1  /********************************************************************
 2   * Description: tcq.c
 3   *\brief queue handling functions for trajectory planner
 4   * These following functions implement the motion queue that
 5   * is fed by tpAddLine/tpAddCircle and consumed by tpRunCycle.
 6   * They have been fully working for a long time and a wise programmer
 7   * won't mess with them.
 8   *
 9   *   Derived from a work by Fred Proctor & Will Shackleford
10   *
11   * Author:
12   * License: GPL Version 2
13   * System: Linux
14   *    
15   * Copyright (c) 2004 All rights reserved.
16   *
17   * Last change:
18   ********************************************************************/
19  
20  /* queue of TC_STRUCT elements*/
21  #ifndef TCQ_H
22  #define TCQ_H
23  
24  #include "tc_types.h"
25  
26  typedef struct {
27      TC_STRUCT *queue;	/* ptr to the tcs */
28      int size;			/* size of queue */
29      int _len;			/* number of tcs now in queue */
30      int _rlen;			/* number of tcs now in reverse history  */
31      int start, end;		/* indices to next to get, next to put */
32      int rend;
33      int allFull;		/* flag meaning it's actually full */
34  } TC_QUEUE_STRUCT;
35  
36  /* TC_QUEUE_STRUCT functions */
37  
38  /* create queue of _size */
39  extern int tcqCreate(TC_QUEUE_STRUCT * const tcq, int _size,
40  		     TC_STRUCT * const tcSpace);
41  
42  /* free up queue */
43  extern int tcqDelete(TC_QUEUE_STRUCT * const tcq);
44  
45  /* reset queue to empty */
46  extern int tcqInit(TC_QUEUE_STRUCT * const tcq);
47  
48  /* put tc on end */
49  extern int tcqPut(TC_QUEUE_STRUCT * const tcq, TC_STRUCT const * const tc);
50  
51  /* remove a single tc from the back of the queue */
52  extern int tcqPopBack(TC_QUEUE_STRUCT * const tcq);
53  
54  extern int tcqPop(TC_QUEUE_STRUCT * const tcq);
55  
56  /* remove n tcs from front */
57  extern int tcqRemove(TC_QUEUE_STRUCT * const tcq, int n);
58  
59  extern int tcqBackStep(TC_QUEUE_STRUCT * const tcq);
60  
61  /* how many tcs on queue */
62  extern int tcqLen(TC_QUEUE_STRUCT const * const tcq);
63  
64  /* look at nth item, first is 0 */
65  extern TC_STRUCT * tcqItem(TC_QUEUE_STRUCT const * const tcq, int n);
66  
67  /**
68   * Get the "end" of the queue, the most recently added item.
69   */
70  extern TC_STRUCT * tcqLast(TC_QUEUE_STRUCT const * const tcq);
71  
72  /* get full status */
73  extern int tcqFull(TC_QUEUE_STRUCT const * const tcq);
74  
75  #endif