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
|
/* $Id$ */
/*
* 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.cpp Implementation of GroundVehicle. */
#include "stdafx.h"
#include "train.h"
#include "roadveh.h"
#include "depot_map.h"
/**
* Recalculates the cached total power of a vehicle. Should be called when the consist is changed.
*/
template <class T, VehicleType Type>
void GroundVehicle<T, Type>::PowerChanged()
{
assert(this->First() == this);
const T *v = T::From(this);
uint32 total_power = 0;
uint32 max_te = 0;
uint32 number_of_parts = 0;
uint16 max_track_speed = v->GetDisplayMaxSpeed();
for (const T *u = v; u != NULL; u = u->Next()) {
uint32 current_power = u->GetPower() + u->GetPoweredPartPower(u);
total_power += current_power;
/* Only powered parts add tractive effort. */
if (current_power > 0) max_te += u->GetWeight() * u->GetTractiveEffort();
number_of_parts++;
/* Get minimum max speed for this track. */
uint16 track_speed = u->GetMaxTrackSpeed();
if (track_speed > 0) max_track_speed = min(max_track_speed, track_speed);
}
byte air_drag;
byte air_drag_value = v->GetAirDrag();
/* If air drag is set to zero (default), the resulting air drag coefficient is dependent on max speed. */
if (air_drag_value == 0) {
uint16 max_speed = v->GetDisplayMaxSpeed();
/* Simplification of the method used in TTDPatch. It uses <= 10 to change more steadily from 128 to 196. */
air_drag = (max_speed <= 10) ? 192 : max(2048 / max_speed, 1);
} else {
/* According to the specs, a value of 0x01 in the air drag property means "no air drag". */
air_drag = (air_drag_value == 1) ? 0 : air_drag_value;
}
this->gcache.cached_air_drag = air_drag + 3 * air_drag * number_of_parts / 20;
max_te *= 10000; // Tractive effort in (tonnes * 1000 * 10 =) N.
max_te /= 256; // Tractive effort is a [0-255] coefficient.
if (this->gcache.cached_power != total_power || this->gcache.cached_max_te != max_te) {
/* Stop the vehicle if it has no power. */
if (total_power == 0) this->vehstatus |= VS_STOPPED;
this->gcache.cached_power = total_power;
this->gcache.cached_max_te = max_te;
SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
SetWindowWidgetDirty(WC_VEHICLE_VIEW, this->index, WID_VV_START_STOP);
}
this->gcache.cached_max_track_speed = max_track_speed;
}
/**
* Recalculates the cached weight of a vehicle and its parts. Should be called each time the cargo on
* the consist changes.
*/
template <class T, VehicleType Type>
void GroundVehicle<T, Type>::CargoChanged()
{
assert(this->First() == this);
uint32 weight = 0;
for (T *u = T::From(this); u != NULL; u = u->Next()) {
uint32 current_weight = u->GetWeight();
weight += current_weight;
/* Slope steepness is in percent, result in N. */
u->gcache.cached_slope_resistance = current_weight * u->GetSlopeSteepness() * 100;
}
/* Store consist weight in cache. */
this->gcache.cached_weight = max<uint32>(1, weight);
/* Friction in bearings and other mechanical parts is 0.1% of the weight (result in N). */
this->gcache.cached_axle_resistance = 10 * weight;
/* Now update vehicle power (tractive effort is dependent on weight). */
this->PowerChanged();
}
/**
* Calculates the acceleration of the vehicle under its current conditions.
* @return Current acceleration of the vehicle.
*/
template <class T, VehicleType Type>
int GroundVehicle<T, Type>::GetAcceleration() const
{
/* Templated class used for function calls for performance reasons. */
const T *v = T::From(this);
int32 speed = v->GetCurrentSpeed(); // [km/h-ish]
/* Weight is stored in tonnes. */
int32 mass = this->gcache.cached_weight;
/* Power is stored in HP, we need it in watts. */
int32 power = this->gcache.cached_power * 746;
int32 resistance = 0;
bool maglev = v->GetAccelerationType() == 2;
const int area = v->GetAirDragArea();
if (!maglev) {
/* Static resistance plus rolling friction. */
resistance = this->gcache.cached_axle_resistance;
resistance += mass * v->GetRollingFriction();
}
/* Air drag; the air drag coefficient is in an arbitrary NewGRF-unit,
* so we need some magic conversion factor. */
resistance += (area * this->gcache.cached_air_drag * speed * speed) / 1000;
resistance += this->GetSlopeResistance();
/* This value allows to know if the vehicle is accelerating or braking. */
AccelStatus mode = v->GetAccelerationStatus();
const int max_te = this->gcache.cached_max_te; // [N]
int force;
if (speed > 0) {
if (!maglev) {
/* Conversion factor from km/h to m/s is 5/18 to get [N] in the end. */
force = power * 18 / (speed * 5);
if (mode == AS_ACCEL && force > max_te) force = max_te;
} else {
force = power / 25;
}
} else {
/* "Kickoff" acceleration. */
force = (mode == AS_ACCEL && !maglev) ? min(max_te, power) : power;
force = max(force, (mass * 8) + resistance);
}
if (mode == AS_ACCEL) {
/* Easy way out when there is no acceleration. */
if (force == resistance) return 0;
/* When we accelerate, make sure we always keep doing that, even when
* the excess force is more than the mass. Otherwise a vehicle going
* down hill will never slow down enough, and a vehicle that came up
* a hill will never speed up enough to (eventually) get back to the
* same (maximum) speed. */
int accel = (force - resistance) / (mass * 4);
return force < resistance ? min(-1, accel) : max(1, accel);
} else {
return min(-force - resistance, -10000) / mass;
}
}
/**
* Check whether the whole vehicle chain is in the depot.
* @return true if and only if the whole chain is in the depot.
*/
template <class T, VehicleType Type>
bool GroundVehicle<T, Type>::IsChainInDepot() const
{
const T *v = this->First();
/* Is the front engine stationary in the depot? */
assert_compile((int)TRANSPORT_RAIL == (int)VEH_TRAIN);
assert_compile((int)TRANSPORT_ROAD == (int)VEH_ROAD);
if (!IsDepotTypeTile(v->tile, (TransportType)Type) || v->cur_speed != 0) return false;
/* Check whether the rest is also already trying to enter the depot. */
for (; v != NULL; v = v->Next()) {
if (!v->T::IsInDepot() || v->tile != this->tile) return false;
}
return true;
}
/* Instantiation for Train */
template struct GroundVehicle<Train, VEH_TRAIN>;
/* Instantiation for RoadVehicle */
template struct GroundVehicle<RoadVehicle, VEH_ROAD>;
|
