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blender-archive/source/blender/blenlib/intern/BLI_kdtree.c

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C

/*
* ***** 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
* All rights reserved.
*
* The Original Code is: none of this file.
*
* Contributor(s): Janne Karhu
* Brecht Van Lommel
*
* ***** END GPL LICENSE BLOCK *****
*/
/** \file blender/blenlib/intern/BLI_kdtree.c
* \ingroup bli
*/
#include "MEM_guardedalloc.h"
#include "BLI_math.h"
#include "BLI_kdtree.h"
#include "BLI_utildefines.h"
typedef struct KDTreeNode {
struct KDTreeNode *left, *right;
float co[3], nor[3];
int index;
short d;
} KDTreeNode;
struct KDTree {
KDTreeNode *nodes;
int totnode;
KDTreeNode *root;
};
KDTree *BLI_kdtree_new(int maxsize)
{
KDTree *tree;
tree = MEM_callocN(sizeof(KDTree), "KDTree");
tree->nodes = MEM_callocN(sizeof(KDTreeNode) * maxsize, "KDTreeNode");
tree->totnode = 0;
return tree;
}
void BLI_kdtree_free(KDTree *tree)
{
if (tree) {
MEM_freeN(tree->nodes);
MEM_freeN(tree);
}
}
void BLI_kdtree_insert(KDTree *tree, int index, const float co[3], const float nor[3])
{
KDTreeNode *node = &tree->nodes[tree->totnode++];
node->index = index;
copy_v3_v3(node->co, co);
if (nor) copy_v3_v3(node->nor, nor);
}
static KDTreeNode *kdtree_balance(KDTreeNode *nodes, int totnode, int axis)
{
KDTreeNode *node;
float co;
int left, right, median, i, j;
if (totnode <= 0)
return NULL;
else if (totnode == 1)
return nodes;
/* quicksort style sorting around median */
left = 0;
right = totnode - 1;
median = totnode / 2;
while (right > left) {
co = nodes[right].co[axis];
i = left - 1;
j = right;
while (1) {
while (nodes[++i].co[axis] < co) ;
while (nodes[--j].co[axis] > co && j > left) ;
if (i >= j) break;
SWAP(KDTreeNode, nodes[i], nodes[j]);
}
SWAP(KDTreeNode, nodes[i], nodes[right]);
if (i >= median)
right = i - 1;
if (i <= median)
left = i + 1;
}
/* set node and sort subnodes */
node = &nodes[median];
node->d = axis;
node->left = kdtree_balance(nodes, median, (axis + 1) % 3);
node->right = kdtree_balance(nodes + median + 1, (totnode - (median + 1)), (axis + 1) % 3);
return node;
}
void BLI_kdtree_balance(KDTree *tree)
{
tree->root = kdtree_balance(tree->nodes, tree->totnode, 0);
}
static float squared_distance(const float v2[3], const float v1[3], const float UNUSED(n1[3]), const float n2[3])
{
float d[3], dist;
d[0] = v2[0] - v1[0];
d[1] = v2[1] - v1[1];
d[2] = v2[2] - v1[2];
dist = dot_v3v3(d, d);
//if (n1 && n2 && (dot_v3v3(n1, n2) < 0.0f))
/* can someone explain why this is done?*/
if (n2 && (dot_v3v3(d, n2) < 0.0f)) {
dist *= 10.0f;
}
return dist;
}
int BLI_kdtree_find_nearest(KDTree *tree, const float co[3], const float nor[3], KDTreeNearest *nearest)
{
KDTreeNode *root, *node, *min_node;
KDTreeNode **stack, *defaultstack[100];
float min_dist, cur_dist;
int totstack, cur = 0;
if (!tree->root)
return -1;
stack = defaultstack;
totstack = 100;
root = tree->root;
min_node = root;
min_dist = squared_distance(root->co, co, root->nor, nor);
if (co[root->d] < root->co[root->d]) {
if (root->right)
stack[cur++] = root->right;
if (root->left)
stack[cur++] = root->left;
}
else {
if (root->left)
stack[cur++] = root->left;
if (root->right)
stack[cur++] = root->right;
}
while (cur--) {
node = stack[cur];
cur_dist = node->co[node->d] - co[node->d];
if (cur_dist < 0.0f) {
cur_dist = -cur_dist * cur_dist;
if (-cur_dist < min_dist) {
cur_dist = squared_distance(node->co, co, node->nor, nor);
if (cur_dist < min_dist) {
min_dist = cur_dist;
min_node = node;
}
if (node->left)
stack[cur++] = node->left;
}
if (node->right)
stack[cur++] = node->right;
}
else {
cur_dist = cur_dist * cur_dist;
if (cur_dist < min_dist) {
cur_dist = squared_distance(node->co, co, node->nor, nor);
if (cur_dist < min_dist) {
min_dist = cur_dist;
min_node = node;
}
if (node->right)
stack[cur++] = node->right;
}
if (node->left)
stack[cur++] = node->left;
}
if (cur + 3 > totstack) {
KDTreeNode **temp = MEM_callocN((totstack + 100) * sizeof(KDTreeNode *), "psys_treestack");
memcpy(temp, stack, totstack * sizeof(KDTreeNode *));
if (stack != defaultstack)
MEM_freeN(stack);
stack = temp;
totstack += 100;
}
}
if (nearest) {
nearest->index = min_node->index;
nearest->dist = sqrt(min_dist);
copy_v3_v3(nearest->co, min_node->co);
}
if (stack != defaultstack)
MEM_freeN(stack);
return min_node->index;
}
static void add_nearest(KDTreeNearest *ptn, int *found, int n, int index, float dist, float *co)
{
int i;
if (*found < n) (*found)++;
for (i = *found - 1; i > 0; i--) {
if (dist >= ptn[i - 1].dist)
break;
else
ptn[i] = ptn[i - 1];
}
ptn[i].index = index;
ptn[i].dist = dist;
copy_v3_v3(ptn[i].co, co);
}
/* finds the nearest n entries in tree to specified coordinates */
int BLI_kdtree_find_n_nearest(KDTree *tree, int n, const float co[3], const float nor[3], KDTreeNearest *nearest)
{
KDTreeNode *root, *node = NULL;
KDTreeNode **stack, *defaultstack[100];
float cur_dist;
int i, totstack, cur = 0, found = 0;
if (!tree->root)
return 0;
stack = defaultstack;
totstack = 100;
root = tree->root;
cur_dist = squared_distance(root->co, co, root->nor, nor);
add_nearest(nearest, &found, n, root->index, cur_dist, root->co);
if (co[root->d] < root->co[root->d]) {
if (root->right)
stack[cur++] = root->right;
if (root->left)
stack[cur++] = root->left;
}
else {
if (root->left)
stack[cur++] = root->left;
if (root->right)
stack[cur++] = root->right;
}
while (cur--) {
node = stack[cur];
cur_dist = node->co[node->d] - co[node->d];
if (cur_dist < 0.0f) {
cur_dist = -cur_dist * cur_dist;
if (found < n || -cur_dist < nearest[found - 1].dist) {
cur_dist = squared_distance(node->co, co, node->nor, nor);
if (found < n || cur_dist < nearest[found - 1].dist)
add_nearest(nearest, &found, n, node->index, cur_dist, node->co);
if (node->left)
stack[cur++] = node->left;
}
if (node->right)
stack[cur++] = node->right;
}
else {
cur_dist = cur_dist * cur_dist;
if (found < n || cur_dist < nearest[found - 1].dist) {
cur_dist = squared_distance(node->co, co, node->nor, nor);
if (found < n || cur_dist < nearest[found - 1].dist)
add_nearest(nearest, &found, n, node->index, cur_dist, node->co);
if (node->right)
stack[cur++] = node->right;
}
if (node->left)
stack[cur++] = node->left;
}
if (cur + 3 > totstack) {
KDTreeNode **temp = MEM_callocN((totstack + 100) * sizeof(KDTreeNode *), "psys_treestack");
memcpy(temp, stack, totstack * sizeof(KDTreeNode *));
if (stack != defaultstack)
MEM_freeN(stack);
stack = temp;
totstack += 100;
}
}
for (i = 0; i < found; i++)
nearest[i].dist = sqrt(nearest[i].dist);
if (stack != defaultstack)
MEM_freeN(stack);
return found;
}
static int range_compare(const void *a, const void *b)
{
const KDTreeNearest *kda = a;
const KDTreeNearest *kdb = b;
if (kda->dist < kdb->dist)
return -1;
else if (kda->dist > kdb->dist)
return 1;
else
return 0;
}
static void add_in_range(KDTreeNearest **ptn, int found, int *totfoundstack, int index, float dist, float *co)
{
KDTreeNearest *to;
if (found + 1 > *totfoundstack) {
KDTreeNearest *temp = MEM_callocN((*totfoundstack + 50) * sizeof(KDTreeNode), "psys_treefoundstack");
memcpy(temp, *ptn, *totfoundstack * sizeof(KDTreeNearest));
if (*ptn)
MEM_freeN(*ptn);
*ptn = temp;
*totfoundstack += 50;
}
to = (*ptn) + found;
to->index = index;
to->dist = sqrt(dist);
copy_v3_v3(to->co, co);
}
int BLI_kdtree_range_search(KDTree *tree, float range, const float co[3], const float nor[3], KDTreeNearest **nearest)
{
KDTreeNode *root, *node = NULL;
KDTreeNode **stack, *defaultstack[100];
KDTreeNearest *foundstack = NULL;
float range2 = range * range, dist2;
int totstack, cur = 0, found = 0, totfoundstack = 0;
if (!tree || !tree->root)
return 0;
stack = defaultstack;
totstack = 100;
root = tree->root;
if (co[root->d] + range < root->co[root->d]) {
if (root->left)
stack[cur++] = root->left;
}
else if (co[root->d] - range > root->co[root->d]) {
if (root->right)
stack[cur++] = root->right;
}
else {
dist2 = squared_distance(root->co, co, root->nor, nor);
if (dist2 <= range2)
add_in_range(&foundstack, found++, &totfoundstack, root->index, dist2, root->co);
if (root->left)
stack[cur++] = root->left;
if (root->right)
stack[cur++] = root->right;
}
while (cur--) {
node = stack[cur];
if (co[node->d] + range < node->co[node->d]) {
if (node->left)
stack[cur++] = node->left;
}
else if (co[node->d] - range > node->co[node->d]) {
if (node->right)
stack[cur++] = node->right;
}
else {
dist2 = squared_distance(node->co, co, node->nor, nor);
if (dist2 <= range2)
add_in_range(&foundstack, found++, &totfoundstack, node->index, dist2, node->co);
if (node->left)
stack[cur++] = node->left;
if (node->right)
stack[cur++] = node->right;
}
if (cur + 3 > totstack) {
KDTreeNode **temp = MEM_callocN((totstack + 100) * sizeof(KDTreeNode *), "psys_treestack");
memcpy(temp, stack, totstack * sizeof(KDTreeNode *));
if (stack != defaultstack)
MEM_freeN(stack);
stack = temp;
totstack += 100;
}
}
if (stack != defaultstack)
MEM_freeN(stack);
if (found)
qsort(foundstack, found, sizeof(KDTreeNearest), range_compare);
*nearest = foundstack;
return found;
}