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Christophe Geuzaine authoredChristophe Geuzaine authored
OctreeInternals.cpp 13.38 KiB
// Gmsh - Copyright (C) 1997-2019 C. Geuzaine, J.-F. Remacle
//
// See the LICENSE.txt file for license information. Please report all
// issues on https://gitlab.onelab.info/gmsh/gmsh/issues.
#include <list>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "GmshMessage.h"
#include "OctreeInternals.h"
int initializeOctantBuckets(double *_orig, double *_size, int _maxElem,
octantBucket **buckets_head,
globalInfo **globalPara)
// Initialize the buckets
// Given by user: orig and size -- information about the domain
// maxElem -- maximum number of elements per bucket
// Return: buckets -- pointer to the begin of buckets
// globalPara -- some info about the buckets
// At last, 1 will be returned if succeed, otherwise, return 0
{
int i, j, k, tmp1;
int p = 1;
int initial_buckets_num; // which is a number of 8^p form for integer p
double tmp[3], error[3];
octantBucket *buckets;
for(i = 0; i < 3; i++) error[i] = _size[i] * 0.01;
initial_buckets_num = (int)pow(8., p); // it is actually 8
(*globalPara) = new globalInfo;
(*globalPara)->maxPrecision = 1;
(*globalPara)->maxElements = _maxElem;
(*globalPara)->ptrToPrevElement = NULL;
for(i = 0; i < 3; i++) {
(*globalPara)->origin[i] = _orig[i];
(*globalPara)->size[i] = _size[i];
}
(*globalPara)->numBuckets = initial_buckets_num;
*buckets_head = new octantBucket;
if(!(*buckets_head)) {
Msg::Error("initializeOctantBuckets could not allocate enough space");
return (0);
} // if could not allocate buckets
buckets = new octantBucket[8];
if(!buckets) {
Msg::Error("initializeOctantBuckets could not allocate enough space");
return (0);
}
(*buckets_head)->next = buckets;
(*buckets_head)->parent = NULL;
(*buckets_head)->numElements = 0;
(*buckets_head)->lhead = NULL;
(*buckets_head)->precision = 0;
for(i = 0; i < 3; i++) {
(*buckets_head)->minPt[i] = _orig[i] - error[i];
(*buckets_head)->maxPt[i] = _size[i] + _orig[i] + error[i];
}
for(i = 0; i < (*globalPara)->numBuckets; i++) {
buckets[i].numElements = 0;
buckets[i].lhead = NULL;
buckets[i].next = NULL;
buckets[i].parent = *buckets_head;
buckets[i].precision = 1;
}
tmp1 = (int)(pow(2., p));
for(i = 0; i < 3; i++) {
tmp[i] = (double)(_size[i] + 2 * error[i]) / tmp1;
}
for(k = 0; k < tmp1; k++) {
for(j = 0; j < tmp1; j++) {
for(i = 0; i < tmp1; i++) {
buckets[i + j * tmp1 + k * tmp1 * tmp1].minPt[0] =
(*buckets_head)->minPt[0] + tmp[0] * i;
buckets[i + j * tmp1 + k * tmp1 * tmp1].minPt[1] =
(*buckets_head)->minPt[1] + tmp[1] * j;
buckets[i + j * tmp1 + k * tmp1 * tmp1].minPt[2] =
(*buckets_head)->minPt[2] + tmp[2] * k;
buckets[i + j * tmp1 + k * tmp1 * tmp1].maxPt[0] =
(*buckets_head)->minPt[0] + tmp[0] * (i + 1);
buckets[i + j * tmp1 + k * tmp1 * tmp1].maxPt[1] =
(*buckets_head)->minPt[1] + tmp[1] * (j + 1);
buckets[i + j * tmp1 + k * tmp1 * tmp1].maxPt[2] =
(*buckets_head)->minPt[2] + tmp[2] * (k + 1);
}
}
}
#if 0
for (i = 0; i < 8; i++) {
printf(" bucket %d : min[0]=%f, min[1]=%f, min[2]=%f, max[0]= %f, max[1]=%f, max[3]=%f\n",
i,buckets[i].minPt[0],buckets[i].minPt[1],
buckets[i].minPt[2], buckets[i].maxPt[0], buckets[i].maxPt[1],
buckets[i].maxPt[2]);
printf("bucket elements link list: bucket->lhead = %d\n", buckets[i].lhead);
}
#endif
return (1);
}
int addElement2Bucket(octantBucket *_bucket, void *_element, double *_minBB,
double *_maxBB, double *_ele_centroid,
globalInfo *_globalPara)
// Add another element to the octant bucket's list.
// If the bucket contains too many elements after adding this element,
// refine this bucket and reallocate the elements of this bucket
// Given:- the octant bucket, - the element
// - the element's minimum and maximum x,y,z
// - the element's centroid, - global information
// Check if element has already been added - if not, return 1
// for successfully adding, otherwise return -1
{
int i, flag = 1;
ELink ptr1, ptr2;
octantBucket *ptrBucket;
// check for duplicates
if(checkElementInBucket(_bucket, _element) == 1) return -1;
// printf("\n addToBucket...\n");
// ptr1 = (ELink) malloc(sizeof(Elem));
ptr1 = new Elem;
(_globalPara->listAllElements).push_back(_element);
ptr1->next = _bucket->lhead;
ptr1->region = _element;
for(i = 0; i < 3; i++) {
ptr1->minPt[i] = _minBB[i];
ptr1->maxPt[i] = _maxBB[i];
ptr1->centroid[i] = _ele_centroid[i];
// printf(" %7.2f->%-7.2f",ptr1->minPt[i], ptr1->maxPt[i]);
}
_bucket->lhead = ptr1;
(_bucket->numElements)++;
#if 0
printf("bucket element list: bucket->lhead = %d", _bucket->lhead);
printf(" numElements = %d\n",_bucket->numElements);
printf("the element is add to this bucket: (%f, %f, %f) to (%f, %f, %f)\n",
_bucket->minPt[0],_bucket->minPt[1], _bucket->minPt[2], _bucket->maxPt[0],
_bucket->maxPt[1], _bucket->maxPt[2]);
#endif
// check whether the number of elements in the bucket > maxElements
// if true, refine the bucket and reallocate the elements
while(flag == 1) {
flag = 0;
if(_bucket->numElements > _globalPara->maxElements) {
// printf(" going to subdivide\n");
subdivideOctantBucket(_bucket, _globalPara);
// printf("finish subdivede \n");
ptr1 = _bucket->lhead;
while(ptr1 != NULL) {
ptrBucket = findElementBucket(_bucket, ptr1->centroid);
ptr2 = ptr1;
ptr1 = ptr1->next;
if(ptrBucket == NULL) {
Msg::Error("Wrong , ptrBucket = NULL. A bug here!");
return 0;
}
ptr2->next = ptrBucket->lhead;
ptrBucket->lhead = ptr2;
(ptrBucket->numElements)++;
if(ptrBucket->numElements > _globalPara->maxElements) {
flag = 1;
_bucket->lhead = NULL;
_bucket = ptrBucket;
}
}
if(flag == 0) _bucket->lhead = NULL;
}
}
return 1;
}
int checkElementInBucket(octantBucket *_bucket, void *_element)
// Given an elememt and an octant bucket, check if the element
// exists in the bucket's element list. return 1 if already exits,
// otherwise, return 0
{
ELink ptr;
for(ptr = _bucket->lhead; ptr != NULL; ptr = ptr->next) {
// changed ****, compare the objected pointed by the void *.
if(ptr->region == _element) return 1;
}
return 0;
}
octantBucket *findElementBucket(octantBucket *_buckets_head, double *_pt)
// Find the leaf bucket which contains the point _pt
// given parameter: _buckets --- the point to buckets head
// _pt --- the point to find
// Return the pointer to the bucket contains the point
// if fail, return NULL
{
int i, j;
int num = 8;
octantBucket *prevbucket = NULL;
octantBucket *tmpbucket = _buckets_head->next;
while(tmpbucket != NULL) {
for(i = 0; i < num; i++) {
for(j = 0; j < 3; j++) {
if(tmpbucket[i].minPt[j] > _pt[j] || tmpbucket[i].maxPt[j] < _pt[j])
break;
}
if(j == 3) {
prevbucket = tmpbucket + i;
tmpbucket = tmpbucket[i].next;
break;
}
} // for loop i
if(i == num) {
// Msg::Error("No bucket contains the given point!");
return NULL;
}
} // for while loop
return prevbucket;
}
int subdivideOctantBucket(octantBucket *_bucket, globalInfo *_globalPara)
// To many elements are in this octant bucket, so try to refine
// Returns 1 for success, 0 for failure (no memory left).
{
int i, j, k, tmp1;
int numBuck = 8;
double tmp[3];
_bucket->next = new octantBucket[8];
// _bucket->next = (octantBucket *) calloc(numBuck,sizeof(octantBucket));
if(!_bucket->next) {
Msg::Error("subdivideOctantBucket could not allocate enough space");
return 0;
}
_globalPara->numBuckets += 8;
if(_bucket->precision == _globalPara->maxPrecision)
_globalPara->maxPrecision++;
for(i = 0; i < numBuck; i++) {
(_bucket->next[i]).numElements = 0;
(_bucket->next[i]).lhead = NULL;
(_bucket->next[i]).next = NULL;
(_bucket->next[i]).parent = _bucket;
(_bucket->next[i]).precision = _bucket->precision + 1;
}
tmp1 = 2;
for(i = 0; i < 3; i++) {
tmp[i] = ((double)(_bucket->maxPt[i] - _bucket->minPt[i])) / tmp1;
}
for(k = 0; k < tmp1; k++) {
for(j = 0; j < tmp1; j++) {
for(i = 0; i < tmp1; i++) {
_bucket->next[i + j * tmp1 + k * tmp1 * tmp1].minPt[0] =
_bucket->minPt[0] + tmp[0] * i;
_bucket->next[i + j * tmp1 + k * tmp1 * tmp1].minPt[1] =
_bucket->minPt[1] + tmp[1] * j;
_bucket->next[i + j * tmp1 + k * tmp1 * tmp1].minPt[2] =
_bucket->minPt[2] + tmp[2] * k;
_bucket->next[i + j * tmp1 + k * tmp1 * tmp1].maxPt[0] =
_bucket->minPt[0] + tmp[0] * (i + 1);
_bucket->next[i + j * tmp1 + k * tmp1 * tmp1].maxPt[1] =
_bucket->minPt[1] + tmp[1] * (j + 1);
_bucket->next[i + j * tmp1 + k * tmp1 * tmp1].maxPt[2] =
_bucket->minPt[2] + tmp[2] * (k + 1);
}
}
}
return 1;
}
void *searchElement(octantBucket *_buckets_head, double *_pt,
globalInfo *_globalPara, BBFunction BBElement,
InEleFunction xyzInElement)
{
int flag;
octantBucket *ptrBucket;
ELink ptr1;
std::vector<void *>::iterator iter;
void *ptrToEle = _globalPara->ptrToPrevElement;
if(ptrToEle) {
flag = xyzInElementBB(_pt, ptrToEle, BBElement);
if(flag == 1) flag = xyzInElement(ptrToEle, _pt);
if(flag == 1) return ptrToEle;
}
ptrBucket = findElementBucket(_buckets_head, _pt);
if(ptrBucket == NULL) {
// this is not an error
Msg::Debug("The point is not in the domain");
return NULL;
}
ptr1 = ptrBucket->lhead;
#if 0
printf("point %lf %lf %lf has been found in bucket %lf %lf %fl -> %lf %lf %lf %p\n",
_pt[0],_pt[1],_pt[2], ptrBucket->minPt[0],ptrBucket->minPt[1],ptrBucket->minPt[2],
ptrBucket->maxPt[0],ptrBucket->maxPt[1],ptrBucket->maxPt[2], ptr1);
if (ptr1 == NULL) {
printf("empty element list for centroid list!?\n, possible!");
}
#endif
while(ptr1 != NULL) {
flag = xyzInElementBB(_pt, ptr1->region, BBElement);
if(flag == 1) flag = xyzInElement(ptr1->region, _pt);
if(flag == 1) {
_globalPara->ptrToPrevElement = ptr1->region;
return ptr1->region;
}
ptr1 = ptr1->next;
}
for(iter = (ptrBucket->listBB).begin(); iter != (ptrBucket->listBB).end();
iter++) {
flag = xyzInElementBB(_pt, *iter, BBElement);
if(flag == 1) flag = xyzInElement(*iter, _pt);
if(flag == 1) {
_globalPara->ptrToPrevElement = *iter;
return *iter;
}
}
// printf("This point is not found in all elements! It is not in the domain
// \n");
return NULL;
}
int xyzInElementBB(double *_xyz, void *_region, BBFunction _bbElement)
// Check if xyz is in the region's bounding box, return 1 if true, 0 otherwise
// BBElement is the function given by user to find the bounding box
{
int i;
double minPt[3]; // corner with smallest x,y,z coords
double maxPt[3]; // corner with largest x,y,z coords
(*_bbElement)(_region, minPt, maxPt);
for(i = 0; i < 3; i++) {
if(_xyz[i] > maxPt[i] || _xyz[i] < minPt[i]) return 0;
} // for ith direction
return 1;
}
void insertOneBB(void *_region, double *_minPt, double *_maxPt,
octantBucket *_bucket)
{
int i;
ELink ptr;
for(i = 0; i < 3; i++) {
if(_bucket->minPt[i] > _maxPt[i] || _bucket->maxPt[i] < _minPt[i]) return;
}
if(_bucket->next == NULL) {
ptr = _bucket->lhead;
while(ptr != NULL) {
if(ptr->region == _region) return;
ptr = ptr->next;
}
//_bucket->listBB.insert(_bucket->listBB.end(),_region);
_bucket->listBB.push_back(_region);
return;
}
for(i = 0; i < 8; i++)
insertOneBB(_region, _minPt, _maxPt, _bucket->next + i);
return;
}
void *searchAllElements(octantBucket *_buckets_head, double *_pt,
globalInfo *_globalPara, BBFunction BBElement,
InEleFunction xyzInElement,
std::vector<void *> *_elements)
{
int flag, flag1;
octantBucket *ptrBucket;
std::vector<void *>::iterator iter;
ptrBucket = findElementBucket(_buckets_head, _pt);
if(ptrBucket == NULL) {
Msg::Debug("The point is not in the domain");
return NULL;
}
#if 0
printf("point %lf %lf %lf has been found in bucket %lf %lf %fl -> %lf %lf %lf %p\n",
_pt[0],_pt[1],_pt[2], ptrBucket->minPt[0],ptrBucket->minPt[1],ptrBucket->minPt[2],
ptrBucket->maxPt[0],ptrBucket->maxPt[1],ptrBucket->maxPt[2], ptr1);
if (ptr1 == NULL) {
printf("empty element list for centroid list!?\n, possible!");
}
#endif
flag1 = 0;
ELink ptr1 = ptrBucket->lhead;
while(ptr1 != NULL) {
flag = xyzInElementBB(_pt, ptr1->region, BBElement);
if(flag == 1) flag = xyzInElement(ptr1->region, _pt);
if(flag == 1) {
_elements->push_back(ptr1->region);
flag1 = 1;
}
ptr1 = ptr1->next;
}
for(iter = (ptrBucket->listBB).begin(); iter != (ptrBucket->listBB).end();
iter++) {
flag = xyzInElementBB(_pt, *iter, BBElement);
if(flag == 1) flag = xyzInElement(*iter, _pt);
if(flag == 1) {
_elements->push_back(*iter);
flag1 = 1;
}
}
if(flag1) return (void *)(_elements);
// Msg::Warning("This point is not found in any element! It is not in the
// domain");
return NULL;
}