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
|
/*
* KdTree.cpp
* RVO2-3D Library
*
* Copyright 2008 University of North Carolina at Chapel Hill
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Please send all bug reports to <geom@cs.unc.edu>.
*
* The authors may be contacted via:
*
* Jur van den Berg, Stephen J. Guy, Jamie Snape, Ming C. Lin, Dinesh Manocha
* Dept. of Computer Science
* 201 S. Columbia St.
* Frederick P. Brooks, Jr. Computer Science Bldg.
* Chapel Hill, N.C. 27599-3175
* United States of America
*
* <http://gamma.cs.unc.edu/RVO2/>
*/
#include "KdTree.h"
#include <algorithm>
#include "Agent.h"
#include "Definitions.h"
namespace RVO {
const size_t RVO_MAX_LEAF_SIZE = 10;
KdTree::KdTree() {}
void KdTree::buildAgentTree(std::vector<Agent *> agents) {
agents_.swap(agents);
if (!agents_.empty()) {
agentTree_.resize(2 * agents_.size() - 1);
buildAgentTreeRecursive(0, agents_.size(), 0);
}
}
void KdTree::buildAgentTreeRecursive(size_t begin, size_t end, size_t node) {
agentTree_[node].begin = begin;
agentTree_[node].end = end;
agentTree_[node].minCoord = agents_[begin]->position_;
agentTree_[node].maxCoord = agents_[begin]->position_;
for (size_t i = begin + 1; i < end; ++i) {
agentTree_[node].maxCoord[0] = std::max(agentTree_[node].maxCoord[0], agents_[i]->position_.x());
agentTree_[node].minCoord[0] = std::min(agentTree_[node].minCoord[0], agents_[i]->position_.x());
agentTree_[node].maxCoord[1] = std::max(agentTree_[node].maxCoord[1], agents_[i]->position_.y());
agentTree_[node].minCoord[1] = std::min(agentTree_[node].minCoord[1], agents_[i]->position_.y());
agentTree_[node].maxCoord[2] = std::max(agentTree_[node].maxCoord[2], agents_[i]->position_.z());
agentTree_[node].minCoord[2] = std::min(agentTree_[node].minCoord[2], agents_[i]->position_.z());
}
if (end - begin > RVO_MAX_LEAF_SIZE) {
/* No leaf node. */
size_t coord;
if (agentTree_[node].maxCoord[0] - agentTree_[node].minCoord[0] > agentTree_[node].maxCoord[1] - agentTree_[node].minCoord[1] && agentTree_[node].maxCoord[0] - agentTree_[node].minCoord[0] > agentTree_[node].maxCoord[2] - agentTree_[node].minCoord[2]) {
coord = 0;
} else if (agentTree_[node].maxCoord[1] - agentTree_[node].minCoord[1] > agentTree_[node].maxCoord[2] - agentTree_[node].minCoord[2]) {
coord = 1;
} else {
coord = 2;
}
const float splitValue = 0.5f * (agentTree_[node].maxCoord[coord] + agentTree_[node].minCoord[coord]);
size_t left = begin;
size_t right = end;
while (left < right) {
while (left < right && agents_[left]->position_[coord] < splitValue) {
++left;
}
while (right > left && agents_[right - 1]->position_[coord] >= splitValue) {
--right;
}
if (left < right) {
std::swap(agents_[left], agents_[right - 1]);
++left;
--right;
}
}
size_t leftSize = left - begin;
if (leftSize == 0) {
++leftSize;
++left;
++right;
}
agentTree_[node].left = node + 1;
agentTree_[node].right = node + 2 * leftSize;
buildAgentTreeRecursive(begin, left, agentTree_[node].left);
buildAgentTreeRecursive(left, end, agentTree_[node].right);
}
}
void KdTree::computeAgentNeighbors(Agent *agent, float rangeSq) const {
queryAgentTreeRecursive(agent, rangeSq, 0);
}
void KdTree::queryAgentTreeRecursive(Agent *agent, float &rangeSq, size_t node) const {
if (agentTree_[node].end - agentTree_[node].begin <= RVO_MAX_LEAF_SIZE) {
for (size_t i = agentTree_[node].begin; i < agentTree_[node].end; ++i) {
agent->insertAgentNeighbor(agents_[i], rangeSq);
}
} else {
const float distSqLeft = sqr(std::max(0.0f, agentTree_[agentTree_[node].left].minCoord[0] - agent->position_.x())) + sqr(std::max(0.0f, agent->position_.x() - agentTree_[agentTree_[node].left].maxCoord[0])) + sqr(std::max(0.0f, agentTree_[agentTree_[node].left].minCoord[1] - agent->position_.y())) + sqr(std::max(0.0f, agent->position_.y() - agentTree_[agentTree_[node].left].maxCoord[1])) + sqr(std::max(0.0f, agentTree_[agentTree_[node].left].minCoord[2] - agent->position_.z())) + sqr(std::max(0.0f, agent->position_.z() - agentTree_[agentTree_[node].left].maxCoord[2]));
const float distSqRight = sqr(std::max(0.0f, agentTree_[agentTree_[node].right].minCoord[0] - agent->position_.x())) + sqr(std::max(0.0f, agent->position_.x() - agentTree_[agentTree_[node].right].maxCoord[0])) + sqr(std::max(0.0f, agentTree_[agentTree_[node].right].minCoord[1] - agent->position_.y())) + sqr(std::max(0.0f, agent->position_.y() - agentTree_[agentTree_[node].right].maxCoord[1])) + sqr(std::max(0.0f, agentTree_[agentTree_[node].right].minCoord[2] - agent->position_.z())) + sqr(std::max(0.0f, agent->position_.z() - agentTree_[agentTree_[node].right].maxCoord[2]));
if (distSqLeft < distSqRight) {
if (distSqLeft < rangeSq) {
queryAgentTreeRecursive(agent, rangeSq, agentTree_[node].left);
if (distSqRight < rangeSq) {
queryAgentTreeRecursive(agent, rangeSq, agentTree_[node].right);
}
}
} else {
if (distSqRight < rangeSq) {
queryAgentTreeRecursive(agent, rangeSq, agentTree_[node].right);
if (distSqLeft < rangeSq) {
queryAgentTreeRecursive(agent, rangeSq, agentTree_[node].left);
}
}
}
}
}
} // namespace RVO
|