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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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 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 *****
*/
/** \file blender/blenlib/intern/BLI_kdopbvh.c
* \ingroup bli
* \brief BVH-tree implementation.
*
* k-DOP BVH (Discrete Oriented Polytope, Bounding Volume Hierarchy).
* A k-DOP is represented as k/2 pairs of min , max values for k/2 directions (intervals, "slabs").
*
* See: http://www.gris.uni-tuebingen.de/people/staff/jmezger/papers/bvh.pdf
*
* implements a bvh-tree structure with support for:
*
* - Ray-cast:
* #BLI_bvhtree_ray_cast, #BVHRayCastData
* - Nearest point on surface:
* #BLI_bvhtree_find_nearest, #BVHNearestData
* - Overlapping 2 trees:
* #BLI_bvhtree_overlap, #BVHOverlapData_Shared, #BVHOverlapData_Thread
* - Range Query:
* #BLI_bvhtree_range_query
*/
#include <assert.h>
#include "MEM_guardedalloc.h"
#include "BLI_utildefines.h"
#include "BLI_alloca.h"
#include "BLI_stack.h"
#include "BLI_kdopbvh.h"
#include "BLI_math.h"
#include "BLI_task.h"
#include "BLI_strict_flags.h"
/* used for iterative_raycast */
// #define USE_SKIP_LINKS
/* Use to print balanced output. */
// #define USE_PRINT_TREE
/* Check tree is valid. */
// #define USE_VERIFY_TREE
#define MAX_TREETYPE 32
/* Setting zero so we can catch bugs in BLI_task/KDOPBVH.
* TODO(sergey): Deduplicate the limits with PBVH from BKE.
*/
#ifdef DEBUG
# define KDOPBVH_THREAD_LEAF_THRESHOLD 0
#else
# define KDOPBVH_THREAD_LEAF_THRESHOLD 1024
#endif
/* -------------------------------------------------------------------- */
/** \name Struct Definitions
* \{ */
typedef unsigned char axis_t;
typedef struct BVHNode {
struct BVHNode **children;
struct BVHNode *parent; /* some user defined traversed need that */
#ifdef USE_SKIP_LINKS
struct BVHNode *skip[2];
#endif
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 main_axis; /* Axis used to split this node */
} BVHNode;
/* keep under 26 bytes for speed purposes */
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;
axis_t start_axis, stop_axis; /* bvhtree_kdop_axes array indices according to axis */
axis_t axis; /* kdop type (6 => OBB, 7 => AABB, ...) */
char tree_type; /* type of tree (4 => quadtree) */
};
/* optimization, ensure we stay small */
BLI_STATIC_ASSERT((sizeof(void *) == 8 && sizeof(BVHTree) <= 48) ||
(sizeof(void *) == 4 && sizeof(BVHTree) <= 32),
"over sized")
/* avoid duplicating vars in BVHOverlapData_Thread */
typedef struct BVHOverlapData_Shared {
const BVHTree *tree1, *tree2;
axis_t start_axis, stop_axis;
/* use for callbacks */
BVHTree_OverlapCallback callback;
void *userdata;
} BVHOverlapData_Shared;
typedef struct BVHOverlapData_Thread {
BVHOverlapData_Shared *shared;
struct BLI_Stack *overlap; /* store BVHTreeOverlap */
/* use for callbacks */
int thread;
} BVHOverlapData_Thread;
typedef struct BVHNearestData {
const BVHTree *tree;
const float *co;
BVHTree_NearestPointCallback callback;
void *userdata;
float proj[13]; /* coordinates projection over axis */
BVHTreeNearest nearest;
} BVHNearestData;
typedef struct BVHRayCastData {
const BVHTree *tree;
BVHTree_RayCastCallback callback;
void *userdata;
BVHTreeRay ray;
#ifdef USE_KDOPBVH_WATERTIGHT
struct IsectRayPrecalc isect_precalc;
#endif
/* initialized by bvhtree_ray_cast_data_precalc */
float ray_dot_axis[13];
float idot_axis[13];
int index[6];
BVHTreeRayHit hit;
} BVHRayCastData;
/** \} */
/**
* 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
*/
const float bvhtree_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}
};
/* -------------------------------------------------------------------- */
/** \name Utility Functions
* \{ */
MINLINE axis_t min_axis(axis_t a, axis_t b)
{
return (a < b) ? a : b;
}
#if 0
MINLINE axis_t max_axis(axis_t a, axis_t b)
{
return (b < a) ? a : b;
}
#endif
#if 0
/*
* Generic push and pop heap
*/
#define PUSH_HEAP_BODY(HEAP_TYPE, PRIORITY, heap, heap_size) \
{ \
HEAP_TYPE element = heap[heap_size - 1]; \
int child = heap_size - 1; \
while (child != 0) { \
int parent = (child - 1) / 2; \
if (PRIORITY(element, heap[parent])) { \
heap[child] = heap[parent]; \
child = parent; \
} \
else { \
break; \
} \
} \
heap[child] = element; \
} (void)0
#define POP_HEAP_BODY(HEAP_TYPE, PRIORITY, heap, heap_size) \
{ \
HEAP_TYPE element = heap[heap_size - 1]; \
int parent = 0; \
while (parent < (heap_size - 1) / 2) { \
int child2 = (parent + 1) * 2; \
if (PRIORITY(heap[child2 - 1], heap[child2])) { \
child2--; \
} \
if (PRIORITY(element, heap[child2])) { \
break; \
} \
heap[parent] = heap[child2]; \
parent = child2; \
} \
heap[parent] = element; \
} (void)0
static bool ADJUST_MEMORY(void *local_memblock, void **memblock, int new_size, int *max_size, int size_per_item)
{
int new_max_size = *max_size * 2;
void *new_memblock = NULL;
if (new_size <= *max_size) {
return true;
}
if (*memblock == local_memblock) {
new_memblock = malloc(size_per_item * new_max_size);
memcpy(new_memblock, *memblock, size_per_item * *max_size);
}
else {
new_memblock = realloc(*memblock, size_per_item * new_max_size);
}
if (new_memblock) {
*memblock = new_memblock;
*max_size = new_max_size;
return true;
}
else {
return false;
}
}
#endif
/**
* 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;
#if 0
/**
* Common methods for all algorithms
*/
static int floor_lg(int a)
{
return (int)(floor(log(a) / log(2)));
}
#endif
static void node_minmax_init(const BVHTree *tree, BVHNode *node)
{
axis_t axis_iter;
float (*bv)[2] = (float (*)[2])node->bv;
for (axis_iter = tree->start_axis; axis_iter != tree->stop_axis; axis_iter++) {
bv[axis_iter][0] = FLT_MAX;
bv[axis_iter][1] = -FLT_MAX;
}
}
/** \} */
/* -------------------------------------------------------------------- */
/** \name Balance Utility Functions
* \{ */
/**
* 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++;
}
}
#if 0
/**
* 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);
}
}
#endif
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];
}
}
#if 0
/*
* 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);
}
}
static void sort_along_axis(BVHTree *tree, int start, int end, int axis)
{
sort(tree->nodes, start, end, axis);
}
#endif
/**
* \note 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 */
static void partition_nth_element(BVHNode **a, int begin, int end, const int n, const int axis)
{
while (end - begin > 3) {
const int 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);
}
#ifdef USE_SKIP_LINKS
static void build_skip_links(BVHTree *tree, BVHNode *node, BVHNode *left, BVHNode *right)
{
int i;
node->skip[0] = left;
node->skip[1] = right;
for (i = 0; i < node->totnode; i++) {
if (i + 1 < node->totnode)
build_skip_links(tree, node->children[i], left, node->children[i + 1]);
else
build_skip_links(tree, node->children[i], left, right);
left = node->children[i];
}
}
#endif
/*
* BVHTree bounding volumes functions
*/
static void create_kdop_hull(const BVHTree *tree, BVHNode *node, const float *co, int numpoints, int moving)
{
float newminmax;
float *bv = node->bv;
int k;
axis_t axis_iter;
/* don't init boudings for the moving case */
if (!moving) {
node_minmax_init(tree, node);
}
for (k = 0; k < numpoints; k++) {
/* for all Axes. */
for (axis_iter = tree->start_axis; axis_iter < tree->stop_axis; axis_iter++) {
newminmax = dot_v3v3(&co[k * 3], bvhtree_kdop_axes[axis_iter]);
if (newminmax < bv[2 * axis_iter])
bv[2 * axis_iter] = newminmax;
if (newminmax > bv[(2 * axis_iter) + 1])
bv[(2 * axis_iter) + 1] = newminmax;
}
}
}
/**
* \note depends on the fact that the BVH's for each face is already build
*/
static void refit_kdop_hull(const BVHTree *tree, BVHNode *node, int start, int end)
{
float newmin, newmax;
float *bv = node->bv;
int j;
axis_t axis_iter;
node_minmax_init(tree, node);
for (j = start; j < end; j++) {
/* for all Axes. */
for (axis_iter = tree->start_axis; axis_iter < tree->stop_axis; axis_iter++) {
newmin = tree->nodes[j]->bv[(2 * axis_iter)];
if ((newmin < bv[(2 * axis_iter)]))
bv[(2 * axis_iter)] = newmin;
newmax = tree->nodes[j]->bv[(2 * axis_iter) + 1];
if ((newmax > bv[(2 * axis_iter) + 1]))
bv[(2 * axis_iter) + 1] = newmax;
}
}
}
/**
* 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(const 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 */
}
}
/**
* bottom-up update of bvh node BV
* join the children on the parent BV */
static void node_join(BVHTree *tree, BVHNode *node)
{
int i;
axis_t axis_iter;
node_minmax_init(tree, node);
for (i = 0; i < tree->tree_type; i++) {
if (node->children[i]) {
for (axis_iter = tree->start_axis; axis_iter < tree->stop_axis; axis_iter++) {
/* update minimum */
if (node->children[i]->bv[(2 * axis_iter)] < node->bv[(2 * axis_iter)])
node->bv[(2 * axis_iter)] = node->children[i]->bv[(2 * axis_iter)];
/* update maximum */
if (node->children[i]->bv[(2 * axis_iter) + 1] > node->bv[(2 * axis_iter) + 1])
node->bv[(2 * axis_iter) + 1] = node->children[i]->bv[(2 * axis_iter) + 1];
}
}
else
break;
}
}
#ifdef USE_PRINT_TREE
/**
* Debug and information functions
*/
static void bvhtree_print_tree(BVHTree *tree, BVHNode *node, int depth)
{
int i;
axis_t axis_iter;
for (i = 0; i < depth; i++) printf(" ");
printf(" - %d (%ld): ", node->index, (long int)(node - tree->nodearray));
for (axis_iter = (axis_t)(2 * tree->start_axis);
axis_iter < (axis_t)(2 * tree->stop_axis);
axis_iter++)
{
printf("%.3f ", node->bv[axis_iter]);
}
printf("\n");
for (i = 0; i < tree->tree_type; i++)
if (node->children[i])
bvhtree_print_tree(tree, node->children[i], depth + 1);
}
static void bvhtree_info(BVHTree *tree)
{
printf("BVHTree Info: tree_type = %d, axis = %d, epsilon = %f\n",
tree->tree_type, tree->axis, tree->epsilon);
printf("nodes = %d, branches = %d, leafs = %d\n",
tree->totbranch + tree->totleaf, tree->totbranch, tree->totleaf);
printf("Memory per node = %ubytes\n",
(uint)(sizeof(BVHNode) + sizeof(BVHNode *) * tree->tree_type + sizeof(float) * tree->axis));
printf("BV memory = %ubytes\n",
(uint)MEM_allocN_len(tree->nodebv));
printf("Total memory = %ubytes\n",
(uint)(sizeof(BVHTree) +
MEM_allocN_len(tree->nodes) +
MEM_allocN_len(tree->nodearray) +
MEM_allocN_len(tree->nodechild) +
MEM_allocN_len(tree->nodebv)));
bvhtree_print_tree(tree, tree->nodes[tree->totleaf], 0);
}
#endif /* USE_PRINT_TREE */
#ifdef USE_VERIFY_TREE
static void bvhtree_verify(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 /* USE_VERIFY_TREE */
/* Helper data and structures to build a min-leaf generalized implicit tree
* This code can be easily reduced
* (basicly this is only method to calculate pow(k, n) in O(1).. and stuff like that) */
typedef struct BVHBuildHelper {
int tree_type; /* */
int totleafs; /* */
int leafs_per_child[32]; /* Min number of leafs that are archievable from a node at depth N */
int branches_on_level[32]; /* Number of nodes at depth N (tree_type^N) */
int remain_leafs; /* Number of leafs that are placed on the level that is not 100% filled */
} BVHBuildHelper;
static void build_implicit_tree_helper(const BVHTree *tree, BVHBuildHelper *data)
{
int depth = 0;
int remain;
int nnodes;
data->totleafs = tree->totleaf;
data->tree_type = tree->tree_type;
/* Calculate the smallest tree_type^n such that tree_type^n >= num_leafs */
for (data->leafs_per_child[0] = 1;
data->leafs_per_child[0] < data->totleafs;
data->leafs_per_child[0] *= data->tree_type)
{
/* pass */
}
data->branches_on_level[0] = 1;
for (depth = 1; (depth < 32) && data->leafs_per_child[depth - 1]; depth++) {
data->branches_on_level[depth] = data->branches_on_level[depth - 1] * data->tree_type;
data->leafs_per_child[depth] = data->leafs_per_child[depth - 1] / data->tree_type;
}
remain = data->totleafs - data->leafs_per_child[1];
nnodes = (remain + data->tree_type - 2) / (data->tree_type - 1);
data->remain_leafs = remain + nnodes;
}
// return the min index of all the leafs archivable with the given branch
static int implicit_leafs_index(const BVHBuildHelper *data, const int depth, const int child_index)
{
int min_leaf_index = child_index * data->leafs_per_child[depth - 1];
if (min_leaf_index <= data->remain_leafs)
return min_leaf_index;
else if (data->leafs_per_child[depth])
return data->totleafs - (data->branches_on_level[depth - 1] - child_index) * data->leafs_per_child[depth];
else
return data->remain_leafs;
}
/**
* Generalized implicit tree build
*
* An implicit tree is a tree where its structure is implied, thus there is no need to store child pointers or indexs.
* Its possible to find the position of the child or the parent with simple maths (multiplication and adittion).
* This type of tree is for example used on heaps.. where node N has its childs at indexs N*2 and N*2+1.
*
* Although in this case the tree type is general.. and not know until runtime.
* tree_type stands for the maximum number of childs that a tree node can have.
* All tree types >= 2 are supported.
*
* Advantages of the used trees include:
* - No need to store child/parent relations (they are implicit);
* - Any node child always has an index greater than the parent;
* - Brother nodes are sequential in memory;
*
*
* Some math relations derived for general implicit trees:
*
* K = tree_type, ( 2 <= K )
* ROOT = 1
* N child of node A = A * K + (2 - K) + N, (0 <= N < K)
*
* Util methods:
* TODO...
* (looping elements, knowing if its a leaf or not.. etc...)
*/
/* This functions returns the number of branches needed to have the requested number of leafs. */
static int implicit_needed_branches(int tree_type, int leafs)
{
return max_ii(1, (leafs + tree_type - 3) / (tree_type - 1));
}
/**
* This function handles the problem of "sorting" the leafs (along the split_axis).
*
* It arranges the elements in the given partitions such that:
* - any element in partition N is less or equal to any element in partition N+1.
* - if all elements are different all partition will get the same subset of elements
* as if the array was sorted.
*
* partition P is described as the elements in the range ( nth[P], nth[P+1] ]
*
* TODO: This can be optimized a bit by doing a specialized nth_element instead of K nth_elements
*/
static void split_leafs(BVHNode **leafs_array, const int nth[], const int partitions, const int split_axis)
{
int i;
for (i = 0; i < partitions - 1; i++) {
if (nth[i] >= nth[partitions])
break;
partition_nth_element(leafs_array, nth[i], nth[partitions], nth[i + 1], split_axis);
}
}
typedef struct BVHDivNodesData {
const BVHTree *tree;
BVHNode *branches_array;
BVHNode **leafs_array;
int tree_type;
int tree_offset;
const BVHBuildHelper *data;
int depth;
int i;
int first_of_next_level;
} BVHDivNodesData;
static void non_recursive_bvh_div_nodes_task_cb(
void *__restrict userdata,
const int j,
const ParallelRangeTLS *__restrict UNUSED(tls))
{
BVHDivNodesData *data = userdata;
int k;
const int parent_level_index = j - data->i;
BVHNode *parent = &data->branches_array[j];
int nth_positions[MAX_TREETYPE + 1];
char split_axis;
int parent_leafs_begin = implicit_leafs_index(data->data, data->depth, parent_level_index);
int parent_leafs_end = implicit_leafs_index(data->data, data->depth, parent_level_index + 1);
/* This calculates the bounding box of this branch
* and chooses the largest axis as the axis to divide leafs */
refit_kdop_hull(data->tree, parent, parent_leafs_begin, parent_leafs_end);
split_axis = get_largest_axis(parent->bv);
/* Save split axis (this can be used on raytracing to speedup the query time) */
parent->main_axis = split_axis / 2;
/* Split the childs along the split_axis, note: its not needed to sort the whole leafs array
* Only to assure that the elements are partitioned on a way that each child takes the elements
* it would take in case the whole array was sorted.
* Split_leafs takes care of that "sort" problem. */
nth_positions[0] = parent_leafs_begin;
nth_positions[data->tree_type] = parent_leafs_end;
for (k = 1; k < data->tree_type; k++) {
const int child_index = j * data->tree_type + data->tree_offset + k;
const int child_level_index = child_index - data->first_of_next_level; /* child level index */
nth_positions[k] = implicit_leafs_index(data->data, data->depth + 1, child_level_index);
}
split_leafs(data->leafs_array, nth_positions, data->tree_type, split_axis);
/* Setup children and totnode counters
* Not really needed but currently most of BVH code relies on having an explicit children structure */
for (k = 0; k < data->tree_type; k++) {
const int child_index = j * data->tree_type + data->tree_offset + k;
const int child_level_index = child_index - data->first_of_next_level; /* child level index */
const int child_leafs_begin = implicit_leafs_index(data->data, data->depth + 1, child_level_index);
const int child_leafs_end = implicit_leafs_index(data->data, data->depth + 1, child_level_index + 1);
if (child_leafs_end - child_leafs_begin > 1) {
parent->children[k] = &data->branches_array[child_index];
parent->children[k]->parent = parent;
}
else if (child_leafs_end - child_leafs_begin == 1) {
parent->children[k] = data->leafs_array[child_leafs_begin];
parent->children[k]->parent = parent;
}
else {
break;
}
}
parent->totnode = (char)k;
}
/**
* This functions builds an optimal implicit tree from the given leafs.
* Where optimal stands for:
* - The resulting tree will have the smallest number of branches;
* - At most only one branch will have NULL childs;
* - All leafs will be stored at level N or N+1.
*
* This function creates an implicit tree on branches_array, the leafs are given on the leafs_array.
*
* The tree is built per depth levels. First branches at depth 1.. then branches at depth 2.. etc..
* The reason is that we can build level N+1 from level N without any data dependencies.. thus it allows
* to use multithread building.
*
* To archive this is necessary to find how much leafs are accessible from a certain branch, BVHBuildHelper
* #implicit_needed_branches and #implicit_leafs_index are auxiliary functions to solve that "optimal-split".
*/
static void non_recursive_bvh_div_nodes(
const BVHTree *tree, BVHNode *branches_array, BVHNode **leafs_array, int num_leafs)
{
int i;
const int tree_type = tree->tree_type;
const int tree_offset = 2 - tree->tree_type; /* this value is 0 (on binary trees) and negative on the others */
const int num_branches = implicit_needed_branches(tree_type, num_leafs);
BVHBuildHelper data;
int depth;
{
/* set parent from root node to NULL */
BVHNode *root = &branches_array[1];
root->parent = NULL;
/* Most of bvhtree code relies on 1-leaf trees having at least one branch
* We handle that special case here */
if (num_leafs == 1) {
refit_kdop_hull(tree, root, 0, num_leafs);
root->main_axis = get_largest_axis(root->bv) / 2;
root->totnode = 1;
root->children[0] = leafs_array[0];
root->children[0]->parent = root;
return;
}
}
build_implicit_tree_helper(tree, &data);
BVHDivNodesData cb_data = {
.tree = tree, .branches_array = branches_array, .leafs_array = leafs_array,
.tree_type = tree_type, .tree_offset = tree_offset, .data = &data,
.first_of_next_level = 0, .depth = 0, .i = 0,
};
/* Loop tree levels (log N) loops */
for (i = 1, depth = 1; i <= num_branches; i = i * tree_type + tree_offset, depth++) {
const int first_of_next_level = i * tree_type + tree_offset;
const int i_stop = min_ii(first_of_next_level, num_branches + 1); /* index of last branch on this level */
/* Loop all branches on this level */
cb_data.first_of_next_level = first_of_next_level;
cb_data.i = i;
cb_data.depth = depth;
if (true) {
ParallelRangeSettings settings;
BLI_parallel_range_settings_defaults(&settings);
settings.use_threading = (num_leafs > KDOPBVH_THREAD_LEAF_THRESHOLD);
BLI_task_parallel_range(
i, i_stop,
&cb_data,
non_recursive_bvh_div_nodes_task_cb,
&settings);
}
else {
/* Less hassle for debugging. */
ParallelRangeTLS tls = {0};
for (int i_task = i; i_task < i_stop; i_task++) {
non_recursive_bvh_div_nodes_task_cb(&cb_data, i_task, &tls);
}
}
}
}
/** \} */
/* -------------------------------------------------------------------- */
/** \name BLI_bvhtree API
* \{ */
/**
* \note many callers don't check for ``NULL`` return.
*/
BVHTree *BLI_bvhtree_new(int maxsize, float epsilon, char tree_type, char axis)
{
BVHTree *tree;
int numnodes, i;
BLI_assert(tree_type >= 2 && tree_type <= MAX_TREETYPE);
tree = MEM_callocN(sizeof(BVHTree), "BVHTree");
/* tree epsilon must be >= FLT_EPSILON
* so that tangent rays can still hit a bounding volume..
* this bug would show up when casting a ray aligned with a kdop-axis and with an edge of 2 faces */
epsilon = max_ff(FLT_EPSILON, epsilon);
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 {
/* should never happen! */
BLI_assert(0);
goto fail;
}
/* Allocate arrays */
numnodes = maxsize + implicit_needed_branches(tree_type, maxsize) + tree_type;
tree->nodes = MEM_callocN(sizeof(BVHNode *) * (size_t)numnodes, "BVHNodes");
tree->nodebv = MEM_callocN(sizeof(float) * (size_t)(axis * numnodes), "BVHNodeBV");
tree->nodechild = MEM_callocN(sizeof(BVHNode *) * (size_t)(tree_type * numnodes), "BVHNodeBV");
tree->nodearray = MEM_callocN(sizeof(BVHNode) * (size_t)numnodes, "BVHNodeArray");
if (UNLIKELY((!tree->nodes) ||
(!tree->nodebv) ||
(!tree->nodechild) ||
(!tree->nodearray)))
{
goto fail;
}
/* 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;
fail:
MEM_SAFE_FREE(tree->nodes);
MEM_SAFE_FREE(tree->nodebv);
MEM_SAFE_FREE(tree->nodechild);
MEM_SAFE_FREE(tree->nodearray);
MEM_freeN(tree);
return NULL;
}
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);
}
}
void BLI_bvhtree_balance(BVHTree *tree)
{
BVHNode **leafs_array = tree->nodes;
/* This function should only be called once
* (some big bug goes here if its being called more than once per tree) */
BLI_assert(tree->totbranch == 0);
/* Build the implicit tree */
non_recursive_bvh_div_nodes(tree, tree->nodearray + (tree->totleaf - 1), leafs_array, tree->totleaf);
/* current code expects the branches to be linked to the nodes array
* we perform that linkage here */
tree->totbranch = implicit_needed_branches(tree->tree_type, tree->totleaf);
for (int i = 0; i < tree->totbranch; i++) {
tree->nodes[tree->totleaf + i] = &tree->nodearray[tree->totleaf + i];
}
#ifdef USE_SKIP_LINKS
build_skip_links(tree, tree->nodes[tree->totleaf], NULL, NULL);
#endif
#ifdef USE_VERIFY_TREE
bvhtree_verify(tree);
#endif
#ifdef USE_PRINT_TREE
bvhtree_info(tree);
#endif
}
void BLI_bvhtree_insert(BVHTree *tree, int index, const float co[3], int numpoints)
{
axis_t axis_iter;
BVHNode *node = NULL;
/* insert should only possible as long as tree->totbranch is 0 */
BLI_assert(tree->totbranch <= 0);
BLI_assert((size_t)tree->totleaf < MEM_allocN_len(tree->nodes) / sizeof(*(tree->nodes)));
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 (axis_iter = tree->start_axis; axis_iter < tree->stop_axis; axis_iter++) {
node->bv[(2 * axis_iter)] -= tree->epsilon; /* minimum */
node->bv[(2 * axis_iter) + 1] += tree->epsilon; /* maximum */
}
}
/* call before BLI_bvhtree_update_tree() */
bool BLI_bvhtree_update_node(BVHTree *tree, int index, const float co[3], const float co_moving[3], int numpoints)
{
BVHNode *node = NULL;
axis_t axis_iter;
/* check if index exists */
if (index > tree->totleaf)
return false;
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 (axis_iter = tree->start_axis; axis_iter < tree->stop_axis; axis_iter++) {
node->bv[(2 * axis_iter)] -= tree->epsilon; /* minimum */
node->bv[(2 * axis_iter) + 1] += tree->epsilon; /* maximum */
}
return true;
}
/* call BLI_bvhtree_update_node() first for every node/point/triangle */
void BLI_bvhtree_update_tree(BVHTree *tree)
{
/* Update bottom=>top
* TRICKY: the way we build the tree all the childs have an index greater than the parent
* This allows us todo a bottom up update by starting on the bigger numbered branch */
BVHNode **root = tree->nodes + tree->totleaf;
BVHNode **index = tree->nodes + tree->totleaf + tree->totbranch - 1;
for (; index >= root; index--)
node_join(tree, *index);
}
/**
* Number of times #BLI_bvhtree_insert has been called.
* mainly useful for asserts functions to check we added the correct number.
*/
int BLI_bvhtree_get_len(const BVHTree *tree)
{
return tree->totleaf;
}
float BLI_bvhtree_get_epsilon(const BVHTree *tree)
{
return tree->epsilon;
}
/** \} */
/* -------------------------------------------------------------------- */
/** \name BLI_bvhtree_overlap
* \{ */
/**
* overlap - is it possible for 2 bv's to collide ?
*/
static bool tree_overlap_test(const BVHNode *node1, const BVHNode *node2, axis_t start_axis, axis_t stop_axis)
{
const float *bv1 = node1->bv + (start_axis << 1);
const float *bv2 = node2->bv + (start_axis << 1);
const float *bv1_end = node1->bv + (stop_axis << 1);
/* test all axis if min + max overlap */
for (; bv1 != bv1_end; bv1 += 2, bv2 += 2) {
if ((bv1[0] > bv2[1]) || (bv2[0] > bv1[1])) {
return 0;
}
}
return 1;
}
static void tree_overlap_traverse(
BVHOverlapData_Thread *data_thread,
const BVHNode *node1, const BVHNode *node2)
{
BVHOverlapData_Shared *data = data_thread->shared;
int j;
if (tree_overlap_test(node1, node2, data->start_axis, data->stop_axis)) {
/* check if node1 is a leaf */
if (!node1->totnode) {
/* check if node2 is a leaf */
if (!node2->totnode) {
BVHTreeOverlap *overlap;
if (UNLIKELY(node1 == node2)) {
return;
}
/* both leafs, insert overlap! */
overlap = BLI_stack_push_r(data_thread->overlap);
overlap->indexA = node1->index;
overlap->indexB = node2->index;
}
else {
for (j = 0; j < data->tree2->tree_type; j++) {
if (node2->children[j]) {
tree_overlap_traverse(data_thread, node1, node2->children[j]);
}
}
}
}
else {
for (j = 0; j < data->tree2->tree_type; j++) {
if (node1->children[j]) {
tree_overlap_traverse(data_thread, node1->children[j], node2);
}
}
}
}
}
/**
* a version of #tree_overlap_traverse that runs a callback to check if the nodes really intersect.
*/
static void tree_overlap_traverse_cb(
BVHOverlapData_Thread *data_thread,
const BVHNode *node1, const BVHNode *node2)
{
BVHOverlapData_Shared *data = data_thread->shared;
int j;
if (tree_overlap_test(node1, node2, data->start_axis, data->stop_axis)) {
/* check if node1 is a leaf */
if (!node1->totnode) {
/* check if node2 is a leaf */
if (!node2->totnode) {
BVHTreeOverlap *overlap;
if (UNLIKELY(node1 == node2)) {
return;
}
/* only difference to tree_overlap_traverse! */
if (data->callback(data->userdata, node1->index, node2->index, data_thread->thread)) {
/* both leafs, insert overlap! */
overlap = BLI_stack_push_r(data_thread->overlap);
overlap->indexA = node1->index;
overlap->indexB = node2->index;
}
}
else {
for (j = 0; j < data->tree2->tree_type; j++) {
if (node2->children[j]) {
tree_overlap_traverse_cb(data_thread, node1, node2->children[j]);
}
}
}
}
else {
for (j = 0; j < data->tree2->tree_type; j++) {
if (node1->children[j]) {
tree_overlap_traverse_cb(data_thread, node1->children[j], node2);
}
}
}
}
}
/**
* Use to check the total number of threads #BLI_bvhtree_overlap will use.
*
* \warning Must be the first tree passed to #BLI_bvhtree_overlap!
*/
int BLI_bvhtree_overlap_thread_num(const BVHTree *tree)
{
return (int)MIN2(tree->tree_type, tree->nodes[tree->totleaf]->totnode);
}
static void bvhtree_overlap_task_cb(
void *__restrict userdata,
const int j,
const ParallelRangeTLS *__restrict UNUSED(tls))
{
BVHOverlapData_Thread *data = &((BVHOverlapData_Thread *)userdata)[j];
BVHOverlapData_Shared *data_shared = data->shared;
if (data_shared->callback) {
tree_overlap_traverse_cb(
data, data_shared->tree1->nodes[data_shared->tree1->totleaf]->children[j],
data_shared->tree2->nodes[data_shared->tree2->totleaf]);
}
else {
tree_overlap_traverse(
data, data_shared->tree1->nodes[data_shared->tree1->totleaf]->children[j],
data_shared->tree2->nodes[data_shared->tree2->totleaf]);
}
}
BVHTreeOverlap *BLI_bvhtree_overlap(
const BVHTree *tree1, const BVHTree *tree2, uint *r_overlap_tot,
/* optional callback to test the overlap before adding (must be thread-safe!) */
BVHTree_OverlapCallback callback, void *userdata)
{
const int thread_num = BLI_bvhtree_overlap_thread_num(tree1);
int j;
size_t total = 0;
BVHTreeOverlap *overlap = NULL, *to = NULL;
BVHOverlapData_Shared data_shared;
BVHOverlapData_Thread *data = BLI_array_alloca(data, (size_t)thread_num);
axis_t start_axis, stop_axis;
/* check for compatibility of both trees (can't compare 14-DOP with 18-DOP) */
if (UNLIKELY((tree1->axis != tree2->axis) &&
(tree1->axis == 14 || tree2->axis == 14) &&
(tree1->axis == 18 || tree2->axis == 18)))
{
BLI_assert(0);
return NULL;
}
start_axis = min_axis(tree1->start_axis, tree2->start_axis);
stop_axis = min_axis(tree1->stop_axis, tree2->stop_axis);
/* fast check root nodes for collision before doing big splitting + traversal */
if (!tree_overlap_test(tree1->nodes[tree1->totleaf], tree2->nodes[tree2->totleaf], start_axis, stop_axis)) {
return NULL;
}
data_shared.tree1 = tree1;
data_shared.tree2 = tree2;
data_shared.start_axis = start_axis;
data_shared.stop_axis = stop_axis;
/* can be NULL */
data_shared.callback = callback;
data_shared.userdata = userdata;
for (j = 0; j < thread_num; j++) {
/* init BVHOverlapData_Thread */
data[j].shared = &data_shared;
data[j].overlap = BLI_stack_new(sizeof(BVHTreeOverlap), __func__);
/* for callback */
data[j].thread = j;
}
ParallelRangeSettings settings;
BLI_parallel_range_settings_defaults(&settings);
settings.use_threading = (tree1->totleaf > KDOPBVH_THREAD_LEAF_THRESHOLD);
BLI_task_parallel_range(
0, thread_num,
data,
bvhtree_overlap_task_cb,
&settings);
for (j = 0; j < thread_num; j++)
total += BLI_stack_count(data[j].overlap);
to = overlap = MEM_mallocN(sizeof(BVHTreeOverlap) * total, "BVHTreeOverlap");
for (j = 0; j < thread_num; j++) {
uint count = (uint)BLI_stack_count(data[j].overlap);
BLI_stack_pop_n(data[j].overlap, to, count);
BLI_stack_free(data[j].overlap);
to += count;
}
*r_overlap_tot = (uint)total;
return overlap;
}
/** \} */
/* -------------------------------------------------------------------- */
/** \name BLI_bvhtree_find_nearest
* \{ */
/* Determines the nearest point of the given node BV. Returns the squared distance to that point. */
static float calc_nearest_point_squared(const float proj[3], BVHNode *node, float nearest[3])
{
int i;
const float *bv = node->bv;
/* nearest on AABB hull */
for (i = 0; i != 3; i++, bv += 2) {
if (bv[0] > proj[i])
nearest[i] = bv[0];
else if (bv[1] < proj[i])
nearest[i] = bv[1];
else
nearest[i] = proj[i];
}
#if 0
/* nearest on a general hull */
copy_v3_v3(nearest, data->co);
for (i = data->tree->start_axis; i != data->tree->stop_axis; i++, bv += 2) {
float proj = dot_v3v3(nearest, bvhtree_kdop_axes[i]);
float dl = bv[0] - proj;
float du = bv[1] - proj;
if (dl > 0) {
madd_v3_v3fl(nearest, bvhtree_kdop_axes[i], dl);
}
else if (du < 0) {
madd_v3_v3fl(nearest, bvhtree_kdop_axes[i], du);
}
}
#endif
return len_squared_v3v3(proj, nearest);
}
/* TODO: use a priority queue to reduce the number of nodes looked on */
static void dfs_find_nearest_dfs(BVHNearestData *data, BVHNode *node)
{
if (node->totnode == 0) {
if (data->callback)
data->callback(data->userdata, node->index, data->co, &data->nearest);
else {
data->nearest.index = node->index;
data->nearest.dist_sq = calc_nearest_point_squared(data->proj, node, data->nearest.co);
}
}
else {
/* Better heuristic to pick the closest node to dive on */
int i;
float nearest[3];
if (data->proj[node->main_axis] <= node->children[0]->bv[node->main_axis * 2 + 1]) {
for (i = 0; i != node->totnode; i++) {
if (calc_nearest_point_squared(data->proj, node->children[i], nearest) >= data->nearest.dist_sq)
continue;
dfs_find_nearest_dfs(data, node->children[i]);
}
}
else {
for (i = node->totnode - 1; i >= 0; i--) {
if (calc_nearest_point_squared(data->proj, node->children[i], nearest) >= data->nearest.dist_sq)
continue;
dfs_find_nearest_dfs(data, node->children[i]);
}
}
}
}
static void dfs_find_nearest_begin(BVHNearestData *data, BVHNode *node)
{
float nearest[3], dist_sq;
dist_sq = calc_nearest_point_squared(data->proj, node, nearest);
if (dist_sq >= data->nearest.dist_sq) {
return;
}
dfs_find_nearest_dfs(data, node);
}
#if 0
typedef struct NodeDistance {
BVHNode *node;
float dist;
} NodeDistance;
#define DEFAULT_FIND_NEAREST_HEAP_SIZE 1024
#define NodeDistance_priority(a, b) ((a).dist < (b).dist)
static void NodeDistance_push_heap(NodeDistance *heap, int heap_size)
PUSH_HEAP_BODY(NodeDistance, NodeDistance_priority, heap, heap_size)
static void NodeDistance_pop_heap(NodeDistance *heap, int heap_size)
POP_HEAP_BODY(NodeDistance, NodeDistance_priority, heap, heap_size)
/* NN function that uses an heap.. this functions leads to an optimal number of min-distance
* but for normal tri-faces and BV 6-dop.. a simple dfs with local heuristics (as implemented
* in source/blender/blenkernel/intern/shrinkwrap.c) works faster.
*
* It may make sense to use this function if the callback queries are very slow.. or if its impossible
* to get a nice heuristic
*
* this function uses "malloc/free" instead of the MEM_* because it intends to be thread safe */
static void bfs_find_nearest(BVHNearestData *data, BVHNode *node)
{
int i;
NodeDistance default_heap[DEFAULT_FIND_NEAREST_HEAP_SIZE];
NodeDistance *heap = default_heap, current;
int heap_size = 0, max_heap_size = sizeof(default_heap) / sizeof(default_heap[0]);
float nearest[3];
int callbacks = 0, push_heaps = 0;
if (node->totnode == 0) {
dfs_find_nearest_dfs(data, node);
return;
}
current.node = node;
current.dist = calc_nearest_point(data->proj, node, nearest);
while (current.dist < data->nearest.dist) {
// printf("%f : %f\n", current.dist, data->nearest.dist);
for (i = 0; i < current.node->totnode; i++) {
BVHNode *child = current.node->children[i];
if (child->totnode == 0) {
callbacks++;
dfs_find_nearest_dfs(data, child);
}
else {
/* adjust heap size */
if ((heap_size >= max_heap_size) &&
ADJUST_MEMORY(default_heap, (void **)&heap,
heap_size + 1, &max_heap_size, sizeof(heap[0])) == false)
{
printf("WARNING: bvh_find_nearest got out of memory\n");
if (heap != default_heap)
free(heap);
return;
}
heap[heap_size].node = current.node->children[i];
heap[heap_size].dist = calc_nearest_point(data->proj, current.node->children[i], nearest);
if (heap[heap_size].dist >= data->nearest.dist) continue;
heap_size++;
NodeDistance_push_heap(heap, heap_size);
// PUSH_HEAP_BODY(NodeDistance, NodeDistance_priority, heap, heap_size);
push_heaps++;
}
}
if (heap_size == 0) break;
current = heap[0];
NodeDistance_pop_heap(heap, heap_size);
// POP_HEAP_BODY(NodeDistance, NodeDistance_priority, heap, heap_size);
heap_size--;
}
// printf("hsize=%d, callbacks=%d, pushs=%d\n", heap_size, callbacks, push_heaps);
if (heap != default_heap)
free(heap);
}
#endif
int BLI_bvhtree_find_nearest(
BVHTree *tree, const float co[3], BVHTreeNearest *nearest,
BVHTree_NearestPointCallback callback, void *userdata)
{
axis_t axis_iter;
BVHNearestData data;
BVHNode *root = tree->nodes[tree->totleaf];
/* init data to search */
data.tree = tree;
data.co = co;
data.callback = callback;
data.userdata = userdata;
for (axis_iter = data.tree->start_axis; axis_iter != data.tree->stop_axis; axis_iter++) {
data.proj[axis_iter] = dot_v3v3(data.co, bvhtree_kdop_axes[axis_iter]);
}
if (nearest) {
memcpy(&data.nearest, nearest, sizeof(*nearest));
}
else {
data.nearest.index = -1;
data.nearest.dist_sq = FLT_MAX;
}
/* dfs search */
if (root)
dfs_find_nearest_begin(&data, root);
/* copy back results */
if (nearest) {
memcpy(nearest, &data.nearest, sizeof(*nearest));
}
return data.nearest.index;
}
/** \} */
/* -------------------------------------------------------------------- */
/** \name BLI_bvhtree_ray_cast
*
* raycast is done by performing a DFS on the BVHTree and saving the closest hit.
*
* \{ */
/* Determines the distance that the ray must travel to hit the bounding volume of the given node */
static float ray_nearest_hit(const BVHRayCastData *data, const float bv[6])
{
int i;
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.radius ||
data->ray.origin[i] > bv[1] + data->ray.radius)
{
return FLT_MAX;
}
}
else {
float ll = (bv[0] - data->ray.radius - data->ray.origin[i]) / data->ray_dot_axis[i];
float lu = (bv[1] + data->ray.radius - data->ray.origin[i]) / data->ray_dot_axis[i];
if (data->ray_dot_axis[i] > 0.0f) {
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;
}
/**
* Determines the distance that the ray must travel to hit the bounding volume of the given node
* Based on Tactical Optimization of Ray/Box Intersection, by Graham Fyffe
* [http://tog.acm.org/resources/RTNews/html/rtnv21n1.html#art9]
*
* TODO this doesn't take data->ray.radius into consideration */
static float fast_ray_nearest_hit(const BVHRayCastData *data, const BVHNode *node)
{
const float *bv = node->bv;
float t1x = (bv[data->index[0]] - data->ray.origin[0]) * data->idot_axis[0];
float t2x = (bv[data->index[1]] - data->ray.origin[0]) * data->idot_axis[0];
float t1y = (bv[data->index[2]] - data->ray.origin[1]) * data->idot_axis[1];
float t2y = (bv[data->index[3]] - data->ray.origin[1]) * data->idot_axis[1];
float t1z = (bv[data->index[4]] - data->ray.origin[2]) * data->idot_axis[2];
float t2z = (bv[data->index[5]] - data->ray.origin[2]) * data->idot_axis[2];
if ((t1x > t2y || t2x < t1y || t1x > t2z || t2x < t1z || t1y > t2z || t2y < t1z) ||
(t2x < 0.0f || t2y < 0.0f || t2z < 0.0f) ||
(t1x > data->hit.dist || t1y > data->hit.dist || t1z > data->hit.dist))
{
return FLT_MAX;
}
else {
return max_fff(t1x, t1y, t1z);
}
}
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 */
/* XXX: temporary solution for particles until fast_ray_nearest_hit supports ray.radius */
float dist = (data->ray.radius == 0.0f) ? fast_ray_nearest_hit(data, node) : ray_nearest_hit(data, node->bv);
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;
madd_v3_v3v3fl(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] > 0.0f) {
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]);
}
}
}
}
/**
* A version of #dfs_raycast with minor changes to reset the index & dist each ray cast.
*/
static void dfs_raycast_all(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 */
/* XXX: temporary solution for particles until fast_ray_nearest_hit supports ray.radius */
float dist = (data->ray.radius == 0.0f) ? fast_ray_nearest_hit(data, node) : ray_nearest_hit(data, node->bv);
if (dist >= data->hit.dist) {
return;
}
if (node->totnode == 0) {
/* no need to check for 'data->callback' (using 'all' only makes sense with a callback). */
dist = data->hit.dist;
data->callback(data->userdata, node->index, &data->ray, &data->hit);
data->hit.index = -1;
data->hit.dist = 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] > 0.0f) {
for (i = 0; i != node->totnode; i++) {
dfs_raycast_all(data, node->children[i]);
}
}
else {
for (i = node->totnode - 1; i >= 0; i--) {
dfs_raycast_all(data, node->children[i]);
}
}
}
}
#if 0
static void iterative_raycast(BVHRayCastData *data, BVHNode *node)
{
while (node) {
float dist = fast_ray_nearest_hit(data, node);
if (dist >= data->hit.dist) {
node = node->skip[1];
continue;
}
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;
madd_v3_v3v3fl(data->hit.co, data->ray.origin, data->ray.direction, dist);
}
node = node->skip[1];
}
else {
node = node->children[0];
}
}
}
#endif
static void bvhtree_ray_cast_data_precalc(BVHRayCastData *data, int flag)
{
int i;
for (i = 0; i < 3; i++) {
data->ray_dot_axis[i] = dot_v3v3(data->ray.direction, bvhtree_kdop_axes[i]);
data->idot_axis[i] = 1.0f / data->ray_dot_axis[i];
if (fabsf(data->ray_dot_axis[i]) < FLT_EPSILON) {
data->ray_dot_axis[i] = 0.0;
}
data->index[2 * i] = data->idot_axis[i] < 0.0f ? 1 : 0;
data->index[2 * i + 1] = 1 - data->index[2 * i];
data->index[2 * i] += 2 * i;
data->index[2 * i + 1] += 2 * i;
}
#ifdef USE_KDOPBVH_WATERTIGHT
if (flag & BVH_RAYCAST_WATERTIGHT) {
isect_ray_tri_watertight_v3_precalc(&data->isect_precalc, data->ray.direction);
data->ray.isect_precalc = &data->isect_precalc;
}
else {
data->ray.isect_precalc = NULL;
}
#else
UNUSED_VARS(flag);
#endif
}
int BLI_bvhtree_ray_cast_ex(
BVHTree *tree, const float co[3], const float dir[3], float radius, BVHTreeRayHit *hit,
BVHTree_RayCastCallback callback, void *userdata,
int flag)
{
BVHRayCastData data;
BVHNode *root = tree->nodes[tree->totleaf];
BLI_ASSERT_UNIT_V3(dir);
data.tree = tree;
data.callback = callback;
data.userdata = userdata;
copy_v3_v3(data.ray.origin, co);
copy_v3_v3(data.ray.direction, dir);
data.ray.radius = radius;
bvhtree_ray_cast_data_precalc(&data, flag);
if (hit) {
memcpy(&data.hit, hit, sizeof(*hit));
}
else {
data.hit.index = -1;
data.hit.dist = BVH_RAYCAST_DIST_MAX;
}
if (root) {
dfs_raycast(&data, root);
// iterative_raycast(&data, root);
}
if (hit)
memcpy(hit, &data.hit, sizeof(*hit));
return data.hit.index;
}
int BLI_bvhtree_ray_cast(
BVHTree *tree, const float co[3], const float dir[3], float radius, BVHTreeRayHit *hit,
BVHTree_RayCastCallback callback, void *userdata)
{
return BLI_bvhtree_ray_cast_ex(tree, co, dir, radius, hit, callback, userdata, BVH_RAYCAST_DEFAULT);
}
float BLI_bvhtree_bb_raycast(const float bv[6], const float light_start[3], const float light_end[3], float pos[3])
{
BVHRayCastData data;
float dist;
data.hit.dist = BVH_RAYCAST_DIST_MAX;
/* get light direction */
sub_v3_v3v3(data.ray.direction, light_end, light_start);
data.ray.radius = 0.0;
copy_v3_v3(data.ray.origin, light_start);
normalize_v3(data.ray.direction);
copy_v3_v3(data.ray_dot_axis, data.ray.direction);
dist = ray_nearest_hit(&data, bv);
madd_v3_v3v3fl(pos, light_start, data.ray.direction, dist);
return dist;
}
/**
* Calls the callback for every ray intersection
*
* \note Using a \a callback which resets or never sets the #BVHTreeRayHit index & dist works too,
* however using this function means existing generic callbacks can be used from custom callbacks without
* having to handle resetting the hit beforehand.
* It also avoid redundant argument and return value which aren't meaningful when collecting multiple hits.
*/
void BLI_bvhtree_ray_cast_all_ex(
BVHTree *tree, const float co[3], const float dir[3], float radius, float hit_dist,
BVHTree_RayCastCallback callback, void *userdata,
int flag)
{
BVHRayCastData data;
BVHNode *root = tree->nodes[tree->totleaf];
BLI_ASSERT_UNIT_V3(dir);
BLI_assert(callback != NULL);
data.tree = tree;
data.callback = callback;
data.userdata = userdata;
copy_v3_v3(data.ray.origin, co);
copy_v3_v3(data.ray.direction, dir);
data.ray.radius = radius;
bvhtree_ray_cast_data_precalc(&data, flag);
data.hit.index = -1;
data.hit.dist = hit_dist;
if (root) {
dfs_raycast_all(&data, root);
}
}
void BLI_bvhtree_ray_cast_all(
BVHTree *tree, const float co[3], const float dir[3], float radius, float hit_dist,
BVHTree_RayCastCallback callback, void *userdata)
{
BLI_bvhtree_ray_cast_all_ex(tree, co, dir, radius, hit_dist, callback, userdata, BVH_RAYCAST_DEFAULT);
}
/** \} */
/* -------------------------------------------------------------------- */
/** \name BLI_bvhtree_range_query
*
* Allocs and fills an array with the indexs of node that are on the given spherical range (center, radius).
* Returns the size of the array.
*
* \{ */
typedef struct RangeQueryData {
BVHTree *tree;
const float *center;
float radius_sq; /* squared radius */
int hits;
BVHTree_RangeQuery callback;
void *userdata;
} RangeQueryData;
static void dfs_range_query(RangeQueryData *data, BVHNode *node)
{
if (node->totnode == 0) {
#if 0 /*UNUSED*/
/* Calculate the node min-coords (if the node was a point then this is the point coordinates) */
float co[3];
co[0] = node->bv[0];
co[1] = node->bv[2];
co[2] = node->bv[4];
#endif
}
else {
int i;
for (i = 0; i != node->totnode; i++) {
float nearest[3];
float dist_sq = calc_nearest_point_squared(data->center, node->children[i], nearest);
if (dist_sq < data->radius_sq) {
/* Its a leaf.. call the callback */
if (node->children[i]->totnode == 0) {
data->hits++;
data->callback(data->userdata, node->children[i]->index, data->center, dist_sq);
}
else
dfs_range_query(data, node->children[i]);
}
}
}
}
int BLI_bvhtree_range_query(
BVHTree *tree, const float co[3], float radius,
BVHTree_RangeQuery callback, void *userdata)
{
BVHNode *root = tree->nodes[tree->totleaf];
RangeQueryData data;
data.tree = tree;
data.center = co;
data.radius_sq = radius * radius;
data.hits = 0;
data.callback = callback;
data.userdata = userdata;
if (root != NULL) {
float nearest[3];
float dist_sq = calc_nearest_point_squared(data.center, root, nearest);
if (dist_sq < data.radius_sq) {
/* Its a leaf.. call the callback */
if (root->totnode == 0) {
data.hits++;
data.callback(data.userdata, root->index, co, dist_sq);
}
else
dfs_range_query(&data, root);
}
}
return data.hits;
}
/** \} */
/* -------------------------------------------------------------------- */
/** \name BLI_bvhtree_walk_dfs
* \{ */
/**
* Runs first among nodes children of the first node before going to the next node in the same layer.
*
* \return false to break out of the search early.
*/
static bool bvhtree_walk_dfs_recursive(
BVHTree_WalkParentCallback walk_parent_cb,
BVHTree_WalkLeafCallback walk_leaf_cb,
BVHTree_WalkOrderCallback walk_order_cb,
const BVHNode *node, void *userdata)
{
if (node->totnode == 0) {
return walk_leaf_cb((const BVHTreeAxisRange *)node->bv, node->index, userdata);
}
else {
/* First pick the closest node to recurse into */
if (walk_order_cb((const BVHTreeAxisRange *)node->bv, node->main_axis, userdata)) {
for (int i = 0; i != node->totnode; i++) {
if (walk_parent_cb((const BVHTreeAxisRange *)node->children[i]->bv, userdata)) {
if (!bvhtree_walk_dfs_recursive(
walk_parent_cb, walk_leaf_cb, walk_order_cb,
node->children[i], userdata))
{
return false;
}
}
}
}
else {
for (int i = node->totnode - 1; i >= 0; i--) {
if (walk_parent_cb((const BVHTreeAxisRange *)node->children[i]->bv, userdata)) {
if (!bvhtree_walk_dfs_recursive(
walk_parent_cb, walk_leaf_cb, walk_order_cb,
node->children[i], userdata))
{
return false;
}
}
}
}
}
return true;
}
/**
* This is a generic function to perform a depth first search on the BVHTree
* where the search order and nodes traversed depend on callbacks passed in.
*
* \param tree: Tree to walk.
* \param walk_parent_cb: Callback on a parents bound-box to test if it should be traversed.
* \param walk_leaf_cb: Callback to test leaf nodes, callback must store its own result,
* returning false exits early.
* \param walk_order_cb: Callback that indicates which direction to search,
* either from the node with the lower or higher k-dop axis value.
* \param userdata: Argument passed to all callbacks.
*/
void BLI_bvhtree_walk_dfs(
BVHTree *tree,
BVHTree_WalkParentCallback walk_parent_cb,
BVHTree_WalkLeafCallback walk_leaf_cb,
BVHTree_WalkOrderCallback walk_order_cb, void *userdata)
{
const BVHNode *root = tree->nodes[tree->totleaf];
if (root != NULL) {
/* first make sure the bv of root passes in the test too */
if (walk_parent_cb((const BVHTreeAxisRange *)root->bv, userdata)) {
bvhtree_walk_dfs_recursive(walk_parent_cb, walk_leaf_cb, walk_order_cb, root, userdata);
}
}
}
/** \} */
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