php-ecs/EntityManager.php at master · WolvesFortress/php-ecs · GitHub

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
<?php

namespace ecs;

use ecs\events\EventManager;
use ecs\events\messages\EntityCreatedMessage;
use ecs\events\messages\EntityDestroyedMessage;

class EntityManager
{
    /**
     * @var int
     */
    private static $entityCount = 0;

    /**
     * @var EventManager
     */
    private $eventManager;

    /**
     * @var Entity[]
     */
    private $entities;

    /**
     * @var int[]
     */
    private $entityFreeIds;

    /**
     * @param EventManager $eventManager
     */
    public function __construct(EventManager $eventManager) {
        $this->entities = [];
        $this->entityFreeIds = [];
        $this->eventManager = $eventManager;
    }

    /**
     * @return Entity
     */
    public function createEntity() {
        $id = $this->fetchNewId();
        $entity = new Entity($this, $this->eventManager, $id);
        $this->entities[$id] = $entity;
        $this->eventManager->emit(new EntityCreatedMessage($entity));

        return $entity;
    }

    /**
     * @param int $id Entity ID
     * @return Entity
     * @throws \Exception
     */
    public function getEntity($id) {
        if (isset($this->entities[$id])) {
            return $this->entities[$id];
        }

        throw new \Exception(sprintf('Entity with ID "%s" not found.', $id));
    }

    /**
     * @param string|string[] $classNames
     * @return Entity[]
     */
    public function getEntitiesByAllComponents($classNames) {
        if (is_string($classNames)) {
            $classNames = [$classNames];
        }

        $entities = [];
        foreach ($this->entities as $entity) {
            if ($entity->hasAllComponents($classNames)) {
                $entities[] = $entity;
            }
        }

        return $entities;
    }

    /**
     * @param string|string[] $classNames
     * @return Entity[]
     */
    public function getEntitiesByAnyComponent($classNames) {
        if (is_string($classNames)) {
            $classNames = [$classNames];
        }

        $entities = [];
        foreach ($this->entities as $entity) {
            if ($entity->hasAnyComponent($classNames)) {
                $entities[] = $entity;
            }
        }

        return $entities;
    }

    /**
     * @param int $id Entity ID
     * @throws \Exception
     */
    public function destroyEntity($id) {
        $entity = $this->getEntity($id);
        $entity->destroy();
        unset($this->entities[$id]);
        $this->entityFreeIds[] = $id;
        $this->eventManager->emit(new EntityDestroyedMessage($entity));
    }

    /**
     * @return int
     */
    private function fetchNewId() {
        if (count($this->entityFreeIds)) {
            $id = array_shift($this->entityFreeIds);
        } else {
            $id = ++static::$entityCount;
        }

        return $id;
    }
}