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 ** $Date$ $Revision$ 39 ** $Header: //depot/main/gfx/lib/glu/libtess/priorityq-heap.h#5 $ 40 */ 41 42 #ifndef __priorityq_heap_h_ 43 #define __priorityq_heap_h_ 44 45 /* Use #define's so that another heap implementation can use this one */ 46 47 #define PQkey PQHeapKey 48 #define PQhandle PQHeapHandle 49 #define PriorityQ PriorityQHeap 50 51 #define pqNewPriorityQ(leq) __gl_pqHeapNewPriorityQ(leq) 52 #define pqDeletePriorityQ(pq) __gl_pqHeapDeletePriorityQ(pq) 53 54 /* The basic operations are insertion of a new key (pqInsert), 55 * and examination/extraction of a key whose value is minimum 56 * (pqMinimum/pqExtractMin). Deletion is also allowed (pqDelete); 57 * for this purpose pqInsert returns a "handle" which is supplied 58 * as the argument. 59 * 60 * An initial heap may be created efficiently by calling pqInsert 61 * repeatedly, then calling pqInit. In any case pqInit must be called 62 * before any operations other than pqInsert are used. 63 * 64 * If the heap is empty, pqMinimum/pqExtractMin will return a NULL key. 65 * This may also be tested with pqIsEmpty. 66 */ 67 #define pqInit(pq) __gl_pqHeapInit(pq) 68 #define pqInsert(pq,key) __gl_pqHeapInsert(pq,key) 69 #define pqMinimum(pq) __gl_pqHeapMinimum(pq) 70 #define pqExtractMin(pq) __gl_pqHeapExtractMin(pq) 71 #define pqDelete(pq,handle) __gl_pqHeapDelete(pq,handle) 72 #define pqIsEmpty(pq) __gl_pqHeapIsEmpty(pq) 73 74 75 /* Since we support deletion the data structure is a little more 76 * complicated than an ordinary heap. "nodes" is the heap itself; 77 * active nodes are stored in the range 1..pq->size. When the 78 * heap exceeds its allocated size (pq->max), its size doubles. 79 * The children of node i are nodes 2i and 2i+1. 80 * 81 * Each node stores an index into an array "handles". Each handle 82 * stores a key, plus a pointer back to the node which currently 83 * represents that key (ie. nodes[handles[i].node].handle == i). 84 */ 85 86 typedef void *PQkey; 87 typedef long PQhandle; 88 typedef struct PriorityQ PriorityQ; 89 90 typedef struct { PQhandle handle; } PQnode; 91 typedef struct { PQkey key; PQhandle node; } PQhandleElem; 92 93 struct PriorityQ { 94 PQnode *nodes; 95 PQhandleElem *handles; 96 long size, max; 97 PQhandle freeList; 98 int initialized; 99 int (*leq)(PQkey key1, PQkey key2); 100 }; 101 102 PriorityQ *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) ); 103 void pqDeletePriorityQ( PriorityQ *pq ); 104 105 void pqInit( PriorityQ *pq ); 106 PQhandle pqInsert( PriorityQ *pq, PQkey key ); 107 PQkey pqExtractMin( PriorityQ *pq ); 108 void pqDelete( PriorityQ *pq, PQhandle handle ); 109 110 111 #define __gl_pqHeapMinimum(pq) ((pq)->handles[(pq)->nodes[1].handle].key) 112 #define __gl_pqHeapIsEmpty(pq) ((pq)->size == 0) 113 114 #endif 115