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|
/**
*
* ***** BEGIN GPL LICENSE BLOCK *****
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* The Original Code is Copyright (C) 2006 by NaN Holding BV.
* All rights reserved.
*
* The Original Code is: all of this file.
*
* Contributor(s): Daniel Genrich, Andre Pinto
*
* ***** END GPL LICENSE BLOCK *****
*/
#include "math.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "MEM_guardedalloc.h"
#include "BKE_utildefines.h"
#include "BLI_kdopbvh.h"
#include "BLI_arithb.h"
#ifdef _OPENMP
#include <omp.h>
#endif
typedef struct BVHNode
{
struct BVHNode **children; // max 8 children
struct BVHNode *parent; // needed for bottom - top update
float *bv; // Bounding volume of all nodes, max 13 axis
int index; /* face, edge, vertex index */
char totnode; // how many nodes are used, used for speedup
char traversed; // how many nodes already traversed until this level?
char main_axis;
} BVHNode;
struct BVHTree
{
BVHNode **nodes;
BVHNode *nodearray; /* pre-alloc branch nodes */
BVHNode **nodechild; // pre-alloc childs for nodes
float *nodebv; // pre-alloc bounding-volumes for nodes
float epsilon; /* epslion is used for inflation of the k-dop */
int totleaf; // leafs
int totbranch;
char tree_type; // type of tree (4 => quadtree)
char axis; // kdop type (6 => OBB, 7 => AABB, ...)
char start_axis, stop_axis; // KDOP_AXES array indices according to axis
};
typedef struct BVHOverlapData
{
BVHTree *tree1, *tree2;
BVHTreeOverlap *overlap;
int i, max_overlap; /* i is number of overlaps */
} BVHOverlapData;
typedef struct BVHNearestData
{
BVHTree *tree;
float *co;
BVHTree_NearestPointCallback callback;
void *userdata;
float proj[13]; //coordinates projection over axis
BVHTreeNearest nearest;
} BVHNearestData;
typedef struct BVHRayCastData
{
BVHTree *tree;
BVHTree_RayCastCallback callback;
void *userdata;
BVHTreeRay ray;
float ray_dot_axis[13];
BVHTreeRayHit hit;
} BVHRayCastData;
////////////////////////////////////////m
////////////////////////////////////////////////////////////////////////
// Bounding Volume Hierarchy Definition
//
// Notes: From OBB until 26-DOP --> all bounding volumes possible, just choose type below
// Notes: You have to choose the type at compile time ITM
// Notes: You can choose the tree type --> binary, quad, octree, choose below
////////////////////////////////////////////////////////////////////////
static float KDOP_AXES[13][3] =
{ {1.0, 0, 0}, {0, 1.0, 0}, {0, 0, 1.0}, {1.0, 1.0, 1.0}, {1.0, -1.0, 1.0}, {1.0, 1.0, -1.0},
{1.0, -1.0, -1.0}, {1.0, 1.0, 0}, {1.0, 0, 1.0}, {0, 1.0, 1.0}, {1.0, -1.0, 0}, {1.0, 0, -1.0},
{0, 1.0, -1.0}
};
//////////////////////////////////////////////////////////////////////////////////////////////////////
// Introsort
// with permission deriven from the following Java code:
// http://ralphunden.net/content/tutorials/a-guide-to-introsort/
// and he derived it from the SUN STL
//////////////////////////////////////////////////////////////////////////////////////////////////////
static int size_threshold = 16;
/*
* Common methods for all algorithms
*/
static int floor_lg(int a)
{
return (int)(floor(log(a)/log(2)));
}
/*
* Insertion sort algorithm
*/
static void bvh_insertionsort(BVHNode **a, int lo, int hi, int axis)
{
int i,j;
BVHNode *t;
for (i=lo; i < hi; i++)
{
j=i;
t = a[i];
while((j!=lo) && (t->bv[axis] < (a[j-1])->bv[axis]))
{
a[j] = a[j-1];
j--;
}
a[j] = t;
}
}
static int bvh_partition(BVHNode **a, int lo, int hi, BVHNode * x, int axis)
{
int i=lo, j=hi;
while (1)
{
while ((a[i])->bv[axis] < x->bv[axis]) i++;
j--;
while (x->bv[axis] < (a[j])->bv[axis]) j--;
if(!(i < j))
return i;
SWAP( BVHNode* , a[i], a[j]);
i++;
}
}
/*
* Heapsort algorithm
*/
static void bvh_downheap(BVHNode **a, int i, int n, int lo, int axis)
{
BVHNode * d = a[lo+i-1];
int child;
while (i<=n/2)
{
child = 2*i;
if ((child < n) && ((a[lo+child-1])->bv[axis] < (a[lo+child])->bv[axis]))
{
child++;
}
if (!(d->bv[axis] < (a[lo+child-1])->bv[axis])) break;
a[lo+i-1] = a[lo+child-1];
i = child;
}
a[lo+i-1] = d;
}
static void bvh_heapsort(BVHNode **a, int lo, int hi, int axis)
{
int n = hi-lo, i;
for (i=n/2; i>=1; i=i-1)
{
bvh_downheap(a, i,n,lo, axis);
}
for (i=n; i>1; i=i-1)
{
SWAP(BVHNode*, a[lo],a[lo+i-1]);
bvh_downheap(a, 1,i-1,lo, axis);
}
}
static BVHNode *bvh_medianof3(BVHNode **a, int lo, int mid, int hi, int axis) // returns Sortable
{
if ((a[mid])->bv[axis] < (a[lo])->bv[axis])
{
if ((a[hi])->bv[axis] < (a[mid])->bv[axis])
return a[mid];
else
{
if ((a[hi])->bv[axis] < (a[lo])->bv[axis])
return a[hi];
else
return a[lo];
}
}
else
{
if ((a[hi])->bv[axis] < (a[mid])->bv[axis])
{
if ((a[hi])->bv[axis] < (a[lo])->bv[axis])
return a[lo];
else
return a[hi];
}
else
return a[mid];
}
}
/*
* Quicksort algorithm modified for Introsort
*/
static void bvh_introsort_loop (BVHNode **a, int lo, int hi, int depth_limit, int axis)
{
int p;
while (hi-lo > size_threshold)
{
if (depth_limit == 0)
{
bvh_heapsort(a, lo, hi, axis);
return;
}
depth_limit=depth_limit-1;
p=bvh_partition(a, lo, hi, bvh_medianof3(a, lo, lo+((hi-lo)/2)+1, hi-1, axis), axis);
bvh_introsort_loop(a, p, hi, depth_limit, axis);
hi=p;
}
}
static void sort(BVHNode **a0, int begin, int end, int axis)
{
if (begin < end)
{
BVHNode **a=a0;
bvh_introsort_loop(a, begin, end, 2*floor_lg(end-begin), axis);
bvh_insertionsort(a, begin, end, axis);
}
}
void sort_along_axis(BVHTree *tree, int start, int end, int axis)
{
sort(tree->nodes, start, end, axis);
}
//after a call to this function you can expect one of:
// every node to left of a[n] are smaller or equal to it
// every node to the right of a[n] are greater or equal to it
int partition_nth_element(BVHNode **a, int _begin, int _end, int n, int axis){
int begin = _begin, end = _end, cut;
while(end-begin > 3)
{
cut = bvh_partition(a, begin, end, bvh_medianof3(a, begin, (begin+end)/2, end-1, axis), axis );
if(cut <= n)
begin = cut;
else
end = cut;
}
bvh_insertionsort(a, begin, end, axis);
return n;
}
//////////////////////////////////////////////////////////////////////////////////////////////////////
void BLI_bvhtree_free(BVHTree *tree)
{
if(tree)
{
MEM_freeN(tree->nodes);
MEM_freeN(tree->nodearray);
MEM_freeN(tree->nodebv);
MEM_freeN(tree->nodechild);
MEM_freeN(tree);
}
}
// calculate max number of branches
int needed_branches(int tree_type, int leafs)
{
#if 1
//Worst case scenary ( return max(0, leafs-tree_type)+1 )
if(leafs <= tree_type)
return 1;
else
return leafs-tree_type+1;
#else
//If our bvh kdop is "almost perfect"
//TODO i dont trust the float arithmetic in here (and I am not sure this formula is according to our splitting method)
int i, numbranches = 0;
for(i = 1; i <= (int)ceil((float)((float)log(leafs)/(float)log(tree_type))); i++)
numbranches += (pow(tree_type, i) / tree_type);
return numbranches;
#endif
}
BVHTree *BLI_bvhtree_new(int maxsize, float epsilon, char tree_type, char axis)
{
BVHTree *tree;
int numnodes, i;
// theres not support for trees below binary-trees :P
if(tree_type < 2)
return NULL;
tree = (BVHTree *)MEM_callocN(sizeof(BVHTree), "BVHTree");
if(tree)
{
tree->epsilon = epsilon;
tree->tree_type = tree_type;
tree->axis = axis;
if(axis == 26)
{
tree->start_axis = 0;
tree->stop_axis = 13;
}
else if(axis == 18)
{
tree->start_axis = 7;
tree->stop_axis = 13;
}
else if(axis == 14)
{
tree->start_axis = 0;
tree->stop_axis = 7;
}
else if(axis == 8) // AABB
{
tree->start_axis = 0;
tree->stop_axis = 4;
}
else if(axis == 6) // OBB
{
tree->start_axis = 0;
tree->stop_axis = 3;
}
else
{
MEM_freeN(tree);
return NULL;
}
//Allocate arrays
numnodes = maxsize + needed_branches(tree_type, maxsize) + tree_type;
tree->nodes = (BVHNode **)MEM_callocN(sizeof(BVHNode *)*numnodes, "BVHNodes");
if(!tree->nodes)
{
MEM_freeN(tree);
return NULL;
}
tree->nodebv = (float*)MEM_callocN(sizeof(float)* axis * numnodes, "BVHNodeBV");
if(!tree->nodebv)
{
MEM_freeN(tree->nodes);
MEM_freeN(tree);
}
tree->nodechild = (BVHNode**)MEM_callocN(sizeof(BVHNode*) * tree_type * numnodes, "BVHNodeBV");
if(!tree->nodechild)
{
MEM_freeN(tree->nodebv);
MEM_freeN(tree->nodes);
MEM_freeN(tree);
}
tree->nodearray = (BVHNode *)MEM_callocN(sizeof(BVHNode)* numnodes, "BVHNodeArray");
if(!tree->nodearray)
{
MEM_freeN(tree->nodechild);
MEM_freeN(tree->nodebv);
MEM_freeN(tree->nodes);
MEM_freeN(tree);
return NULL;
}
//link the dynamic bv and child links
for(i=0; i< numnodes; i++)
{
tree->nodearray[i].bv = tree->nodebv + i * axis;
tree->nodearray[i].children = tree->nodechild + i * tree_type;
}
}
return tree;
}
static void create_kdop_hull(BVHTree *tree, BVHNode *node, float *co, int numpoints, int moving)
{
float newminmax;
float *bv = node->bv;
int i, k;
// don't init boudings for the moving case
if(!moving)
{
for (i = tree->start_axis; i < tree->stop_axis; i++)
{
bv[2*i] = FLT_MAX;
bv[2*i + 1] = -FLT_MAX;
}
}
for(k = 0; k < numpoints; k++)
{
// for all Axes.
for (i = tree->start_axis; i < tree->stop_axis; i++)
{
newminmax = INPR(&co[k * 3], KDOP_AXES[i]);
if (newminmax < bv[2 * i])
bv[2 * i] = newminmax;
if (newminmax > bv[(2 * i) + 1])
bv[(2 * i) + 1] = newminmax;
}
}
}
// depends on the fact that the BVH's for each face is already build
static void refit_kdop_hull(BVHTree *tree, BVHNode *node, int start, int end)
{
float newmin,newmax;
int i, j;
float *bv = node->bv;
for (i = tree->start_axis; i < tree->stop_axis; i++)
{
bv[2*i] = FLT_MAX;
bv[2*i + 1] = -FLT_MAX;
}
for (j = start; j < end; j++)
{
// for all Axes.
for (i = tree->start_axis; i < tree->stop_axis; i++)
{
newmin = tree->nodes[j]->bv[(2 * i)];
if ((newmin < bv[(2 * i)]))
bv[(2 * i)] = newmin;
newmax = tree->nodes[j]->bv[(2 * i) + 1];
if ((newmax > bv[(2 * i) + 1]))
bv[(2 * i) + 1] = newmax;
}
}
}
int BLI_bvhtree_insert(BVHTree *tree, int index, float *co, int numpoints)
{
int i;
BVHNode *node = NULL;
// insert should only possible as long as tree->totbranch is 0
if(tree->totbranch > 0)
return 0;
if(tree->totleaf+1 >= MEM_allocN_len(tree->nodes)/sizeof(*(tree->nodes)))
return 0;
// TODO check if have enough nodes in array
node = tree->nodes[tree->totleaf] = &(tree->nodearray[tree->totleaf]);
tree->totleaf++;
create_kdop_hull(tree, node, co, numpoints, 0);
node->index= index;
// inflate the bv with some epsilon
for (i = tree->start_axis; i < tree->stop_axis; i++)
{
node->bv[(2 * i)] -= tree->epsilon; // minimum
node->bv[(2 * i) + 1] += tree->epsilon; // maximum
}
return 1;
}
// only supports x,y,z axis in the moment
// but we should use a plain and simple function here for speed sake
static char get_largest_axis(float *bv)
{
float middle_point[3];
middle_point[0] = (bv[1]) - (bv[0]); // x axis
middle_point[1] = (bv[3]) - (bv[2]); // y axis
middle_point[2] = (bv[5]) - (bv[4]); // z axis
if (middle_point[0] > middle_point[1])
{
if (middle_point[0] > middle_point[2])
return 1; // max x axis
else
return 5; // max z axis
}
else
{
if (middle_point[1] > middle_point[2])
return 3; // max y axis
else
return 5; // max z axis
}
}
static void bvh_div_nodes(BVHTree *tree, BVHNode *node, int start, int end, int free_node_index)
{
int i;
const char laxis = get_largest_axis(node->bv); //determine longest axis to split along
const int slice = (end-start)/tree->tree_type; //division rounded down
const int rest = (end-start)%tree->tree_type; //remainder of division
assert( node->totnode == 0 );
node->main_axis = laxis/2;
// split nodes along longest axis
for (i=0; start < end; node->totnode = ++i) //i counts the current child
{
int tend = start + slice + (i < rest ? 1 : 0);
assert( tend <= end);
if(tend-start == 1) // ok, we have 1 left for this node
{
node->children[i] = tree->nodes[start];
node->children[i]->parent = node;
}
else
{
BVHNode *tnode = node->children[i] = tree->nodes[free_node_index] = &(tree->nodearray[free_node_index]);
// printf("Used %d (%d)\n", free_node_index, tend-start);
tnode->parent = node;
if(tend != end)
partition_nth_element(tree->nodes, start, end, tend, laxis);
refit_kdop_hull(tree, tnode, start, tend);
bvh_div_nodes(tree, tnode, start, tend, free_node_index+1);
free_node_index += needed_branches(tree->tree_type, tend-start);
}
start = tend;
}
return;
}
static void omp_bvh_div_nodes(BVHTree *tree, BVHNode *node, int start, int end, int free_node_index)
{
int i;
const char laxis = get_largest_axis(node->bv); //determine longest axis to split along
const int slice = (end-start)/tree->tree_type; //division rounded down
const int rest = (end-start)%tree->tree_type; //remainder of division
int omp_data_start[tree->tree_type];
int omp_data_end [tree->tree_type];
int omp_data_index[tree->tree_type];
assert( node->totnode == 0 );
node->main_axis = laxis/2;
// split nodes along longest axis
for (i=0; start < end; node->totnode = ++i) //i counts the current child
{
//Split the rest from left to right (TODO: this doenst makes an optimal tree)
int tend = start + slice + (i < rest ? 1 : 0);
assert( tend <= end);
//save data for later OMP
omp_data_start[i] = start;
omp_data_end [i] = tend;
omp_data_index[i] = free_node_index;
if(tend-start == 1)
{
node->children[i] = tree->nodes[start];
node->children[i]->parent = node;
}
else
{
node->children[i] = tree->nodes[free_node_index] = &(tree->nodearray[free_node_index]);
if(tend != end)
partition_nth_element(tree->nodes, start, end, tend, laxis);
free_node_index += needed_branches(tree->tree_type, tend-start);
}
start = tend;
}
#pragma omp parallel for private(i) schedule(static)
for( i = 0; i < node->totnode; i++)
{
if(omp_data_end[i]-omp_data_start[i] > 1)
{
BVHNode *tnode = node->children[i];
refit_kdop_hull(tree, tnode, omp_data_start[i], omp_data_end[i]);
bvh_div_nodes (tree, tnode, omp_data_start[i], omp_data_end[i], omp_data_index[i]+1);
}
}
return;
}
#if 0
static void verify_tree(BVHTree *tree)
{
int i, j, check = 0;
// check the pointer list
for(i = 0; i < tree->totleaf; i++)
{
if(tree->nodes[i]->parent == NULL)
printf("Leaf has no parent: %d\n", i);
else
{
for(j = 0; j < tree->tree_type; j++)
{
if(tree->nodes[i]->parent->children[j] == tree->nodes[i])
check = 1;
}
if(!check)
{
printf("Parent child relationship doesn't match: %d\n", i);
}
check = 0;
}
}
// check the leaf list
for(i = 0; i < tree->totleaf; i++)
{
if(tree->nodearray[i].parent == NULL)
printf("Leaf has no parent: %d\n", i);
else
{
for(j = 0; j < tree->tree_type; j++)
{
if(tree->nodearray[i].parent->children[j] == &tree->nodearray[i])
check = 1;
}
if(!check)
{
printf("Parent child relationship doesn't match: %d\n", i);
}
check = 0;
}
}
printf("branches: %d, leafs: %d, total: %d\n", tree->totbranch, tree->totleaf, tree->totbranch + tree->totleaf);
}
#endif
void BLI_bvhtree_balance(BVHTree *tree)
{
assert(tree->totbranch == 0);
if(tree->totleaf != 0)
{
// create root node
BVHNode *node = tree->nodes[tree->totleaf] = &(tree->nodearray[tree->totleaf]);
tree->totbranch++;
// refit root bvh node
refit_kdop_hull(tree, node, 0, tree->totleaf);
// create + balance tree
omp_bvh_div_nodes(tree, node, 0, tree->totleaf, tree->totleaf+1);
tree->totbranch = needed_branches( tree->tree_type, tree->totleaf );
// verify_tree(tree);
}
}
// overlap - is it possbile for 2 bv's to collide ?
static int tree_overlap(BVHNode *node1, BVHNode *node2, int start_axis, int stop_axis)
{
float *bv1 = node1->bv;
float *bv2 = node2->bv;
float *bv1_end = bv1 + (stop_axis<<1);
bv1 += start_axis<<1;
bv2 += start_axis<<1;
// test all axis if min + max overlap
for (; bv1 != bv1_end; bv1+=2, bv2+=2)
{
if ((*(bv1) > *(bv2 + 1)) || (*(bv2) > *(bv1 + 1)))
return 0;
}
return 1;
}
static void traverse(BVHOverlapData *data, BVHNode *node1, BVHNode *node2)
{
int j;
if(tree_overlap(node1, node2, MIN2(data->tree1->start_axis, data->tree2->start_axis), MIN2(data->tree1->stop_axis, data->tree2->stop_axis)))
{
// check if node1 is a leaf
if(!node1->totnode)
{
// check if node2 is a leaf
if(!node2->totnode)
{
if(node1 == node2)
{
return;
}
if(data->i >= data->max_overlap)
{
// try to make alloc'ed memory bigger
data->overlap = realloc(data->overlap, sizeof(BVHTreeOverlap)*data->max_overlap*2);
if(!data->overlap)
{
printf("Out of Memory in traverse\n");
return;
}
data->max_overlap *= 2;
}
// both leafs, insert overlap!
data->overlap[data->i].indexA = node1->index;
data->overlap[data->i].indexB = node2->index;
data->i++;
}
else
{
for(j = 0; j < data->tree2->tree_type; j++)
{
if(node2->children[j])
traverse(data, node1, node2->children[j]);
}
}
}
else
{
for(j = 0; j < data->tree2->tree_type; j++)
{
if(node1->children[j])
traverse(data, node1->children[j], node2);
}
}
}
return;
}
BVHTreeOverlap *BLI_bvhtree_overlap(BVHTree *tree1, BVHTree *tree2, int *result)
{
int j, total = 0;
BVHTreeOverlap *overlap = NULL, *to = NULL;
BVHOverlapData **data;
// check for compatibility of both trees (can't compare 14-DOP with 18-DOP)
if((tree1->axis != tree2->axis) && ((tree1->axis == 14) || tree2->axis == 14))
return 0;
// fast check root nodes for collision before doing big splitting + traversal
if(!tree_overlap(tree1->nodes[tree1->totleaf], tree2->nodes[tree2->totleaf], MIN2(tree1->start_axis, tree2->start_axis), MIN2(tree1->stop_axis, tree2->stop_axis)))
return 0;
data = MEM_callocN(sizeof(BVHOverlapData *)* tree1->tree_type, "BVHOverlapData_star");
for(j = 0; j < tree1->tree_type; j++)
{
data[j] = (BVHOverlapData *)MEM_callocN(sizeof(BVHOverlapData), "BVHOverlapData");
// init BVHOverlapData
data[j]->overlap = (BVHTreeOverlap *)malloc(sizeof(BVHTreeOverlap)*MAX2(tree1->totleaf, tree2->totleaf));
data[j]->tree1 = tree1;
data[j]->tree2 = tree2;
data[j]->max_overlap = MAX2(tree1->totleaf, tree2->totleaf);
data[j]->i = 0;
}
#pragma omp parallel for private(j) schedule(static)
for(j = 0; j < MIN2(tree1->tree_type, tree1->nodes[tree1->totleaf]->totnode); j++)
{
traverse(data[j], tree1->nodes[tree1->totleaf]->children[j], tree2->nodes[tree2->totleaf]);
}
for(j = 0; j < tree1->tree_type; j++)
total += data[j]->i;
to = overlap = (BVHTreeOverlap *)MEM_callocN(sizeof(BVHTreeOverlap)*total, "BVHTreeOverlap");
for(j = 0; j < tree1->tree_type; j++)
{
memcpy(to, data[j]->overlap, data[j]->i*sizeof(BVHTreeOverlap));
to+=data[j]->i;
}
for(j = 0; j < tree1->tree_type; j++)
{
free(data[j]->overlap);
MEM_freeN(data[j]);
}
MEM_freeN(data);
(*result) = total;
return overlap;
}
// bottom up update of bvh tree:
// join the 4 children here
static void node_join(BVHTree *tree, BVHNode *node)
{
int i, j;
for (i = tree->start_axis; i < tree->stop_axis; i++)
{
node->bv[2*i] = FLT_MAX;
node->bv[2*i + 1] = -FLT_MAX;
}
for (i = 0; i < tree->tree_type; i++)
{
if (node->children[i])
{
for (j = tree->start_axis; j < tree->stop_axis; j++)
{
// update minimum
if (node->children[i]->bv[(2 * j)] < node->bv[(2 * j)])
node->bv[(2 * j)] = node->children[i]->bv[(2 * j)];
// update maximum
if (node->children[i]->bv[(2 * j) + 1] > node->bv[(2 * j) + 1])
node->bv[(2 * j) + 1] = node->children[i]->bv[(2 * j) + 1];
}
}
else
break;
}
}
// call before BLI_bvhtree_update_tree()
int BLI_bvhtree_update_node(BVHTree *tree, int index, float *co, float *co_moving, int numpoints)
{
int i;
BVHNode *node= NULL;
// check if index exists
if(index > tree->totleaf)
return 0;
node = tree->nodearray + index;
create_kdop_hull(tree, node, co, numpoints, 0);
if(co_moving)
create_kdop_hull(tree, node, co_moving, numpoints, 1);
// inflate the bv with some epsilon
for (i = tree->start_axis; i < tree->stop_axis; i++)
{
node->bv[(2 * i)] -= tree->epsilon; // minimum
node->bv[(2 * i) + 1] += tree->epsilon; // maximum
}
return 1;
}
// call BLI_bvhtree_update_node() first for every node/point/triangle
void BLI_bvhtree_update_tree(BVHTree *tree)
{
BVHNode *leaf, *parent;
// reset tree traversing flag
for (leaf = tree->nodearray + tree->totleaf; leaf != tree->nodearray + tree->totleaf + tree->totbranch; leaf++)
leaf->traversed = 0;
for (leaf = tree->nodearray; leaf != tree->nodearray + tree->totleaf; leaf++)
{
for (parent = leaf->parent; parent; parent = parent->parent)
{
parent->traversed++; // we tried to go up in hierarchy
if (parent->traversed < parent->totnode)
break; // we do not need to check further
else
node_join(tree, parent);
}
}
}
float BLI_bvhtree_getepsilon(BVHTree *tree)
{
return tree->epsilon;
}
/*
* Nearest neighbour
*/
static float squared_dist(const float *a, const float *b)
{
float tmp[3];
VECSUB(tmp, a, b);
return INPR(tmp, tmp);
}
static float calc_nearest_point(BVHNearestData *data, BVHNode *node, float *nearest)
{
int i;
const float *bv = node->bv;
//nearest on AABB hull
for(i=0; i != 3; i++, bv += 2)
{
if(bv[0] > data->proj[i])
nearest[i] = bv[0];
else if(bv[1] < data->proj[i])
nearest[i] = bv[1];
else
nearest[i] = data->proj[i];
}
/*
//nearest on a general hull
VECCOPY(nearest, data->co);
for(i = data->tree->start_axis; i != data->tree->stop_axis; i++, bv+=2)
{
float proj = INPR( nearest, KDOP_AXES[i]);
float dl = bv[0] - proj;
float du = bv[1] - proj;
if(dl > 0)
{
VECADDFAC(nearest, nearest, KDOP_AXES[i], dl);
}
else if(du < 0)
{
VECADDFAC(nearest, nearest, KDOP_AXES[i], du);
}
}
*/
return squared_dist(data->co, nearest);
}
// TODO: use a priority queue to reduce the number of nodes looked on
static void dfs_find_nearest(BVHNearestData *data, BVHNode *node)
{
int i;
float nearest[3], sdist;
sdist = calc_nearest_point(data, node, nearest);
if(sdist >= data->nearest.dist) return;
if(node->totnode == 0)
{
if(data->callback)
data->callback(data->userdata , node->index, data->co, &data->nearest);
else
{
data->nearest.index = node->index;
VECCOPY(data->nearest.co, nearest);
data->nearest.dist = sdist;
}
}
else
{
for(i=0; i != node->totnode; i++)
dfs_find_nearest(data, node->children[i]);
}
}
int BLI_bvhtree_find_nearest(BVHTree *tree, const float *co, BVHTreeNearest *nearest, BVHTree_NearestPointCallback callback, void *userdata)
{
int i;
BVHNearestData data;
//init data to search
data.tree = tree;
data.co = co;
data.callback = callback;
data.userdata = userdata;
for(i = data.tree->start_axis; i != data.tree->stop_axis; i++)
{
data.proj[i] = INPR(data.co, KDOP_AXES[i]);
}
if(nearest)
{
memcpy( &data.nearest , nearest, sizeof(*nearest) );
}
else
{
data.nearest.index = -1;
data.nearest.dist = FLT_MAX;
}
//dfs search
dfs_find_nearest(&data, tree->nodes[tree->totleaf] );
//copy back results
if(nearest)
{
memcpy(nearest, &data.nearest, sizeof(*nearest));
}
return data.nearest.index;
}
/*
* Ray cast
*/
static float ray_nearest_hit(BVHRayCastData *data, BVHNode *node)
{
int i;
const float *bv = node->bv;
float low = 0, upper = data->hit.dist;
for(i=0; i != 3; i++, bv += 2)
{
if(data->ray_dot_axis[i] == 0.0f)
{
//axis aligned ray
if(data->ray.origin[i] < bv[0]
|| data->ray.origin[i] > bv[1])
return FLT_MAX;
}
else
{
float ll = (bv[0] - data->ray.origin[i]) / data->ray_dot_axis[i];
float lu = (bv[1] - data->ray.origin[i]) / data->ray_dot_axis[i];
if(data->ray_dot_axis[i] > 0)
{
if(ll > low) low = ll;
if(lu < upper) upper = lu;
}
else
{
if(lu > low) low = lu;
if(ll < upper) upper = ll;
}
if(low > upper) return FLT_MAX;
}
}
return low;
}
static void dfs_raycast(BVHRayCastData *data, BVHNode *node)
{
int i;
//ray-bv is really fast.. and simple tests revealed its worth to test it
//before calling the ray-primitive functions
float dist = ray_nearest_hit(data, node);
if(dist >= data->hit.dist) return;
if(node->totnode == 0)
{
if(data->callback)
data->callback(data->userdata, node->index, &data->ray, &data->hit);
else
{
data->hit.index = node->index;
data->hit.dist = dist;
VECADDFAC(data->hit.co, data->ray.origin, data->ray.direction, dist);
}
}
else
{
//pick loop direction to dive into the tree (based on ray direction and split axis)
if(data->ray_dot_axis[ node->main_axis ] > 0)
{
for(i=0; i != node->totnode; i++)
{
dfs_raycast(data, node->children[i]);
}
}
else
{
for(i=node->totnode-1; i >= 0; i--)
{
dfs_raycast(data, node->children[i]);
}
}
}
}
int BLI_bvhtree_ray_cast(BVHTree *tree, const float *co, const float *dir, BVHTreeRayHit *hit, BVHTree_RayCastCallback callback, void *userdata)
{
int i;
BVHRayCastData data;
data.tree = tree;
data.callback = callback;
data.userdata = userdata;
VECCOPY(data.ray.origin, co);
VECCOPY(data.ray.direction, dir);
Normalize(data.ray.direction);
for(i=0; i<3; i++)
{
data.ray_dot_axis[i] = INPR( data.ray.direction, KDOP_AXES[i]);
if(fabs(data.ray_dot_axis[i]) < 1e-7)
data.ray_dot_axis[i] = 0.0;
}
if(hit)
memcpy( &data.hit, hit, sizeof(*hit) );
else
{
data.hit.index = -1;
data.hit.dist = FLT_MAX;
}
dfs_raycast(&data, tree->nodes[tree->totleaf]);
if(hit)
memcpy( hit, &data.hit, sizeof(*hit) );
return data.hit.index;
}
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