diff options
Diffstat (limited to 'src/glu/sgi/libtess/priorityq-heap.h')
| -rw-r--r-- | src/glu/sgi/libtess/priorityq-heap.h | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/src/glu/sgi/libtess/priorityq-heap.h b/src/glu/sgi/libtess/priorityq-heap.h new file mode 100644 index 00000000000..39c33c3921e --- /dev/null +++ b/src/glu/sgi/libtess/priorityq-heap.h @@ -0,0 +1,114 @@ +/* +** License Applicability. Except to the extent portions of this file are +** made subject to an alternative license as permitted in the SGI Free +** Software License B, Version 1.1 (the "License"), the contents of this +** file are subject only to the provisions of the License. You may not use +** this file except in compliance with the License. You may obtain a copy +** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600 +** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at: +** +** http://oss.sgi.com/projects/FreeB +** +** Note that, as provided in the License, the Software is distributed on an +** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS +** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND +** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A +** PARTICULAR PURPOSE, AND NON-INFRINGEMENT. +** +** Original Code. The Original Code is: OpenGL Sample Implementation, +** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics, +** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc. +** Copyright in any portions created by third parties is as indicated +** elsewhere herein. All Rights Reserved. +** +** Additional Notice Provisions: The application programming interfaces +** established by SGI in conjunction with the Original Code are The +** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released +** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version +** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X +** Window System(R) (Version 1.3), released October 19, 1998. This software +** was created using the OpenGL(R) version 1.2.1 Sample Implementation +** published by SGI, but has not been independently verified as being +** compliant with the OpenGL(R) version 1.2.1 Specification. +** +*/ +/* +** Author: Eric Veach, July 1994. +** +** $Date: 2001/03/17 00:25:41 $ $Revision: 1.1 $ +** $Header: /home/krh/git/sync/mesa-cvs-repo/Mesa/src/glu/sgi/libtess/priorityq-heap.h,v 1.1 2001/03/17 00:25:41 brianp Exp $ +*/ + +#ifndef __priorityq_heap_h_ +#define __priorityq_heap_h_ + +/* Use #define's so that another heap implementation can use this one */ + +#define PQkey PQHeapKey +#define PQhandle PQHeapHandle +#define PriorityQ PriorityQHeap + +#define pqNewPriorityQ(leq) __gl_pqHeapNewPriorityQ(leq) +#define pqDeletePriorityQ(pq) __gl_pqHeapDeletePriorityQ(pq) + +/* The basic operations are insertion of a new key (pqInsert), + * and examination/extraction of a key whose value is minimum + * (pqMinimum/pqExtractMin). Deletion is also allowed (pqDelete); + * for this purpose pqInsert returns a "handle" which is supplied + * as the argument. + * + * An initial heap may be created efficiently by calling pqInsert + * repeatedly, then calling pqInit. In any case pqInit must be called + * before any operations other than pqInsert are used. + * + * If the heap is empty, pqMinimum/pqExtractMin will return a NULL key. + * This may also be tested with pqIsEmpty. + */ +#define pqInit(pq) __gl_pqHeapInit(pq) +#define pqInsert(pq,key) __gl_pqHeapInsert(pq,key) +#define pqMinimum(pq) __gl_pqHeapMinimum(pq) +#define pqExtractMin(pq) __gl_pqHeapExtractMin(pq) +#define pqDelete(pq,handle) __gl_pqHeapDelete(pq,handle) +#define pqIsEmpty(pq) __gl_pqHeapIsEmpty(pq) + + +/* Since we support deletion the data structure is a little more + * complicated than an ordinary heap. "nodes" is the heap itself; + * active nodes are stored in the range 1..pq->size. When the + * heap exceeds its allocated size (pq->max), its size doubles. + * The children of node i are nodes 2i and 2i+1. + * + * Each node stores an index into an array "handles". Each handle + * stores a key, plus a pointer back to the node which currently + * represents that key (ie. nodes[handles[i].node].handle == i). + */ + +typedef void *PQkey; +typedef long PQhandle; +typedef struct PriorityQ PriorityQ; + +typedef struct { PQhandle handle; } PQnode; +typedef struct { PQkey key; PQhandle node; } PQhandleElem; + +struct PriorityQ { + PQnode *nodes; + PQhandleElem *handles; + long size, max; + PQhandle freeList; + int initialized; + int (*leq)(PQkey key1, PQkey key2); +}; + +PriorityQ *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) ); +void pqDeletePriorityQ( PriorityQ *pq ); + +void pqInit( PriorityQ *pq ); +PQhandle pqInsert( PriorityQ *pq, PQkey key ); +PQkey pqExtractMin( PriorityQ *pq ); +void pqDelete( PriorityQ *pq, PQhandle handle ); + + +#define __gl_pqHeapMinimum(pq) ((pq)->handles[(pq)->nodes[1].handle].key) +#define __gl_pqHeapIsEmpty(pq) ((pq)->size == 0) + +#endif |