skia2/third_party/glu/libtess/priorityq-heap.c
senorblanco@chromium.org 7eb492e839 Add the GLU tesselator source files to third_party. Add a libtess static
library build target to the .gyp file (not required by any executable yet).  Fix
some build errors with SampleApp on Linux and Win32.  Add a gyp_skia python
script which invokes gyp with the correct arguments, and is recursively callable
by the Makefile when skia.gyp is changed.

Review URL:  http://codereview.appspot.com/4280069/



git-svn-id: http://skia.googlecode.com/svn/trunk@1007 2bbb7eff-a529-9590-31e7-b0007b416f81
2011-03-25 17:41:34 +00:00

261 lines
6.7 KiB
C

/*
** 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.
**
** $Date$ $Revision$
** $Header: //depot/main/gfx/lib/glu/libtess/priorityq-heap.c#5 $
*/
#include <assert.h>
#include <limits.h>
#include <stddef.h>
#include "memalloc.h"
#include "priorityq-heap.h"
#define INIT_SIZE 32
#define TRUE 1
#define FALSE 0
#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;
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 = curr;
} else {
free = pq->freeList;
pq->freeList = pq->handles[free].node;
}
pq->nodes[curr].handle = free;
pq->handles[free].node = curr;
pq->handles[free].key = keyNew;
if( pq->initialized ) {
FloatUp( pq, curr );
}
assert(free != LONG_MAX);
return free;
}
/* 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;
}