src/glu/sgi/libtess/priorityq-sort.h

   1 /*
   2  * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
   3  * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice including the dates of first publication and
  13  * either this permission notice or a reference to
  14  * http://oss.sgi.com/projects/FreeB/
  15  * shall be included in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  20  * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  21  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
  22  * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE.
  24  *
  25  * Except as contained in this notice, the name of Silicon Graphics, Inc.
  26  * shall not be used in advertising or otherwise to promote the sale, use or
  27  * other dealings in this Software without prior written authorization from
  28  * Silicon Graphics, Inc.
  29  */
  30 /*
  31 ** Author: Eric Veach, July 1994.
  32 **
  33 ** $Date: 2001/03/17 00:25:41 $ $Revision: 1.1 $
  34 ** $Header: /home/krh/git/sync/mesa-cvs-repo/Mesa/src/glu/sgi/libtess/priorityq-sort.h,v 1.1 2001/03/17 00:25:41 brianp Exp $
  35 */
  36
  37 #ifndef __priorityq_sort_h_
  38 #define __priorityq_sort_h_
  39
  40 #include "priorityq-heap.h"
  41
  42 #undef PQkey
  43 #undef PQhandle
  44 #undef PriorityQ
  45 #undef pqNewPriorityQ
  46 #undef pqDeletePriorityQ
  47 #undef pqInit
  48 #undef pqInsert
  49 #undef pqMinimum
  50 #undef pqExtractMin
  51 #undef pqDelete
  52 #undef pqIsEmpty
  53
  54 /* Use #define's so that another heap implementation can use this one */
  55
  56 #define PQkey                   PQSortKey
  57 #define PQhandle                PQSortHandle
  58 #define PriorityQ               PriorityQSort
  59
  60 #define pqNewPriorityQ(leq)     __gl_pqSortNewPriorityQ(leq)
  61 #define pqDeletePriorityQ(pq)   __gl_pqSortDeletePriorityQ(pq)
  62
  63 /* The basic operations are insertion of a new key (pqInsert),
  64  * and examination/extraction of a key whose value is minimum
  65  * (pqMinimum/pqExtractMin).  Deletion is also allowed (pqDelete);
  66  * for this purpose pqInsert returns a "handle" which is supplied
  67  * as the argument.
  68  *
  69  * An initial heap may be created efficiently by calling pqInsert
  70  * repeatedly, then calling pqInit.  In any case pqInit must be called
  71  * before any operations other than pqInsert are used.
  72  *
  73  * If the heap is empty, pqMinimum/pqExtractMin will return a NULL key.
  74  * This may also be tested with pqIsEmpty.
  75  */
  76 #define pqInit(pq)              __gl_pqSortInit(pq)
  77 #define pqInsert(pq,key)        __gl_pqSortInsert(pq,key)
  78 #define pqMinimum(pq)           __gl_pqSortMinimum(pq)
  79 #define pqExtractMin(pq)        __gl_pqSortExtractMin(pq)
  80 #define pqDelete(pq,handle)     __gl_pqSortDelete(pq,handle)
  81 #define pqIsEmpty(pq)           __gl_pqSortIsEmpty(pq)
  82
  83
  84 /* Since we support deletion the data structure is a little more
  85  * complicated than an ordinary heap.  "nodes" is the heap itself;
  86  * active nodes are stored in the range 1..pq->size.  When the
  87  * heap exceeds its allocated size (pq->max), its size doubles.
  88  * The children of node i are nodes 2i and 2i+1.
  89  *
  90  * Each node stores an index into an array "handles".  Each handle
  91  * stores a key, plus a pointer back to the node which currently
  92  * represents that key (ie. nodes[handles[i].node].handle == i).
  93  */
  94
  95 typedef PQHeapKey PQkey;
  96 typedef PQHeapHandle PQhandle;
  97 typedef struct PriorityQ PriorityQ;
  98
  99 struct PriorityQ {
 100   PriorityQHeap *heap;
 101   PQkey         *keys;
 102   PQkey         **order;
 103   PQhandle      size, max;
 104   int           initialized;
 105   int           (*leq)(PQkey key1, PQkey key2);
 106 };
 107
 108 PriorityQ       *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) );
 109 void            pqDeletePriorityQ( PriorityQ *pq );
 110
 111 int             pqInit( PriorityQ *pq );
 112 PQhandle        pqInsert( PriorityQ *pq, PQkey key );
 113 PQkey           pqExtractMin( PriorityQ *pq );
 114 void            pqDelete( PriorityQ *pq, PQhandle handle );
 115
 116 PQkey           pqMinimum( PriorityQ *pq );
 117 int             pqIsEmpty( PriorityQ *pq );
 118
 119 #endif