godot/core/math/aabb.cpp
2021-05-05 15:02:01 +02:00

376 lines
10 KiB
C++

/*************************************************************************/
/* aabb.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2021 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. */
/*************************************************************************/
#include "aabb.h"
#include "core/print_string.h"
real_t AABB::get_area() const {
return size.x * size.y * size.z;
}
bool AABB::operator==(const AABB &p_rval) const {
return ((position == p_rval.position) && (size == p_rval.size));
}
bool AABB::operator!=(const AABB &p_rval) const {
return ((position != p_rval.position) || (size != p_rval.size));
}
void AABB::merge_with(const AABB &p_aabb) {
Vector3 beg_1, beg_2;
Vector3 end_1, end_2;
Vector3 min, max;
beg_1 = position;
beg_2 = p_aabb.position;
end_1 = Vector3(size.x, size.y, size.z) + beg_1;
end_2 = Vector3(p_aabb.size.x, p_aabb.size.y, p_aabb.size.z) + beg_2;
min.x = (beg_1.x < beg_2.x) ? beg_1.x : beg_2.x;
min.y = (beg_1.y < beg_2.y) ? beg_1.y : beg_2.y;
min.z = (beg_1.z < beg_2.z) ? beg_1.z : beg_2.z;
max.x = (end_1.x > end_2.x) ? end_1.x : end_2.x;
max.y = (end_1.y > end_2.y) ? end_1.y : end_2.y;
max.z = (end_1.z > end_2.z) ? end_1.z : end_2.z;
position = min;
size = max - min;
}
bool AABB::is_equal_approx(const AABB &p_aabb) const {
return position.is_equal_approx(p_aabb.position) && size.is_equal_approx(p_aabb.size);
}
AABB AABB::intersection(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;
Vector3 min, max;
if (src_min.x > dst_max.x || src_max.x < dst_min.x) {
return AABB();
} else {
min.x = (src_min.x > dst_min.x) ? src_min.x : dst_min.x;
max.x = (src_max.x < dst_max.x) ? src_max.x : dst_max.x;
}
if (src_min.y > dst_max.y || src_max.y < dst_min.y) {
return AABB();
} else {
min.y = (src_min.y > dst_min.y) ? src_min.y : dst_min.y;
max.y = (src_max.y < dst_max.y) ? src_max.y : dst_max.y;
}
if (src_min.z > dst_max.z || src_max.z < dst_min.z) {
return AABB();
} else {
min.z = (src_min.z > dst_min.z) ? src_min.z : dst_min.z;
max.z = (src_max.z < dst_max.z) ? src_max.z : dst_max.z;
}
return AABB(min, max - min);
}
bool AABB::intersects_ray(const Vector3 &p_from, const Vector3 &p_dir, Vector3 *r_clip, Vector3 *r_normal) const {
Vector3 c1, c2;
Vector3 end = position + size;
real_t near = -1e20;
real_t far = 1e20;
int axis = 0;
for (int i = 0; i < 3; i++) {
if (p_dir[i] == 0) {
if ((p_from[i] < position[i]) || (p_from[i] > end[i])) {
return false;
}
} else { // ray not parallel to planes in this direction
c1[i] = (position[i] - p_from[i]) / p_dir[i];
c2[i] = (end[i] - p_from[i]) / p_dir[i];
if (c1[i] > c2[i]) {
SWAP(c1, c2);
}
if (c1[i] > near) {
near = c1[i];
axis = i;
}
if (c2[i] < far) {
far = c2[i];
}
if ((near > far) || (far < 0)) {
return false;
}
}
}
if (r_clip) {
*r_clip = c1;
}
if (r_normal) {
*r_normal = Vector3();
(*r_normal)[axis] = p_dir[axis] ? -1 : 1;
}
return true;
}
bool AABB::intersects_segment(const Vector3 &p_from, const Vector3 &p_to, Vector3 *r_clip, Vector3 *r_normal) const {
real_t min = 0, max = 1;
int axis = 0;
real_t sign = 0;
for (int i = 0; i < 3; i++) {
real_t seg_from = p_from[i];
real_t seg_to = p_to[i];
real_t box_begin = position[i];
real_t box_end = box_begin + size[i];
real_t cmin, cmax;
real_t csign;
if (seg_from < seg_to) {
if (seg_from > box_end || seg_to < box_begin) {
return false;
}
real_t length = seg_to - seg_from;
cmin = (seg_from < box_begin) ? ((box_begin - seg_from) / length) : 0;
cmax = (seg_to > box_end) ? ((box_end - seg_from) / length) : 1;
csign = -1.0;
} else {
if (seg_to > box_end || seg_from < box_begin) {
return false;
}
real_t length = seg_to - seg_from;
cmin = (seg_from > box_end) ? (box_end - seg_from) / length : 0;
cmax = (seg_to < box_begin) ? (box_begin - seg_from) / length : 1;
csign = 1.0;
}
if (cmin > min) {
min = cmin;
axis = i;
sign = csign;
}
if (cmax < max) {
max = cmax;
}
if (max < min) {
return false;
}
}
Vector3 rel = p_to - p_from;
if (r_normal) {
Vector3 normal;
normal[axis] = sign;
*r_normal = normal;
}
if (r_clip) {
*r_clip = p_from + rel * min;
}
return true;
}
bool AABB::intersects_plane(const Plane &p_plane) const {
Vector3 points[8] = {
Vector3(position.x, position.y, position.z),
Vector3(position.x, position.y, position.z + size.z),
Vector3(position.x, position.y + size.y, position.z),
Vector3(position.x, position.y + size.y, position.z + size.z),
Vector3(position.x + size.x, position.y, position.z),
Vector3(position.x + size.x, position.y, position.z + size.z),
Vector3(position.x + size.x, position.y + size.y, position.z),
Vector3(position.x + size.x, position.y + size.y, position.z + size.z),
};
bool over = false;
bool under = false;
for (int i = 0; i < 8; i++) {
if (p_plane.distance_to(points[i]) > 0) {
over = true;
} else {
under = true;
}
}
return under && over;
}
Vector3 AABB::get_longest_axis() const {
Vector3 axis(1, 0, 0);
real_t max_size = size.x;
if (size.y > max_size) {
axis = Vector3(0, 1, 0);
max_size = size.y;
}
if (size.z > max_size) {
axis = Vector3(0, 0, 1);
}
return axis;
}
int AABB::get_longest_axis_index() const {
int axis = 0;
real_t max_size = size.x;
if (size.y > max_size) {
axis = 1;
max_size = size.y;
}
if (size.z > max_size) {
axis = 2;
}
return axis;
}
Vector3 AABB::get_shortest_axis() const {
Vector3 axis(1, 0, 0);
real_t max_size = size.x;
if (size.y < max_size) {
axis = Vector3(0, 1, 0);
max_size = size.y;
}
if (size.z < max_size) {
axis = Vector3(0, 0, 1);
}
return axis;
}
int AABB::get_shortest_axis_index() const {
int axis = 0;
real_t max_size = size.x;
if (size.y < max_size) {
axis = 1;
max_size = size.y;
}
if (size.z < max_size) {
axis = 2;
}
return axis;
}
AABB AABB::merge(const AABB &p_with) const {
AABB aabb = *this;
aabb.merge_with(p_with);
return aabb;
}
AABB AABB::expand(const Vector3 &p_vector) const {
AABB aabb = *this;
aabb.expand_to(p_vector);
return aabb;
}
AABB AABB::grow(real_t p_by) const {
AABB aabb = *this;
aabb.grow_by(p_by);
return aabb;
}
void AABB::get_edge(int p_edge, Vector3 &r_from, Vector3 &r_to) const {
ERR_FAIL_INDEX(p_edge, 12);
switch (p_edge) {
case 0: {
r_from = Vector3(position.x + size.x, position.y, position.z);
r_to = Vector3(position.x, position.y, position.z);
} break;
case 1: {
r_from = Vector3(position.x + size.x, position.y, position.z + size.z);
r_to = Vector3(position.x + size.x, position.y, position.z);
} break;
case 2: {
r_from = Vector3(position.x, position.y, position.z + size.z);
r_to = Vector3(position.x + size.x, position.y, position.z + size.z);
} break;
case 3: {
r_from = Vector3(position.x, position.y, position.z);
r_to = Vector3(position.x, position.y, position.z + size.z);
} break;
case 4: {
r_from = Vector3(position.x, position.y + size.y, position.z);
r_to = Vector3(position.x + size.x, position.y + size.y, position.z);
} break;
case 5: {
r_from = Vector3(position.x + size.x, position.y + size.y, position.z);
r_to = Vector3(position.x + size.x, position.y + size.y, position.z + size.z);
} break;
case 6: {
r_from = Vector3(position.x + size.x, position.y + size.y, position.z + size.z);
r_to = Vector3(position.x, position.y + size.y, position.z + size.z);
} break;
case 7: {
r_from = Vector3(position.x, position.y + size.y, position.z + size.z);
r_to = Vector3(position.x, position.y + size.y, position.z);
} break;
case 8: {
r_from = Vector3(position.x, position.y, position.z + size.z);
r_to = Vector3(position.x, position.y + size.y, position.z + size.z);
} break;
case 9: {
r_from = Vector3(position.x, position.y, position.z);
r_to = Vector3(position.x, position.y + size.y, position.z);
} break;
case 10: {
r_from = Vector3(position.x + size.x, position.y, position.z);
r_to = Vector3(position.x + size.x, position.y + size.y, position.z);
} break;
case 11: {
r_from = Vector3(position.x + size.x, position.y, position.z + size.z);
r_to = Vector3(position.x + size.x, position.y + size.y, position.z + size.z);
} break;
}
}
AABB::operator String() const {
return String() + position + " - " + size;
}