ashd.core.node source code

1 /**
2  * The base class for a node.
3  * 
4  * A node is a set of different components that are required by a system.
5  *
6  * A system can request a collection of nodes from the engine. 
7  * Subsequently the Engine object creates a node for every entity that has _all_ of the components 
8  * in the node class and adds these nodes to the list obtained by the system. 
9  *
10  * The engine keeps the list up to date as entities are added
11  * to and removed from the engine and as the components on entities change.</p>
12  */
13 
14 module ashd.core.node;
15 
16 import ashd.core.entity   : Entity;
17 
18 
19 abstract class Node
20 {
21     protected
22     {
23         /**
24          * The entity whose components are included in the node.
25          */
26         Entity mEntity;
27  
28         /**
29          * Used by the NodeList class. The previous node in a node list.
30          */
31         Node mPrevious;
32         
33         /**
34          * Used by the NodeList class. The next node in a node list.
35          */
36         Node mNext;
37 
38     }
39 
40     @property
41     {
42         Entity entity() { return mEntity; }
43         void entity( Entity entity_a ) { mEntity = entity_a; }
44     }
45 
46     @property
47     {
48         Node next() { return mNext; }
49         void next( Node node_a ) { mNext = node_a; }
50     }
51 
52     @property
53     {
54         Node previous() { return mPrevious; }
55         void previous( Node node_a ) { mPrevious = node_a; }
56     }
57 
58 }
59