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 86typedef void *PQkey; 87typedef long PQhandle; 88typedef struct PriorityQ PriorityQ; 89 90typedef struct { PQhandle handle; } PQnode; 91typedef struct { PQkey key; PQhandle node; } PQhandleElem; 92 93struct 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 102PriorityQ *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) ); 103void pqDeletePriorityQ( PriorityQ *pq ); 104 105void pqInit( PriorityQ *pq ); 106PQhandle pqInsert( PriorityQ *pq, PQkey key ); 107PQkey pqExtractMin( PriorityQ *pq ); 108void 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