summaryrefslogtreecommitdiff
path: root/src/ground_vehicle.hpp
blob: c2bd9715172b32481a85e777be7f18029b3db090 (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
/* $Id$ */

/*
 * 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 ground_vehicle.hpp Base class and functions for all vehicles that move through ground. */

#ifndef GROUND_VEHICLE_HPP
#define GROUND_VEHICLE_HPP

#include "vehicle_base.h"
#include "vehicle_gui.h"
#include "landscape.h"
#include "window_func.h"

/** What is the status of our acceleration? */
enum AccelStatus {
	AS_ACCEL, ///< We want to go faster, if possible of course.
	AS_BRAKE  ///< We want to stop.
};

/**
 * Cached, frequently calculated values.
 * All of these values except cached_slope_resistance are set only for the first part of a vehicle.
 */
struct GroundVehicleCache {
	/* Cached acceleration values, recalculated when the cargo on a vehicle changes (in addition to the conditions below) */
	uint32 cached_weight;           ///< Total weight of the consist (valid only for the first engine).
	uint32 cached_slope_resistance; ///< Resistance caused by weight when this vehicle part is at a slope.
	uint32 cached_max_te;           ///< Maximum tractive effort of consist (valid only for the first engine).
	uint16 cached_axle_resistance;  ///< Resistance caused by the axles of the vehicle (valid only for the first engine).

	/* Cached acceleration values, recalculated on load and each time a vehicle is added to/removed from the consist. */
	uint16 cached_max_track_speed;  ///< Maximum consist speed limited by track type (valid only for the first engine).
	uint32 cached_power;            ///< Total power of the consist (valid only for the first engine).
	uint32 cached_air_drag;         ///< Air drag coefficient of the vehicle (valid only for the first engine).

	/* Cached NewGRF values, recalculated on load and each time a vehicle is added to/removed from the consist. */
	uint16 cached_total_length;     ///< Length of the whole vehicle (valid only for the first engine).
	EngineID first_engine;          ///< Cached EngineID of the front vehicle. INVALID_ENGINE for the front vehicle itself.
	uint8 cached_veh_length;        ///< Length of this vehicle in units of 1/8 of normal length. It is cached because this can be set by a callback.

	/* Cached UI information. */
	uint16 last_speed;              ///< The last speed we did display, so we only have to redraw when this changes.
};

/** Ground vehicle flags. */
enum GroundVehicleFlags {
	GVF_GOINGUP_BIT       = 0,
	GVF_GOINGDOWN_BIT     = 1,
};

/**
 * Base class for all vehicles that move through ground.
 *
 * Child classes must define all of the following functions.
 * These functions are not defined as pure virtual functions at this class to improve performance.
 *
 * virtual uint16      GetPower() const = 0;
 * virtual uint16      GetPoweredPartPower(const T *head) const = 0;
 * virtual uint16      GetWeight() const = 0;
 * virtual byte        GetTractiveEffort() const = 0;
 * virtual byte        GetAirDrag() const = 0;
 * virtual byte        GetAirDragArea() const = 0;
 * virtual AccelStatus GetAccelerationStatus() const = 0;
 * virtual uint16      GetCurrentSpeed() const = 0;
 * virtual uint32      GetRollingFriction() const = 0;
 * virtual int         GetAccelerationType() const = 0;
 * virtual int32       GetSlopeSteepness() const = 0;
 * virtual int         GetDisplayMaxSpeed() const = 0;
 * virtual uint16      GetMaxTrackSpeed() const = 0;
 * virtual bool        TileMayHaveSlopedTrack() const = 0;
 */
template <class T, VehicleType Type>
struct GroundVehicle : public SpecializedVehicle<T, Type> {
	GroundVehicleCache gcache; ///< Cache of often calculated values.
	uint16 gv_flags;           ///< @see GroundVehicleFlags.

	typedef GroundVehicle<T, Type> GroundVehicleBase; ///< Our type

	/**
	 * The constructor at SpecializedVehicle must be called.
	 */
	GroundVehicle() : SpecializedVehicle<T, Type>() {}

	void PowerChanged();
	void CargoChanged();
	int GetAcceleration() const;

	/**
	 * Common code executed for crashed ground vehicles
	 * @param flooded was this vehicle flooded?
	 * @return number of victims
	 */
	/* virtual */ uint Crash(bool flooded)
	{
		/* Crashed vehicles aren't going up or down */
		for (T *v = T::From(this); v != NULL; v = v->Next()) {
			ClrBit(v->gv_flags, GVF_GOINGUP_BIT);
			ClrBit(v->gv_flags, GVF_GOINGDOWN_BIT);
		}
		return this->Vehicle::Crash(flooded);
	}

	/**
	 * Calculates the total slope resistance for this vehicle.
	 * @return Slope resistance.
	 */
	FORCEINLINE int32 GetSlopeResistance() const
	{
		int32 incl = 0;

		for (const T *u = T::From(this); u != NULL; u = u->Next()) {
			if (HasBit(u->gv_flags, GVF_GOINGUP_BIT)) {
				incl += u->gcache.cached_slope_resistance;
			} else if (HasBit(u->gv_flags, GVF_GOINGDOWN_BIT)) {
				incl -= u->gcache.cached_slope_resistance;
			}
		}

		return incl;
	}

	/**
	 * Updates vehicle's Z position and inclination.
	 * Used when the vehicle entered given tile.
	 * @pre The vehicle has to be at (or near to) a border of the tile,
	 *      directed towards tile centre
	 */
	FORCEINLINE void UpdateZPositionAndInclination()
	{
		this->z_pos = GetSlopeZ(this->x_pos, this->y_pos);
		ClrBit(this->gv_flags, GVF_GOINGUP_BIT);
		ClrBit(this->gv_flags, GVF_GOINGDOWN_BIT);

		if (T::From(this)->TileMayHaveSlopedTrack()) {
			/* To check whether the current tile is sloped, and in which
			 * direction it is sloped, we get the 'z' at the center of
			 * the tile (middle_z) and the edge of the tile (old_z),
			 * which we then can compare. */
			byte middle_z = GetSlopeZ((this->x_pos & ~TILE_UNIT_MASK) | HALF_TILE_SIZE, (this->y_pos & ~TILE_UNIT_MASK) | HALF_TILE_SIZE);

			if (middle_z != this->z_pos) {
				SetBit(this->gv_flags, (middle_z > this->z_pos) ? GVF_GOINGUP_BIT : GVF_GOINGDOWN_BIT);
			}
		}
	}

	/**
	 * Updates vehicle's Z position.
	 * Inclination can't change in the middle of a tile.
	 * The faster code is used for trains and road vehicles unless they are
	 * reversing on a sloped tile.
	 */
	FORCEINLINE void UpdateZPosition()
	{
#if 0
		/* The following code does this: */

		if (HasBit(this->gv_flags, GVF_GOINGUP_BIT)) {
			switch (this->direction) {
				case DIR_NE:
					this->z_pos += (this->x_pos & 1); break;
				case DIR_SW:
					this->z_pos += (this->x_pos & 1) ^ 1; break;
				case DIR_NW:
					this->z_pos += (this->y_pos & 1); break;
				case DIR_SE:
					this->z_pos += (this->y_pos & 1) ^ 1; break;
				default: break;
			}
		} else if (HasBit(this->gv_flags, GVF_GOINGDOWN_BIT)) {
			switch (this->direction) {
				case DIR_NE:
					this->z_pos -= (this->x_pos & 1); break;
				case DIR_SW:
					this->z_pos -= (this->x_pos & 1) ^ 1; break;
				case DIR_NW:
					this->z_pos -= (this->y_pos & 1); break;
				case DIR_SE:
					this->z_pos -= (this->y_pos & 1) ^ 1; break;
				default: break;
			}
		}

		/* But gcc 4.4.5 isn't able to nicely optimise it, and the resulting
		 * code is full of conditional jumps. */
#endif

		/* Vehicle's Z position can change only if it has GVF_GOINGUP_BIT or GVF_GOINGDOWN_BIT set.
		 * Furthermore, if this function is called once every time the vehicle's position changes,
		 * we know the Z position changes by +/-1 at certain moments - when x_pos, y_pos is odd/even,
		 * depending on orientation of the slope and vehicle's direction */

		if (HasBit(this->gv_flags, GVF_GOINGUP_BIT) || HasBit(this->gv_flags, GVF_GOINGDOWN_BIT)) {
			if (T::From(this)->HasToUseGetSlopeZ()) {
				/* In some cases, we have to use GetSlopeZ() */
				this->z_pos = GetSlopeZ(this->x_pos, this->y_pos);
				return;
			}
			/* DirToDiagDir() is a simple right shift */
			DiagDirection dir = DirToDiagDir(this->direction);
			/* Read variables, so the compiler knows the access doesn't trap */
			int8 x_pos = this->x_pos;
			int8 y_pos = this->y_pos;
			/* DiagDirToAxis() is a simple mask */
			int8 d = DiagDirToAxis(dir) == AXIS_X ? x_pos : y_pos;
			/* We need only the least significant bit */
			d &= 1;
			/* Conditional "^ 1". Optimised to "(dir - 1) <= 1". */
			d ^= (int8)(dir == DIAGDIR_SW || dir == DIAGDIR_SE);
			/* Subtraction instead of addition because we are testing for GVF_GOINGUP_BIT.
			 * GVF_GOINGUP_BIT is used because it's bit 0, so simple AND can be used,
			 * without any shift */
			this->z_pos += HasBit(this->gv_flags, GVF_GOINGUP_BIT) ? d : -d;
		}

		assert(this->z_pos == GetSlopeZ(this->x_pos, this->y_pos));
	}

	/**
	 * Checks if the vehicle is in a slope and sets the required flags in that case.
	 * @param new_tile True if the vehicle reached a new tile.
	 * @param turned Indicates if the vehicle has turned.
	 * @return Old height of the vehicle.
	 */
	FORCEINLINE byte UpdateInclination(bool new_tile, bool turned)
	{
		byte old_z = this->z_pos;

		if (new_tile) {
			this->UpdateZPositionAndInclination();
		} else {
			this->UpdateZPosition();
		}

		this->UpdateViewport(true, turned);
		return old_z;
	}

	/**
	 * Set front engine state.
	 */
	FORCEINLINE void SetFrontEngine() { SetBit(this->subtype, GVSF_FRONT); }

	/**
	 * Remove the front engine state.
	 */
	FORCEINLINE void ClearFrontEngine() { ClrBit(this->subtype, GVSF_FRONT); }

	/**
	 * Set a vehicle to be an articulated part.
	 */
	FORCEINLINE void SetArticulatedPart() { SetBit(this->subtype, GVSF_ARTICULATED_PART); }

	/**
	 * Clear a vehicle from being an articulated part.
	 */
	FORCEINLINE void ClearArticulatedPart() { ClrBit(this->subtype, GVSF_ARTICULATED_PART); }

	/**
	 * Set a vehicle to be a wagon.
	 */
	FORCEINLINE void SetWagon() { SetBit(this->subtype, GVSF_WAGON); }

	/**
	 * Clear wagon property.
	 */
	FORCEINLINE void ClearWagon() { ClrBit(this->subtype, GVSF_WAGON); }

	/**
	 * Set engine status.
	 */
	FORCEINLINE void SetEngine() { SetBit(this->subtype, GVSF_ENGINE); }

	/**
	 * Clear engine status.
	 */
	FORCEINLINE void ClearEngine() { ClrBit(this->subtype, GVSF_ENGINE); }

	/**
	 * Set a vehicle as a free wagon.
	 */
	FORCEINLINE void SetFreeWagon() { SetBit(this->subtype, GVSF_FREE_WAGON); }

	/**
	 * Clear a vehicle from being a free wagon.
	 */
	FORCEINLINE void ClearFreeWagon() { ClrBit(this->subtype, GVSF_FREE_WAGON); }

	/**
	 * Set a vehicle as a multiheaded engine.
	 */
	FORCEINLINE void SetMultiheaded() { SetBit(this->subtype, GVSF_MULTIHEADED); }

	/**
	 * Clear multiheaded engine property.
	 */
	FORCEINLINE void ClearMultiheaded() { ClrBit(this->subtype, GVSF_MULTIHEADED); }

	/**
	 * Check if the vehicle is a free wagon (got no engine in front of it).
	 * @return Returns true if the vehicle is a free wagon.
	 */
	FORCEINLINE bool IsFreeWagon() const { return HasBit(this->subtype, GVSF_FREE_WAGON); }

	/**
	 * Check if a vehicle is an engine (can be first in a consist).
	 * @return Returns true if vehicle is an engine.
	 */
	FORCEINLINE bool IsEngine() const { return HasBit(this->subtype, GVSF_ENGINE); }

	/**
	 * Check if a vehicle is a wagon.
	 * @return Returns true if vehicle is a wagon.
	 */
	FORCEINLINE bool IsWagon() const { return HasBit(this->subtype, GVSF_WAGON); }

	/**
	 * Check if the vehicle is a multiheaded engine.
	 * @return Returns true if the vehicle is a multiheaded engine.
	 */
	FORCEINLINE bool IsMultiheaded() const { return HasBit(this->subtype, GVSF_MULTIHEADED); }

	/**
	 * Tell if we are dealing with the rear end of a multiheaded engine.
	 * @return True if the engine is the rear part of a dualheaded engine.
	 */
	FORCEINLINE bool IsRearDualheaded() const { return this->IsMultiheaded() && !this->IsEngine(); }

	/**
	 * Update the GUI variant of the current speed of the vehicle.
	 * Also mark the widget dirty when that is needed, i.e. when
	 * the speed of this vehicle has changed.
	 */
	FORCEINLINE void SetLastSpeed()
	{
		if (this->cur_speed != this->gcache.last_speed) {
			if (_settings_client.gui.vehicle_speed || (this->gcache.last_speed == 0) != (this->cur_speed == 0)) {
				SetWindowWidgetDirty(WC_VEHICLE_VIEW, this->index, VVW_WIDGET_START_STOP_VEH);
			}
			this->gcache.last_speed = this->cur_speed;
		}
	}

protected:
	/**
	 * Update the speed of the vehicle.
	 *
	 * It updates the cur_speed and subspeed variables depending on the state
	 * of the vehicle; in this case the current acceleration, minimum and
	 * maximum speeds of the vehicle. It returns the distance that that the
	 * vehicle can drive this tick. #Vehicle::GetAdvanceDistance() determines
	 * the distance to drive before moving a step on the map.
	 * @param accel     The acceleration we would like to give this vehicle.
	 * @param min_speed The minimum speed here, in vehicle specific units.
	 * @param max_speed The maximum speed here, in vehicle specific units.
	 * @return Distance to drive.
	 */
	FORCEINLINE uint DoUpdateSpeed(uint accel, int min_speed, int max_speed)
	{
		uint spd = this->subspeed + accel;
		this->subspeed = (byte)spd;

		/* When we are going faster than the maximum speed, reduce the speed
		 * somewhat gradually. But never lower than the maximum speed. */
		int tempmax = max_speed;
		if (this->cur_speed > max_speed) {
			tempmax = max(this->cur_speed - (this->cur_speed / 10) - 1, max_speed);
		}

		/* Enforce a maximum and minimum speed. Normally we would use something like
		 * Clamp for this, but in this case min_speed might be below the maximum speed
		 * threshold for some reason. That makes acceleration fail and assertions
		 * happen in Clamp. So make it explicit that min_speed overrules the maximum
		 * speed by explicit ordering of min and max. */
		this->cur_speed = spd = max(min(this->cur_speed + ((int)spd >> 8), tempmax), min_speed);

		int scaled_spd = this->GetAdvanceSpeed(spd);

		scaled_spd += this->progress;
		this->progress = 0; // set later in *Handler or *Controller
		return scaled_spd;
	}
};

#endif /* GROUND_VEHICLE_HPP */