mirror of
https://github.com/godotengine/godot.git
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8247667a3e
We've been using standard C library functions `memcpy`/`memset` for these since
2016 with 67f65f6639.
There was still the possibility for third-party platform ports to override the
definitions with a custom header, but this doesn't seem useful anymore.
478 lines
15 KiB
C++
478 lines
15 KiB
C++
/*************************************************************************/
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/* dynamic_bvh.h */
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/*************************************************************************/
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/* This file is part of: */
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/* GODOT ENGINE */
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/* https://godotengine.org */
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/*************************************************************************/
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/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */
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/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md). */
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/* */
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/* Permission is hereby granted, free of charge, to any person obtaining */
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/* a copy of this software and associated documentation files (the */
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/* "Software"), to deal in the Software without restriction, including */
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/* without limitation the rights to use, copy, modify, merge, publish, */
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/* distribute, sublicense, and/or sell copies of the Software, and to */
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/* permit persons to whom the Software is furnished to do so, subject to */
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/* the following conditions: */
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/* */
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/* The above copyright notice and this permission notice shall be */
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/* included in all copies or substantial portions of the Software. */
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/* */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
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/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
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/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
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/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
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/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
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/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
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/*************************************************************************/
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#ifndef DYNAMICBVH_H
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#define DYNAMICBVH_H
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#include "core/math/aabb.h"
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#include "core/templates/list.h"
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#include "core/templates/local_vector.h"
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#include "core/templates/paged_allocator.h"
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#include "core/typedefs.h"
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// Based on bullet Dbvh
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/*
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Bullet Continuous Collision Detection and Physics Library
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Copyright (c) 2003-2013 Erwin Coumans http://bulletphysics.org
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This software is provided 'as-is', without any express or implied warranty.
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In no event will the authors be held liable for any damages arising from the use of this software.
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute it freely,
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subject to the following restrictions:
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1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
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2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
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3. This notice may not be removed or altered from any source distribution.
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*/
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///DynamicBVH implementation by Nathanael Presson
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// The DynamicBVH class implements a fast dynamic bounding volume tree based on axis aligned bounding boxes (aabb tree).
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class DynamicBVH {
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struct Node;
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public:
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struct ID {
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Node *node = nullptr;
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public:
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_FORCE_INLINE_ bool is_valid() const { return node != nullptr; }
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};
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private:
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struct Volume {
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Vector3 min, max;
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_FORCE_INLINE_ Vector3 get_center() const { return ((min + max) / 2); }
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_FORCE_INLINE_ Vector3 get_length() const { return (max - min); }
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_FORCE_INLINE_ bool contains(const Volume &a) const {
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return ((min.x <= a.min.x) &&
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(min.y <= a.min.y) &&
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(min.z <= a.min.z) &&
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(max.x >= a.max.x) &&
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(max.y >= a.max.y) &&
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(max.z >= a.max.z));
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}
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_FORCE_INLINE_ Volume merge(const Volume &b) const {
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Volume r;
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for (int i = 0; i < 3; ++i) {
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if (min[i] < b.min[i]) {
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r.min[i] = min[i];
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} else {
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r.min[i] = b.min[i];
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}
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if (max[i] > b.max[i]) {
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r.max[i] = max[i];
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} else {
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r.max[i] = b.max[i];
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}
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}
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return r;
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}
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_FORCE_INLINE_ real_t get_size() const {
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const Vector3 edges = get_length();
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return (edges.x * edges.y * edges.z +
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edges.x + edges.y + edges.z);
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}
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_FORCE_INLINE_ bool is_not_equal_to(const Volume &b) const {
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return ((min.x != b.min.x) ||
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(min.y != b.min.y) ||
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(min.z != b.min.z) ||
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(max.x != b.max.x) ||
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(max.y != b.max.y) ||
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(max.z != b.max.z));
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}
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_FORCE_INLINE_ real_t get_proximity_to(const Volume &b) const {
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const Vector3 d = (min + max) - (b.min + b.max);
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return (Math::abs(d.x) + Math::abs(d.y) + Math::abs(d.z));
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}
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_FORCE_INLINE_ int select_by_proximity(const Volume &a, const Volume &b) const {
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return (get_proximity_to(a) < get_proximity_to(b) ? 0 : 1);
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}
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//
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_FORCE_INLINE_ bool intersects(const Volume &b) const {
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return ((min.x <= b.max.x) &&
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(max.x >= b.min.x) &&
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(min.y <= b.max.y) &&
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(max.y >= b.min.y) &&
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(min.z <= b.max.z) &&
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(max.z >= b.min.z));
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}
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_FORCE_INLINE_ bool intersects_convex(const Plane *p_planes, int p_plane_count, const Vector3 *p_points, int p_point_count) const {
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Vector3 half_extents = (max - min) * 0.5;
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Vector3 ofs = min + half_extents;
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for (int i = 0; i < p_plane_count; i++) {
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const Plane &p = p_planes[i];
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Vector3 point(
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(p.normal.x > 0) ? -half_extents.x : half_extents.x,
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(p.normal.y > 0) ? -half_extents.y : half_extents.y,
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(p.normal.z > 0) ? -half_extents.z : half_extents.z);
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point += ofs;
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if (p.is_point_over(point)) {
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return false;
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}
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}
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// Make sure all points in the shape aren't fully separated from the AABB on
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// each axis.
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int bad_point_counts_positive[3] = { 0 };
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int bad_point_counts_negative[3] = { 0 };
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for (int k = 0; k < 3; k++) {
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for (int i = 0; i < p_point_count; i++) {
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if (p_points[i].coord[k] > ofs.coord[k] + half_extents.coord[k]) {
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bad_point_counts_positive[k]++;
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}
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if (p_points[i].coord[k] < ofs.coord[k] - half_extents.coord[k]) {
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bad_point_counts_negative[k]++;
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}
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}
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if (bad_point_counts_negative[k] == p_point_count) {
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return false;
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}
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if (bad_point_counts_positive[k] == p_point_count) {
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return false;
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}
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}
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return true;
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}
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};
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struct Node {
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Volume volume;
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Node *parent = nullptr;
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union {
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Node *childs[2];
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void *data;
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};
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_FORCE_INLINE_ bool is_leaf() const { return childs[1] == nullptr; }
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_FORCE_INLINE_ bool is_internal() const { return (!is_leaf()); }
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_FORCE_INLINE_ int get_index_in_parent() const {
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ERR_FAIL_COND_V(!parent, 0);
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return (parent->childs[1] == this) ? 1 : 0;
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}
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void get_max_depth(int depth, int &maxdepth) {
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if (is_internal()) {
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childs[0]->get_max_depth(depth + 1, maxdepth);
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childs[1]->get_max_depth(depth + 1, maxdepth);
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} else {
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maxdepth = MAX(maxdepth, depth);
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}
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}
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//
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int count_leaves() const {
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if (is_internal()) {
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return childs[0]->count_leaves() + childs[1]->count_leaves();
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} else {
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return (1);
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}
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}
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bool is_left_of_axis(const Vector3 &org, const Vector3 &axis) const {
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return axis.dot(volume.get_center() - org) <= 0;
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}
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Node() {
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childs[0] = nullptr;
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childs[1] = nullptr;
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}
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};
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PagedAllocator<Node> node_allocator;
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// Fields
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Node *bvh_root = nullptr;
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int lkhd = -1;
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int total_leaves = 0;
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uint32_t opath = 0;
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uint32_t index = 0;
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enum {
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ALLOCA_STACK_SIZE = 128
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};
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_FORCE_INLINE_ void _delete_node(Node *p_node);
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void _recurse_delete_node(Node *p_node);
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_FORCE_INLINE_ Node *_create_node(Node *p_parent, void *p_data);
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_FORCE_INLINE_ DynamicBVH::Node *_create_node_with_volume(Node *p_parent, const Volume &p_volume, void *p_data);
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_FORCE_INLINE_ void _insert_leaf(Node *p_root, Node *p_leaf);
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_FORCE_INLINE_ Node *_remove_leaf(Node *leaf);
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void _fetch_leaves(Node *p_root, LocalVector<Node *> &r_leaves, int p_depth = -1);
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static int _split(Node **leaves, int p_count, const Vector3 &p_org, const Vector3 &p_axis);
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static Volume _bounds(Node **leaves, int p_count);
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void _bottom_up(Node **leaves, int p_count);
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Node *_top_down(Node **leaves, int p_count, int p_bu_threshold);
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Node *_node_sort(Node *n, Node *&r);
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_FORCE_INLINE_ void _update(Node *leaf, int lookahead = -1);
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void _extract_leaves(Node *p_node, List<ID> *r_elements);
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_FORCE_INLINE_ bool _ray_aabb(const Vector3 &rayFrom, const Vector3 &rayInvDirection, const unsigned int raySign[3], const Vector3 bounds[2], real_t &tmin, real_t lambda_min, real_t lambda_max) {
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real_t tmax, tymin, tymax, tzmin, tzmax;
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tmin = (bounds[raySign[0]].x - rayFrom.x) * rayInvDirection.x;
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tmax = (bounds[1 - raySign[0]].x - rayFrom.x) * rayInvDirection.x;
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tymin = (bounds[raySign[1]].y - rayFrom.y) * rayInvDirection.y;
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tymax = (bounds[1 - raySign[1]].y - rayFrom.y) * rayInvDirection.y;
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if ((tmin > tymax) || (tymin > tmax)) {
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return false;
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}
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if (tymin > tmin) {
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tmin = tymin;
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}
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if (tymax < tmax) {
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tmax = tymax;
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}
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tzmin = (bounds[raySign[2]].z - rayFrom.z) * rayInvDirection.z;
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tzmax = (bounds[1 - raySign[2]].z - rayFrom.z) * rayInvDirection.z;
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if ((tmin > tzmax) || (tzmin > tmax)) {
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return false;
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}
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if (tzmin > tmin) {
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tmin = tzmin;
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}
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if (tzmax < tmax) {
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tmax = tzmax;
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}
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return ((tmin < lambda_max) && (tmax > lambda_min));
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}
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public:
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// Methods
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void clear();
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bool is_empty() const { return (nullptr == bvh_root); }
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void optimize_bottom_up();
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void optimize_top_down(int bu_threshold = 128);
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void optimize_incremental(int passes);
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ID insert(const AABB &p_box, void *p_userdata);
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bool update(const ID &p_id, const AABB &p_box);
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void remove(const ID &p_id);
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void get_elements(List<ID> *r_elements);
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int get_leaf_count() const;
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int get_max_depth() const;
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/* Discouraged, but works as a reference on how it must be used */
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struct DefaultQueryResult {
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virtual bool operator()(void *p_data) = 0; //return true whether you want to continue the query
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virtual ~DefaultQueryResult() {}
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};
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template <class QueryResult>
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_FORCE_INLINE_ void aabb_query(const AABB &p_aabb, QueryResult &r_result);
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template <class QueryResult>
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_FORCE_INLINE_ void convex_query(const Plane *p_planes, int p_plane_count, const Vector3 *p_points, int p_point_count, QueryResult &r_result);
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template <class QueryResult>
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_FORCE_INLINE_ void ray_query(const Vector3 &p_from, const Vector3 &p_to, QueryResult &r_result);
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void set_index(uint32_t p_index);
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uint32_t get_index() const;
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~DynamicBVH();
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};
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template <class QueryResult>
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void DynamicBVH::aabb_query(const AABB &p_box, QueryResult &r_result) {
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if (!bvh_root) {
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return;
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}
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Volume volume;
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volume.min = p_box.position;
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volume.max = p_box.position + p_box.size;
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const Node **stack = (const Node **)alloca(ALLOCA_STACK_SIZE * sizeof(const Node *));
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stack[0] = bvh_root;
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int32_t depth = 1;
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int32_t threshold = ALLOCA_STACK_SIZE - 2;
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LocalVector<const Node *> aux_stack; //only used in rare occasions when you run out of alloca memory because tree is too unbalanced. Should correct itself over time.
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do {
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depth--;
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const Node *n = stack[depth];
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if (n->volume.intersects(volume)) {
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if (n->is_internal()) {
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if (depth > threshold) {
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if (aux_stack.is_empty()) {
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aux_stack.resize(ALLOCA_STACK_SIZE * 2);
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memcpy(aux_stack.ptr(), stack, ALLOCA_STACK_SIZE * sizeof(const Node *));
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} else {
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aux_stack.resize(aux_stack.size() * 2);
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}
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stack = aux_stack.ptr();
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threshold = aux_stack.size() - 2;
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}
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stack[depth++] = n->childs[0];
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stack[depth++] = n->childs[1];
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} else {
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if (r_result(n->data)) {
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return;
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}
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}
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}
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} while (depth > 0);
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}
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template <class QueryResult>
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void DynamicBVH::convex_query(const Plane *p_planes, int p_plane_count, const Vector3 *p_points, int p_point_count, QueryResult &r_result) {
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if (!bvh_root) {
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return;
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}
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//generate a volume anyway to improve pre-testing
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Volume volume;
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for (int i = 0; i < p_point_count; i++) {
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if (i == 0) {
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volume.min = p_points[0];
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volume.max = p_points[0];
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} else {
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volume.min.x = MIN(volume.min.x, p_points[i].x);
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volume.min.y = MIN(volume.min.y, p_points[i].y);
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volume.min.z = MIN(volume.min.z, p_points[i].z);
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volume.max.x = MAX(volume.max.x, p_points[i].x);
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volume.max.y = MAX(volume.max.y, p_points[i].y);
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volume.max.z = MAX(volume.max.z, p_points[i].z);
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}
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}
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const Node **stack = (const Node **)alloca(ALLOCA_STACK_SIZE * sizeof(const Node *));
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stack[0] = bvh_root;
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int32_t depth = 1;
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int32_t threshold = ALLOCA_STACK_SIZE - 2;
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LocalVector<const Node *> aux_stack; //only used in rare occasions when you run out of alloca memory because tree is too unbalanced. Should correct itself over time.
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do {
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depth--;
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const Node *n = stack[depth];
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if (n->volume.intersects(volume) && n->volume.intersects_convex(p_planes, p_plane_count, p_points, p_point_count)) {
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if (n->is_internal()) {
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if (depth > threshold) {
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if (aux_stack.is_empty()) {
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aux_stack.resize(ALLOCA_STACK_SIZE * 2);
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memcpy(aux_stack.ptr(), stack, ALLOCA_STACK_SIZE * sizeof(const Node *));
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} else {
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aux_stack.resize(aux_stack.size() * 2);
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}
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stack = aux_stack.ptr();
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threshold = aux_stack.size() - 2;
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}
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stack[depth++] = n->childs[0];
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stack[depth++] = n->childs[1];
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} else {
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if (r_result(n->data)) {
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return;
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}
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}
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}
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} while (depth > 0);
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}
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template <class QueryResult>
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void DynamicBVH::ray_query(const Vector3 &p_from, const Vector3 &p_to, QueryResult &r_result) {
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if (!bvh_root) {
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return;
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}
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Vector3 ray_dir = (p_to - p_from);
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ray_dir.normalize();
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///what about division by zero? --> just set rayDirection[i] to INF/B3_LARGE_FLOAT
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Vector3 inv_dir;
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inv_dir[0] = ray_dir[0] == real_t(0.0) ? real_t(1e20) : real_t(1.0) / ray_dir[0];
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inv_dir[1] = ray_dir[1] == real_t(0.0) ? real_t(1e20) : real_t(1.0) / ray_dir[1];
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inv_dir[2] = ray_dir[2] == real_t(0.0) ? real_t(1e20) : real_t(1.0) / ray_dir[2];
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unsigned int signs[3] = { inv_dir[0] < 0.0, inv_dir[1] < 0.0, inv_dir[2] < 0.0 };
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real_t lambda_max = ray_dir.dot(p_to - p_from);
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Vector3 bounds[2];
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const Node **stack = (const Node **)alloca(ALLOCA_STACK_SIZE * sizeof(const Node *));
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stack[0] = bvh_root;
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int32_t depth = 1;
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int32_t threshold = ALLOCA_STACK_SIZE - 2;
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LocalVector<const Node *> aux_stack; //only used in rare occasions when you run out of alloca memory because tree is too unbalanced. Should correct itself over time.
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do {
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depth--;
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const Node *node = stack[depth];
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bounds[0] = node->volume.min;
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bounds[1] = node->volume.max;
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real_t tmin = 1.f, lambda_min = 0.f;
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unsigned int result1 = false;
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result1 = _ray_aabb(p_from, inv_dir, signs, bounds, tmin, lambda_min, lambda_max);
|
|
if (result1) {
|
|
if (node->is_internal()) {
|
|
if (depth > threshold) {
|
|
if (aux_stack.is_empty()) {
|
|
aux_stack.resize(ALLOCA_STACK_SIZE * 2);
|
|
memcpy(aux_stack.ptr(), stack, ALLOCA_STACK_SIZE * sizeof(const Node *));
|
|
} else {
|
|
aux_stack.resize(aux_stack.size() * 2);
|
|
}
|
|
stack = aux_stack.ptr();
|
|
threshold = aux_stack.size() - 2;
|
|
}
|
|
stack[depth++] = node->childs[0];
|
|
stack[depth++] = node->childs[1];
|
|
} else {
|
|
if (r_result(node->data)) {
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
} while (depth > 0);
|
|
}
|
|
|
|
#endif // DYNAMICBVH_H
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