1/**************************************************************************/
2/* face3.h */
3/**************************************************************************/
4/* This file is part of: */
5/* GODOT ENGINE */
6/* https://godotengine.org */
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8/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
9/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
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21/* */
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29/**************************************************************************/
30
31#ifndef FACE3_H
32#define FACE3_H
33
34#include "core/math/aabb.h"
35#include "core/math/plane.h"
36#include "core/math/transform_3d.h"
37#include "core/math/vector3.h"
38
39struct _NO_DISCARD_ Face3 {
40 enum Side {
41 SIDE_OVER,
42 SIDE_UNDER,
43 SIDE_SPANNING,
44 SIDE_COPLANAR
45 };
46
47 Vector3 vertex[3];
48
49 /**
50 * @param p_plane plane used to split the face
51 * @param p_res array of at least 3 faces, amount used in function return
52 * @param p_is_point_over array of at least 3 booleans, determining which face is over the plane, amount used in function return
53 * @return amount of faces generated by the split, either 0 (means no split possible), 2 or 3
54 */
55 int split_by_plane(const Plane &p_plane, Face3 *p_res, bool *p_is_point_over) const;
56
57 Plane get_plane(ClockDirection p_dir = CLOCKWISE) const;
58 Vector3 get_random_point_inside() const;
59
60 bool is_degenerate() const;
61 real_t get_area() const;
62
63 Vector3 get_closest_point_to(const Vector3 &p_point) const;
64
65 bool intersects_ray(const Vector3 &p_from, const Vector3 &p_dir, Vector3 *p_intersection = nullptr) const;
66 bool intersects_segment(const Vector3 &p_from, const Vector3 &p_dir, Vector3 *p_intersection = nullptr) const;
67
68 void get_support(const Vector3 &p_normal, const Transform3D &p_transform, Vector3 *p_vertices, int *p_count, int p_max) const;
69 void project_range(const Vector3 &p_normal, const Transform3D &p_transform, real_t &r_min, real_t &r_max) const;
70
71 AABB get_aabb() const {
72 AABB aabb(vertex[0], Vector3());
73 aabb.expand_to(vertex[1]);
74 aabb.expand_to(vertex[2]);
75 return aabb;
76 }
77
78 bool intersects_aabb(const AABB &p_aabb) const;
79 _FORCE_INLINE_ bool intersects_aabb2(const AABB &p_aabb) const;
80 operator String() const;
81
82 inline Face3() {}
83 inline Face3(const Vector3 &p_v1, const Vector3 &p_v2, const Vector3 &p_v3) {
84 vertex[0] = p_v1;
85 vertex[1] = p_v2;
86 vertex[2] = p_v3;
87 }
88};
89
90bool Face3::intersects_aabb2(const AABB &p_aabb) const {
91 Vector3 perp = (vertex[0] - vertex[2]).cross(vertex[0] - vertex[1]);
92
93 Vector3 half_extents = p_aabb.size * 0.5f;
94 Vector3 ofs = p_aabb.position + half_extents;
95
96 Vector3 sup = Vector3(
97 (perp.x > 0) ? -half_extents.x : half_extents.x,
98 (perp.y > 0) ? -half_extents.y : half_extents.y,
99 (perp.z > 0) ? -half_extents.z : half_extents.z);
100
101 real_t d = perp.dot(vertex[0]);
102 real_t dist_a = perp.dot(ofs + sup) - d;
103 real_t dist_b = perp.dot(ofs - sup) - d;
104
105 if (dist_a * dist_b > 0) {
106 return false; //does not intersect the plane
107 }
108
109#define TEST_AXIS(m_ax) \
110 { \
111 real_t aabb_min = p_aabb.position.m_ax; \
112 real_t aabb_max = p_aabb.position.m_ax + p_aabb.size.m_ax; \
113 real_t tri_min, tri_max; \
114 for (int i = 0; i < 3; i++) { \
115 if (i == 0 || vertex[i].m_ax > tri_max) \
116 tri_max = vertex[i].m_ax; \
117 if (i == 0 || vertex[i].m_ax < tri_min) \
118 tri_min = vertex[i].m_ax; \
119 } \
120 \
121 if (tri_max < aabb_min || aabb_max < tri_min) \
122 return false; \
123 }
124
125 TEST_AXIS(x);
126 TEST_AXIS(y);
127 TEST_AXIS(z);
128
129#undef TEST_AXIS
130
131 const Vector3 edge_norms[3] = {
132 vertex[0] - vertex[1],
133 vertex[1] - vertex[2],
134 vertex[2] - vertex[0],
135 };
136
137 for (int i = 0; i < 12; i++) {
138 Vector3 from, to;
139 switch (i) {
140 case 0: {
141 from = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y, p_aabb.position.z);
142 to = Vector3(p_aabb.position.x, p_aabb.position.y, p_aabb.position.z);
143 } break;
144 case 1: {
145 from = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y, p_aabb.position.z + p_aabb.size.z);
146 to = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y, p_aabb.position.z);
147 } break;
148 case 2: {
149 from = Vector3(p_aabb.position.x, p_aabb.position.y, p_aabb.position.z + p_aabb.size.z);
150 to = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y, p_aabb.position.z + p_aabb.size.z);
151
152 } break;
153 case 3: {
154 from = Vector3(p_aabb.position.x, p_aabb.position.y, p_aabb.position.z);
155 to = Vector3(p_aabb.position.x, p_aabb.position.y, p_aabb.position.z + p_aabb.size.z);
156
157 } break;
158 case 4: {
159 from = Vector3(p_aabb.position.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z);
160 to = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z);
161 } break;
162 case 5: {
163 from = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z);
164 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);
165 } break;
166 case 6: {
167 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);
168 to = Vector3(p_aabb.position.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z + p_aabb.size.z);
169
170 } break;
171 case 7: {
172 from = Vector3(p_aabb.position.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z + p_aabb.size.z);
173 to = Vector3(p_aabb.position.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z);
174
175 } break;
176 case 8: {
177 from = Vector3(p_aabb.position.x, p_aabb.position.y, p_aabb.position.z + p_aabb.size.z);
178 to = Vector3(p_aabb.position.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z + p_aabb.size.z);
179
180 } break;
181 case 9: {
182 from = Vector3(p_aabb.position.x, p_aabb.position.y, p_aabb.position.z);
183 to = Vector3(p_aabb.position.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z);
184
185 } break;
186 case 10: {
187 from = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y, p_aabb.position.z);
188 to = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y + p_aabb.size.y, p_aabb.position.z);
189
190 } break;
191 case 11: {
192 from = Vector3(p_aabb.position.x + p_aabb.size.x, p_aabb.position.y, p_aabb.position.z + p_aabb.size.z);
193 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);
194
195 } break;
196 }
197
198 Vector3 e1 = from - to;
199 for (int j = 0; j < 3; j++) {
200 Vector3 e2 = edge_norms[j];
201
202 Vector3 axis = vec3_cross(e1, e2);
203
204 if (axis.length_squared() < 0.0001f) {
205 continue; // coplanar
206 }
207 //axis.normalize();
208
209 Vector3 sup2 = Vector3(
210 (axis.x > 0) ? -half_extents.x : half_extents.x,
211 (axis.y > 0) ? -half_extents.y : half_extents.y,
212 (axis.z > 0) ? -half_extents.z : half_extents.z);
213
214 real_t maxB = axis.dot(ofs + sup2);
215 real_t minB = axis.dot(ofs - sup2);
216 if (minB > maxB) {
217 SWAP(maxB, minB);
218 }
219
220 real_t minT = 1e20, maxT = -1e20;
221 for (int k = 0; k < 3; k++) {
222 real_t vert_d = axis.dot(vertex[k]);
223
224 if (vert_d > maxT) {
225 maxT = vert_d;
226 }
227
228 if (vert_d < minT) {
229 minT = vert_d;
230 }
231 }
232
233 if (maxB < minT || maxT < minB) {
234 return false;
235 }
236 }
237 }
238 return true;
239}
240
241#endif // FACE3_H
242