summaryrefslogtreecommitdiff
path: root/src/linkgraph/linkgraph.cpp
blob: 01b3d1ee2f0252b3c790295e8f4a1c0f47baf218 (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
/* $Id$ */

/*
 * 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 linkgraph.cpp Definition of link graph classes used for cargo distribution. */

#include "../stdafx.h"
#include "../core/pool_func.hpp"
#include "linkgraph.h"

#include "../safeguards.h"

/* Initialize the link-graph-pool */
LinkGraphPool _link_graph_pool("LinkGraph");
INSTANTIATE_POOL_METHODS(LinkGraph)

/**
 * Create a node or clear it.
 * @param st ID of the associated station.
 * @param demand Demand for cargo at the station.
 */
inline void LinkGraph::BaseNode::Init(StationID st, uint demand)
{
	this->supply = 0;
	this->demand = demand;
	this->station = st;
	this->last_update = INVALID_DATE;
}

/**
 * Create an edge.
 * @param distance Length of the link as manhattan distance.
 */
inline void LinkGraph::BaseEdge::Init(uint distance)
{
	this->distance = distance;
	this->capacity = 0;
	this->usage = 0;
	this->last_unrestricted_update = INVALID_DATE;
	this->last_restricted_update = INVALID_DATE;
	this->next_edge = INVALID_NODE;
}

/**
 * Shift all dates by given interval.
 * This is useful if the date has been modified with the cheat menu.
 * @param interval Number of days to be added or subtracted.
 */
void LinkGraph::ShiftDates(int interval)
{
	this->last_compression += interval;
	for (NodeID node1 = 0; node1 < this->Size(); ++node1) {
		BaseNode &source = this->nodes[node1];
		if (source.last_update != INVALID_DATE) source.last_update += interval;
		for (NodeID node2 = 0; node2 < this->Size(); ++node2) {
			BaseEdge &edge = this->edges[node1][node2];
			if (edge.last_unrestricted_update != INVALID_DATE) edge.last_unrestricted_update += interval;
			if (edge.last_restricted_update != INVALID_DATE) edge.last_restricted_update += interval;
		}
	}
}

void LinkGraph::Compress()
{
	this->last_compression = (_date + this->last_compression) / 2;
	for (NodeID node1 = 0; node1 < this->Size(); ++node1) {
		this->nodes[node1].supply /= 2;
		for (NodeID node2 = 0; node2 < this->Size(); ++node2) {
			BaseEdge &edge = this->edges[node1][node2];
			if (edge.capacity > 0) {
				edge.capacity = max(1U, edge.capacity / 2);
				edge.usage /= 2;
			}
		}
	}
}

/**
 * Merge a link graph with another one.
 * @param other LinkGraph to be merged into this one.
 */
void LinkGraph::Merge(LinkGraph *other)
{
	Date age = _date - this->last_compression + 1;
	Date other_age = _date - other->last_compression + 1;
	NodeID first = this->Size();
	for (NodeID node1 = 0; node1 < other->Size(); ++node1) {
		Station *st = Station::Get(other->nodes[node1].station);
		NodeID new_node = this->AddNode(st);
		this->nodes[new_node].supply = LinkGraph::Scale(other->nodes[node1].supply, age, other_age);
		st->goods[this->cargo].link_graph = this->index;
		st->goods[this->cargo].node = new_node;
		for (NodeID node2 = 0; node2 < node1; ++node2) {
			BaseEdge &forward = this->edges[new_node][first + node2];
			BaseEdge &backward = this->edges[first + node2][new_node];
			forward = other->edges[node1][node2];
			backward = other->edges[node2][node1];
			forward.capacity = LinkGraph::Scale(forward.capacity, age, other_age);
			forward.usage = LinkGraph::Scale(forward.usage, age, other_age);
			if (forward.next_edge != INVALID_NODE) forward.next_edge += first;
			backward.capacity = LinkGraph::Scale(backward.capacity, age, other_age);
			backward.usage = LinkGraph::Scale(backward.usage, age, other_age);
			if (backward.next_edge != INVALID_NODE) backward.next_edge += first;
		}
		BaseEdge &new_start = this->edges[new_node][new_node];
		new_start = other->edges[node1][node1];
		if (new_start.next_edge != INVALID_NODE) new_start.next_edge += first;
	}
	delete other;
}

/**
 * Remove a node from the link graph by overwriting it with the last node.
 * @param id ID of the node to be removed.
 */
void LinkGraph::RemoveNode(NodeID id)
{
	assert(id < this->Size());

	NodeID last_node = this->Size() - 1;
	for (NodeID i = 0; i <= last_node; ++i) {
		(*this)[i].RemoveEdge(id);
		BaseEdge *node_edges = this->edges[i];
		NodeID prev = i;
		NodeID next = node_edges[i].next_edge;
		while (next != INVALID_NODE) {
			if (next == last_node) {
				node_edges[prev].next_edge = id;
				break;
			}
			prev = next;
			next = node_edges[prev].next_edge;
		}
		node_edges[id] = node_edges[last_node];
	}
	Station::Get(this->nodes[last_node].station)->goods[this->cargo].node = id;
	this->nodes.Erase(this->nodes.Get(id));
	this->edges.EraseColumn(id);
	/* Not doing EraseRow here, as having the extra invalid row doesn't hurt
	 * and removing it would trigger a lot of memmove. The data has already
	 * been copied around in the loop above. */
}

/**
 * Update distances between the given node and all others.
 * @param id Node that changed position.
 * @param xy New position of the node.
 */
void LinkGraph::UpdateDistances(NodeID id, TileIndex xy)
{
	assert(id < this->Size());
	for (NodeID other = 0; other < this->Size(); ++other) {
		if (other == id) continue;
		this->edges[id][other].distance = this->edges[other][id].distance =
				DistanceMaxPlusManhattan(xy, Station::Get(this->nodes[other].station)->xy);
	}
}

/**
 * Add a node to the component and create empty edges associated with it. Set
 * the station's last_component to this component. Calculate the distances to all
 * other nodes. The distances to _all_ nodes are important as the demand
 * calculator relies on their availability.
 * @param st New node's station.
 * @return New node's ID.
 */
NodeID LinkGraph::AddNode(const Station *st)
{
	const GoodsEntry &good = st->goods[this->cargo];

	NodeID new_node = this->Size();
	this->nodes.Append();
	/* Avoid reducing the height of the matrix as that is expensive and we
	 * most likely will increase it again later which is again expensive. */
	this->edges.Resize(new_node + 1U,
			max(new_node + 1U, this->edges.Height()));

	this->nodes[new_node].Init(st->index,
			HasBit(good.status, GoodsEntry::GES_ACCEPTANCE));

	BaseEdge *new_edges = this->edges[new_node];

	/* Reset the first edge starting at the new node */
	new_edges[new_node].next_edge = INVALID_NODE;

	for (NodeID i = 0; i <= new_node; ++i) {
		uint distance = DistanceMaxPlusManhattan(st->xy, Station::Get(this->nodes[i].station)->xy);
		new_edges[i].Init(distance);
		this->edges[i][new_node].Init(distance);
	}
	return new_node;
}

/**
 * Fill an edge with values from a link. Set the restricted or unrestricted
 * update timestamp according to the given update mode.
 * @param to Destination node of the link.
 * @param capacity Capacity of the link.
 * @param usage Usage to be added.
 * @param mode Update mode to be used.
 */
void LinkGraph::Node::AddEdge(NodeID to, uint capacity, uint usage, EdgeUpdateMode mode)
{
	assert(this->index != to);
	BaseEdge &edge = this->edges[to];
	BaseEdge &first = this->edges[this->index];
	edge.capacity = capacity;
	edge.usage = usage;
	edge.next_edge = first.next_edge;
	first.next_edge = to;
	if (mode & EUM_UNRESTRICTED)  edge.last_unrestricted_update = _date;
	if (mode & EUM_RESTRICTED) edge.last_restricted_update = _date;
}

/**
 * Creates an edge if none exists yet or updates an existing edge.
 * @param to Target node.
 * @param capacity Capacity of the link.
 * @param usage Usage to be added.
 * @param mode Update mode to be used.
 */
void LinkGraph::Node::UpdateEdge(NodeID to, uint capacity, uint usage, EdgeUpdateMode mode)
{
	assert(capacity > 0);
	assert(usage <= capacity);
	if (this->edges[to].capacity == 0) {
		this->AddEdge(to, capacity, usage, mode);
	} else {
		(*this)[to].Update(capacity, usage, mode);
	}
}

/**
 * Remove an outgoing edge from this node.
 * @param to ID of destination node.
 */
void LinkGraph::Node::RemoveEdge(NodeID to)
{
	if (this->index == to) return;
	BaseEdge &edge = this->edges[to];
	edge.capacity = 0;
	edge.last_unrestricted_update = INVALID_DATE;
	edge.last_restricted_update = INVALID_DATE;
	edge.usage = 0;

	NodeID prev = this->index;
	NodeID next = this->edges[this->index].next_edge;
	while (next != INVALID_NODE) {
		if (next == to) {
			/* Will be removed, skip it. */
			this->edges[prev].next_edge = edge.next_edge;
			edge.next_edge = INVALID_NODE;
			break;
		} else {
			prev = next;
			next = this->edges[next].next_edge;
		}
	}
}

/**
 * Update an edge. If mode contains UM_REFRESH refresh the edge to have at
 * least the given capacity and usage, otherwise add the capacity and usage.
 * In any case set the respective update timestamp(s), according to the given
 * mode.
 * @param from Start node of the edge.
 * @param to End node of the edge.
 * @param capacity Capacity to be added/updated.
 * @param usage Usage to be added.
 * @param mode Update mode to be applied.
 */
void LinkGraph::Edge::Update(uint capacity, uint usage, EdgeUpdateMode mode)
{
	assert(this->edge.capacity > 0);
	assert(capacity >= usage);

	if (mode & EUM_INCREASE) {
		this->edge.capacity += capacity;
		this->edge.usage += usage;
	} else if (mode & EUM_REFRESH) {
		this->edge.capacity = max(this->edge.capacity, capacity);
		this->edge.usage = max(this->edge.usage, usage);
	}
	if (mode & EUM_UNRESTRICTED) this->edge.last_unrestricted_update = _date;
	if (mode & EUM_RESTRICTED) this->edge.last_restricted_update = _date;
}

/**
 * Resize the component and fill it with empty nodes and edges. Used when
 * loading from save games. The component is expected to be empty before.
 * @param size New size of the component.
 */
void LinkGraph::Init(uint size)
{
	assert(this->Size() == 0);
	this->edges.Resize(size, size);
	this->nodes.Resize(size);

	for (uint i = 0; i < size; ++i) {
		this->nodes[i].Init();
		BaseEdge *column = this->edges[i];
		for (uint j = 0; j < size; ++j) column[j].Init();
	}
}