virtualx-engine/core/math/aabb.h
2020-04-02 13:38:00 +02:00

367 lines
12 KiB
C++

/*************************************************************************/
/* aabb.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#ifndef AABB_H
#define AABB_H
#include "core/math/math_defs.h"
#include "core/math/plane.h"
#include "core/math/vector3.h"
/**
* AABB / AABB (Axis Aligned Bounding Box)
* This is implemented by a point (position) and the box size
*/
class AABB {
public:
Vector3 position;
Vector3 size;
real_t get_area() const; /// get area
_FORCE_INLINE_ bool has_no_area() const {
return (size.x <= 0 || size.y <= 0 || size.z <= 0);
}
_FORCE_INLINE_ bool has_no_surface() const {
return (size.x <= 0 && size.y <= 0 && size.z <= 0);
}
const Vector3 &get_position() const { return position; }
void set_position(const Vector3 &p_pos) { position = p_pos; }
const Vector3 &get_size() const { return size; }
void set_size(const Vector3 &p_size) { size = p_size; }
bool operator==(const AABB &p_rval) const;
bool operator!=(const AABB &p_rval) const;
bool is_equal_approx(const AABB &p_aabb) const;
_FORCE_INLINE_ bool intersects(const AABB &p_aabb) const; /// Both AABBs overlap
_FORCE_INLINE_ bool intersects_inclusive(const AABB &p_aabb) const; /// Both AABBs (or their faces) overlap
_FORCE_INLINE_ bool encloses(const AABB &p_aabb) const; /// p_aabb is completely inside this
AABB merge(const AABB &p_with) const;
void merge_with(const AABB &p_aabb); ///merge with another AABB
AABB intersection(const AABB &p_aabb) const; ///get box where two intersect, empty if no intersection occurs
bool intersects_segment(const Vector3 &p_from, const Vector3 &p_to, Vector3 *r_clip = nullptr, Vector3 *r_normal = nullptr) const;
bool intersects_ray(const Vector3 &p_from, const Vector3 &p_dir, Vector3 *r_clip = nullptr, Vector3 *r_normal = nullptr) const;
_FORCE_INLINE_ bool smits_intersect_ray(const Vector3 &p_from, const Vector3 &p_dir, real_t t0, real_t t1) const;
_FORCE_INLINE_ bool intersects_convex_shape(const Plane *p_planes, int p_plane_count) const;
_FORCE_INLINE_ bool inside_convex_shape(const Plane *p_planes, int p_plane_count) const;
bool intersects_plane(const Plane &p_plane) const;
_FORCE_INLINE_ bool has_point(const Vector3 &p_point) const;
_FORCE_INLINE_ Vector3 get_support(const Vector3 &p_normal) const;
Vector3 get_longest_axis() const;
int get_longest_axis_index() const;
_FORCE_INLINE_ real_t get_longest_axis_size() const;
Vector3 get_shortest_axis() const;
int get_shortest_axis_index() const;
_FORCE_INLINE_ real_t get_shortest_axis_size() const;
AABB grow(real_t p_by) const;
_FORCE_INLINE_ void grow_by(real_t p_amount);
void get_edge(int p_edge, Vector3 &r_from, Vector3 &r_to) const;
_FORCE_INLINE_ Vector3 get_endpoint(int p_point) const;
AABB expand(const Vector3 &p_vector) const;
_FORCE_INLINE_ void project_range_in_plane(const Plane &p_plane, real_t &r_min, real_t &r_max) const;
_FORCE_INLINE_ void expand_to(const Vector3 &p_vector); /** expand to contain a point if necessary */
operator String() const;
_FORCE_INLINE_ AABB() {}
inline AABB(const Vector3 &p_pos, const Vector3 &p_size) :
position(p_pos),
size(p_size) {
}
};
inline bool AABB::intersects(const AABB &p_aabb) const {
if (position.x >= (p_aabb.position.x + p_aabb.size.x))
return false;
if ((position.x + size.x) <= p_aabb.position.x)
return false;
if (position.y >= (p_aabb.position.y + p_aabb.size.y))
return false;
if ((position.y + size.y) <= p_aabb.position.y)
return false;
if (position.z >= (p_aabb.position.z + p_aabb.size.z))
return false;
if ((position.z + size.z) <= p_aabb.position.z)
return false;
return true;
}
inline bool AABB::intersects_inclusive(const AABB &p_aabb) const {
if (position.x > (p_aabb.position.x + p_aabb.size.x))
return false;
if ((position.x + size.x) < p_aabb.position.x)
return false;
if (position.y > (p_aabb.position.y + p_aabb.size.y))
return false;
if ((position.y + size.y) < p_aabb.position.y)
return false;
if (position.z > (p_aabb.position.z + p_aabb.size.z))
return false;
if ((position.z + size.z) < p_aabb.position.z)
return false;
return true;
}
inline bool AABB::encloses(const AABB &p_aabb) const {
Vector3 src_min = position;
Vector3 src_max = position + size;
Vector3 dst_min = p_aabb.position;
Vector3 dst_max = p_aabb.position + p_aabb.size;
return (
(src_min.x <= dst_min.x) &&
(src_max.x > dst_max.x) &&
(src_min.y <= dst_min.y) &&
(src_max.y > dst_max.y) &&
(src_min.z <= dst_min.z) &&
(src_max.z > dst_max.z));
}
Vector3 AABB::get_support(const Vector3 &p_normal) const {
Vector3 half_extents = size * 0.5;
Vector3 ofs = position + half_extents;
return Vector3(
(p_normal.x > 0) ? -half_extents.x : half_extents.x,
(p_normal.y > 0) ? -half_extents.y : half_extents.y,
(p_normal.z > 0) ? -half_extents.z : half_extents.z) +
ofs;
}
Vector3 AABB::get_endpoint(int p_point) const {
switch (p_point) {
case 0: return Vector3(position.x, position.y, position.z);
case 1: return Vector3(position.x, position.y, position.z + size.z);
case 2: return Vector3(position.x, position.y + size.y, position.z);
case 3: return Vector3(position.x, position.y + size.y, position.z + size.z);
case 4: return Vector3(position.x + size.x, position.y, position.z);
case 5: return Vector3(position.x + size.x, position.y, position.z + size.z);
case 6: return Vector3(position.x + size.x, position.y + size.y, position.z);
case 7: return Vector3(position.x + size.x, position.y + size.y, position.z + size.z);
};
ERR_FAIL_V(Vector3());
}
bool AABB::intersects_convex_shape(const Plane *p_planes, int p_plane_count) const {
Vector3 half_extents = size * 0.5;
Vector3 ofs = position + half_extents;
for (int i = 0; i < p_plane_count; i++) {
const Plane &p = p_planes[i];
Vector3 point(
(p.normal.x > 0) ? -half_extents.x : half_extents.x,
(p.normal.y > 0) ? -half_extents.y : half_extents.y,
(p.normal.z > 0) ? -half_extents.z : half_extents.z);
point += ofs;
if (p.is_point_over(point))
return false;
}
return true;
}
bool AABB::inside_convex_shape(const Plane *p_planes, int p_plane_count) const {
Vector3 half_extents = size * 0.5;
Vector3 ofs = position + half_extents;
for (int i = 0; i < p_plane_count; i++) {
const Plane &p = p_planes[i];
Vector3 point(
(p.normal.x < 0) ? -half_extents.x : half_extents.x,
(p.normal.y < 0) ? -half_extents.y : half_extents.y,
(p.normal.z < 0) ? -half_extents.z : half_extents.z);
point += ofs;
if (p.is_point_over(point))
return false;
}
return true;
}
bool AABB::has_point(const Vector3 &p_point) const {
if (p_point.x < position.x)
return false;
if (p_point.y < position.y)
return false;
if (p_point.z < position.z)
return false;
if (p_point.x > position.x + size.x)
return false;
if (p_point.y > position.y + size.y)
return false;
if (p_point.z > position.z + size.z)
return false;
return true;
}
inline void AABB::expand_to(const Vector3 &p_vector) {
Vector3 begin = position;
Vector3 end = position + size;
if (p_vector.x < begin.x)
begin.x = p_vector.x;
if (p_vector.y < begin.y)
begin.y = p_vector.y;
if (p_vector.z < begin.z)
begin.z = p_vector.z;
if (p_vector.x > end.x)
end.x = p_vector.x;
if (p_vector.y > end.y)
end.y = p_vector.y;
if (p_vector.z > end.z)
end.z = p_vector.z;
position = begin;
size = end - begin;
}
void AABB::project_range_in_plane(const Plane &p_plane, real_t &r_min, real_t &r_max) const {
Vector3 half_extents(size.x * 0.5, size.y * 0.5, size.z * 0.5);
Vector3 center(position.x + half_extents.x, position.y + half_extents.y, position.z + half_extents.z);
real_t length = p_plane.normal.abs().dot(half_extents);
real_t distance = p_plane.distance_to(center);
r_min = distance - length;
r_max = distance + length;
}
inline real_t AABB::get_longest_axis_size() const {
real_t max_size = size.x;
if (size.y > max_size) {
max_size = size.y;
}
if (size.z > max_size) {
max_size = size.z;
}
return max_size;
}
inline real_t AABB::get_shortest_axis_size() const {
real_t max_size = size.x;
if (size.y < max_size) {
max_size = size.y;
}
if (size.z < max_size) {
max_size = size.z;
}
return max_size;
}
bool AABB::smits_intersect_ray(const Vector3 &p_from, const Vector3 &p_dir, real_t t0, real_t t1) const {
real_t divx = 1.0 / p_dir.x;
real_t divy = 1.0 / p_dir.y;
real_t divz = 1.0 / p_dir.z;
Vector3 upbound = position + size;
real_t tmin, tmax, tymin, tymax, tzmin, tzmax;
if (p_dir.x >= 0) {
tmin = (position.x - p_from.x) * divx;
tmax = (upbound.x - p_from.x) * divx;
} else {
tmin = (upbound.x - p_from.x) * divx;
tmax = (position.x - p_from.x) * divx;
}
if (p_dir.y >= 0) {
tymin = (position.y - p_from.y) * divy;
tymax = (upbound.y - p_from.y) * divy;
} else {
tymin = (upbound.y - p_from.y) * divy;
tymax = (position.y - p_from.y) * divy;
}
if ((tmin > tymax) || (tymin > tmax))
return false;
if (tymin > tmin)
tmin = tymin;
if (tymax < tmax)
tmax = tymax;
if (p_dir.z >= 0) {
tzmin = (position.z - p_from.z) * divz;
tzmax = (upbound.z - p_from.z) * divz;
} else {
tzmin = (upbound.z - p_from.z) * divz;
tzmax = (position.z - p_from.z) * divz;
}
if ((tmin > tzmax) || (tzmin > tmax))
return false;
if (tzmin > tmin)
tmin = tzmin;
if (tzmax < tmax)
tmax = tzmax;
return ((tmin < t1) && (tmax > t0));
}
void AABB::grow_by(real_t p_amount) {
position.x -= p_amount;
position.y -= p_amount;
position.z -= p_amount;
size.x += 2.0 * p_amount;
size.y += 2.0 * p_amount;
size.z += 2.0 * p_amount;
}
#endif // AABB_H