summaryrefslogtreecommitdiff
path: root/src/terraform_cmd.cpp
blob: 25c193299c94d9f1a57c4910a6e5f913bc3cb006 (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
/* $Id$ */

/** @file terraform_cmd.cpp Commands related to terraforming. */

#include "stdafx.h"
#include "openttd.h"
#include "strings_type.h"
#include "command_func.h"
#include "tile_map.h"
#include "tunnel_map.h"
#include "bridge_map.h"
#include "variables.h"
#include "functions.h"
#include "economy_func.h"

#include "table/strings.h"

/*
 * In one terraforming command all four corners of a initial tile can be raised/lowered (though this is not available to the player).
 * The maximal amount of height modifications is archieved when raising a complete flat land from sea level to MAX_TILE_HEIGHT or vice versa.
 * This affects all corners with a manhatten distance smaller than MAX_TILE_HEIGHT to one of the initial 4 corners.
 * Their maximal amount is computed to 4 * \sum_{i=1}^{h_max} i  =  2 * h_max * (h_max + 1).
 */
static const int TERRAFORMER_MODHEIGHT_SIZE = 2 * MAX_TILE_HEIGHT * (MAX_TILE_HEIGHT + 1);

/*
 * The maximal amount of affected tiles (i.e. the tiles that incident with one of the corners above, is computed similiar to
 * 1 + 4 * \sum_{i=1}^{h_max} (i+1)  =  1 + 2 * h_max + (h_max + 3).
 */
static const int TERRAFORMER_TILE_TABLE_SIZE = 1 + 2 * MAX_TILE_HEIGHT * (MAX_TILE_HEIGHT + 3);

struct TerraformerHeightMod {
	TileIndex tile;   ///< Referenced tile.
	byte height;      ///< New TileHeight (height of north corner) of the tile.
};

struct TerraformerState {
	int modheight_count;  ///< amount of entries in "modheight".
	int tile_table_count; ///< amount of entries in "tile_table".

	/**
	 * Dirty tiles, i.e.\ at least one corner changed.
	 *
	 * This array contains the tiles which are or will be marked as dirty.
	 *
	 * @ingroup dirty
	 */
	TileIndex tile_table[TERRAFORMER_TILE_TABLE_SIZE];
	TerraformerHeightMod modheight[TERRAFORMER_MODHEIGHT_SIZE];  ///< Height modifications.
};

TileIndex _terraform_err_tile; ///< first tile we couldn't terraform

/**
 * Gets the TileHeight (height of north corner) of a tile as of current terraforming progress.
 *
 * @param ts TerraformerState.
 * @param tile Tile.
 * @return TileHeight.
 */
static int TerraformGetHeightOfTile(const TerraformerState *ts, TileIndex tile)
{
	const TerraformerHeightMod *mod = ts->modheight;

	for (int count = ts->modheight_count; count != 0; count--, mod++) {
		if (mod->tile == tile) return mod->height;
	}

	/* TileHeight unchanged so far, read value from map. */
	return TileHeight(tile);
}

/**
 * Stores the TileHeight (height of north corner) of a tile in a TerraformerState.
 *
 * @param ts TerraformerState.
 * @param tile Tile.
 * @param height New TileHeight.
 */
static void TerraformSetHeightOfTile(TerraformerState *ts, TileIndex tile, int height)
{
	/* Find tile in the "modheight" table.
	 * Note: In a normal user-terraform command the tile will not be found in the "modheight" table.
	 *       But during house- or industry-construction multiple corners can be terraformed at once. */
	TerraformerHeightMod *mod = ts->modheight;
	int count = ts->modheight_count;

	while ((count > 0) && (mod->tile != tile)) {
		mod++;
		count--;
	}

	/* New entry? */
	if (count == 0) {
		assert(ts->modheight_count < TERRAFORMER_MODHEIGHT_SIZE);
		ts->modheight_count++;
	}

	/* Finally store the new value */
	mod->tile = tile;
	mod->height = (byte)height;
}

/**
 * Adds a tile to the "tile_table" in a TerraformerState.
 *
 * @param ts TerraformerState.
 * @param tile Tile.
 * @ingroup dirty
 */
static void TerraformAddDirtyTile(TerraformerState *ts, TileIndex tile)
{
	int count = ts->tile_table_count;

	for (TileIndex *t = ts->tile_table; count != 0; count--, t++) {
		if (*t == tile) return;
	}

	assert(ts->tile_table_count < TERRAFORMER_TILE_TABLE_SIZE);

	ts->tile_table[ts->tile_table_count++] = tile;
}

/**
 * Adds all tiles that incident with the north corner of a specific tile to the "tile_table" in a TerraformerState.
 *
 * @param ts TerraformerState.
 * @param tile Tile.
 * @ingroup dirty
 */
static void TerraformAddDirtyTileAround(TerraformerState *ts, TileIndex tile)
{
	TerraformAddDirtyTile(ts, tile + TileDiffXY( 0, -1));
	TerraformAddDirtyTile(ts, tile + TileDiffXY(-1, -1));
	TerraformAddDirtyTile(ts, tile + TileDiffXY(-1,  0));
	TerraformAddDirtyTile(ts, tile);
}

/**
 * Terraform the north corner of a tile to a specific height.
 *
 * @param ts TerraformerState.
 * @param tile Tile.
 * @param height Aimed height.
 * @param return Error code or cost.
 */
static CommandCost TerraformTileHeight(TerraformerState *ts, TileIndex tile, int height)
{
	assert(tile < MapSize());

	/* Check range of destination height */
	if (height < 0) return_cmd_error(STR_1003_ALREADY_AT_SEA_LEVEL);
	if (height > MAX_TILE_HEIGHT) return_cmd_error(STR_1004_TOO_HIGH);

	/*
	 * Check if the terraforming has any effect.
	 * This can only be true, if multiple corners of the start-tile are terraformed (i.e. the terraforming is done by towns/industries etc.).
	 * In this case the terraforming should fail. (Don't know why.)
	 */
	if (height == TerraformGetHeightOfTile(ts, tile)) return CMD_ERROR;

	/* Check "too close to edge of map" */
	uint x = TileX(tile);
	uint y = TileY(tile);
	if ((x <= 1) || (y <= 1) || (x >= MapMaxX() - 1) || (y >= MapMaxY() - 1)) {
		/*
		 * Determine a sensible error tile
		 */
		if (x == 1) x = 0;
		if (y == 1) y = 0;
		_terraform_err_tile = TileXY(x, y);
		return_cmd_error(STR_0002_TOO_CLOSE_TO_EDGE_OF_MAP);
	}

	/* Mark incident tiles, that are involved in the terraforming */
	TerraformAddDirtyTileAround(ts, tile);

	/* Store the height modification */
	TerraformSetHeightOfTile(ts, tile, height);

	CommandCost total_cost(EXPENSES_CONSTRUCTION);

	/* Increment cost */
	total_cost.AddCost(_price.terraform);

	/* Recurse to neighboured corners if height difference is larger than 1 */
	{
		const TileIndexDiffC *ttm;

		static const TileIndexDiffC _terraform_tilepos[] = {
			{ 1,  0}, // move to tile in SE
			{-2,  0}, // undo last move, and move to tile in NW
			{ 1,  1}, // undo last move, and move to tile in SW
			{ 0, -2}  // undo last move, and move to tile in NE
		};

		for (ttm = _terraform_tilepos; ttm != endof(_terraform_tilepos); ttm++) {
			tile += ToTileIndexDiff(*ttm);

			/* Get TileHeight of neighboured tile as of current terraform progress */
			int r = TerraformGetHeightOfTile(ts, tile);
			int height_diff = height - r;

			/* Is the height difference to the neighboured corner greater than 1? */
			if (abs(height_diff) > 1) {
				/* Terraform the neighboured corner. The resulting height difference should be 1. */
				height_diff += (height_diff < 0 ? 1 : -1);
				CommandCost cost = TerraformTileHeight(ts, tile, r + height_diff);
				if (CmdFailed(cost)) return cost;
				total_cost.AddCost(cost);
			}
		}
	}

	return total_cost;
}

/** Terraform land
 * @param tile tile to terraform
 * @param flags for this command type
 * @param p1 corners to terraform (SLOPE_xxx)
 * @param p2 direction; eg up (non-zero) or down (zero)
 * @return error or cost of terraforming
 */
CommandCost CmdTerraformLand(TileIndex tile, uint32 flags, uint32 p1, uint32 p2, const char *text)
{
	/* Make an extra check for map-bounds cause we add tiles to the originating tile */
	if (tile + TileDiffXY(1, 1) >= MapSize()) return CMD_ERROR;

	_terraform_err_tile = INVALID_TILE;

	CommandCost total_cost(EXPENSES_CONSTRUCTION);
	int direction = (p2 != 0 ? 1 : -1);
	TerraformerState ts;

	ts.modheight_count = ts.tile_table_count = 0;

	/* Compute the costs and the terraforming result in a model of the landscape */
	if ((p1 & SLOPE_W) != 0) {
		TileIndex t = tile + TileDiffXY(1, 0);
		CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
		if (CmdFailed(cost)) return cost;
		total_cost.AddCost(cost);
	}

	if ((p1 & SLOPE_S) != 0) {
		TileIndex t = tile + TileDiffXY(1, 1);
		CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
		if (CmdFailed(cost)) return cost;
		total_cost.AddCost(cost);
	}

	if ((p1 & SLOPE_E) != 0) {
		TileIndex t = tile + TileDiffXY(0, 1);
		CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
		if (CmdFailed(cost)) return cost;
		total_cost.AddCost(cost);
	}

	if ((p1 & SLOPE_N) != 0) {
		TileIndex t = tile + TileDiffXY(0, 0);
		CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
		if (CmdFailed(cost)) return cost;
		total_cost.AddCost(cost);
	}

	/* Check if the terraforming is valid wrt. tunnels, bridges and objects on the surface */
	{
		TileIndex *ti = ts.tile_table;

		for (int count = ts.tile_table_count; count != 0; count--, ti++) {
			TileIndex tile = *ti;

			/* Find new heights of tile corners */
			uint z_N = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 0));
			uint z_W = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 0));
			uint z_S = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 1));
			uint z_E = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 1));

			/* Find min and max height of tile */
			uint z_min = min(min(z_N, z_W), min(z_S, z_E));
			uint z_max = max(max(z_N, z_W), max(z_S, z_E));

			/* Compute tile slope */
			Slope tileh = (z_max > z_min + 1 ? SLOPE_STEEP : SLOPE_FLAT);
			if (z_W > z_min) tileh |= SLOPE_W;
			if (z_S > z_min) tileh |= SLOPE_S;
			if (z_E > z_min) tileh |= SLOPE_E;
			if (z_N > z_min) tileh |= SLOPE_N;

			/* Check if bridge would take damage */
			if (direction == 1 && MayHaveBridgeAbove(tile) && IsBridgeAbove(tile) &&
					GetBridgeHeight(GetSouthernBridgeEnd(tile)) <= z_max * TILE_HEIGHT) {
				_terraform_err_tile = tile; // highlight the tile under the bridge
				return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
			}
			/* Check if tunnel would take damage */
			if (direction == -1 && IsTunnelInWay(tile, z_min * TILE_HEIGHT)) {
				_terraform_err_tile = tile; // highlight the tile above the tunnel
				return_cmd_error(STR_1002_EXCAVATION_WOULD_DAMAGE);
			}
			/* Check tiletype-specific things, and add extra-cost */
			const bool curr_gen = _generating_world;
			if (_game_mode == GM_EDITOR) _generating_world = true; // used to create green terraformed land
			CommandCost cost = _tile_type_procs[GetTileType(tile)]->terraform_tile_proc(tile, flags | DC_AUTO, z_min * TILE_HEIGHT, tileh);
			_generating_world = curr_gen;
			if (CmdFailed(cost)) {
				_terraform_err_tile = tile;
				return cost;
			}
			total_cost.AddCost(cost);
		}
	}

	if (flags & DC_EXEC) {
		/* change the height */
		{
			int count;
			TerraformerHeightMod *mod;

			mod = ts.modheight;
			for (count = ts.modheight_count; count != 0; count--, mod++) {
				TileIndex til = mod->tile;

				SetTileHeight(til, mod->height);
			}
		}

		/* finally mark the dirty tiles dirty */
		{
			int count;
			TileIndex *ti = ts.tile_table;
			for (count = ts.tile_table_count; count != 0; count--, ti++) {
				MarkTileDirtyByTile(*ti);
			}
		}
	}
	return total_cost;
}


/** Levels a selected (rectangle) area of land
 * @param tile end tile of area-drag
 * @param flags for this command type
 * @param p1 start tile of area drag
 * @param p2 height difference; eg raise (+1), lower (-1) or level (0)
 * @return  error or cost of terraforming
 */
CommandCost CmdLevelLand(TileIndex tile, uint32 flags, uint32 p1, uint32 p2, const char *text)
{
	if (p1 >= MapSize()) return CMD_ERROR;

	_terraform_err_tile = INVALID_TILE;

	/* remember level height */
	uint oldh = TileHeight(p1);

	/* compute new height */
	uint h = oldh + p2;

	/* Check range of destination height */
	if (h > MAX_TILE_HEIGHT) return_cmd_error((oldh == 0) ? STR_1003_ALREADY_AT_SEA_LEVEL : STR_1004_TOO_HIGH);
	if (p2 == 0) _error_message = STR_ALREADY_LEVELLED;

	/* make sure sx,sy are smaller than ex,ey */
	int ex = TileX(tile);
	int ey = TileY(tile);
	int sx = TileX(p1);
	int sy = TileY(p1);
	if (ex < sx) Swap(ex, sx);
	if (ey < sy) Swap(ey, sy);
	tile = TileXY(sx, sy);

	int size_x = ex - sx + 1;
	int size_y = ey - sy + 1;

	Money money = GetAvailableMoneyForCommand();
	CommandCost cost(EXPENSES_CONSTRUCTION);

	BEGIN_TILE_LOOP(tile2, size_x, size_y, tile) {
		uint curh = TileHeight(tile2);
		while (curh != h) {
			CommandCost ret = DoCommand(tile2, SLOPE_N, (curh > h) ? 0 : 1, flags & ~DC_EXEC, CMD_TERRAFORM_LAND);
			if (CmdFailed(ret)) break;

			if (flags & DC_EXEC) {
				money -= ret.GetCost();
				if (money < 0) {
					_additional_cash_required = ret.GetCost();
					return cost;
				}
				DoCommand(tile2, SLOPE_N, (curh > h) ? 0 : 1, flags, CMD_TERRAFORM_LAND);
			}

			cost.AddCost(ret);
			curh += (curh > h) ? -1 : 1;
		}
	} END_TILE_LOOP(tile2, size_x, size_y, tile)

	return (cost.GetCost() == 0) ? CMD_ERROR : cost;
}