virtualx-engine/core/math/face3.h
lawnjelly b411a731fe Add nodiscard to core math classes to catch c++ errors.
A common source of errors is to call functions (such as round()) expecting them to work in place, but them actually being designed only to return the processed value. Not using the return value in this case in indicative of a bug, and can be flagged as a warning by using the [[nodiscard]] attribute.
2022-01-20 13:07:49 +00:00

250 lines
9.5 KiB
C++

/*************************************************************************/
/* face3.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2022 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 FACE3_H
#define FACE3_H
#include "core/math/aabb.h"
#include "core/math/plane.h"
#include "core/math/transform_3d.h"
#include "core/math/vector3.h"
class _NO_DISCARD_ Face3 {
public:
enum Side {
SIDE_OVER,
SIDE_UNDER,
SIDE_SPANNING,
SIDE_COPLANAR
};
Vector3 vertex[3];
/**
*
* @param p_plane plane used to split the face
* @param p_res array of at least 3 faces, amount used in function return
* @param p_is_point_over array of at least 3 booleans, determining which face is over the plane, amount used in function return
* @param _epsilon constant used for numerical error rounding, to add "thickness" to the plane (so coplanar points can happen)
* @return amount of faces generated by the split, either 0 (means no split possible), 2 or 3
*/
int split_by_plane(const Plane &p_plane, Face3 *p_res, bool *p_is_point_over) const;
Plane get_plane(ClockDirection p_dir = CLOCKWISE) const;
Vector3 get_random_point_inside() const;
Side get_side_of(const Face3 &p_face, ClockDirection p_clock_dir = CLOCKWISE) const;
bool is_degenerate() const;
real_t get_area() const;
Vector3 get_median_point() const;
Vector3 get_closest_point_to(const Vector3 &p_point) const;
bool intersects_ray(const Vector3 &p_from, const Vector3 &p_dir, Vector3 *p_intersection = nullptr) const;
bool intersects_segment(const Vector3 &p_from, const Vector3 &p_dir, Vector3 *p_intersection = nullptr) const;
ClockDirection get_clock_dir() const; ///< todo, test if this is returning the proper clockwisity
void get_support(const Vector3 &p_normal, const Transform3D &p_transform, Vector3 *p_vertices, int *p_count, int p_max) const;
void project_range(const Vector3 &p_normal, const Transform3D &p_transform, real_t &r_min, real_t &r_max) const;
AABB get_aabb() const {
AABB aabb(vertex[0], Vector3());
aabb.expand_to(vertex[1]);
aabb.expand_to(vertex[2]);
return aabb;
}
bool intersects_aabb(const AABB &p_aabb) const;
_FORCE_INLINE_ bool intersects_aabb2(const AABB &p_aabb) const;
operator String() const;
inline Face3() {}
inline Face3(const Vector3 &p_v1, const Vector3 &p_v2, const Vector3 &p_v3) {
vertex[0] = p_v1;
vertex[1] = p_v2;
vertex[2] = p_v3;
}
};
bool Face3::intersects_aabb2(const AABB &p_aabb) const {
Vector3 perp = (vertex[0] - vertex[2]).cross(vertex[0] - vertex[1]);
Vector3 half_extents = p_aabb.size * 0.5;
Vector3 ofs = p_aabb.position + half_extents;
Vector3 sup = Vector3(
(perp.x > 0) ? -half_extents.x : half_extents.x,
(perp.y > 0) ? -half_extents.y : half_extents.y,
(perp.z > 0) ? -half_extents.z : half_extents.z);
real_t d = perp.dot(vertex[0]);
real_t dist_a = perp.dot(ofs + sup) - d;
real_t dist_b = perp.dot(ofs - sup) - d;
if (dist_a * dist_b > 0) {
return false; //does not intersect the plane
}
#define TEST_AXIS(m_ax) \
{ \
real_t aabb_min = p_aabb.position.m_ax; \
real_t aabb_max = p_aabb.position.m_ax + p_aabb.size.m_ax; \
real_t tri_min, tri_max; \
for (int i = 0; i < 3; i++) { \
if (i == 0 || vertex[i].m_ax > tri_max) \
tri_max = vertex[i].m_ax; \
if (i == 0 || vertex[i].m_ax < tri_min) \
tri_min = vertex[i].m_ax; \
} \
\
if (tri_max < aabb_min || aabb_max < tri_min) \
return false; \
}
TEST_AXIS(x);
TEST_AXIS(y);
TEST_AXIS(z);
#undef TEST_AXIS
Vector3 edge_norms[3] = {
vertex[0] - vertex[1],
vertex[1] - vertex[2],
vertex[2] - vertex[0],
};
for (int i = 0; i < 12; i++) {
Vector3 from, to;
switch (i) {
case 0: {
from = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y, p_aabb.position.z);
to = Vector3(p_aabb.position.x, p_aabb.position.y, p_aabb.position.z);
} break;
case 1: {
from = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y, p_aabb.position.z + p_aabb.size.z);
to = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y, p_aabb.position.z);
} break;
case 2: {
from = Vector3(p_aabb.position.x, p_aabb.position.y, p_aabb.position.z + p_aabb.size.z);
to = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y, p_aabb.position.z + p_aabb.size.z);
} break;
case 3: {
from = Vector3(p_aabb.position.x, p_aabb.position.y, p_aabb.position.z);
to = Vector3(p_aabb.position.x, p_aabb.position.y, p_aabb.position.z + p_aabb.size.z);
} break;
case 4: {
from = Vector3(p_aabb.position.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z);
to = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z);
} break;
case 5: {
from = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z);
to = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z + p_aabb.size.z);
} break;
case 6: {
from = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z + p_aabb.size.z);
to = Vector3(p_aabb.position.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z + p_aabb.size.z);
} break;
case 7: {
from = Vector3(p_aabb.position.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z + p_aabb.size.z);
to = Vector3(p_aabb.position.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z);
} break;
case 8: {
from = Vector3(p_aabb.position.x, p_aabb.position.y, p_aabb.position.z + p_aabb.size.z);
to = Vector3(p_aabb.position.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z + p_aabb.size.z);
} break;
case 9: {
from = Vector3(p_aabb.position.x, p_aabb.position.y, p_aabb.position.z);
to = Vector3(p_aabb.position.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z);
} break;
case 10: {
from = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y, p_aabb.position.z);
to = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z);
} break;
case 11: {
from = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y, p_aabb.position.z + p_aabb.size.z);
to = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z + p_aabb.size.z);
} break;
}
Vector3 e1 = from - to;
for (int j = 0; j < 3; j++) {
Vector3 e2 = edge_norms[j];
Vector3 axis = vec3_cross(e1, e2);
if (axis.length_squared() < 0.0001) {
continue; // coplanar
}
//axis.normalize();
Vector3 sup2 = Vector3(
(axis.x > 0) ? -half_extents.x : half_extents.x,
(axis.y > 0) ? -half_extents.y : half_extents.y,
(axis.z > 0) ? -half_extents.z : half_extents.z);
real_t maxB = axis.dot(ofs + sup2);
real_t minB = axis.dot(ofs - sup2);
if (minB > maxB) {
SWAP(maxB, minB);
}
real_t minT = 1e20, maxT = -1e20;
for (int k = 0; k < 3; k++) {
real_t vert_d = axis.dot(vertex[k]);
if (vert_d > maxT) {
maxT = vert_d;
}
if (vert_d < minT) {
minT = vert_d;
}
}
if (maxB < minT || maxT < minB) {
return false;
}
}
}
return true;
}
#endif // FACE3_H