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Diffstat (limited to 'src/glu/sgi/libtess/priorityq.c')
| -rw-r--r-- | src/glu/sgi/libtess/priorityq.c | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/src/glu/sgi/libtess/priorityq.c b/src/glu/sgi/libtess/priorityq.c new file mode 100644 index 00000000000..fffa1d5255a --- /dev/null +++ b/src/glu/sgi/libtess/priorityq.c @@ -0,0 +1,267 @@ +/* +** 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.c,v 1.1 2001/03/17 00:25:41 brianp Exp $ +*/ + +#include "gluos.h" +#include <stddef.h> +#include <assert.h> +#include <limits.h> /* LONG_MAX */ +#include "memalloc.h" + +/* Include all the code for the regular heap-based queue here. */ + +#include "priorityq-heap.c" + +/* Now redefine all the function names to map to their "Sort" versions. */ + +#include "priorityq-sort.h" + +/* really __gl_pqSortNewPriorityQ */ +PriorityQ *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) ) +{ + PriorityQ *pq = (PriorityQ *)memAlloc( sizeof( PriorityQ )); + if (pq == NULL) return NULL; + + pq->heap = __gl_pqHeapNewPriorityQ( leq ); + if (pq->heap == NULL) { + memFree(pq); + return NULL; + } + + pq->keys = (PQHeapKey *)memAlloc( INIT_SIZE * sizeof(pq->keys[0]) ); + if (pq->keys == NULL) { + __gl_pqHeapDeletePriorityQ(pq->heap); + memFree(pq); + return NULL; + } + + pq->size = 0; + pq->max = INIT_SIZE; + pq->initialized = FALSE; + pq->leq = leq; + return pq; +} + +/* really __gl_pqSortDeletePriorityQ */ +void pqDeletePriorityQ( PriorityQ *pq ) +{ + assert(pq != NULL); + if (pq->heap != NULL) __gl_pqHeapDeletePriorityQ( pq->heap ); + if (pq->order != NULL) memFree( pq->order ); + if (pq->keys != NULL) memFree( pq->keys ); + memFree( pq ); +} + + +#define LT(x,y) (! LEQ(y,x)) +#define GT(x,y) (! LEQ(x,y)) +#define Swap(a,b) if(1){PQkey *tmp = *a; *a = *b; *b = tmp;}else + +/* really __gl_pqSortInit */ +int pqInit( PriorityQ *pq ) +{ + PQkey **p, **r, **i, **j, *piv; + struct { PQkey **p, **r; } Stack[50], *top = Stack; + unsigned long seed = 2016473283; + + /* Create an array of indirect pointers to the keys, so that we + * the handles we have returned are still valid. + */ +/* + pq->order = (PQHeapKey **)memAlloc( (size_t) + (pq->size * sizeof(pq->order[0])) ); +*/ + pq->order = (PQHeapKey **)memAlloc( (size_t) + ((pq->size+1) * sizeof(pq->order[0])) ); +/* the previous line is a patch to compensate for the fact that IBM */ +/* machines return a null on a malloc of zero bytes (unlike SGI), */ +/* so we have to put in this defense to guard against a memory */ +/* fault four lines down. from [email protected]. */ + if (pq->order == NULL) return 0; + + p = pq->order; + r = p + pq->size - 1; + for( piv = pq->keys, i = p; i <= r; ++piv, ++i ) { + *i = piv; + } + + /* Sort the indirect pointers in descending order, + * using randomized Quicksort + */ + top->p = p; top->r = r; ++top; + while( --top >= Stack ) { + p = top->p; + r = top->r; + while( r > p + 10 ) { + seed = seed * 1539415821 + 1; + i = p + seed % (r - p + 1); + piv = *i; + *i = *p; + *p = piv; + i = p - 1; + j = r + 1; + do { + do { ++i; } while( GT( **i, *piv )); + do { --j; } while( LT( **j, *piv )); + Swap( i, j ); + } while( i < j ); + Swap( i, j ); /* Undo last swap */ + if( i - p < r - j ) { + top->p = j+1; top->r = r; ++top; + r = i-1; + } else { + top->p = p; top->r = i-1; ++top; + p = j+1; + } + } + /* Insertion sort small lists */ + for( i = p+1; i <= r; ++i ) { + piv = *i; + for( j = i; j > p && LT( **(j-1), *piv ); --j ) { + *j = *(j-1); + } + *j = piv; + } + } + pq->max = pq->size; + pq->initialized = TRUE; + __gl_pqHeapInit( pq->heap ); /* always succeeds */ + +#ifndef NDEBUG + p = pq->order; + r = p + pq->size - 1; + for( i = p; i < r; ++i ) { + assert( LEQ( **(i+1), **i )); + } +#endif + + return 1; +} + +/* really __gl_pqSortInsert */ +/* returns LONG_MAX iff out of memory */ +PQhandle pqInsert( PriorityQ *pq, PQkey keyNew ) +{ + long curr; + + if( pq->initialized ) { + return __gl_pqHeapInsert( pq->heap, keyNew ); + } + curr = pq->size; + if( ++ pq->size >= pq->max ) { + PQkey *saveKey= pq->keys; + + /* If the heap overflows, double its size. */ + pq->max <<= 1; + pq->keys = (PQHeapKey *)memRealloc( pq->keys, + (size_t) + (pq->max * sizeof( pq->keys[0] ))); + if (pq->keys == NULL) { + pq->keys = saveKey; /* restore ptr to free upon return */ + return LONG_MAX; + } + } + assert(curr != LONG_MAX); + pq->keys[curr] = keyNew; + + /* Negative handles index the sorted array. */ + return -(curr+1); +} + +/* really __gl_pqSortExtractMin */ +PQkey pqExtractMin( PriorityQ *pq ) +{ + PQkey sortMin, heapMin; + + if( pq->size == 0 ) { + return __gl_pqHeapExtractMin( pq->heap ); + } + sortMin = *(pq->order[pq->size-1]); + if( ! __gl_pqHeapIsEmpty( pq->heap )) { + heapMin = __gl_pqHeapMinimum( pq->heap ); + if( LEQ( heapMin, sortMin )) { + return __gl_pqHeapExtractMin( pq->heap ); + } + } + do { + -- pq->size; + } while( pq->size > 0 && *(pq->order[pq->size-1]) == NULL ); + return sortMin; +} + +/* really __gl_pqSortMinimum */ +PQkey pqMinimum( PriorityQ *pq ) +{ + PQkey sortMin, heapMin; + + if( pq->size == 0 ) { + return __gl_pqHeapMinimum( pq->heap ); + } + sortMin = *(pq->order[pq->size-1]); + if( ! __gl_pqHeapIsEmpty( pq->heap )) { + heapMin = __gl_pqHeapMinimum( pq->heap ); + if( LEQ( heapMin, sortMin )) { + return heapMin; + } + } + return sortMin; +} + +/* really __gl_pqSortIsEmpty */ +int pqIsEmpty( PriorityQ *pq ) +{ + return (pq->size == 0) && __gl_pqHeapIsEmpty( pq->heap ); +} + +/* really __gl_pqSortDelete */ +void pqDelete( PriorityQ *pq, PQhandle curr ) +{ + if( curr >= 0 ) { + __gl_pqHeapDelete( pq->heap, curr ); + return; + } + curr = -(curr+1); + assert( curr < pq->max && pq->keys[curr] != NULL ); + + pq->keys[curr] = NULL; + while( pq->size > 0 && *(pq->order[pq->size-1]) == NULL ) { + -- pq->size; + } +} |