add comments to struct maze

The ordered sets are created by `dtopen` with descriptor `chanItemDisc`
and method `Dtoset`.

The method is defined with

 #define DT_OSET         0000004 /* ordered set (self-adjusting tree)    */

Channels are added with function `addChan` and are retrieved by `chanSearch`

diff --git a/lib/ortho/maze.h b/lib/ortho/maze.h
index 005b86181f0011041b9511098013631d011aaf47..a429326ec451946eaf62ccf0e08258653f9126e5 100644 (file)
--- a/lib/ortho/maze.h
+++ b/lib/ortho/maze.h
@@ -66,9 +66,9 @@ typedef struct {
   int ncells, ngcells;
   cell* cells;     ///< @brief cells not corresponding to graph nodes
   cell* gcells;    ///< @brief cells corresponding to graph nodes
-  sgraph* sg;
-  Dt_t* hchans;
-  Dt_t* vchans;
+  sgraph* sg;      ///< @brief search graph
+  Dt_t* hchans;    ///< @brief set of horizontal @ref channel "channels", created by @ref extractHChans.
+  Dt_t* vchans;    ///< @brief set of vertical @ref channel "channels", created by @ref extractVChans
 } maze;
 
 extern maze* mkMaze(graph_t*);