mirror of
https://github.com/godotengine/godot.git
synced 2024-11-27 09:16:35 +08:00
392 lines
11 KiB
C++
392 lines
11 KiB
C++
/*************************************************************************/
|
|
/* face3.cpp */
|
|
/*************************************************************************/
|
|
/* 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. */
|
|
/*************************************************************************/
|
|
|
|
#include "face3.h"
|
|
|
|
#include "core/math/geometry_3d.h"
|
|
|
|
int Face3::split_by_plane(const Plane &p_plane, Face3 p_res[3], bool p_is_point_over[3]) const {
|
|
ERR_FAIL_COND_V(is_degenerate(), 0);
|
|
|
|
Vector3 above[4];
|
|
int above_count = 0;
|
|
|
|
Vector3 below[4];
|
|
int below_count = 0;
|
|
|
|
for (int i = 0; i < 3; i++) {
|
|
if (p_plane.has_point(vertex[i], CMP_EPSILON)) { // point is in plane
|
|
|
|
ERR_FAIL_COND_V(above_count >= 4, 0);
|
|
above[above_count++] = vertex[i];
|
|
ERR_FAIL_COND_V(below_count >= 4, 0);
|
|
below[below_count++] = vertex[i];
|
|
|
|
} else {
|
|
if (p_plane.is_point_over(vertex[i])) {
|
|
//Point is over
|
|
ERR_FAIL_COND_V(above_count >= 4, 0);
|
|
above[above_count++] = vertex[i];
|
|
|
|
} else {
|
|
//Point is under
|
|
ERR_FAIL_COND_V(below_count >= 4, 0);
|
|
below[below_count++] = vertex[i];
|
|
}
|
|
|
|
/* Check for Intersection between this and the next vertex*/
|
|
|
|
Vector3 inters;
|
|
if (!p_plane.intersects_segment(vertex[i], vertex[(i + 1) % 3], &inters)) {
|
|
continue;
|
|
}
|
|
|
|
/* Intersection goes to both */
|
|
ERR_FAIL_COND_V(above_count >= 4, 0);
|
|
above[above_count++] = inters;
|
|
ERR_FAIL_COND_V(below_count >= 4, 0);
|
|
below[below_count++] = inters;
|
|
}
|
|
}
|
|
|
|
int polygons_created = 0;
|
|
|
|
ERR_FAIL_COND_V(above_count >= 4 && below_count >= 4, 0); //bug in the algo
|
|
|
|
if (above_count >= 3) {
|
|
p_res[polygons_created] = Face3(above[0], above[1], above[2]);
|
|
p_is_point_over[polygons_created] = true;
|
|
polygons_created++;
|
|
|
|
if (above_count == 4) {
|
|
p_res[polygons_created] = Face3(above[2], above[3], above[0]);
|
|
p_is_point_over[polygons_created] = true;
|
|
polygons_created++;
|
|
}
|
|
}
|
|
|
|
if (below_count >= 3) {
|
|
p_res[polygons_created] = Face3(below[0], below[1], below[2]);
|
|
p_is_point_over[polygons_created] = false;
|
|
polygons_created++;
|
|
|
|
if (below_count == 4) {
|
|
p_res[polygons_created] = Face3(below[2], below[3], below[0]);
|
|
p_is_point_over[polygons_created] = false;
|
|
polygons_created++;
|
|
}
|
|
}
|
|
|
|
return polygons_created;
|
|
}
|
|
|
|
bool Face3::intersects_ray(const Vector3 &p_from, const Vector3 &p_dir, Vector3 *p_intersection) const {
|
|
return Geometry3D::ray_intersects_triangle(p_from, p_dir, vertex[0], vertex[1], vertex[2], p_intersection);
|
|
}
|
|
|
|
bool Face3::intersects_segment(const Vector3 &p_from, const Vector3 &p_dir, Vector3 *p_intersection) const {
|
|
return Geometry3D::segment_intersects_triangle(p_from, p_dir, vertex[0], vertex[1], vertex[2], p_intersection);
|
|
}
|
|
|
|
bool Face3::is_degenerate() const {
|
|
Vector3 normal = vec3_cross(vertex[0] - vertex[1], vertex[0] - vertex[2]);
|
|
return (normal.length_squared() < CMP_EPSILON2);
|
|
}
|
|
|
|
Face3::Side Face3::get_side_of(const Face3 &p_face, ClockDirection p_clock_dir) const {
|
|
int over = 0, under = 0;
|
|
|
|
Plane plane = get_plane(p_clock_dir);
|
|
|
|
for (int i = 0; i < 3; i++) {
|
|
const Vector3 &v = p_face.vertex[i];
|
|
|
|
if (plane.has_point(v)) { //coplanar, don't bother
|
|
continue;
|
|
}
|
|
|
|
if (plane.is_point_over(v)) {
|
|
over++;
|
|
} else {
|
|
under++;
|
|
}
|
|
}
|
|
|
|
if (over > 0 && under == 0) {
|
|
return SIDE_OVER;
|
|
} else if (under > 0 && over == 0) {
|
|
return SIDE_UNDER;
|
|
} else if (under == 0 && over == 0) {
|
|
return SIDE_COPLANAR;
|
|
} else {
|
|
return SIDE_SPANNING;
|
|
}
|
|
}
|
|
|
|
Vector3 Face3::get_random_point_inside() const {
|
|
real_t a = Math::random(0, 1);
|
|
real_t b = Math::random(0, 1);
|
|
if (a > b) {
|
|
SWAP(a, b);
|
|
}
|
|
|
|
return vertex[0] * a + vertex[1] * (b - a) + vertex[2] * (1.0 - b);
|
|
}
|
|
|
|
Plane Face3::get_plane(ClockDirection p_dir) const {
|
|
return Plane(vertex[0], vertex[1], vertex[2], p_dir);
|
|
}
|
|
|
|
Vector3 Face3::get_median_point() const {
|
|
return (vertex[0] + vertex[1] + vertex[2]) / 3.0;
|
|
}
|
|
|
|
real_t Face3::get_area() const {
|
|
return vec3_cross(vertex[0] - vertex[1], vertex[0] - vertex[2]).length();
|
|
}
|
|
|
|
ClockDirection Face3::get_clock_dir() const {
|
|
Vector3 normal = vec3_cross(vertex[0] - vertex[1], vertex[0] - vertex[2]);
|
|
//printf("normal is %g,%g,%g x %g,%g,%g- wtfu is %g\n",tofloat(normal.x),tofloat(normal.y),tofloat(normal.z),tofloat(vertex[0].x),tofloat(vertex[0].y),tofloat(vertex[0].z),tofloat( normal.dot( vertex[0] ) ) );
|
|
return (normal.dot(vertex[0]) >= 0) ? CLOCKWISE : COUNTERCLOCKWISE;
|
|
}
|
|
|
|
bool Face3::intersects_aabb(const AABB &p_aabb) const {
|
|
/** TEST PLANE **/
|
|
if (!p_aabb.intersects_plane(get_plane())) {
|
|
return false;
|
|
}
|
|
|
|
#define TEST_AXIS(m_ax) \
|
|
/** TEST FACE AXIS */ \
|
|
{ \
|
|
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 = vertex[0].m_ax; \
|
|
real_t tri_max = vertex[0].m_ax; \
|
|
for (int i = 1; i < 3; i++) { \
|
|
if (vertex[i].m_ax > tri_max) \
|
|
tri_max = vertex[i].m_ax; \
|
|
if (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);
|
|
|
|
/** TEST ALL EDGES **/
|
|
|
|
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;
|
|
p_aabb.get_edge(i, from, to);
|
|
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();
|
|
|
|
real_t minA, maxA, minB, maxB;
|
|
p_aabb.project_range_in_plane(Plane(axis, 0), minA, maxA);
|
|
project_range(axis, Transform(), minB, maxB);
|
|
|
|
if (maxA < minB || maxB < minA) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
Face3::operator String() const {
|
|
return String() + vertex[0] + ", " + vertex[1] + ", " + vertex[2];
|
|
}
|
|
|
|
void Face3::project_range(const Vector3 &p_normal, const Transform &p_transform, real_t &r_min, real_t &r_max) const {
|
|
for (int i = 0; i < 3; i++) {
|
|
Vector3 v = p_transform.xform(vertex[i]);
|
|
real_t d = p_normal.dot(v);
|
|
|
|
if (i == 0 || d > r_max) {
|
|
r_max = d;
|
|
}
|
|
|
|
if (i == 0 || d < r_min) {
|
|
r_min = d;
|
|
}
|
|
}
|
|
}
|
|
|
|
void Face3::get_support(const Vector3 &p_normal, const Transform &p_transform, Vector3 *p_vertices, int *p_count, int p_max) const {
|
|
#define _FACE_IS_VALID_SUPPORT_THRESHOLD 0.98
|
|
#define _EDGE_IS_VALID_SUPPORT_THRESHOLD 0.05
|
|
|
|
if (p_max <= 0) {
|
|
return;
|
|
}
|
|
|
|
Vector3 n = p_transform.basis.xform_inv(p_normal);
|
|
|
|
/** TEST FACE AS SUPPORT **/
|
|
if (get_plane().normal.dot(n) > _FACE_IS_VALID_SUPPORT_THRESHOLD) {
|
|
*p_count = MIN(3, p_max);
|
|
|
|
for (int i = 0; i < *p_count; i++) {
|
|
p_vertices[i] = p_transform.xform(vertex[i]);
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
/** FIND SUPPORT VERTEX **/
|
|
|
|
int vert_support_idx = -1;
|
|
real_t support_max = 0;
|
|
|
|
for (int i = 0; i < 3; i++) {
|
|
real_t d = n.dot(vertex[i]);
|
|
|
|
if (i == 0 || d > support_max) {
|
|
support_max = d;
|
|
vert_support_idx = i;
|
|
}
|
|
}
|
|
|
|
/** TEST EDGES AS SUPPORT **/
|
|
|
|
for (int i = 0; i < 3; i++) {
|
|
if (i != vert_support_idx && i + 1 != vert_support_idx) {
|
|
continue;
|
|
}
|
|
|
|
// check if edge is valid as a support
|
|
real_t dot = (vertex[i] - vertex[(i + 1) % 3]).normalized().dot(n);
|
|
dot = ABS(dot);
|
|
if (dot < _EDGE_IS_VALID_SUPPORT_THRESHOLD) {
|
|
*p_count = MIN(2, p_max);
|
|
|
|
for (int j = 0; j < *p_count; j++) {
|
|
p_vertices[j] = p_transform.xform(vertex[(j + i) % 3]);
|
|
}
|
|
|
|
return;
|
|
}
|
|
}
|
|
|
|
*p_count = 1;
|
|
p_vertices[0] = p_transform.xform(vertex[vert_support_idx]);
|
|
}
|
|
|
|
Vector3 Face3::get_closest_point_to(const Vector3 &p_point) const {
|
|
Vector3 edge0 = vertex[1] - vertex[0];
|
|
Vector3 edge1 = vertex[2] - vertex[0];
|
|
Vector3 v0 = vertex[0] - p_point;
|
|
|
|
real_t a = edge0.dot(edge0);
|
|
real_t b = edge0.dot(edge1);
|
|
real_t c = edge1.dot(edge1);
|
|
real_t d = edge0.dot(v0);
|
|
real_t e = edge1.dot(v0);
|
|
|
|
real_t det = a * c - b * b;
|
|
real_t s = b * e - c * d;
|
|
real_t t = b * d - a * e;
|
|
|
|
if (s + t < det) {
|
|
if (s < 0.f) {
|
|
if (t < 0.f) {
|
|
if (d < 0.f) {
|
|
s = CLAMP(-d / a, 0.f, 1.f);
|
|
t = 0.f;
|
|
} else {
|
|
s = 0.f;
|
|
t = CLAMP(-e / c, 0.f, 1.f);
|
|
}
|
|
} else {
|
|
s = 0.f;
|
|
t = CLAMP(-e / c, 0.f, 1.f);
|
|
}
|
|
} else if (t < 0.f) {
|
|
s = CLAMP(-d / a, 0.f, 1.f);
|
|
t = 0.f;
|
|
} else {
|
|
real_t invDet = 1.f / det;
|
|
s *= invDet;
|
|
t *= invDet;
|
|
}
|
|
} else {
|
|
if (s < 0.f) {
|
|
real_t tmp0 = b + d;
|
|
real_t tmp1 = c + e;
|
|
if (tmp1 > tmp0) {
|
|
real_t numer = tmp1 - tmp0;
|
|
real_t denom = a - 2 * b + c;
|
|
s = CLAMP(numer / denom, 0.f, 1.f);
|
|
t = 1 - s;
|
|
} else {
|
|
t = CLAMP(-e / c, 0.f, 1.f);
|
|
s = 0.f;
|
|
}
|
|
} else if (t < 0.f) {
|
|
if (a + d > b + e) {
|
|
real_t numer = c + e - b - d;
|
|
real_t denom = a - 2 * b + c;
|
|
s = CLAMP(numer / denom, 0.f, 1.f);
|
|
t = 1 - s;
|
|
} else {
|
|
s = CLAMP(-d / a, 0.f, 1.f);
|
|
t = 0.f;
|
|
}
|
|
} else {
|
|
real_t numer = c + e - b - d;
|
|
real_t denom = a - 2 * b + c;
|
|
s = CLAMP(numer / denom, 0.f, 1.f);
|
|
t = 1.f - s;
|
|
}
|
|
}
|
|
|
|
return vertex[0] + s * edge0 + t * edge1;
|
|
}
|