summaryrefslogtreecommitdiff
path: root/src/tree_cmd.cpp
blob: 9798c2bb56cfe02e03eb4615f72577a278cbe02a (plain)
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
/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD 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 General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file tree_cmd.cpp Handling of tree tiles. */

#include "stdafx.h"
#include "clear_map.h"
#include "landscape.h"
#include "tree_map.h"
#include "viewport_func.h"
#include "command_func.h"
#include "town.h"
#include "genworld.h"
#include "clear_func.h"
#include "company_func.h"
#include "sound_func.h"
#include "water.h"
#include "company_base.h"
#include "core/random_func.hpp"
#include "newgrf_generic.h"
#include "date_func.h"

#include "table/strings.h"
#include "table/tree_land.h"
#include "table/clear_land.h"

#include "safeguards.h"

/**
 * List of tree placer algorithm.
 *
 * This enumeration defines all possible tree placer algorithm in the game.
 */
enum TreePlacer {
	TP_NONE,     ///< No tree placer algorithm
	TP_ORIGINAL, ///< The original algorithm
	TP_IMPROVED, ///< A 'improved' algorithm
};

/** Where to place trees while in-game? */
enum ExtraTreePlacement {
	ETP_NO_SPREAD,           ///< Grow trees on tiles that have them but don't spread to new ones
	ETP_SPREAD_RAINFOREST,   ///< Grow trees on tiles that have them, only spread to new ones in rainforests
	ETP_SPREAD_ALL,          ///< Grow trees and spread them without restrictions
	ETP_NO_GROWTH_NO_SPREAD, ///< Don't grow trees and don't spread them at all
};

/** Determines when to consider building more trees. */
byte _trees_tick_ctr;

static const uint16 DEFAULT_TREE_STEPS = 1000;             ///< Default number of attempts for placing trees.
static const uint16 DEFAULT_RAINFOREST_TREE_STEPS = 15000; ///< Default number of attempts for placing extra trees at rainforest in tropic.
static const uint16 EDITOR_TREE_DIV = 5;                   ///< Game editor tree generation divisor factor.

/**
 * Tests if a tile can be converted to MP_TREES
 * This is true for clear ground without farms or rocks.
 *
 * @param tile the tile of interest
 * @param allow_desert Allow planting trees on CLEAR_DESERT?
 * @return true if trees can be built.
 */
static bool CanPlantTreesOnTile(TileIndex tile, bool allow_desert)
{
	switch (GetTileType(tile)) {
		case MP_WATER:
			return !IsBridgeAbove(tile) && IsCoast(tile) && !IsSlopeWithOneCornerRaised(GetTileSlope(tile));

		case MP_CLEAR:
			return !IsBridgeAbove(tile) && !IsClearGround(tile, CLEAR_FIELDS) && GetRawClearGround(tile) != CLEAR_ROCKS &&
			       (allow_desert || !IsClearGround(tile, CLEAR_DESERT));

		default: return false;
	}
}

/**
 * Creates a tree tile
 * Ground type and density is preserved.
 *
 * @pre the tile must be suitable for trees.
 *
 * @param tile where to plant the trees.
 * @param treetype The type of the tree
 * @param count the number of trees (minus 1)
 * @param growth the growth status
 */
static void PlantTreesOnTile(TileIndex tile, TreeType treetype, uint count, uint growth)
{
	assert(treetype != TREE_INVALID);
	assert(CanPlantTreesOnTile(tile, true));

	TreeGround ground;
	uint density = 3;

	switch (GetTileType(tile)) {
		case MP_WATER:
			ground = TREE_GROUND_SHORE;
			break;

		case MP_CLEAR:
			switch (GetClearGround(tile)) {
				case CLEAR_GRASS:  ground = TREE_GROUND_GRASS;       break;
				case CLEAR_ROUGH:  ground = TREE_GROUND_ROUGH;       break;
				case CLEAR_SNOW:   ground = GetRawClearGround(tile) == CLEAR_ROUGH ? TREE_GROUND_ROUGH_SNOW : TREE_GROUND_SNOW_DESERT; break;
				default:           ground = TREE_GROUND_SNOW_DESERT; break;
			}
			if (GetClearGround(tile) != CLEAR_ROUGH) density = GetClearDensity(tile);
			break;

		default: NOT_REACHED();
	}

	MakeTree(tile, treetype, count, growth, ground, density);
}

/**
 * Get a random TreeType for the given tile based on a given seed
 *
 * This function returns a random TreeType which can be placed on the given tile.
 * The seed for randomness must be less or equal 256, use #GB on the value of Random()
 * to get such a value.
 *
 * @param tile The tile to get a random TreeType from
 * @param seed The seed for randomness, must be less or equal 256
 * @return The random tree type
 */
static TreeType GetRandomTreeType(TileIndex tile, uint seed)
{
	switch (_settings_game.game_creation.landscape) {
		case LT_TEMPERATE:
			return (TreeType)(seed * TREE_COUNT_TEMPERATE / 256 + TREE_TEMPERATE);

		case LT_ARCTIC:
			return (TreeType)(seed * TREE_COUNT_SUB_ARCTIC / 256 + TREE_SUB_ARCTIC);

		case LT_TROPIC:
			switch (GetTropicZone(tile)) {
				case TROPICZONE_NORMAL:  return (TreeType)(seed * TREE_COUNT_SUB_TROPICAL / 256 + TREE_SUB_TROPICAL);
				case TROPICZONE_DESERT:  return (TreeType)((seed > 12) ? TREE_INVALID : TREE_CACTUS);
				default:                 return (TreeType)(seed * TREE_COUNT_RAINFOREST / 256 + TREE_RAINFOREST);
			}

		default:
			return (TreeType)(seed * TREE_COUNT_TOYLAND / 256 + TREE_TOYLAND);
	}
}

/**
 * Make a random tree tile of the given tile
 *
 * Create a new tree-tile for the given tile. The second parameter is used for
 * randomness like type and number of trees.
 *
 * @param tile The tile to make a tree-tile from
 * @param r The randomness value from a Random() value
 */
static void PlaceTree(TileIndex tile, uint32 r)
{
	TreeType tree = GetRandomTreeType(tile, GB(r, 24, 8));

	if (tree != TREE_INVALID) {
		PlantTreesOnTile(tile, tree, GB(r, 22, 2), std::min<byte>(GB(r, 16, 3), 6));
		MarkTileDirtyByTile(tile);

		/* Rerandomize ground, if neither snow nor shore */
		TreeGround ground = GetTreeGround(tile);
		if (ground != TREE_GROUND_SNOW_DESERT && ground != TREE_GROUND_ROUGH_SNOW && ground != TREE_GROUND_SHORE) {
			SetTreeGroundDensity(tile, (TreeGround)GB(r, 28, 1), 3);
		}

		/* Set the counter to a random start value */
		SetTreeCounter(tile, (TreeGround)GB(r, 24, 4));
	}
}

/**
 * Creates a number of tree groups.
 * The number of trees in each group depends on how many trees are actually placed around the given tile.
 *
 * @param num_groups Number of tree groups to place.
 */
static void PlaceTreeGroups(uint num_groups)
{
	do {
		TileIndex center_tile = RandomTile();

		for (uint i = 0; i < DEFAULT_TREE_STEPS; i++) {
			uint32 r = Random();
			int x = GB(r, 0, 5) - 16;
			int y = GB(r, 8, 5) - 16;
			uint dist = abs(x) + abs(y);
			TileIndex cur_tile = TileAddWrap(center_tile, x, y);

			IncreaseGeneratingWorldProgress(GWP_TREE);

			if (cur_tile != INVALID_TILE && dist <= 13 && CanPlantTreesOnTile(cur_tile, true)) {
				PlaceTree(cur_tile, r);
			}
		}

	} while (--num_groups);
}

/**
 * Place a tree at the same height as an existing tree.
 *
 * Add a new tree around the given tile which is at the same
 * height or at some offset (2 units) of it.
 *
 * @param tile The base tile to add a new tree somewhere around
 * @param height The height (like the one from the tile)
 */
static void PlaceTreeAtSameHeight(TileIndex tile, int height)
{
	for (uint i = 0; i < DEFAULT_TREE_STEPS; i++) {
		uint32 r = Random();
		int x = GB(r, 0, 5) - 16;
		int y = GB(r, 8, 5) - 16;
		TileIndex cur_tile = TileAddWrap(tile, x, y);
		if (cur_tile == INVALID_TILE) continue;

		/* Keep in range of the existing tree */
		if (abs(x) + abs(y) > 16) continue;

		/* Clear tile, no farm-tiles or rocks */
		if (!CanPlantTreesOnTile(cur_tile, true)) continue;

		/* Not too much height difference */
		if (Delta(GetTileZ(cur_tile), height) > 2) continue;

		/* Place one tree and quit */
		PlaceTree(cur_tile, r);
		break;
	}
}

/**
 * Place some trees randomly
 *
 * This function just place some trees randomly on the map.
 */
void PlaceTreesRandomly()
{
	int i, j, ht;

	i = ScaleByMapSize(DEFAULT_TREE_STEPS);
	if (_game_mode == GM_EDITOR) i /= EDITOR_TREE_DIV;
	do {
		uint32 r = Random();
		TileIndex tile = RandomTileSeed(r);

		IncreaseGeneratingWorldProgress(GWP_TREE);

		if (CanPlantTreesOnTile(tile, true)) {
			PlaceTree(tile, r);
			if (_settings_game.game_creation.tree_placer != TP_IMPROVED) continue;

			/* Place a number of trees based on the tile height.
			 *  This gives a cool effect of multiple trees close together.
			 *  It is almost real life ;) */
			ht = GetTileZ(tile);
			/* The higher we get, the more trees we plant */
			j = GetTileZ(tile) * 2;
			/* Above snowline more trees! */
			if (_settings_game.game_creation.landscape == LT_ARCTIC && ht > GetSnowLine()) j *= 3;
			while (j--) {
				PlaceTreeAtSameHeight(tile, ht);
			}
		}
	} while (--i);

	/* place extra trees at rainforest area */
	if (_settings_game.game_creation.landscape == LT_TROPIC) {
		i = ScaleByMapSize(DEFAULT_RAINFOREST_TREE_STEPS);
		if (_game_mode == GM_EDITOR) i /= EDITOR_TREE_DIV;

		do {
			uint32 r = Random();
			TileIndex tile = RandomTileSeed(r);

			IncreaseGeneratingWorldProgress(GWP_TREE);

			if (GetTropicZone(tile) == TROPICZONE_RAINFOREST && CanPlantTreesOnTile(tile, false)) {
				PlaceTree(tile, r);
			}
		} while (--i);
	}
}

/**
 * Place some trees in a radius around a tile.
 * The trees are placed in an quasi-normal distribution around the indicated tile, meaning that while
 * the radius does define a square, the distribution inside the square will be roughly circular.
 * @note This function the interactive RNG and must only be used in editor and map generation.
 * @param tile      Tile to place trees around.
 * @param treetype  Type of trees to place. Must be a valid tree type for the climate.
 * @param radius    Maximum distance (on each axis) from tile to place trees.
 * @param count     Maximum number of trees to place.
 * @return Number of trees actually placed.
 */
uint PlaceTreeGroupAroundTile(TileIndex tile, TreeType treetype, uint radius, uint count)
{
	assert(treetype < TREE_TOYLAND + TREE_COUNT_TOYLAND);
	const bool allow_desert = treetype == TREE_CACTUS;
	uint planted = 0;

	for (; count > 0; count--) {
		/* Simple quasi-normal distribution with range [-radius; radius) */
		auto mkcoord = [&]() -> int32 {
			const uint32 rand = InteractiveRandom();
			const int32 dist = GB<int32>(rand, 0, 8) + GB<int32>(rand, 8, 8) + GB<int32>(rand, 16, 8) + GB<int32>(rand, 24, 8);
			const int32 scu = dist * radius / 512;
			return scu - radius;
		};
		const int32 xofs = mkcoord();
		const int32 yofs = mkcoord();
		const TileIndex tile_to_plant = TileAddWrap(tile, xofs, yofs);
		if (tile_to_plant != INVALID_TILE) {
			if (IsTileType(tile_to_plant, MP_TREES) && GetTreeCount(tile_to_plant) < 4) {
				AddTreeCount(tile_to_plant, 1);
				SetTreeGrowth(tile_to_plant, 0);
				MarkTileDirtyByTile(tile_to_plant, 0);
				planted++;
			} else if (CanPlantTreesOnTile(tile_to_plant, allow_desert)) {
				PlantTreesOnTile(tile_to_plant, treetype, 0, 3);
				MarkTileDirtyByTile(tile_to_plant, 0);
				planted++;
			}
		}
	}

	return planted;
}

/**
 * Place new trees.
 *
 * This function takes care of the selected tree placer algorithm and
 * place randomly the trees for a new game.
 */
void GenerateTrees()
{
	uint i, total;

	if (_settings_game.game_creation.tree_placer == TP_NONE) return;

	switch (_settings_game.game_creation.tree_placer) {
		case TP_ORIGINAL: i = _settings_game.game_creation.landscape == LT_ARCTIC ? 15 : 6; break;
		case TP_IMPROVED: i = _settings_game.game_creation.landscape == LT_ARCTIC ?  4 : 2; break;
		default: NOT_REACHED();
	}

	total = ScaleByMapSize(DEFAULT_TREE_STEPS);
	if (_settings_game.game_creation.landscape == LT_TROPIC) total += ScaleByMapSize(DEFAULT_RAINFOREST_TREE_STEPS);
	total *= i;
	uint num_groups = (_settings_game.game_creation.landscape != LT_TOYLAND) ? ScaleByMapSize(GB(Random(), 0, 5) + 25) : 0;
	total += num_groups * DEFAULT_TREE_STEPS;
	SetGeneratingWorldProgress(GWP_TREE, total);

	if (num_groups != 0) PlaceTreeGroups(num_groups);

	for (; i != 0; i--) {
		PlaceTreesRandomly();
	}
}

/**
 * Plant a tree.
 * @param tile end tile of area-drag
 * @param flags type of operation
 * @param p1 tree type, TREE_INVALID means random.
 * @param p2 start tile of area-drag of tree plantation
 * @param text unused
 * @return the cost of this operation or an error
 */
CommandCost CmdPlantTree(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
{
	StringID msg = INVALID_STRING_ID;
	CommandCost cost(EXPENSES_OTHER);
	const byte tree_to_plant = GB(p1, 0, 8); // We cannot use Extract as min and max are climate specific.

	if (p2 >= MapSize()) return CMD_ERROR;
	/* Check the tree type within the current climate */
	if (tree_to_plant != TREE_INVALID && !IsInsideBS(tree_to_plant, _tree_base_by_landscape[_settings_game.game_creation.landscape], _tree_count_by_landscape[_settings_game.game_creation.landscape])) return CMD_ERROR;

	Company *c = (_game_mode != GM_EDITOR) ? Company::GetIfValid(_current_company) : nullptr;
	int limit = (c == nullptr ? INT32_MAX : GB(c->tree_limit, 16, 16));

	TileArea ta(tile, p2);
	for (TileIndex tile : ta) {
		switch (GetTileType(tile)) {
			case MP_TREES:
				/* no more space for trees? */
				if (GetTreeCount(tile) == 4) {
					msg = STR_ERROR_TREE_ALREADY_HERE;
					continue;
				}

				/* Test tree limit. */
				if (--limit < 1) {
					msg = STR_ERROR_TREE_PLANT_LIMIT_REACHED;
					break;
				}

				if (flags & DC_EXEC) {
					AddTreeCount(tile, 1);
					MarkTileDirtyByTile(tile);
					if (c != nullptr) c->tree_limit -= 1 << 16;
				}
				/* 2x as expensive to add more trees to an existing tile */
				cost.AddCost(_price[PR_BUILD_TREES] * 2);
				break;

			case MP_WATER:
				if (!IsCoast(tile) || IsSlopeWithOneCornerRaised(GetTileSlope(tile))) {
					msg = STR_ERROR_CAN_T_BUILD_ON_WATER;
					continue;
				}
				FALLTHROUGH;

			case MP_CLEAR: {
				if (IsBridgeAbove(tile)) {
					msg = STR_ERROR_SITE_UNSUITABLE;
					continue;
				}

				TreeType treetype = (TreeType)tree_to_plant;
				/* Be a bit picky about which trees go where. */
				if (_settings_game.game_creation.landscape == LT_TROPIC && treetype != TREE_INVALID && (
						/* No cacti outside the desert */
						(treetype == TREE_CACTUS && GetTropicZone(tile) != TROPICZONE_DESERT) ||
						/* No rain forest trees outside the rain forest, except in the editor mode where it makes those tiles rain forest tile */
						(IsInsideMM(treetype, TREE_RAINFOREST, TREE_CACTUS) && GetTropicZone(tile) != TROPICZONE_RAINFOREST && _game_mode != GM_EDITOR) ||
						/* And no subtropical trees in the desert/rain forest */
						(IsInsideMM(treetype, TREE_SUB_TROPICAL, TREE_TOYLAND) && GetTropicZone(tile) != TROPICZONE_NORMAL))) {
					msg = STR_ERROR_TREE_WRONG_TERRAIN_FOR_TREE_TYPE;
					continue;
				}

				/* Test tree limit. */
				if (--limit < 1) {
					msg = STR_ERROR_TREE_PLANT_LIMIT_REACHED;
					break;
				}

				if (IsTileType(tile, MP_CLEAR)) {
					/* Remove fields or rocks. Note that the ground will get barrened */
					switch (GetRawClearGround(tile)) {
						case CLEAR_FIELDS:
						case CLEAR_ROCKS: {
							CommandCost ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
							if (ret.Failed()) return ret;
							cost.AddCost(ret);
							break;
						}

						default: break;
					}
				}

				if (_game_mode != GM_EDITOR && Company::IsValidID(_current_company)) {
					Town *t = ClosestTownFromTile(tile, _settings_game.economy.dist_local_authority);
					if (t != nullptr) ChangeTownRating(t, RATING_TREE_UP_STEP, RATING_TREE_MAXIMUM, flags);
				}

				if (flags & DC_EXEC) {
					if (treetype == TREE_INVALID) {
						treetype = GetRandomTreeType(tile, GB(Random(), 24, 8));
						if (treetype == TREE_INVALID) treetype = TREE_CACTUS;
					}

					/* Plant full grown trees in scenario editor */
					PlantTreesOnTile(tile, treetype, 0, _game_mode == GM_EDITOR ? 3 : 0);
					MarkTileDirtyByTile(tile);
					if (c != nullptr) c->tree_limit -= 1 << 16;

					/* When planting rainforest-trees, set tropiczone to rainforest in editor. */
					if (_game_mode == GM_EDITOR && IsInsideMM(treetype, TREE_RAINFOREST, TREE_CACTUS)) {
						SetTropicZone(tile, TROPICZONE_RAINFOREST);
					}
				}
				cost.AddCost(_price[PR_BUILD_TREES]);
				break;
			}

			default:
				msg = STR_ERROR_SITE_UNSUITABLE;
				break;
		}

		/* Tree limit used up? No need to check more. */
		if (limit < 0) break;
	}

	if (cost.GetCost() == 0) {
		return_cmd_error(msg);
	} else {
		return cost;
	}
}

struct TreeListEnt : PalSpriteID {
	byte x, y;
};

static void DrawTile_Trees(TileInfo *ti)
{
	switch (GetTreeGround(ti->tile)) {
		case TREE_GROUND_SHORE: DrawShoreTile(ti->tileh); break;
		case TREE_GROUND_GRASS: DrawClearLandTile(ti, GetTreeDensity(ti->tile)); break;
		case TREE_GROUND_ROUGH: DrawHillyLandTile(ti); break;
		default: DrawGroundSprite(_clear_land_sprites_snow_desert[GetTreeDensity(ti->tile)] + SlopeToSpriteOffset(ti->tileh), PAL_NONE); break;
	}

	/* Do not draw trees when the invisible trees setting is set */
	if (IsInvisibilitySet(TO_TREES)) return;

	uint tmp = CountBits(ti->tile + ti->x + ti->y);
	uint index = GB(tmp, 0, 2) + (GetTreeType(ti->tile) << 2);

	/* different tree styles above one of the grounds */
	if ((GetTreeGround(ti->tile) == TREE_GROUND_SNOW_DESERT || GetTreeGround(ti->tile) == TREE_GROUND_ROUGH_SNOW) &&
			GetTreeDensity(ti->tile) >= 2 &&
			IsInsideMM(index, TREE_SUB_ARCTIC << 2, TREE_RAINFOREST << 2)) {
		index += 164 - (TREE_SUB_ARCTIC << 2);
	}

	assert(index < lengthof(_tree_layout_sprite));

	const PalSpriteID *s = _tree_layout_sprite[index];
	const TreePos *d = _tree_layout_xy[GB(tmp, 2, 2)];

	/* combine trees into one sprite object */
	StartSpriteCombine();

	TreeListEnt te[4];

	/* put the trees to draw in a list */
	uint trees = GetTreeCount(ti->tile);

	for (uint i = 0; i < trees; i++) {
		SpriteID sprite = s[0].sprite + (i == trees - 1 ? GetTreeGrowth(ti->tile) : 3);
		PaletteID pal = s[0].pal;

		te[i].sprite = sprite;
		te[i].pal    = pal;
		te[i].x = d->x;
		te[i].y = d->y;
		s++;
		d++;
	}

	/* draw them in a sorted way */
	int z = ti->z + GetSlopeMaxPixelZ(ti->tileh) / 2;

	for (; trees > 0; trees--) {
		uint min = te[0].x + te[0].y;
		uint mi = 0;

		for (uint i = 1; i < trees; i++) {
			if ((uint)(te[i].x + te[i].y) < min) {
				min = te[i].x + te[i].y;
				mi = i;
			}
		}

		AddSortableSpriteToDraw(te[mi].sprite, te[mi].pal, ti->x + te[mi].x, ti->y + te[mi].y, 16 - te[mi].x, 16 - te[mi].y, 0x30, z, IsTransparencySet(TO_TREES), -te[mi].x, -te[mi].y);

		/* replace the removed one with the last one */
		te[mi] = te[trees - 1];
	}

	EndSpriteCombine();
}


static int GetSlopePixelZ_Trees(TileIndex tile, uint x, uint y)
{
	int z;
	Slope tileh = GetTilePixelSlope(tile, &z);

	return z + GetPartialPixelZ(x & 0xF, y & 0xF, tileh);
}

static Foundation GetFoundation_Trees(TileIndex tile, Slope tileh)
{
	return FOUNDATION_NONE;
}

static CommandCost ClearTile_Trees(TileIndex tile, DoCommandFlag flags)
{
	uint num;

	if (Company::IsValidID(_current_company)) {
		Town *t = ClosestTownFromTile(tile, _settings_game.economy.dist_local_authority);
		if (t != nullptr) ChangeTownRating(t, RATING_TREE_DOWN_STEP, RATING_TREE_MINIMUM, flags);
	}

	num = GetTreeCount(tile);
	if (IsInsideMM(GetTreeType(tile), TREE_RAINFOREST, TREE_CACTUS)) num *= 4;

	if (flags & DC_EXEC) DoClearSquare(tile);

	return CommandCost(EXPENSES_CONSTRUCTION, num * _price[PR_CLEAR_TREES]);
}

static void GetTileDesc_Trees(TileIndex tile, TileDesc *td)
{
	TreeType tt = GetTreeType(tile);

	if (IsInsideMM(tt, TREE_RAINFOREST, TREE_CACTUS)) {
		td->str = STR_LAI_TREE_NAME_RAINFOREST;
	} else {
		td->str = tt == TREE_CACTUS ? STR_LAI_TREE_NAME_CACTUS_PLANTS : STR_LAI_TREE_NAME_TREES;
	}

	td->owner[0] = GetTileOwner(tile);
}

static void TileLoopTreesDesert(TileIndex tile)
{
	switch (GetTropicZone(tile)) {
		case TROPICZONE_DESERT:
			if (GetTreeGround(tile) != TREE_GROUND_SNOW_DESERT) {
				SetTreeGroundDensity(tile, TREE_GROUND_SNOW_DESERT, 3);
				MarkTileDirtyByTile(tile);
			}
			break;

		case TROPICZONE_RAINFOREST: {
			static const SoundFx forest_sounds[] = {
				SND_42_RAINFOREST_1,
				SND_43_RAINFOREST_2,
				SND_44_RAINFOREST_3,
				SND_48_RAINFOREST_4
			};
			uint32 r = Random();

			if (Chance16I(1, 200, r) && _settings_client.sound.ambient) SndPlayTileFx(forest_sounds[GB(r, 16, 2)], tile);
			break;
		}

		default: break;
	}
}

static void TileLoopTreesAlps(TileIndex tile)
{
	int k = GetTileZ(tile) - GetSnowLine() + 1;

	if (k < 0) {
		switch (GetTreeGround(tile)) {
			case TREE_GROUND_SNOW_DESERT: SetTreeGroundDensity(tile, TREE_GROUND_GRASS, 3); break;
			case TREE_GROUND_ROUGH_SNOW:  SetTreeGroundDensity(tile, TREE_GROUND_ROUGH, 3); break;
			default: return;
		}
	} else {
		uint density = std::min<uint>(k, 3);

		if (GetTreeGround(tile) != TREE_GROUND_SNOW_DESERT && GetTreeGround(tile) != TREE_GROUND_ROUGH_SNOW) {
			TreeGround tg = GetTreeGround(tile) == TREE_GROUND_ROUGH ? TREE_GROUND_ROUGH_SNOW : TREE_GROUND_SNOW_DESERT;
			SetTreeGroundDensity(tile, tg, density);
		} else if (GetTreeDensity(tile) != density) {
			SetTreeGroundDensity(tile, GetTreeGround(tile), density);
		} else {
			if (GetTreeDensity(tile) == 3) {
				uint32 r = Random();
				if (Chance16I(1, 200, r) && _settings_client.sound.ambient) {
					SndPlayTileFx((r & 0x80000000) ? SND_39_ARCTIC_SNOW_2 : SND_34_ARCTIC_SNOW_1, tile);
				}
			}
			return;
		}
	}
	MarkTileDirtyByTile(tile);
}

static bool CanPlantExtraTrees(TileIndex tile)
{
	return ((_settings_game.game_creation.landscape == LT_TROPIC && GetTropicZone(tile) == TROPICZONE_RAINFOREST) ?
		(_settings_game.construction.extra_tree_placement == ETP_SPREAD_ALL || _settings_game.construction.extra_tree_placement == ETP_SPREAD_RAINFOREST) :
		_settings_game.construction.extra_tree_placement == ETP_SPREAD_ALL);
}

static void TileLoop_Trees(TileIndex tile)
{
	if (GetTreeGround(tile) == TREE_GROUND_SHORE) {
		TileLoop_Water(tile);
	} else {
		switch (_settings_game.game_creation.landscape) {
			case LT_TROPIC: TileLoopTreesDesert(tile); break;
			case LT_ARCTIC: TileLoopTreesAlps(tile);   break;
		}
	}

	AmbientSoundEffect(tile);

	uint treeCounter = GetTreeCounter(tile);

	/* Handle growth of grass (under trees/on MP_TREES tiles) at every 8th processings, like it's done for grass on MP_CLEAR tiles. */
	if ((treeCounter & 7) == 7 && GetTreeGround(tile) == TREE_GROUND_GRASS) {
		uint density = GetTreeDensity(tile);
		if (density < 3) {
			SetTreeGroundDensity(tile, TREE_GROUND_GRASS, density + 1);
			MarkTileDirtyByTile(tile);
		}
	}

	if (_settings_game.construction.extra_tree_placement == ETP_NO_GROWTH_NO_SPREAD) return;

	if (GetTreeCounter(tile) < 15) {
		AddTreeCounter(tile, 1);
		return;
	}
	SetTreeCounter(tile, 0);

	switch (GetTreeGrowth(tile)) {
		case 3: // regular sized tree
			if (_settings_game.game_creation.landscape == LT_TROPIC &&
					GetTreeType(tile) != TREE_CACTUS &&
					GetTropicZone(tile) == TROPICZONE_DESERT) {
				AddTreeGrowth(tile, 1);
			} else {
				switch (GB(Random(), 0, 3)) {
					case 0: // start destructing
						AddTreeGrowth(tile, 1);
						break;

					case 1: // add a tree
						if (GetTreeCount(tile) < 4 && CanPlantExtraTrees(tile)) {
							AddTreeCount(tile, 1);
							SetTreeGrowth(tile, 0);
							break;
						}
						FALLTHROUGH;

					case 2: { // add a neighbouring tree
						if (!CanPlantExtraTrees(tile)) break;

						TreeType treetype = GetTreeType(tile);

						tile += TileOffsByDir((Direction)(Random() & 7));

						/* Cacti don't spread */
						if (!CanPlantTreesOnTile(tile, false)) return;

						/* Don't plant trees, if ground was freshly cleared */
						if (IsTileType(tile, MP_CLEAR) && GetClearGround(tile) == CLEAR_GRASS && GetClearDensity(tile) != 3) return;

						PlantTreesOnTile(tile, treetype, 0, 0);

						break;
					}

					default:
						return;
				}
			}
			break;

		case 6: // final stage of tree destruction
			if (!CanPlantExtraTrees(tile)) {
				/* if trees can't spread just plant a new one to prevent deforestation */
				SetTreeGrowth(tile, 0);
			} else if (GetTreeCount(tile) > 1) {
				/* more than one tree, delete it */
				AddTreeCount(tile, -1);
				SetTreeGrowth(tile, 3);
			} else {
				/* just one tree, change type into MP_CLEAR */
				switch (GetTreeGround(tile)) {
					case TREE_GROUND_SHORE: MakeShore(tile); break;
					case TREE_GROUND_GRASS: MakeClear(tile, CLEAR_GRASS, GetTreeDensity(tile)); break;
					case TREE_GROUND_ROUGH: MakeClear(tile, CLEAR_ROUGH, 3); break;
					case TREE_GROUND_ROUGH_SNOW: {
						uint density = GetTreeDensity(tile);
						MakeClear(tile, CLEAR_ROUGH, 3);
						MakeSnow(tile, density);
						break;
					}
					default: // snow or desert
						if (_settings_game.game_creation.landscape == LT_TROPIC) {
							MakeClear(tile, CLEAR_DESERT, GetTreeDensity(tile));
						} else {
							uint density = GetTreeDensity(tile);
							MakeClear(tile, CLEAR_GRASS, 3);
							MakeSnow(tile, density);
						}
						break;
				}
			}
			break;

		default:
			AddTreeGrowth(tile, 1);
			break;
	}

	MarkTileDirtyByTile(tile);
}

/**
 * Decrement the tree tick counter.
 * The interval is scaled by map size to allow for the same density regardless of size.
 * Adjustment for map sizes below the standard 256 * 256 are handled earlier.
 * @return true if the counter was decremented past zero
 */
bool DecrementTreeCounter()
{
	/* Ensure _trees_tick_ctr can be decremented past zero only once for the largest map size. */
	static_assert(2 * (MAX_MAP_SIZE_BITS - MIN_MAP_SIZE_BITS) - 4 <= std::numeric_limits<byte>::digits);

	/* byte underflow */
	byte old_trees_tick_ctr = _trees_tick_ctr;
	_trees_tick_ctr -= ScaleByMapSize(1);
	return old_trees_tick_ctr <= _trees_tick_ctr;
}

void OnTick_Trees()
{
	/* Don't spread trees if that's not allowed */
	if (_settings_game.construction.extra_tree_placement == ETP_NO_SPREAD || _settings_game.construction.extra_tree_placement == ETP_NO_GROWTH_NO_SPREAD) return;

	uint32 r;
	TileIndex tile;
	TreeType tree;

	/* Skip some tree ticks for map sizes below 256 * 256. 64 * 64 is 16 times smaller, so
	 * this is the maximum number of ticks that are skipped. Number of ticks to skip is
	 * inversely proportional to map size, so that is handled to create a mask. */
	int skip = ScaleByMapSize(16);
	if (skip < 16 && (_tick_counter & (16 / skip - 1)) != 0) return;

	/* place a tree at a random rainforest spot */
	if (_settings_game.game_creation.landscape == LT_TROPIC) {
		for (uint c = ScaleByMapSize(1); c > 0; c--) {
			if ((r = Random(), tile = RandomTileSeed(r), GetTropicZone(tile) == TROPICZONE_RAINFOREST) &&
				CanPlantTreesOnTile(tile, false) &&
				(tree = GetRandomTreeType(tile, GB(r, 24, 8))) != TREE_INVALID) {
				PlantTreesOnTile(tile, tree, 0, 0);
			}
		}
	}

	if (!DecrementTreeCounter() || _settings_game.construction.extra_tree_placement == ETP_SPREAD_RAINFOREST) return;

	/* place a tree at a random spot */
	r = Random();
	tile = RandomTileSeed(r);
	if (CanPlantTreesOnTile(tile, false) && (tree = GetRandomTreeType(tile, GB(r, 24, 8))) != TREE_INVALID) {
		PlantTreesOnTile(tile, tree, 0, 0);
	}
}

static TrackStatus GetTileTrackStatus_Trees(TileIndex tile, TransportType mode, uint sub_mode, DiagDirection side)
{
	return 0;
}

static void ChangeTileOwner_Trees(TileIndex tile, Owner old_owner, Owner new_owner)
{
	/* not used */
}

void InitializeTrees()
{
	_trees_tick_ctr = 0;
}

static CommandCost TerraformTile_Trees(TileIndex tile, DoCommandFlag flags, int z_new, Slope tileh_new)
{
	return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
}


extern const TileTypeProcs _tile_type_trees_procs = {
	DrawTile_Trees,           // draw_tile_proc
	GetSlopePixelZ_Trees,     // get_slope_z_proc
	ClearTile_Trees,          // clear_tile_proc
	nullptr,                     // add_accepted_cargo_proc
	GetTileDesc_Trees,        // get_tile_desc_proc
	GetTileTrackStatus_Trees, // get_tile_track_status_proc
	nullptr,                     // click_tile_proc
	nullptr,                     // animate_tile_proc
	TileLoop_Trees,           // tile_loop_proc
	ChangeTileOwner_Trees,    // change_tile_owner_proc
	nullptr,                     // add_produced_cargo_proc
	nullptr,                     // vehicle_enter_tile_proc
	GetFoundation_Trees,      // get_foundation_proc
	TerraformTile_Trees,      // terraform_tile_proc
};