mutter/cogl/tesselator/priorityq-heap.c
Neil Roberts a0a06f0342 cogl/tesselator: Update to the latest code from GLU
This grabs the latest code for libtess from git Mesa. This is mostly
so that we can get the following commit which fixes a lot of compiler
warnings in Clutter:

commit 75acb896c6da758d03e86f8725d6ca0cb2c6ad82
Author: Neil Roberts <neil@linux.intel.com>
Date:   Wed Jun 30 12:41:11 2010 +0100

    glu: Fix some compiler warnings in libtess
    
    When compiled with the more aggressive compiler warnings such as
    -Wshadow and -Wempty-body the libtess code gives a lot more
    warnings. This fixes the following issues:
    
    * The 'Swap' macro tries to combine multiple statements into one and
      then consume the trailing semicolon by using if(1){/*...*/}else.
      This gives warnings because the else part ends up with an empty
      statement. It also seems a bit dangerous because if the semicolon
      were missed then it would still be valid syntax but it would just
      ignore the following statement. This patch replaces it with the more
      common idiom do { /*...*/ } while(0).
    
    * 'free' was being used as a local variable name but this shadows the
      global function. This has been renamed to 'free_handle'
    
    * TRUE and FALSE were being unconditionally defined. Although this
      isn't currently a problem it seems better to guard them with #ifndef
      because it's quite common for them to be defined in other headers.
    
    https://bugs.freedesktop.org/show_bug.cgi?id=28845
2010-06-30 16:35:33 +01:00

257 lines
6.4 KiB
C

/*
* SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
* Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
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* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice including the dates of first publication and
* either this permission notice or a reference to
* http://oss.sgi.com/projects/FreeB/
* shall be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
* OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* Except as contained in this notice, the name of Silicon Graphics, Inc.
* shall not be used in advertising or otherwise to promote the sale, use or
* other dealings in this Software without prior written authorization from
* Silicon Graphics, Inc.
*/
/*
** Author: Eric Veach, July 1994.
**
*/
#include <stddef.h>
#include <assert.h>
#include "priorityq-heap.h"
#include "memalloc.h"
#define INIT_SIZE 32
#ifndef TRUE
#define TRUE 1
#endif
#ifndef FALSE
#define FALSE 0
#endif
#ifdef FOR_TRITE_TEST_PROGRAM
#define LEQ(x,y) (*pq->leq)(x,y)
#else
/* Violates modularity, but a little faster */
#include "geom.h"
#define LEQ(x,y) VertLeq((GLUvertex *)x, (GLUvertex *)y)
#endif
/* really __gl_pqHeapNewPriorityQ */
PriorityQ *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) )
{
PriorityQ *pq = (PriorityQ *)memAlloc( sizeof( PriorityQ ));
if (pq == NULL) return NULL;
pq->size = 0;
pq->max = INIT_SIZE;
pq->nodes = (PQnode *)memAlloc( (INIT_SIZE + 1) * sizeof(pq->nodes[0]) );
if (pq->nodes == NULL) {
memFree(pq);
return NULL;
}
pq->handles = (PQhandleElem *)memAlloc( (INIT_SIZE + 1) * sizeof(pq->handles[0]) );
if (pq->handles == NULL) {
memFree(pq->nodes);
memFree(pq);
return NULL;
}
pq->initialized = FALSE;
pq->freeList = 0;
pq->leq = leq;
pq->nodes[1].handle = 1; /* so that Minimum() returns NULL */
pq->handles[1].key = NULL;
return pq;
}
/* really __gl_pqHeapDeletePriorityQ */
void pqDeletePriorityQ( PriorityQ *pq )
{
memFree( pq->handles );
memFree( pq->nodes );
memFree( pq );
}
static void FloatDown( PriorityQ *pq, long curr )
{
PQnode *n = pq->nodes;
PQhandleElem *h = pq->handles;
PQhandle hCurr, hChild;
long child;
hCurr = n[curr].handle;
for( ;; ) {
child = curr << 1;
if( child < pq->size && LEQ( h[n[child+1].handle].key,
h[n[child].handle].key )) {
++child;
}
assert(child <= pq->max);
hChild = n[child].handle;
if( child > pq->size || LEQ( h[hCurr].key, h[hChild].key )) {
n[curr].handle = hCurr;
h[hCurr].node = curr;
break;
}
n[curr].handle = hChild;
h[hChild].node = curr;
curr = child;
}
}
static void FloatUp( PriorityQ *pq, long curr )
{
PQnode *n = pq->nodes;
PQhandleElem *h = pq->handles;
PQhandle hCurr, hParent;
long parent;
hCurr = n[curr].handle;
for( ;; ) {
parent = curr >> 1;
hParent = n[parent].handle;
if( parent == 0 || LEQ( h[hParent].key, h[hCurr].key )) {
n[curr].handle = hCurr;
h[hCurr].node = curr;
break;
}
n[curr].handle = hParent;
h[hParent].node = curr;
curr = parent;
}
}
/* really __gl_pqHeapInit */
void pqInit( PriorityQ *pq )
{
long i;
/* This method of building a heap is O(n), rather than O(n lg n). */
for( i = pq->size; i >= 1; --i ) {
FloatDown( pq, i );
}
pq->initialized = TRUE;
}
/* really __gl_pqHeapInsert */
/* returns LONG_MAX iff out of memory */
PQhandle pqInsert( PriorityQ *pq, PQkey keyNew )
{
long curr;
PQhandle free_handle;
curr = ++ pq->size;
if( (curr*2) > pq->max ) {
PQnode *saveNodes= pq->nodes;
PQhandleElem *saveHandles= pq->handles;
/* If the heap overflows, double its size. */
pq->max <<= 1;
pq->nodes = (PQnode *)memRealloc( pq->nodes,
(size_t)
((pq->max + 1) * sizeof( pq->nodes[0] )));
if (pq->nodes == NULL) {
pq->nodes = saveNodes; /* restore ptr to free upon return */
return LONG_MAX;
}
pq->handles = (PQhandleElem *)memRealloc( pq->handles,
(size_t)
((pq->max + 1) *
sizeof( pq->handles[0] )));
if (pq->handles == NULL) {
pq->handles = saveHandles; /* restore ptr to free upon return */
return LONG_MAX;
}
}
if( pq->freeList == 0 ) {
free_handle = curr;
} else {
free_handle = pq->freeList;
pq->freeList = pq->handles[free_handle].node;
}
pq->nodes[curr].handle = free_handle;
pq->handles[free_handle].node = curr;
pq->handles[free_handle].key = keyNew;
if( pq->initialized ) {
FloatUp( pq, curr );
}
assert(free_handle != LONG_MAX);
return free_handle;
}
/* really __gl_pqHeapExtractMin */
PQkey pqExtractMin( PriorityQ *pq )
{
PQnode *n = pq->nodes;
PQhandleElem *h = pq->handles;
PQhandle hMin = n[1].handle;
PQkey min = h[hMin].key;
if( pq->size > 0 ) {
n[1].handle = n[pq->size].handle;
h[n[1].handle].node = 1;
h[hMin].key = NULL;
h[hMin].node = pq->freeList;
pq->freeList = hMin;
if( -- pq->size > 0 ) {
FloatDown( pq, 1 );
}
}
return min;
}
/* really __gl_pqHeapDelete */
void pqDelete( PriorityQ *pq, PQhandle hCurr )
{
PQnode *n = pq->nodes;
PQhandleElem *h = pq->handles;
long curr;
assert( hCurr >= 1 && hCurr <= pq->max && h[hCurr].key != NULL );
curr = h[hCurr].node;
n[curr].handle = n[pq->size].handle;
h[n[curr].handle].node = curr;
if( curr <= -- pq->size ) {
if( curr <= 1 || LEQ( h[n[curr>>1].handle].key, h[n[curr].handle].key )) {
FloatDown( pq, curr );
} else {
FloatUp( pq, curr );
}
}
h[hCurr].key = NULL;
h[hCurr].node = pq->freeList;
pq->freeList = hCurr;
}