|
1
|
|
|
<?php |
|
2
|
|
|
|
|
3
|
|
|
namespace Hexogen\KDTree; |
|
4
|
|
|
|
|
5
|
|
|
class KDTree implements KDTreeInterface |
|
6
|
|
|
{ |
|
7
|
|
|
/** |
|
8
|
|
|
* @var NodeInterface |
|
9
|
|
|
*/ |
|
10
|
|
|
private $root; |
|
11
|
|
|
|
|
12
|
|
|
/** |
|
13
|
|
|
* @var ItemInterface[]|null array of items or null after tree has been built |
|
14
|
|
|
*/ |
|
15
|
|
|
private $items; |
|
16
|
|
|
|
|
17
|
|
|
/** |
|
18
|
|
|
* @var array |
|
19
|
|
|
*/ |
|
20
|
|
|
private $maxBoundary; |
|
21
|
|
|
|
|
22
|
|
|
/** |
|
23
|
|
|
* @var array |
|
24
|
|
|
*/ |
|
25
|
|
|
private $minBoundary; |
|
26
|
|
|
|
|
27
|
|
|
/** |
|
28
|
|
|
* @var int number of items in the tree |
|
29
|
|
|
*/ |
|
30
|
|
|
private $length; |
|
31
|
|
|
|
|
32
|
|
|
/** |
|
33
|
|
|
* @var int |
|
34
|
|
|
*/ |
|
35
|
|
|
private $dimensions; |
|
36
|
|
|
|
|
37
|
42 |
|
public function __construct(ItemList $itemList) |
|
38
|
|
|
{ |
|
39
|
42 |
|
$this->dimensions = $itemList->getDimensionCount(); |
|
40
|
42 |
|
$this->items = $itemList->getItems(); |
|
41
|
42 |
|
$this->length = count($this->items); |
|
42
|
|
|
|
|
43
|
42 |
|
$this->maxBoundary = []; |
|
44
|
42 |
|
$this->minBoundary = []; |
|
45
|
|
|
|
|
46
|
42 |
|
for ($i = 0; $i < $this->dimensions; $i++) { |
|
47
|
42 |
|
$this->maxBoundary[$i] = -INF; |
|
48
|
42 |
|
$this->minBoundary[$i] = INF; |
|
49
|
|
|
} |
|
50
|
|
|
|
|
51
|
42 |
|
foreach ($this->items as $item) { |
|
52
|
39 |
|
for ($i = 0; $i < $this->dimensions; $i++) { |
|
53
|
39 |
|
$this->maxBoundary[$i] = max($this->maxBoundary[$i], $item->getNthDimension($i)); |
|
54
|
39 |
|
$this->minBoundary[$i] = min($this->minBoundary[$i], $item->getNthDimension($i)); |
|
55
|
|
|
} |
|
56
|
|
|
} |
|
57
|
|
|
|
|
58
|
42 |
|
$this->root = null; |
|
59
|
42 |
|
if ($this->length > 0) { |
|
60
|
39 |
|
$hi = $this->length - 1; |
|
61
|
39 |
|
$mid = (int)($hi / 2); |
|
62
|
39 |
|
$item = $this->select($mid, 0, $hi, 0); |
|
63
|
|
|
|
|
64
|
39 |
|
$this->root = new Node($item); |
|
65
|
|
|
|
|
66
|
39 |
|
$nextDimension = 1 % $this->dimensions; |
|
67
|
39 |
|
if ($mid > 0) { |
|
68
|
36 |
|
$this->root->setLeft($this->buildSubTree(0, $mid - 1, $nextDimension)); |
|
69
|
|
|
} |
|
70
|
39 |
|
if ($mid < $hi) { |
|
71
|
36 |
|
$this->root->setRight($this->buildSubTree($mid + 1, $hi, $nextDimension)); |
|
72
|
|
|
} |
|
73
|
|
|
} |
|
74
|
42 |
|
$this->items = null; |
|
75
|
42 |
|
} |
|
76
|
|
|
|
|
77
|
3 |
|
public function getItemCount(): int |
|
78
|
|
|
{ |
|
79
|
3 |
|
return $this->length; |
|
80
|
|
|
} |
|
81
|
|
|
|
|
82
|
27 |
|
public function getRoot(): NodeInterface |
|
83
|
|
|
{ |
|
84
|
27 |
|
return $this->root; |
|
85
|
|
|
} |
|
86
|
|
|
|
|
87
|
3 |
|
public function getMinBoundary(): array |
|
88
|
|
|
{ |
|
89
|
3 |
|
return $this->minBoundary; |
|
90
|
|
|
} |
|
91
|
|
|
|
|
92
|
3 |
|
public function getMaxBoundary(): array |
|
93
|
|
|
{ |
|
94
|
3 |
|
return $this->maxBoundary; |
|
95
|
|
|
} |
|
96
|
|
|
|
|
97
|
3 |
|
public function getDimensionCount(): int |
|
98
|
|
|
{ |
|
99
|
3 |
|
return $this->dimensions; |
|
100
|
|
|
} |
|
101
|
|
|
|
|
102
|
36 |
|
private function buildSubTree(int $lo, int $hi, int $d): Node |
|
103
|
|
|
{ |
|
104
|
36 |
|
$mid = (int)(($hi - $lo) / 2) + $lo; |
|
105
|
|
|
|
|
106
|
36 |
|
$item = $this->select($mid, $lo, $hi, $d); |
|
107
|
36 |
|
$node = new Node($item); |
|
108
|
|
|
|
|
109
|
36 |
|
$d++; |
|
110
|
36 |
|
$d = $d % $this->dimensions; |
|
111
|
|
|
|
|
112
|
36 |
|
if ($mid > $lo) { |
|
113
|
30 |
|
$node->setLeft($this->buildSubTree($lo, $mid - 1, $d)); |
|
114
|
|
|
} |
|
115
|
36 |
|
if ($mid < $hi) { |
|
116
|
36 |
|
$node->setRight($this->buildSubTree($mid + 1, $hi, $d)); |
|
117
|
|
|
} |
|
118
|
36 |
|
return $node; |
|
119
|
|
|
} |
|
120
|
|
|
|
|
121
|
36 |
|
private function exch(int $i, int $j) |
|
122
|
|
|
{ |
|
123
|
36 |
|
$tmp = $this->items[$i]; |
|
124
|
36 |
|
$this->items[$i] = $this->items[$j]; |
|
125
|
36 |
|
$this->items[$j] = $tmp; |
|
126
|
36 |
|
} |
|
127
|
|
|
|
|
128
|
|
|
/** |
|
129
|
|
|
* @param int $k |
|
130
|
|
|
* @param int $lo |
|
131
|
|
|
* @param int $hi |
|
132
|
|
|
* @param int $d |
|
133
|
|
|
* @return ItemInterface |
|
134
|
|
|
*/ |
|
135
|
39 |
|
private function select(int $k, int $lo, int $hi, int $d) |
|
136
|
|
|
{ |
|
137
|
39 |
|
while ($hi > $lo) { |
|
138
|
36 |
|
$j = $this->partition($lo, $hi, $d); |
|
139
|
36 |
|
if ($j > $k) { |
|
140
|
33 |
|
$hi = $j - 1; |
|
141
|
36 |
|
} elseif ($j < $k) { |
|
142
|
36 |
|
$lo = $j + 1; |
|
143
|
|
|
} else { |
|
144
|
36 |
|
return $this->items[$k]; |
|
145
|
|
|
} |
|
146
|
|
|
} |
|
147
|
39 |
|
return $this->items[$k]; |
|
148
|
|
|
} |
|
149
|
|
|
|
|
150
|
|
|
/** |
|
151
|
|
|
* @param int $lo |
|
152
|
|
|
* @param int $hi |
|
153
|
|
|
* @param int $d |
|
154
|
|
|
* @return int |
|
155
|
|
|
*/ |
|
156
|
36 |
|
private function partition(int $lo, int $hi, int $d) |
|
157
|
|
|
{ |
|
158
|
36 |
|
$i = $lo; |
|
159
|
36 |
|
$j = $hi + 1; |
|
160
|
36 |
|
$v = $this->items[$lo]; |
|
161
|
36 |
|
$val = $v->getNthDimension($d); |
|
162
|
36 |
|
while (true) { |
|
163
|
36 |
|
while ($this->items[++$i]->getNthDimension($d) < $val) { |
|
164
|
33 |
|
if ($i == $hi) { |
|
165
|
33 |
|
break; |
|
166
|
|
|
} |
|
167
|
|
|
} |
|
168
|
|
|
|
|
169
|
36 |
|
while ($this->items[--$j]->getNthDimension($d) > $val) { |
|
170
|
|
|
} |
|
171
|
|
|
|
|
172
|
36 |
|
if ($i >= $j) { |
|
173
|
36 |
|
break; |
|
174
|
|
|
} |
|
175
|
|
|
|
|
176
|
30 |
|
$this->exch($i, $j); |
|
177
|
|
|
} |
|
178
|
|
|
|
|
179
|
36 |
|
$this->exch($lo, $j); |
|
180
|
|
|
|
|
181
|
36 |
|
return $j; |
|
182
|
|
|
} |
|
183
|
|
|
} |
|
184
|
|
|
|
hexogen /
kdtree
