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** License Applicability. Except to the extent portions of this file are
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** made subject to an alternative license as permitted in the SGI Free
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** Software License B, Version 1.1 (the "License"), the contents of this
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** file are subject only to the provisions of the License. You may not use
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** this file except in compliance with the License. You may obtain a copy
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** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
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** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
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** http://oss.sgi.com/projects/FreeB
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** 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
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** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
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** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
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** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
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** Original Code. The Original Code is: OpenGL Sample Implementation,
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** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
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** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
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** Copyright in any portions created by third parties is as indicated
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** elsewhere herein. All Rights Reserved.
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** Additional Notice Provisions: The application programming interfaces
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** established by SGI in conjunction with the Original Code are The
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** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
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** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
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** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
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** Window System(R) (Version 1.3), released October 19, 1998. This software
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** was created using the OpenGL(R) version 1.2.1 Sample Implementation
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** published by SGI, but has not been independently verified as being
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** compliant with the OpenGL(R) version 1.2.1 Specification.
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** Author: Eric Veach, July 1994.
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** $Header: //depot/main/gfx/lib/glu/libtess/priorityq.c#5 $
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#include <limits.h> /* LONG_MAX */
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/* Include all the code for the regular heap-based queue here. */
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#include "priorityq-heap.c"
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/* Now redefine all the function names to map to their "Sort" versions. */
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#include "priorityq-sort.h"
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/* really __gl_pqSortNewPriorityQ */
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PriorityQ *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) )
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PriorityQ *pq = (PriorityQ *)memAlloc( sizeof( PriorityQ ));
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if (pq == NULL) return NULL;
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pq->heap = __gl_pqHeapNewPriorityQ( leq );
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if (pq->heap == NULL) {
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pq->keys = (PQHeapKey *)memAlloc( INIT_SIZE * sizeof(pq->keys[0]) );
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if (pq->keys == NULL) {
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__gl_pqHeapDeletePriorityQ(pq->heap);
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pq->initialized = FALSE;
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/* really __gl_pqSortDeletePriorityQ */
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void pqDeletePriorityQ( PriorityQ *pq )
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if (pq->heap != NULL) __gl_pqHeapDeletePriorityQ( pq->heap );
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if (pq->order != NULL) memFree( pq->order );
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if (pq->keys != NULL) memFree( pq->keys );
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#define LT(x,y) (! LEQ(y,x))
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#define GT(x,y) (! LEQ(x,y))
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#define Swap(a,b) if(1){PQkey *tmp = *a; *a = *b; *b = tmp;}else
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/* really __gl_pqSortInit */
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int pqInit( PriorityQ *pq )
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PQkey **p, **r, **i, **j, *piv;
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struct { PQkey **p, **r; } Stack[50], *top = Stack;
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unsigned long seed = 2016473283;
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/* Create an array of indirect pointers to the keys, so that we
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* the handles we have returned are still valid.
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pq->order = (PQHeapKey **)memAlloc( (size_t)
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(pq->size * sizeof(pq->order[0])) );
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pq->order = (PQHeapKey **)memAlloc( (size_t)
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((pq->size+1) * sizeof(pq->order[0])) );
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/* the previous line is a patch to compensate for the fact that IBM */
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/* machines return a null on a malloc of zero bytes (unlike SGI), */
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/* so we have to put in this defense to guard against a memory */
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/* fault four lines down. from fossum@austin.ibm.com. */
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if (pq->order == NULL) return 0;
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r = p + pq->size - 1;
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for( piv = pq->keys, i = p; i <= r; ++piv, ++i ) {
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/* Sort the indirect pointers in descending order,
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* using randomized Quicksort
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top->p = p; top->r = r; ++top;
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while( --top >= Stack ) {
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while( r > p + 10 ) {
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seed = seed * 1539415821 + 1;
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i = p + seed % (r - p + 1);
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do { ++i; } while( GT( **i, *piv ));
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do { --j; } while( LT( **j, *piv ));
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Swap( i, j ); /* Undo last swap */
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if( i - p < r - j ) {
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top->p = j+1; top->r = r; ++top;
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top->p = p; top->r = i-1; ++top;
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/* Insertion sort small lists */
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for( i = p+1; i <= r; ++i ) {
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for( j = i; j > p && LT( **(j-1), *piv ); --j ) {
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pq->initialized = TRUE;
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__gl_pqHeapInit( pq->heap ); /* always succeeds */
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r = p + pq->size - 1;
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for( i = p; i < r; ++i ) {
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assert( LEQ( **(i+1), **i ));
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/* really __gl_pqSortInsert */
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/* returns LONG_MAX iff out of memory */
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PQhandle pqInsert( PriorityQ *pq, PQkey keyNew )
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if( pq->initialized ) {
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return __gl_pqHeapInsert( pq->heap, keyNew );
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if( ++ pq->size >= pq->max ) {
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PQkey *saveKey= pq->keys;
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/* If the heap overflows, double its size. */
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pq->keys = (PQHeapKey *)memRealloc( pq->keys,
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(pq->max * sizeof( pq->keys[0] )));
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if (pq->keys == NULL) {
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pq->keys = saveKey; /* restore ptr to free upon return */
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assert(curr != LONG_MAX);
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pq->keys[curr] = keyNew;
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/* Negative handles index the sorted array. */
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/* really __gl_pqSortExtractMin */
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PQkey pqExtractMin( PriorityQ *pq )
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PQkey sortMin, heapMin;
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if( pq->size == 0 ) {
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return __gl_pqHeapExtractMin( pq->heap );
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sortMin = *(pq->order[pq->size-1]);
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if( ! __gl_pqHeapIsEmpty( pq->heap )) {
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heapMin = __gl_pqHeapMinimum( pq->heap );
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if( LEQ( heapMin, sortMin )) {
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return __gl_pqHeapExtractMin( pq->heap );
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} while( pq->size > 0 && *(pq->order[pq->size-1]) == NULL );
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/* really __gl_pqSortMinimum */
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PQkey pqMinimum( PriorityQ *pq )
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PQkey sortMin, heapMin;
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if( pq->size == 0 ) {
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return __gl_pqHeapMinimum( pq->heap );
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sortMin = *(pq->order[pq->size-1]);
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if( ! __gl_pqHeapIsEmpty( pq->heap )) {
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heapMin = __gl_pqHeapMinimum( pq->heap );
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if( LEQ( heapMin, sortMin )) {
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/* really __gl_pqSortIsEmpty */
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int pqIsEmpty( PriorityQ *pq )
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return (pq->size == 0) && __gl_pqHeapIsEmpty( pq->heap );
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/* really __gl_pqSortDelete */
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void pqDelete( PriorityQ *pq, PQhandle curr )
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__gl_pqHeapDelete( pq->heap, curr );
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assert( curr < pq->max && pq->keys[curr] != NULL );
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pq->keys[curr] = NULL;
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while( pq->size > 0 && *(pq->order[pq->size-1]) == NULL ) {