summaryrefslogblamecommitdiffstats
path: root/src/Generating/ProtIntGen.h
blob: a3d10c4ef083321b9768a4896df77a6249cdcf92 (plain) (tree)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008















































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































                                                                                                                                       

// ProtIntGen.h

// Declares the prototyping integer generators - cProtIntGen class and its descendants

/*
These classes generate 2D arrays of integers that have various interpretations. The main purpose of these
classes is to provide fast prototyping for cIntGen classes - unlike cIntGen classes, these are not
template-based and so they take care of the underlying sizes automatically. This makes them easier to chain
and re-chain, since the size parameters don't need to be adjusted after each such case. Their performance is,
however, slightly worse, which is why we use cIntGen classes in the final generator.

Because there is no SizeX / SizeZ template param, the generators would have to either alloc memory for each
underlying generator's values, or use a maximum-size buffer. We chose the latter, to avoid memory allocation
overhead; this however means that there's (an arbitrary) limit to the size of the generated data.
*/





#pragma once

// We need the biome group constants defined there:
#include "IntGen.h"





/** Interface that all the generator classes provide. */
class cProtIntGen
{
protected:
	/** Maximum size of the generated area.
	Adjust the constant if you need larger areas, these are just so that we can use fixed-size buffers. */
	static const int m_BufferSize = 900;

public:

	/** Type of the generic interface used for storing links to the underlying generators. */
	typedef std::shared_ptr<cProtIntGen> Underlying;


	/** Force a virtual destructor in all descendants.
	Descendants contain virtual functions and are referred to via pointer-to-base, so they need a virtual destructor. */
	virtual ~cProtIntGen() {}

	/** Generates the array of specified size into a_Values, based on given min coords. */
	virtual void GetInts(int a_MinX, int a_MinZ, int a_SizeX, int a_SizeZ, int * a_Values) = 0;
};





/** Provides additional cNoise member and its helper functions. */
class cProtIntGenWithNoise :
	public cProtIntGen
{
	typedef cProtIntGen super;

public:
	cProtIntGenWithNoise(int a_Seed) :
		m_Noise(a_Seed)
	{
	}

protected:
	cNoise m_Noise;

	/** Chooses one of a_Val1 or a_Val2, based on m_Noise and the coordinates for querying the noise. */
	int ChooseRandomOne(int a_RndX, int a_RndZ, int a_Val1, int a_Val2)
	{
		int rnd = m_Noise.IntNoise2DInt(a_RndX, a_RndZ) / 7;
		return ((rnd & 1) == 0) ? a_Val1 : a_Val2;
	}

	/** Chooses one of a_ValN, based on m_Noise and the coordinates for querying the noise. */
	int ChooseRandomOne(int a_RndX, int a_RndZ, int a_Val1, int a_Val2, int a_Val3, int a_Val4)
	{
		int rnd = m_Noise.IntNoise2DInt(a_RndX, a_RndZ) / 7;
		switch (rnd % 4)
		{
			case 0:  return a_Val1;
			case 1:  return a_Val2;
			case 2:  return a_Val3;
			default: return a_Val4;
		}
	}
};






/** Generates a 2D array of random integers in the specified range [0 .. Range). */
class cProtIntGenChoice :
	public cProtIntGenWithNoise
{
	typedef cProtIntGenWithNoise super;

public:
	cProtIntGenChoice(int a_Seed, int a_Range) :
		super(a_Seed),
		m_Range(a_Range)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, int a_SizeX, int a_SizeZ, int * a_Values) override
	{
		for (int z = 0; z < a_SizeZ; z++)
		{
			int BaseZ = a_MinZ + z;
			for (int x = 0; x < a_SizeX; x++)
			{
				a_Values[x + a_SizeX * z] = (super::m_Noise.IntNoise2DInt(a_MinX + x, BaseZ) / 7) % m_Range;
			}
		}  // for z
	}

protected:
	int m_Range;
};






/** Decides between the ocean and landmass biomes.
Has a threshold (in percent) of how much land, the larger the threshold, the more land.
Generates 0 for ocean, biome group ID for landmass. */
class cProtIntGenLandOcean :
	public cProtIntGenWithNoise
{
	typedef cProtIntGenWithNoise super;

public:
	cProtIntGenLandOcean(int a_Seed, int a_Threshold) :
		super(a_Seed),
		m_Threshold(a_Threshold)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, int a_SizeX, int a_SizeZ, int * a_Values) override
	{
		for (int z = 0; z < a_SizeZ; z++)
		{
			int BaseZ = a_MinZ + z;
			for (int x = 0; x < a_SizeX; x++)
			{
				int rnd = (super::m_Noise.IntNoise2DInt(a_MinX + x, BaseZ) / 7);
				a_Values[x + a_SizeX * z] = ((rnd % 100) < m_Threshold) ? ((rnd / 128) % bgLandOceanMax + 1) : 0;
			}
		}

		// If the centerpoint of the world is within the area, set it to bgTemperate, always:
		if ((a_MinX <= 0) && (a_MinZ <= 0) && (a_MinX + a_SizeX > 0) && (a_MinZ + a_SizeZ > 0))
		{
			a_Values[-a_MinX - a_MinZ * a_SizeX] = bgTemperate;
		}
	}

protected:
	int m_Threshold;
};





class cProtIntGenZoom :
	public cProtIntGenWithNoise
{
	typedef cProtIntGenWithNoise super;

public:
	cProtIntGenZoom(int a_Seed, Underlying a_UnderlyingGen) :
		super(a_Seed),
		m_UnderlyingGen(a_UnderlyingGen)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, int a_SizeX, int a_SizeZ, int * a_Values) override
	{
		// Get the coords for the lower generator:
		int lowerMinX = a_MinX >> 1;
		int lowerMinZ = a_MinZ >> 1;
		int lowerSizeX = a_SizeX / 2 + 2;
		int lowerSizeZ = a_SizeZ / 2 + 2;
		ASSERT(lowerSizeX * lowerSizeZ <= m_BufferSize);
		ASSERT(lowerSizeX > 0);
		ASSERT(lowerSizeZ > 0);

		// Generate the underlying data with half the resolution:
		int lowerData[m_BufferSize];
		m_UnderlyingGen->GetInts(lowerMinX, lowerMinZ, lowerSizeX, lowerSizeZ, lowerData);
		const int lowStepX = (lowerSizeX - 1) * 2;
		int Cache[m_BufferSize];

		// Discreet-interpolate the values into twice the size:
		for (int z = 0; z < lowerSizeZ - 1; ++z)
		{
			int idx = (z * 2) * lowStepX;
			int PrevZ0 = lowerData[z * lowerSizeX];
			int PrevZ1 = lowerData[(z + 1) * lowerSizeX];

			for (int x = 0; x < lowerSizeX - 1; ++x)
			{
				int ValX1Z0 = lowerData[x + 1 + z * lowerSizeX];
				int ValX1Z1 = lowerData[x + 1 + (z + 1) * lowerSizeX];
				int RndX = (x + lowerMinX) * 2;
				int RndZ = (z + lowerMinZ) * 2;
				Cache[idx] = PrevZ0;
				Cache[idx + lowStepX] = super::ChooseRandomOne(RndX, RndZ, PrevZ0, PrevZ1);
				idx++;
				Cache[idx] = super::ChooseRandomOne(RndX, RndZ, PrevZ0, ValX1Z0);
				Cache[idx + lowStepX] = super::ChooseRandomOne(RndX, RndZ, PrevZ0, ValX1Z0, PrevZ1, ValX1Z1);
				idx++;
				PrevZ0 = ValX1Z0;
				PrevZ1 = ValX1Z1;
			}
		}

		// Copy from Cache into a_Values; take into account the even/odd offsets in a_Min:
		for (int z = 0; z < a_SizeZ; ++z)
		{
			memcpy(a_Values + z * a_SizeX, Cache + (z + (a_MinZ & 1)) * lowStepX + (a_MinX & 1), a_SizeX * sizeof(int));
		}
	}

protected:
	Underlying m_UnderlyingGen;
};





class cProtIntGenSmooth :
	public cProtIntGenWithNoise
{
	typedef cProtIntGenWithNoise super;

public:
	cProtIntGenSmooth(int a_Seed, Underlying a_Underlying) :
		super(a_Seed),
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, int a_SizeX, int a_SizeZ, int * a_Values) override
	{
		// Generate the underlying values:
		int lowerSizeX = a_SizeX + 2;
		int lowerSizeZ = a_SizeZ + 2;
		ASSERT(lowerSizeX * lowerSizeZ <= m_BufferSize);
		int lowerData[m_BufferSize];
		m_Underlying->GetInts(a_MinX - 1, a_MinZ - 1, lowerSizeX, lowerSizeZ, lowerData);

		// Smooth - for each square check if the surroundings are the same, if so, expand them diagonally.
		// Also get rid of single-pixel irregularities (A-B-A):
		for (int z = 0; z < a_SizeZ; z++)
		{
			int NoiseZ = a_MinZ + z;
			for (int x = 0; x < a_SizeX; x++)
			{
				int val   = lowerData[x + 1 + (z + 1) * lowerSizeX];
				int Above = lowerData[x + 1 +  z      * lowerSizeX];
				int Below = lowerData[x + 1 + (z + 2) * lowerSizeX];
				int Left  = lowerData[x     + (z + 1) * lowerSizeX];
				int Right = lowerData[x + 2 + (z + 1) * lowerSizeX];

				if ((Left == Right) && (Above == Below))
				{
					if (((super::m_Noise.IntNoise2DInt(a_MinX + x, NoiseZ) / 7) % 2) == 0)
					{
						val = Left;
					}
					else
					{
						val = Above;
					}
				}
				else
				{
					if (Left == Right)
					{
						val = Left;
					}

					if (Above == Below)
					{
						val = Above;
					}
				}

				a_Values[x + z * a_SizeX] = val;
			}
		}
	}

protected:
	Underlying m_Underlying;
};





class cProtIntGenBeaches :
	public cProtIntGen
{
	typedef cProtIntGen super;

public:
	cProtIntGenBeaches(Underlying a_Underlying) :
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, int a_SizeX, int a_SizeZ, int * a_Values) override
	{
		// Map for biome -> its beach:
		static const int ToBeach[] =
		{
			/* biOcean            */ biOcean,
			/* biPlains           */ biBeach,
			/* biDesert           */ biBeach,
			/* biExtremeHills     */ biStoneBeach,
			/* biForest           */ biBeach,
			/* biTaiga            */ biColdBeach,
			/* biSwampland        */ biSwampland,
			/* biRiver            */ biRiver,
			/* biNether           */ biNether,
			/* biEnd              */ biEnd,
			/* biFrozenOcean      */ biColdBeach,
			/* biFrozenRiver      */ biColdBeach,
			/* biIcePlains        */ biColdBeach,
			/* biIceMountains     */ biColdBeach,
			/* biMushroomIsland   */ biMushroomShore,
			/* biMushroomShore    */ biMushroomShore,
			/* biBeach            */ biBeach,
			/* biDesertHills      */ biBeach,
			/* biForestHills      */ biBeach,
			/* biTaigaHills       */ biColdBeach,
			/* biExtremeHillsEdge */ biStoneBeach,
			/* biJungle           */ biBeach,
			/* biJungleHills      */ biBeach,
			/* biJungleEdge       */ biBeach,
			/* biDeepOcean        */ biOcean,
			/* biStoneBeach       */ biStoneBeach,
			/* biColdBeach        */ biColdBeach,
			/* biBirchForest      */ biBeach,
			/* biBirchForestHills */ biBeach,
			/* biRoofedForest     */ biBeach,
			/* biColdTaiga        */ biColdBeach,
			/* biColdTaigaHills   */ biColdBeach,
			/* biMegaTaiga        */ biStoneBeach,
			/* biMegaTaigaHills   */ biStoneBeach,
			/* biExtremeHillsPlus */ biStoneBeach,
			/* biSavanna          */ biBeach,
			/* biSavannaPlateau   */ biBeach,
			/* biMesa             */ biMesa,
			/* biMesaPlateauF     */ biMesa,
			/* biMesaPlateau      */ biMesa,
		};

		// Generate the underlying values:
		int lowerSizeX = a_SizeX + 2;
		int lowerSizeZ = a_SizeZ + 2;
		ASSERT(lowerSizeX * lowerSizeZ <= m_BufferSize);
		int lowerValues[m_BufferSize];
		m_Underlying->GetInts(a_MinX - 1, a_MinZ - 1, lowerSizeX, lowerSizeZ, lowerValues);

		// Add beaches between ocean and biomes:
		for (int z = 0; z < a_SizeZ; z++)
		{
			for (int x = 0; x < a_SizeX; x++)
			{
				int val   = lowerValues[x + 1 + (z + 1) * lowerSizeX];
				int Above = lowerValues[x + 1 + z       * lowerSizeX];
				int Below = lowerValues[x + 1 + (z + 2) * lowerSizeX];
				int Left  = lowerValues[x     + (z + 1) * lowerSizeX];
				int Right = lowerValues[x + 2 + (z + 1) * lowerSizeX];
				if (!IsBiomeOcean(val))
				{
					if (IsBiomeOcean(Above) || IsBiomeOcean(Below) || IsBiomeOcean(Left) || IsBiomeOcean(Right))
					{
						val = ToBeach[(val % 128) % ARRAYCOUNT(ToBeach)];
					}
				}
				a_Values[x + z * a_SizeX] = val;
			}
		}
	}

protected:
	Underlying m_Underlying;
};





/** Generates the underlying numbers and then randomly changes some zeroes into nonzeroes. */
class cProtIntGenAddIslands :
	public cProtIntGenWithNoise
{
	typedef cProtIntGenWithNoise super;

public:
	typedef std::shared_ptr<cProtIntGen> Underlying;


	cProtIntGenAddIslands(int a_Seed, int a_Threshold, Underlying a_Underlying) :
		super(a_Seed),
		m_Threshold(a_Threshold),
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, int a_SizeX, int a_SizeZ, int * a_Values) override
	{
		m_Underlying->GetInts(a_MinX, a_MinZ, a_SizeX, a_SizeZ, a_Values);
		for (int z = 0; z < a_SizeZ; z++)
		{
			for (int x = 0; x < a_SizeX; x++)
			{
				if (a_Values[x + z * a_SizeX] == bgOcean)
				{
					int rnd = super::m_Noise.IntNoise2DInt(a_MinX + x, a_MinZ + z) / 7;
					if (rnd % 100 < m_Threshold)
					{
						a_Values[x + z * a_SizeX] = (rnd / 100) % bgLandOceanMax;
					}
				}
			}
		}
	}

protected:
	int m_Threshold;

	Underlying m_Underlying;
};





/** A filter that adds an edge biome group between two biome groups that need an edge between them. */
class cProtIntGenBiomeGroupEdges :
	public cProtIntGen
{
	typedef cProtIntGen super;

public:
	cProtIntGenBiomeGroupEdges(Underlying a_Underlying) :
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, int a_SizeX, int a_SizeZ, int * a_Values)
	{
		// Generate the underlying biome groups:
		int lowerSizeX = a_SizeX + 2;
		int lowerSizeZ = a_SizeZ + 2;
		ASSERT(lowerSizeX * lowerSizeZ <= m_BufferSize);
		int lowerValues[m_BufferSize];
		m_Underlying->GetInts(a_MinX, a_MinZ, lowerSizeX, lowerSizeZ, lowerValues);

		// Change the biomes on incompatible edges into an edge biome:
		for (int z = 0; z < a_SizeZ; z++)
		{
			for (int x = 0; x < a_SizeX; x++)
			{
				int val   = lowerValues[x + 1 + (z + 1) * lowerSizeX];
				int Above = lowerValues[x + 1 + z       * lowerSizeX];
				int Below = lowerValues[x + 1 + (z + 2) * lowerSizeX];
				int Left  = lowerValues[x     + (z + 1) * lowerSizeX];
				int Right = lowerValues[x + 2 + (z + 1) * lowerSizeX];
				switch (val)
				{
					// Desert should neighbor only oceans, desert and temperates; change to temperate when another:
					case bgDesert:
					{
						if (
							!isDesertCompatible(Above) ||
							!isDesertCompatible(Below) ||
							!isDesertCompatible(Left) ||
							!isDesertCompatible(Right)
						)
						{
							val = bgTemperate;
						}
						break;
					}  // case bgDesert

					// Ice should not neighbor deserts; change to temperate:
					case bgIce:
					{
						if (
							(Above == bgDesert) ||
							(Below == bgDesert) ||
							(Left  == bgDesert) ||
							(Right == bgDesert)
						)
						{
							val = bgTemperate;
						}
						break;
					}  // case bgIce

					// Jungle should not neighbor Desert or Ice; change to temperate:
					case bgJungle:
					{
						if (
							!isJungleCompatible(Above) ||
							!isJungleCompatible(Below) ||
							!isJungleCompatible(Left) ||
							!isJungleCompatible(Right)
						)
						{
							val = bgTemperate;
						}
					}  // case bgJungle

					// Mesa should neighbor only oceans and deserts; change to desert when another:
					case bgMesa:
					{
						if (
							!isMesaCompatible(Above) ||
							!isMesaCompatible(Below) ||
							!isMesaCompatible(Left) ||
							!isMesaCompatible(Right)
						)
						{
							val = bgDesert;
						}
						break;
					}  // case bgDesert
				}
				a_Values[x + z * a_SizeX] = val;
			}  // for x
		}  // for z
	}

protected:
	Underlying m_Underlying;


	inline bool isDesertCompatible(int a_BiomeGroup)
	{
		switch (a_BiomeGroup)
		{
			case bgOcean:
			case bgDesert:
			case bgTemperate:
			case bgMesa:
			{
				return true;
			}
			default:
			{
				return false;
			}
		}
	}

	inline bool isJungleCompatible(int a_BiomeGroup)
	{
		return ((a_BiomeGroup != bgDesert) && (a_BiomeGroup != bgMesa) && (a_BiomeGroup != bgIce));
	}

	inline bool isMesaCompatible(int a_BiomeGroup)
	{
		return ((a_BiomeGroup == bgOcean) || (a_BiomeGroup == bgDesert));
	}
};





/** Turns biome group indices into real biomes.
For each pixel, takes its biome group and chooses a random biome from that group; replaces the value with
that biome. */
class cProtIntGenBiomes :
	public cProtIntGenWithNoise
{
	typedef cProtIntGenWithNoise super;

public:
	cProtIntGenBiomes(int a_Seed, Underlying a_Underlying) :
		super(a_Seed),
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, int a_SizeX, int a_SizeZ, int * a_Values) override
	{
		// Define the per-biome-group biomes:
		static const int oceanBiomes[] =
		{
			biOcean, // biDeepOcean,
		};

		static const int desertBiomes[] =
		{
			biDesert, biDesert, biDesert, biDesert, biDesert, biDesert, biSavanna, biSavanna, biPlains,
		};

		static const int temperateBiomes[] =
		{
			biForest, biForest, biRoofedForest, biExtremeHills, biPlains, biBirchForest, biSwampland,
		};

		static const int mountainBiomes[] =
		{
			biExtremeHills, biForest, biTaiga, biPlains,
		};

		static const int jungleBiomes[] =
		{
			biJungle, biJungle, biJungle, biForest,
		};

		static const int iceBiomes[] =
		{
			biIcePlains, biIcePlains, biIcePlains, biIcePlains, biColdTaiga,
		};

		static const int mesaBiomes[] =
		{
			biMesa, biMesaPlateau,
		};

		static const cBiomesInGroups BiomesInGroups[] =
		{
			/* bgOcean */     { static_cast<int>(ARRAYCOUNT(oceanBiomes)),     oceanBiomes},
			/* bgDesert */    { static_cast<int>(ARRAYCOUNT(desertBiomes)),    desertBiomes},
			/* bgTemperate */ { static_cast<int>(ARRAYCOUNT(temperateBiomes)), temperateBiomes},
			/* bgMountains */ { static_cast<int>(ARRAYCOUNT(mountainBiomes)),  mountainBiomes},
			/* bgJungle */    { static_cast<int>(ARRAYCOUNT(jungleBiomes)),    jungleBiomes},
			/* bgIce */       { static_cast<int>(ARRAYCOUNT(iceBiomes)),       iceBiomes},
			/* bgMesa */      { static_cast<int>(ARRAYCOUNT(mesaBiomes)),      mesaBiomes},
		};

		// Generate the underlying values, representing biome groups:
		m_Underlying->GetInts(a_MinX, a_MinZ, a_SizeX, a_SizeZ, a_Values);

		// Overwrite each biome group with a random biome from that group:
		for (int z = 0; z < a_SizeZ; z++)
		{
			int IdxZ = z * a_SizeX;
			for (int x = 0; x < a_SizeX; x++)
			{
				int val = a_Values[x + IdxZ];
				const cBiomesInGroups & Biomes = BiomesInGroups[val % ARRAYCOUNT(BiomesInGroups)];
				int rnd = (super::m_Noise.IntNoise2DInt(x + a_MinX, z + a_MinZ) / 7);
				a_Values[x + IdxZ] = Biomes.Biomes[rnd % Biomes.Count];
			}
		}
	}

protected:

	struct cBiomesInGroups
	{
		const int Count;
		const int * Biomes;
	};


	/** The underlying int generator */
	Underlying m_Underlying;
};





class cProtIntGenReplaceRandomly :
	public cProtIntGenWithNoise
{
	typedef cProtIntGenWithNoise super;

public:
	typedef std::shared_ptr<cProtIntGen> Underlying;


	cProtIntGenReplaceRandomly(int a_From, int a_To, int a_Chance, int a_Seed, Underlying a_Underlying) :
		super(a_Seed),
		m_From(a_From),
		m_To(a_To),
		m_Chance(a_Chance),
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, int a_SizeX, int a_SizeZ, int * a_Values) override
	{
		// Generate the underlying values:
		m_Underlying->GetInts(a_MinX, a_MinZ, a_SizeX, a_SizeZ, a_Values);

		// Replace some of the values:
		for (int z = 0; z < a_SizeZ; z++)
		{
			int idxZ = z * a_SizeX;
			for (int x = 0; x < a_SizeX; x++)
			{
				int idx = x + idxZ;
				if (a_Values[idx] == m_From)
				{
					int rnd = super::m_Noise.IntNoise2DInt(x + a_MinX, z + a_MinZ) / 7;
					if (rnd % 100 < m_Chance)
					{
						a_Values[idx] = m_To;
					}
				}
			}
		}  // for z
	}


protected:
	int m_From;
	int m_To;
	int m_Chance;
	Underlying m_Underlying;
};





/** Mixer that joins together finalized biomes and rivers.
It first checks for oceans; if there's no ocean, it checks for a river. */
class cProtIntGenMixRivers:
	public cProtIntGen
{
	typedef cProtIntGen super;

public:
	cProtIntGenMixRivers(Underlying a_Biomes, Underlying a_Rivers):
		m_Biomes(a_Biomes),
		m_Rivers(a_Rivers)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, int a_SizeX, int a_SizeZ, int * a_Values) override
	{
		// Generate the underlying data:
		ASSERT(a_SizeX * a_SizeZ <= m_BufferSize);
		m_Biomes->GetInts(a_MinX, a_MinZ, a_SizeX, a_SizeZ, a_Values);
		int riverData[m_BufferSize];
		m_Rivers->GetInts(a_MinX, a_MinZ, a_SizeX, a_SizeZ, riverData);

		// Mix the values:
		for (int z = 0; z < a_SizeZ; z++)
		{
			int idxZ = z * a_SizeX;
			for (int x = 0; x < a_SizeX; x++)
			{
				int idx = x + idxZ;
				if (IsBiomeOcean(a_Values[idx]))
				{
					// Oceans are kept without any changes
					continue;
				}
				if (riverData[idx] != biRiver)
				{
					// There's no river, keep the current value
					continue;
				}

				// There's a river, change the output to a river or a frozen river, based on the original biome:
				if (IsBiomeVeryCold((EMCSBiome)a_Values[idx]))
				{
					a_Values[idx] = biFrozenRiver;
				}
				else
				{
					a_Values[idx] = biRiver;
				}
			}  // for x
		}  // for z
	}

protected:
	Underlying m_Biomes;
	Underlying m_Rivers;
};





/** Generates a river based on the underlying data.
This is basically an edge detector over the underlying data. The rivers are the edges where the underlying
data changes from one pixel to its neighbor. */
class cProtIntGenRiver:
	public cProtIntGenWithNoise
{
	typedef cProtIntGenWithNoise super;

public:
	cProtIntGenRiver(int a_Seed, Underlying a_Underlying):
		super(a_Seed),
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, int a_SizeX, int a_SizeZ, int * a_Values) override
	{
		// Generate the underlying data:
		int lowerSizeX = a_SizeX + 2;
		int lowerSizeZ = a_SizeZ + 2;
		ASSERT(lowerSizeX * lowerSizeZ <= m_BufferSize);
		int lowerValues[m_BufferSize];
		m_Underlying->GetInts(a_MinX - 1, a_MinZ - 1, lowerSizeX, lowerSizeZ, lowerValues);

		// Detect the edges:
		for (int z = 0; z < a_SizeZ; z++)
		{
			for (int x = 0; x < a_SizeX; x++)
			{
				int Above = lowerValues[x + 1 + z       * lowerSizeX];
				int Below = lowerValues[x + 1 + (z + 2) * lowerSizeX];
				int Left  = lowerValues[x +     (z + 1) * lowerSizeX];
				int Right = lowerValues[x + 2 + (z + 1) * lowerSizeX];
				int val   = lowerValues[x + 1 + (z + 1) * lowerSizeX];

				if ((val == Above) && (val == Below) && (val == Left) && (val == Right))
				{
					val = 0;
				}
				else
				{
					val = biRiver;
				}
				a_Values[x + z * a_SizeX] = val;
			}  // for x
		}  // for z
	}

protected:
	Underlying m_Underlying;
};





/** Turns some of the oceans into the specified biome. Used for mushroom and deep ocean.
The biome is only placed if at least 3 of its neighbors are ocean and only with the specified chance. */
class cProtIntGenAddToOcean:
	public cProtIntGenWithNoise
{
	typedef cProtIntGenWithNoise super;

public:
	cProtIntGenAddToOcean(int a_Seed, int a_Chance, int a_ToValue, Underlying a_Underlying):
		super(a_Seed),
		m_Chance(a_Chance),
		m_ToValue(a_ToValue),
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, int a_SizeX, int a_SizeZ, int * a_Values) override
	{
		// Generate the underlying data:
		int lowerSizeX = a_SizeX + 2;
		int lowerSizeZ = a_SizeZ + 2;
		ASSERT(lowerSizeX * lowerSizeZ <= m_BufferSize);
		int lowerValues[m_BufferSize];
		m_Underlying->GetInts(a_MinX - 1, a_MinZ - 1, lowerSizeX, lowerSizeZ, lowerValues);

		// Add the mushroom islands:
		for (int z = 0; z < a_SizeZ; z++)
		{
			for (int x = 0; x < a_SizeX; x++)
			{
				int val = lowerValues[x + 1 + (z + 1) * lowerSizeX];
				if (!IsBiomeOcean(val))
				{
					a_Values[x + z * a_SizeX] = val;
					continue;
				}

				// Count the ocean neighbors:
				int Above = lowerValues[x + 1 + z       * lowerSizeX];
				int Below = lowerValues[x + 1 + (z + 2) * lowerSizeX];
				int Left  = lowerValues[x +     (z + 1) * lowerSizeX];
				int Right = lowerValues[x + 2 + (z + 1) * lowerSizeX];
				int NumOceanNeighbors = 0;
				if (IsBiomeOcean(Above))
				{
					NumOceanNeighbors += 1;
				}
				if (IsBiomeOcean(Below))
				{
					NumOceanNeighbors += 1;
				}
				if (IsBiomeOcean(Left))
				{
					NumOceanNeighbors += 1;
				}
				if (IsBiomeOcean(Right))
				{
					NumOceanNeighbors += 1;
				}

				// If at least 3 ocean neighbors and the chance is right, change:
				if (
					(NumOceanNeighbors >= 3) &&
					((super::m_Noise.IntNoise2DInt(x + a_MinX, z + a_MinZ) / 7) % 1000 < m_Chance)
				)
				{
					a_Values[x + z * a_SizeX] = m_ToValue;
				}
				else
				{
					a_Values[x + z * a_SizeX] = val;
				}
			}  // for x
		}  // for z
	}

protected:
	/** Chance, in permille, of changing the biome. */
	int m_Chance;

	/** The value to change the ocean into. */
	int m_ToValue;

	Underlying m_Underlying;
};





/** Changes random pixels of the underlying data to the specified value. */
class cProtIntGenSetRandomly :
	public cProtIntGenWithNoise
{
	typedef cProtIntGenWithNoise super;

public:
	cProtIntGenSetRandomly(int a_Seed, int a_Chance, int a_ToValue, Underlying a_Underlying) :
		super(a_Seed),
		m_Chance(a_Chance),
		m_ToValue(a_ToValue),
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, int a_SizeX, int a_SizeZ, int * a_Values) override
	{
		// Generate the underlying data:
		m_Underlying->GetInts(a_MinX, a_MinZ, a_SizeX, a_SizeZ, a_Values);

		// Change random pixels to bgOcean:
		for (int z = 0; z < a_SizeZ; z++)
		{
			for (int x = 0; x < a_SizeX; x++)
			{
				int rnd = super::m_Noise.IntNoise2DInt(x + a_MinX, z + a_MinZ) / 7;
				if (rnd % 1000 < m_Chance)
				{
					a_Values[x + z * a_SizeX] = m_ToValue;
				}
			}
		}
	}

protected:
	/** Chance, in permille, of changing each pixel. */
	int m_Chance;

	/** The value to which to set the pixel. */
	int m_ToValue;

	Underlying m_Underlying;
};