============
Direct Graph
============

Directs a graph from the root node to the leafs.
With ``start_id`` as downstream node and ``end_id`` as upstream node.

Parameter
---------

+-----------------------+------------------------+------------------------------------------------------------------------+
|        Name           |          Type          |       Description                                                      |
+=======================+========================+========================================================================+
|view_name              | STRING                 | lead view name                                                         |
+-----------------------+------------------------+------------------------------------------------------------------------+
|root_node              | INT                    | id of the root node. Ignored when node_name is set                     |
+-----------------------+------------------------+------------------------------------------------------------------------+
|node_name              | STRING                 | name of view containing the root node (optional)                       |
+-----------------------+------------------------+------------------------------------------------------------------------+

Data-stream
-----------

+--------------------+---------------------------+------------------+-------+------------------------------------------+
|        View        |          Attribute        |       Type       |Access |    Description                           |
+====================+===========================+==================+=======+==========================================+
| view_name          |                           | EDGE             | read  |                                          |
+--------------------+---------------------------+------------------+-------+------------------------------------------+
|                    | start_id                  | INT              | modify| downstream node                          |
+--------------------+---------------------------+------------------+-------+------------------------------------------+
|                    | end_id                    | INT              | modify| upstream node                            |
+--------------------+---------------------------+------------------+-------+------------------------------------------+
|                    | visited                   | INT              | write |                                          |
+--------------------+---------------------------+------------------+-------+------------------------------------------+
|                    |                           |                  |       |                                          |
+--------------------+---------------------------+------------------+-------+------------------------------------------+
| node_name          |                           | NODE             | read  |                                          |
+--------------------+---------------------------+------------------+-------+------------------------------------------+
|                    | node_id                   | INT              | read  | id if root node                          |
+--------------------+---------------------------+------------------+-------+------------------------------------------+

Module Name
-----------

:index:`DM_DirectGraph <GDALModules; DM_DirectGraph | Direct graph>`