OpenTTD: src/linkgraph/linkgraph.cpp Source File

OpenTTD

- Main Page
- Related Pages
- Modules
- Namespaces
- Data Structures
- Files

- File List
- Globals

linkgraph.cpp
Go to the documentation of this file.
1 /* $Id: linkgraph.cpp 26646 2014-06-14 13:35:39Z fonsinchen $ */
2
3 /*
4 * This file is part of OpenTTD.
5 * 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.
6 * 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.
7 * 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/>.
8 */
9
12 #include "../stdafx.h"
13 #include "../core/pool_func.hpp"
14 #include "linkgraph.h"
15
16 #include "../safeguards.h"
17
18 /* Initialize the link-graph-pool */
19 LinkGraphPool _link_graph_pool("LinkGraph");
20 INSTANTIATE_POOL_METHODS(LinkGraph)
21
22
28 inline void LinkGraph::BaseNode::Init(TileIndex xy, StationID st, uint demand)
29 {
30 this->xy = xy;
31 this->supply = 0;
32 this->demand = demand;
33 this->station = st;
34 this->last_update = INVALID_DATE;
35 }
36
40 inline void LinkGraph::BaseEdge::Init()
41 {
42 this->capacity = 0;
43 this->usage = 0;
44 this->last_unrestricted_update = INVALID_DATE;
45 this->last_restricted_update = INVALID_DATE;
46 this->next_edge = INVALID_NODE;
47 }
48
54 void LinkGraph::ShiftDates(int interval)
55 {
56 this->last_compression += interval;
57 for (NodeID node1 = 0; node1 < this->Size(); ++node1) {
58 BaseNode &source = this->nodes[node1];
59 if (source.last_update != INVALID_DATE) source.last_update += interval;
60 for (NodeID node2 = 0; node2 < this->Size(); ++node2) {
61 BaseEdge &edge = this->edges[node1][node2];
62 if (edge.last_unrestricted_update != INVALID_DATE) edge.last_unrestricted_update += interval;
63 if (edge.last_restricted_update != INVALID_DATE) edge.last_restricted_update += interval;
64 }
65 }
66 }
67
68 void LinkGraph::Compress()
69 {
70 this->last_compression = (_date + this->last_compression) / 2;
71 for (NodeID node1 = 0; node1 < this->Size(); ++node1) {
72 this->nodes[node1].supply /= 2;
73 for (NodeID node2 = 0; node2 < this->Size(); ++node2) {
74 BaseEdge &edge = this->edges[node1][node2];
75 if (edge.capacity > 0) {
76 edge.capacity = max(1U, edge.capacity / 2);
77 edge.usage /= 2;
78 }
79 }
80 }
81 }
82
87 void LinkGraph::Merge(LinkGraph *other)
88 {
89 Date age = _date - this->last_compression + 1;
90 Date other_age = _date - other->last_compression + 1;
91 NodeID first = this->Size();
92 for (NodeID node1 = 0; node1 < other->Size(); ++node1) {
93 Station *st = Station::Get(other->nodes[node1].station);
94 NodeID new_node = this->AddNode(st);
95 this->nodes[new_node].supply = LinkGraph::Scale(other->nodes[node1].supply, age, other_age);
96 st->goods[this->cargo].link_graph = this->index;
97 st->goods[this->cargo].node = new_node;
98 for (NodeID node2 = 0; node2 < node1; ++node2) {
99 BaseEdge &forward = this->edges[new_node][first + node2];
100 BaseEdge &backward = this->edges[first + node2][new_node];
101 forward = other->edges[node1][node2];
102 backward = other->edges[node2][node1];
103 forward.capacity = LinkGraph::Scale(forward.capacity, age, other_age);
104 forward.usage = LinkGraph::Scale(forward.usage, age, other_age);
105 if (forward.next_edge != INVALID_NODE) forward.next_edge += first;
106 backward.capacity = LinkGraph::Scale(backward.capacity, age, other_age);
107 backward.usage = LinkGraph::Scale(backward.usage, age, other_age);
108 if (backward.next_edge != INVALID_NODE) backward.next_edge += first;
109 }
110 BaseEdge &new_start = this->edges[new_node][new_node];
111 new_start = other->edges[node1][node1];
112 if (new_start.next_edge != INVALID_NODE) new_start.next_edge += first;
113 }
114 delete other;
115 }
116
121 void LinkGraph::RemoveNode(NodeID id)
122 {
123 assert(id < this->Size());
124
125 NodeID last_node = this->Size() - 1;
126 for (NodeID i = 0; i <= last_node; ++i) {
127 (*this)[i].RemoveEdge(id);
128 BaseEdge *node_edges = this->edges[i];
129 NodeID prev = i;
130 NodeID next = node_edges[i].next_edge;
131 while (next != INVALID_NODE) {
132 if (next == last_node) {
133 node_edges[prev].next_edge = id;
134 break;
135 }
136 prev = next;
137 next = node_edges[prev].next_edge;
138 }
139 node_edges[id] = node_edges[last_node];
140 }
141 Station::Get(this->nodes[last_node].station)->goods[this->cargo].node = id;
142 this->nodes.Erase(this->nodes.Get(id));
143 this->edges.EraseColumn(id);
144 /* Not doing EraseRow here, as having the extra invalid row doesn't hurt
145 * and removing it would trigger a lot of memmove. The data has already
146 * been copied around in the loop above. */
147 }
148
157 NodeID LinkGraph::AddNode(const Station *st)
158 {
159 const GoodsEntry &good = st->goods[this->cargo];
160
161 NodeID new_node = this->Size();
162 this->nodes.Append();
163 /* Avoid reducing the height of the matrix as that is expensive and we
164 * most likely will increase it again later which is again expensive. */
165 this->edges.Resize(new_node + 1U,
166 max(new_node + 1U, this->edges.Height()));
167
168 this->nodes[new_node].Init(st->xy, st->index,
169 HasBit(good.status, GoodsEntry::GES_ACCEPTANCE));
170
171 BaseEdge *new_edges = this->edges[new_node];
172
173 /* Reset the first edge starting at the new node */
174 new_edges[new_node].next_edge = INVALID_NODE;
175
176 for (NodeID i = 0; i <= new_node; ++i) {
177 new_edges[i].Init();
178 this->edges[i][new_node].Init();
179 }
180 return new_node;
181 }
182
191 void LinkGraph::Node::AddEdge(NodeID to, uint capacity, uint usage, EdgeUpdateMode mode)
192 {
193 assert(this->index != to);
194 BaseEdge &edge = this->edges[to];
195 BaseEdge &first = this->edges[this->index];
196 edge.capacity = capacity;
197 edge.usage = usage;
198 edge.next_edge = first.next_edge;
199 first.next_edge = to;
200 if (mode & EUM_UNRESTRICTED) edge.last_unrestricted_update = _date;
201 if (mode & EUM_RESTRICTED) edge.last_restricted_update = _date;
202 }
203
211 void LinkGraph::Node::UpdateEdge(NodeID to, uint capacity, uint usage, EdgeUpdateMode mode)
212 {
213 assert(capacity > 0);
214 assert(usage <= capacity);
215 if (this->edges[to].capacity == 0) {
216 this->AddEdge(to, capacity, usage, mode);
217 } else {
218 (*this)[to].Update(capacity, usage, mode);
219 }
220 }
221
226 void LinkGraph::Node::RemoveEdge(NodeID to)
227 {
228 if (this->index == to) return;
229 BaseEdge &edge = this->edges[to];
230 edge.capacity = 0;
231 edge.last_unrestricted_update = INVALID_DATE;
232 edge.last_restricted_update = INVALID_DATE;
233 edge.usage = 0;
234
235 NodeID prev = this->index;
236 NodeID next = this->edges[this->index].next_edge;
237 while (next != INVALID_NODE) {
238 if (next == to) {
239 /* Will be removed, skip it. */
240 this->edges[prev].next_edge = edge.next_edge;
241 edge.next_edge = INVALID_NODE;
242 break;
243 } else {
244 prev = next;
245 next = this->edges[next].next_edge;
246 }
247 }
248 }
249
261 void LinkGraph::Edge::Update(uint capacity, uint usage, EdgeUpdateMode mode)
262 {
263 assert(this->edge.capacity > 0);
264 assert(capacity >= usage);
265
266 if (mode & EUM_INCREASE) {
267 this->edge.capacity += capacity;
268 this->edge.usage += usage;
269 } else if (mode & EUM_REFRESH) {
270 this->edge.capacity = max(this->edge.capacity, capacity);
271 this->edge.usage = max(this->edge.usage, usage);
272 }
273 if (mode & EUM_UNRESTRICTED) this->edge.last_unrestricted_update = _date;
274 if (mode & EUM_RESTRICTED) this->edge.last_restricted_update = _date;
275 }
276
282 void LinkGraph::Init(uint size)
283 {
284 assert(this->Size() == 0);
285 this->edges.Resize(size, size);
286 this->nodes.Resize(size);
287
288 for (uint i = 0; i < size; ++i) {
289 this->nodes[i].Init();
290 BaseEdge *column = this->edges[i];
291 for (uint j = 0; j < size; ++j) column[j].Init();
292 }
293 }