src/glu/sgi/libtess/priorityq.h

   1 /*
   2 ** License Applicability. Except to the extent portions of this file are
   3 ** made subject to an alternative license as permitted in the SGI Free
   4 ** Software License B, Version 1.1 (the "License"), the contents of this
   5 ** file are subject only to the provisions of the License. You may not use
   6 ** this file except in compliance with the License. You may obtain a copy
   7 ** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
   8 ** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
   9 **
  10 ** http://oss.sgi.com/projects/FreeB
  11 **
  12 ** Note that, as provided in the License, the Software is distributed on an
  13 ** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
  14 ** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
  15 ** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
  16 ** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
  17 **
  18 ** Original Code. The Original Code is: OpenGL Sample Implementation,
  19 ** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
  20 ** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
  21 ** Copyright in any portions created by third parties is as indicated
  22 ** elsewhere herein. All Rights Reserved.
  23 **
  24 ** Additional Notice Provisions: The application programming interfaces
  25 ** established by SGI in conjunction with the Original Code are The
  26 ** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
  27 ** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
  28 ** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
  29 ** Window System(R) (Version 1.3), released October 19, 1998. This software
  30 ** was created using the OpenGL(R) version 1.2.1 Sample Implementation
  31 ** published by SGI, but has not been independently verified as being
  32 ** compliant with the OpenGL(R) version 1.2.1 Specification.
  33 **
  34 */
  35 /*
  36 ** Author: Eric Veach, July 1994.
  37 **
  38 */
  39
  40 #ifndef __priorityq_sort_h_
  41 #define __priorityq_sort_h_
  42
  43 #include "priorityq-heap.h"
  44
  45 #undef PQkey
  46 #undef PQhandle
  47 #undef PriorityQ
  48 #undef pqNewPriorityQ
  49 #undef pqDeletePriorityQ
  50 #undef pqInit
  51 #undef pqInsert
  52 #undef pqMinimum
  53 #undef pqExtractMin
  54 #undef pqDelete
  55 #undef pqIsEmpty
  56
  57 /* Use #define's so that another heap implementation can use this one */
  58
  59 #define PQkey                   PQSortKey
  60 #define PQhandle                PQSortHandle
  61 #define PriorityQ               PriorityQSort
  62
  63 #define pqNewPriorityQ(leq)     __gl_pqSortNewPriorityQ(leq)
  64 #define pqDeletePriorityQ(pq)   __gl_pqSortDeletePriorityQ(pq)
  65
  66 /* The basic operations are insertion of a new key (pqInsert),
  67  * and examination/extraction of a key whose value is minimum
  68  * (pqMinimum/pqExtractMin).  Deletion is also allowed (pqDelete);
  69  * for this purpose pqInsert returns a "handle" which is supplied
  70  * as the argument.
  71  *
  72  * An initial heap may be created efficiently by calling pqInsert
  73  * repeatedly, then calling pqInit.  In any case pqInit must be called
  74  * before any operations other than pqInsert are used.
  75  *
  76  * If the heap is empty, pqMinimum/pqExtractMin will return a NULL key.
  77  * This may also be tested with pqIsEmpty.
  78  */
  79 #define pqInit(pq)              __gl_pqSortInit(pq)
  80 #define pqInsert(pq,key)        __gl_pqSortInsert(pq,key)
  81 #define pqMinimum(pq)           __gl_pqSortMinimum(pq)
  82 #define pqExtractMin(pq)        __gl_pqSortExtractMin(pq)
  83 #define pqDelete(pq,handle)     __gl_pqSortDelete(pq,handle)
  84 #define pqIsEmpty(pq)           __gl_pqSortIsEmpty(pq)
  85
  86
  87 /* Since we support deletion the data structure is a little more
  88  * complicated than an ordinary heap.  "nodes" is the heap itself;
  89  * active nodes are stored in the range 1..pq->size.  When the
  90  * heap exceeds its allocated size (pq->max), its size doubles.
  91  * The children of node i are nodes 2i and 2i+1.
  92  *
  93  * Each node stores an index into an array "handles".  Each handle
  94  * stores a key, plus a pointer back to the node which currently
  95  * represents that key (ie. nodes[handles[i].node].handle == i).
  96  */
  97
  98 typedef PQHeapKey PQkey;
  99 typedef PQHeapHandle PQhandle;
 100 typedef struct PriorityQ PriorityQ;
 101
 102 struct PriorityQ {
 103   PriorityQHeap *heap;
 104   PQkey         *keys;
 105   PQkey         **order;
 106   PQhandle      size, max;
 107   int           initialized;
 108   int           (*leq)(PQkey key1, PQkey key2);
 109 };
 110
 111 PriorityQ       *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) );
 112 void            pqDeletePriorityQ( PriorityQ *pq );
 113
 114 int             pqInit( PriorityQ *pq );
 115 PQhandle        pqInsert( PriorityQ *pq, PQkey key );
 116 PQkey           pqExtractMin( PriorityQ *pq );
 117 void            pqDelete( PriorityQ *pq, PQhandle handle );
 118
 119 PQkey           pqMinimum( PriorityQ *pq );
 120 int             pqIsEmpty( PriorityQ *pq );
 121
 122 #endif