include "emerge.h"
34 #include "dungeongen.h"
35 #include "cavegen.h"
36 #include "treegen.h"
37 #include "mg_biome.h"
38 #include "mg_ore.h"
39 #include "mg_decoration.h"
40 #include "mapgen_v5.h"
41
42
43 FlagDesc flagdesc_mapgen_v5[] = {
44         {NULL,         0}
45 };
46
47
48 MapgenV5::MapgenV5(int mapgenid, MapgenParams *params, EmergeManager *emerge)
49         : Mapgen(mapgenid, params, emerge)
50 {
51         this->m_emerge = emerge;
52         this->bmgr     = emerge->biomemgr;
53
54         // amount of elements to skip for the next index
55         // for noise/height/biome maps (not vmanip)
56         this->ystride = csize.X;
57         this->zstride = csize.X * (csize.Y + 2);
58
59         this->biomemap  = new u8[csize.X * csize.Z];
60         this->heightmap = new s16[csize.X * csize.Z];
61         this->heatmap   = NULL;
62         this->humidmap  = NULL;
63
64         MapgenV5Params *sp = (MapgenV5Params *)params->sparams;
65         this->spflags      = sp->spflags;
66
67         // Terrain noise
68         noise_filler_depth = new Noise(&sp->np_filler_depth, seed, csize.X, csize.Z);
69         noise_factor       = new Noise(&sp->np_factor,       seed, csize.X, csize.Z);
70         noise_height       = new Noise(&sp->np_height,       seed, csize.X, csize.Z);
71
72         // 3D terrain noise
73         noise_cave1  = new Noise(&sp->np_cave1,  seed, csize.X, csize.Y + 2, csize.Z);
74         noise_cave2  = new Noise(&sp->np_cave2,  seed, csize.X, csize.Y + 2, csize.Z);
75         noise_ground = new Noise(&sp->np_ground, seed, csize.X, csize.Y + 2, csize.Z);
76
77         // Biome noise
78         noise_heat           = new Noise(&params->np_biome_heat,           seed, csize.X, csize.Z);
79         noise_humidity       = new Noise(&params->np_biome_humidity,       seed, csize.X, csize.Z);
80         noise_heat_blend     = new Noise(&params->np_biome_heat_blend,     seed, csize.X, csize.Z);
81         noise_humidity_blend = new Noise(&params->np_biome_humidity_blend, seed, csize.X, csize.Z);
82
83         //// Resolve nodes to be used
84         INodeDefManager *ndef = emerge->ndef;
85
86         c_stone                = ndef->getId("mapgen_stone");
87         c_water_source         = ndef->getId("mapgen_water_source");
88         c_lava_source          = ndef->getId("mapgen_lava_source");
89         c_desert_stone         = ndef->getId("mapgen_desert_stone");
90         c_ice                  = ndef->getId("mapgen_ice");
91         c_sandstone            = ndef->getId("mapgen_sandstone");
92
93         c_cobble               = ndef->getId("mapgen_cobble");
94         c_stair_cobble         = ndef->getId("mapgen_stair_cobble");
95         c_mossycobble          = ndef->getId("mapgen_mossycobble");
96         c_sandstonebrick       = ndef->getId("mapgen_sandstonebrick");
97         c_stair_sandstonebrick = ndef->getId("mapgen_stair_sandstonebrick");
98
99         if (c_ice == CONTENT_IGNORE)
100                 c_ice = CONTENT_AIR;
101         if (c_mossycobble == CONTENT_IGNORE)
102                 c_mossycobble = c_cobble;
103         if (c_stair_cobble == CONTENT_IGNORE)
104                 c_stair_cobble = c_cobble;
105         if (c_sandstonebrick == CONTENT_IGNORE)
106                 c_sandstonebrick = c_sandstone;
107         if (c_stair_sandstonebrick == CONTENT_IGNORE)
108                 c_stair_sandstonebrick = c_sandstone;
109 }
110
111
112 MapgenV5::~MapgenV5()
113 {
114         delete noise_filler_depth;
115         delete noise_factor;
116         delete noise_height;
117         delete noise_cave1;
118         delete noise_cave2;
119         delete noise_ground;
120
121         delete noise_heat;
122         delete noise_humidity;
123         delete noise_heat_blend;
124         delete noise_humidity_blend;
125
126         delete[] heightmap;
127         delete[] biomemap;
128 }
129
130
131 MapgenV5Params::MapgenV5Params()
132 {
133         spflags = 0;
134
135         np_filler_depth = NoiseParams(0, 1,  v3f(150, 150, 150), 261,    4, 0.7,  2.0);
136         np_factor       = NoiseParams(0, 1,  v3f(250, 250, 250), 920381, 3, 0.45, 2.0);
137         np_height       = NoiseParams(0, 10, v3f(250, 250, 250), 84174,  4, 0.5,  2.0);
138         np_cave1        = NoiseParams(0, 12, v3f(50,  50,  50),  52534,  4, 0.5,  2.0);
139         np_cave2        = NoiseParams(0, 12, v3f(50,  50,  50),  10325,  4, 0.5,  2.0);
140         np_ground       = NoiseParams(0, 40, v3f(80,  80,  80),  983240, 4, 0.55, 2.0, NOISE_FLAG_EASED);
141 }
142
143
144 //#define CAVE_NOISE_SCALE 12.0
145 //#define CAVE_NOISE_THRESHOLD (1.5/CAVE_NOISE_SCALE) = 0.125
146
147
148 void MapgenV5Params::readParams(const Settings *settings)
149 {
150         settings->getFlagStrNoEx("mgv5_spflags", spflags, flagdesc_mapgen_v5);
151
152         settings->getNoiseParams("mgv5_np_filler_depth", np_filler_depth);
153         settings->getNoiseParams("mgv5_np_factor",       np_factor);
154         settings->getNoiseParams("mgv5_np_height",       np_height);
155         settings->getNoiseParams("mgv5_np_cave1",        np_cave1);
156         settings->getNoiseParams("mgv5_np_cave2",        np_cave2);
157         settings->getNoiseParams("mgv5_np_ground",       np_ground);
158 }
159
160
161 void MapgenV5Params::writeParams(Settings *settings) const
162 {
163         settings->setFlagStr("mgv5_spflags", spflags, flagdesc_mapgen_v5, U32_MAX);
164
165         settings->setNoiseParams("mgv5_np_filler_depth", np_filler_depth);
166         settings->setNoiseParams("mgv5_np_factor",       np_factor);
167         settings->setNoiseParams("mgv5_np_height",       np_height);
168         settings->setNoiseParams("mgv5_np_cave1",        np_cave1);
169         settings->setNoiseParams("mgv5_np_cave2",        np_cave2);
170         settings->setNoiseParams("mgv5_np_ground",       np_ground);
171 }
172
173
174 int MapgenV5::getGroundLevelAtPoint(v2s16 p)
175 {
176         //TimeTaker t("getGroundLevelAtPoint", NULL, PRECISION_MICRO);
177
178         float f = 0.55 + NoisePerlin2D(&noise_factor->np, p.X, p.Y, seed);
179         if (f < 0.01)
180                 f = 0.01;
181         else if (f >= 1.0)
182                 f *= 1.6;
183         float h = NoisePerlin2D(&noise_height->np, p.X, p.Y, seed);
184
185         s16 search_start = 128; // Only bother searching this range, actual
186         s16 search_end = -128;  // ground level is rarely higher or lower.
187
188         for (s16 y = search_start; y >= search_end; y--) {
189                 float n_ground = NoisePerlin3D(&noise_ground->np, p.X, y, p.Y, seed);
190                 // If solid
191                 if (n_ground * f > y - h) {
192                         // If either top 2 nodes of search are solid this is inside a
193                         // mountain or floatland with no space for the player to spawn.
194                         if (y >= search_start - 1)
195                                 return MAX_MAP_GENERATION_LIMIT;
196                         else
197                                 return y; // Ground below at least 2 nodes of space
198                 }
199         }
200
201         //printf("getGroundLevelAtPoint: %dus\n", t.stop());
202         return -MAX_MAP_GENERATION_LIMIT;
203 }
204
205
206 void MapgenV5::makeChunk(BlockMakeData *data)
207 {
208         // Pre-conditions
209         assert(data->vmanip);
210         assert(data->nodedef);
211         assert(data->blockpos_requested.X >= data->blockpos_min.X &&
212                 data->blockpos_requested.Y >= data->blockpos_min.Y &&
213                 data->blockpos_requested.Z >= data->blockpos_min.Z);
214         assert(data->blockpos_requested.X <= data->blockpos_max.X &&
215                 data->blockpos_requested.Y <= data->blockpos_max.Y &&
216                 data->blockpos_requested.Z <= data->blockpos_max.Z);
217
218         this->generating = true;
219         this->vm   = data->vmanip;
220         this->ndef = data->nodedef;
221         //TimeTaker t("makeChunk");
222
223         v3s16 blockpos_min = data->blockpos_min;
224         v3s16 blockpos_max = data->blockpos_max;
225         node_min = blockpos_min * MAP_BLOCKSIZE;
226         node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
227         full_node_min = (blockpos_min - 1) * MAP_BLOCKSIZE;
228         full_node_max = (blockpos_max + 2) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
229
230         // Create a block-specific seed
231         blockseed = getBlockSeed2(full_node_min, seed);
232
233         // Make some noise
234         calculateNoise();
235
236         // Generate base terrain
237         s16 stone_surface_max_y = generateBaseTerrain();
238
239         // Create heightmap
240         updateHeightmap(node_min, node_max);
241
242         // Create biomemap at heightmap surface
243         bmgr->calcBiomes(csize.X, csize.Z, noise_heat->result,
244                 noise_humidity->result, heightmap, biomemap);
245
246         // Actually place the biome-specific nodes
247         MgStoneType stone_type = generateBiomes(noise_heat->result, noise_humidity->result);
248
249         // Generate caves
250         if ((flags & MG_CAVES) && (stone_surface_max_y >= node_min.Y))
251                 generateCaves(stone_surface_max_y);
252
253         // Generate dungeons and desert temples
254         if ((flags & MG_DUNGEONS) && (stone_surface_max_y >= node_min.Y)) {
255                 DungeonParams dp;
256
257                 dp.np_rarity  = nparams_dungeon_rarity;
258                 dp.np_density = nparams_dungeon_density;
259                 dp.np_wetness = nparams_dungeon_wetness;
260                 dp.c_water    = c_water_source;
261                 if (stone_type == STONE) {
262                         dp.c_cobble = c_cobble;
263                         dp.c_moss   = c_mossycobble;
264                         dp.c_stair  = c_stair_cobble;
265
266                         dp.diagonal_dirs = false;
267                         dp.mossratio     = 3.0;
268                         dp.holesize      = v3s16(1, 2, 1);
269                         dp.roomsize      = v3s16(0, 0, 0);
270                         dp.notifytype    = GENNOTIFY_DUNGEON;
271                 } else if (stone_type == DESERT_STONE) {
272                         dp.c_cobble = c_desert_stone;
273                         dp.c_moss   = c_desert_stone;
274                         dp.c_stair  = c_desert_stone;
275
276                         dp.diagonal_dirs = true;
277                         dp.mossratio     = 0.0;
278                         dp.holesize      = v3s16(2, 3, 2);
279                         dp.roomsize      = v3s16(2, 5, 2);
280                         dp.notifytype    = GENNOTIFY_TEMPLE;
281                 } else if (stone_type == SANDSTONE) {
282                         dp.c_cobble = c_sandstonebrick;
283                         dp.c_moss   = c_sandstonebrick;
284                         dp.c_stair  = c_sandstonebrick;
285
286                         dp.diagonal_dirs = false;
287                         dp.mossratio     = 0.0;
288                         dp.holesize      = v3s16(2, 2, 2);
289                         dp.roomsize      = v3s16(2, 0, 2);
290                         dp.notifytype    = GENNOTIFY_DUNGEON;
291                 }
292
293                 DungeonGen dgen(this, &dp);
294                 dgen.generate(blockseed, full_node_min, full_node_max);
295         }
296
297         // Generate the registered decorations
298         if (flags & MG_DECORATIONS)
299                 m_emerge->decomgr->placeAllDecos(this, blockseed, node_min, node_max);
300
301         // Generate the registered ores
302         m_emerge->oremgr->placeAllOres(this, blockseed, node_min, node_max);
303
304         // Sprinkle some dust on top after everything else was generated
305         dustTopNodes();
306
307         //printf("makeChunk: %dms\n", t.stop());
308
309         // Add top and bottom side of water to transforming_liquid queue
310         updateLiquid(&data->transforming_liquid, full_node_min, full_node_max);
311
312         // Calculate lighting
313         if (flags & MG_LIGHT) {
314                 calcLighting(node_min - v3s16(0, 1, 0), node_max + v3s16(0, 1, 0),
315                         full_node_min, full_node_max);
316         }
317
318         this->generating = false;
319 }
320
321
322 void MapgenV5::calculateNoise()
323 {
324         //TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
325         s16 x = node_min.X;
326         s16 y = node_min.Y - 1;
327         s16 z = node_min.Z;
328
329         noise_factor->perlinMap2D(x, z);
330         noise_height->perlinMap2D(x, z);
331         noise_ground->perlinMap3D(x, y, z);
332
333         // Cave noises are calculated in generateCaves()
334         // only if solid terrain is present in mapchunk
335
336         noise_filler_depth->perlinMap2D(x, z);
337         noise_heat->perlinMap2D(x, z);
338         noise_humidity->perlinMap2D(x, z);
339         noise_heat_blend->perlinMap2D(x, z);
340         noise_humidity_blend->perlinMap2D(x, z);
341
342         for (s32 i = 0; i < csize.X * csize.Z; i++) {
343                 noise_heat->result[i] += noise_heat_blend->result[i];
344                 noise_humidity->result[i] += noise_humidity_blend->result[i];
345         }
346
347         heatmap = noise_heat->result;
348         humidmap = noise_humidity->result;
349         //printf("calculateNoise: %dus\n", t.stop());
350 }
351
352
353 //bool is_cave(u32 index) {
354 //      double d1 = contour(noise_cave1->result[index]);
355 //      double d2 = contour(noise_cave2->result[index]);
356 //      return d1*d2 > CAVE_NOISE_THRESHOLD;
357 //}
358
359 //bool val_is_ground(v3s16 p, u32 index, u32 index2d) {
360 //      double f = 0.55 + noise_factor->result[index2d];
361 //      if(f < 0.01)
362 //              f = 0.01;
363 //      else if(f >= 1.0)
364 //              f *= 1.6;
365 //      double h = WATER_LEVEL + 10 * noise_height->result[index2d];
366 //      return (noise_ground->result[index] * f > (double)p.Y - h);
367 //}
368
369
370 int MapgenV5::generateBaseTerrain()
371 {
372         u32 index = 0;
373         u32 index2d = 0;
374         int stone_surface_max_y = -MAX_MAP_GENERATION_LIMIT;
375
376         for (s16 z=node_min.Z; z<=node_max.Z; z++) {
377                 for (s16 y=node_min.Y - 1; y<=node_max.Y + 1; y++) {
378                         u32 vi = vm->m_area.index(node_min.X, y, z);
379                         for (s16 x=node_min.X; x<=node_max.X; x++, vi++, index++, index2d++) {
380                                 if (vm->m_data[vi].getContent() != CONTENT_IGNORE)
381                                         continue;
382
383                                 float f = 0.55 + noise_factor->result[index2d];
384                                 if (f < 0.01)
385                                         f = 0.01;
386                                 else if (f >= 1.0)
387                                         f *= 1.6;
388                                 float h = noise_height->result[index2d];
389
390                                 if (noise_ground->result[index] * f < y - h) {
391                                         if (y <= water_level)
392                                                 vm->m_data[vi] = MapNode(c_water_source);
393                                         else
394                                                 vm->m_data[vi] = MapNode(CONTENT_AIR);
395                                 } else {
396                                         vm->m_data[vi] = MapNode(c_stone);
397                                         if (y > stone_surface_max_y)
398                                                 stone_surface_max_y = y;
399                                 }
400                         }
401                         index2d -= ystride;
402                 }
403                 index2d += ystride;
404         }
405
406         return stone_surface_max_y;
407 }
408
409
410 MgStoneType MapgenV5::generateBiomes(float *heat_map, float *humidity_map)
411 {
412         v3s16 em = vm->m_area.getExtent();
413         u32 index = 0;
414         MgStoneType stone_type = STONE;
415
416         for (s16 z = node_min.Z; z <= node_max.Z; z++)
417         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
418                 Biome *biome = NULL;
419                 u16 depth_top = 0;
420                 u16 base_filler = 0;
421                 u16 depth_water_top = 0;
422                 u32 vi = vm->m_area.index(x, node_max.Y, z);
423
424                 // Check node at base of mapchunk above, either a node of a previously
425                 // generated mapchunk or if not, a node of overgenerated base terrain.
426                 content_t c_above = vm->m_data[vi + em.X].getContent();
427                 bool air_above = c_above == CONTENT_AIR;
428                 bool water_above = c_above == c_water_source;
429
430                 // If there is air or water above enable top/filler placement, otherwise force
431                 // nplaced to stone level by setting a number exceeding any possible filler depth.
432                 u16 nplaced = (air_above || water_above) ? 0 : U16_MAX;
433
434                 for (s16 y = node_max.Y; y >= node_min.Y; y--) {
435                         content_t c = vm->m_data[vi].getContent();
436
437                         // Biome is recalculated each time an upper surface is detected while
438                         // working down a column. The selected biome then remains in effect for
439                         // all nodes below until the next surface and biome recalculation.
440                         // Biome is recalculated:
441                         // 1. At the surface of stone below air or water.
442                         // 2. At the surface of water below air.
443                         // 3. When stone or water is detected but biome has not yet been calculated.
444                         if ((c == c_stone && (air_above || water_above || !biome)) ||
445                                         (c == c_water_source && (air_above || !biome))) {
446                                 biome = bmgr->getBiome(heat_map[index], humidity_map[index], y);
447                                 depth_top = biome->depth_top;
448                                 base_filler = MYMAX(depth_top + biome->depth_filler
449                                                 + noise_filler_depth->result[index], 0);
450                                 depth_water_top = biome->depth_water_top;
451
452                                 // Detect stone type for dungeons during every biome calculation.
453                                 // This is more efficient than detecting per-node and will not
454                                 // miss any desert stone or sandstone biomes.
455                                 if (biome->c_stone == c_desert_stone)
456                                         stone_type = DESERT_STONE;
457                                 else if (biome->c_stone == c_sandstone)
458                                         stone_type = SANDSTONE;
459                         }
460
461                         if (c == c_stone) {
462                                 content_t c_below = vm->m_data[vi - em.X].getContent();
463
464                                 // If the node below isn't solid, make this node stone, so that
465                                 // any top/filler nodes above are structurally supported.
466                                 // This is done by aborting the cycle of top/filler placement
467                                 // immediately by forcing nplaced to stone level.
468                                 if (c_below == CONTENT_AIR || c_below == c_water_source)
469                                         nplaced = U16_MAX;
470
471                                 if (nplaced < depth_top) {
472                                         vm->m_data[vi] = MapNode(biome->c_top);
473                                         nplaced++;
474                                 } else if (nplaced < base_filler) {
475                                         vm->m_data[vi] = MapNode(biome->c_filler);
476                                         nplaced++;
477                                 } else {
478                                         vm->m_data[vi] = MapNode(biome->c_stone);
479                                 }
480
481                                 air_above = false;
482                                 water_above = false;
483                         } else if (c == c_water_source) {
484                                 vm->m_data[vi] = MapNode((y > (s32)(water_level - depth_water_top)) ?
485                                                 biome->c_water_top : biome->c_water);
486                                 nplaced = 0;  // Enable top/filler placement for next surface
487                                 air_above = false;
488                                 water_above = true;
489                         } else if (c == CONTENT_AIR) {
490                                 nplaced = 0;  // Enable top/filler placement for next surface
491                                 air_above = true;
492                                 water_above = false;
493                         } else {  // Possible various nodes overgenerated from neighbouring mapchunks
494                                 nplaced = U16_MAX;  // Disable top/filler placement
495                                 air_above = false;
496                                 water_above = false;
497                         }
498
499                         vm->m_area.add_y(em, vi, -1);
500                 }
501         }
502
503         return stone_type;
504 }
505
506
507 void MapgenV5::generateCaves(int max_stone_y)
508 {
509         if (max_stone_y < node_min.Y)
510                 return;
511
512         noise_cave1->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
513         noise_cave2->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
514
515         u32 index = 0;
516
517         for (s16 z = node_min.Z; z <= node_max.Z; z++)
518         for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
519                 u32 vi = vm->m_area.index(node_min.X, y, z);
520                 for (s16 x = node_min.X; x <= node_max.X; x++, vi++, index++) {
521                         float d1 = contour(noise_cave1->result[index]);
522                         float d2 = contour(noise_cave2->result[index]);
523                         if (d1 * d2 > 0.125f) {
524                                 content_t c = vm->m_data[vi].getContent();
525                                 if (!ndef->get(c).is_ground_content || c == CONTENT_AIR)
526                                         continue;
527
528                                 vm->m_data[vi] = MapNode(CONTENT_AIR);
529                         }
530                 }
531         }
532
533         if (node_max.Y > MGV5_LARGE_CAVE_DEPTH)
534                 return;
535
536         PseudoRandom ps(blockseed + 21343);
537         u32 bruises_count = ps.range(0, 2);
538         for (u32 i = 0; i < bruises_count; i++) {
539                 CaveV5 cave(this, &ps);
540                 cave.makeCave(node_min, node_max, max_stone_y);
541         }
542 }
543
544
545 void MapgenV5::dustTopNodes()
546 {
547         if (node_max.Y < water_level)
548                 return;
549
550         v3s16 em = vm->m_area.getExtent();
551         u32 index = 0;
552
553         for (s16 z = node_min.Z; z <= node_max.Z; z++)
554         for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
555                 Biome *biome = (Biome *)bmgr->getRaw(biomemap[index]);
556
557                 if (biome->c_dust == CONTENT_IGNORE)
558                         continue;
559
560                 u32 vi = vm->m_area.index(x, full_node_max.Y, z);
561                 content_t c_full_max = vm->m_data[vi].getContent();
562                 s16 y_start;
563
564                 if (c_full_max == CONTENT_AIR) {
565                         y_start = full_node_max.Y - 1;
566                 } else if (c_full_max == CONTENT_IGNORE) {
567                         vi = vm->m_area.index(x, node_max.Y + 1, z);
568                         content_t c_max = vm->m_data[vi].getContent();
569
570                         if (c_max == CONTENT_AIR)
571                                 y_start = node_max.Y;
572                         else
573                                 continue;
574                 } else {
575                         continue;
576                 }
577
578                 vi = vm->m_area.index(x, y_start, z);
579                 for (s16 y = y_start; y >= node_min.Y - 1; y--) {
580                         if (vm->m_data[vi].getContent() != CONTENT_AIR)
581                                 break;
582
583                         vm->m_area.add_y(em, vi, -1);
584                 }
585
586                 content_t c = vm->m_data[vi].getContent();
587                 if (!ndef->get(c).buildable_to && c != CONTENT_IGNORE && c != biome->c_dust) {
588                         vm->m_area.add_y(em, vi, 1);
589                         vm->m_data[vi] = MapNode(biome->c_dust);
590                 }
591         }
592 }