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godot/modules/csg/csg.cpp

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/*************************************************************************/
/* csg.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 "csg.h"
#include "core/math/geometry.h"
#include "core/math/math_funcs.h"
#include "core/sort_array.h"
// Static helper functions.
inline static bool is_snapable(const Vector3 &p_point1, const Vector3 &p_point2, real_t p_distance) {
return (p_point1 - p_point2).length_squared() < p_distance * p_distance;
}
inline static Vector2 interpolate_segment_uv(const Vector2 p_segement_points[2], const Vector2 p_uvs[2], const Vector2 &p_interpolation_point) {
float segment_length = (p_segement_points[1] - p_segement_points[0]).length();
if (segment_length < CMP_EPSILON) {
return p_uvs[0];
}
float distance = (p_interpolation_point - p_segement_points[0]).length();
float fraction = distance / segment_length;
return p_uvs[0].linear_interpolate(p_uvs[1], fraction);
}
inline static Vector2 interpolate_triangle_uv(const Vector2 p_vertices[3], const Vector2 p_uvs[3], const Vector2 &p_interpolation_point) {
if (p_interpolation_point.distance_squared_to(p_vertices[0]) < CMP_EPSILON2) {
return p_uvs[0];
}
if (p_interpolation_point.distance_squared_to(p_vertices[1]) < CMP_EPSILON2) {
return p_uvs[1];
}
if (p_interpolation_point.distance_squared_to(p_vertices[2]) < CMP_EPSILON2) {
return p_uvs[2];
}
Vector2 edge1 = p_vertices[1] - p_vertices[0];
Vector2 edge2 = p_vertices[2] - p_vertices[0];
Vector2 interpolation = p_interpolation_point - p_vertices[0];
float edge1_on_edge1 = edge1.dot(edge1);
float edge1_on_edge2 = edge1.dot(edge2);
float edge2_on_edge2 = edge2.dot(edge2);
float inter_on_edge1 = interpolation.dot(edge1);
float inter_on_edge2 = interpolation.dot(edge2);
float scale = (edge1_on_edge1 * edge2_on_edge2 - edge1_on_edge2 * edge1_on_edge2);
if (scale == 0) {
return p_uvs[0];
}
float v = (edge2_on_edge2 * inter_on_edge1 - edge1_on_edge2 * inter_on_edge2) / scale;
float w = (edge1_on_edge1 * inter_on_edge2 - edge1_on_edge2 * inter_on_edge1) / scale;
float u = 1.0f - v - w;
return p_uvs[0] * u + p_uvs[1] * v + p_uvs[2] * w;
}
static inline bool ray_intersects_triangle(const Vector3 &p_from, const Vector3 &p_dir, const Vector3 p_vertices[3], float p_tolerance, Vector3 &r_intersection_point) {
Vector3 edge1 = p_vertices[1] - p_vertices[0];
Vector3 edge2 = p_vertices[2] - p_vertices[0];
Vector3 h = p_dir.cross(edge2);
real_t a = edge1.dot(h);
// Check if ray is parallel to triangle.
if (Math::is_zero_approx(a)) {
return false;
}
real_t f = 1.0 / a;
Vector3 s = p_from - p_vertices[0];
real_t u = f * s.dot(h);
if (u < 0.0 - p_tolerance || u > 1.0 + p_tolerance) {
return false;
}
Vector3 q = s.cross(edge1);
real_t v = f * p_dir.dot(q);
if (v < 0.0 - p_tolerance || u + v > 1.0 + p_tolerance) {
return false;
}
// Ray intersects triangle.
// Calculate distance.
real_t t = f * edge2.dot(q);
// Confirm triangle is in front of ray.
if (t >= p_tolerance) {
r_intersection_point = p_from + p_dir * t;
return true;
} else {
return false;
}
}
inline bool is_point_in_triangle(const Vector3 &p_point, const Vector3 p_vertices[3], int p_shifted = 0) {
real_t det = p_vertices[0].dot(p_vertices[1].cross(p_vertices[2]));
// If determinant is, zero try shift the triangle and the point.
if (Math::is_zero_approx(det)) {
if (p_shifted > 2) {
// Triangle appears degenerate, so ignore it.
return false;
}
Vector3 shift_by;
shift_by[p_shifted] = 1;
Vector3 shifted_point = p_point + shift_by;
Vector3 shifted_vertices[3] = { p_vertices[0] + shift_by, p_vertices[1] + shift_by, p_vertices[2] + shift_by };
return is_point_in_triangle(shifted_point, shifted_vertices, p_shifted + 1);
}
// Find the barycentric coordinates of the point with respect to the vertices.
real_t lambda[3];
lambda[0] = p_vertices[1].cross(p_vertices[2]).dot(p_point) / det;
lambda[1] = p_vertices[2].cross(p_vertices[0]).dot(p_point) / det;
lambda[2] = p_vertices[0].cross(p_vertices[1]).dot(p_point) / det;
// Point is in the plane if all lambdas sum to 1.
if (!Math::is_equal_approx(lambda[0] + lambda[1] + lambda[2], 1)) {
return false;
}
// Point is inside the triangle if all lambdas are positive.
if (lambda[0] < 0 || lambda[1] < 0 || lambda[2] < 0) {
return false;
}
return true;
}
inline static bool is_triangle_degenerate(const Vector2 p_vertices[3], real_t p_vertex_snap2) {
real_t det = p_vertices[0].x * p_vertices[1].y - p_vertices[0].x * p_vertices[2].y +
p_vertices[0].y * p_vertices[2].x - p_vertices[0].y * p_vertices[1].x +
p_vertices[1].x * p_vertices[2].y - p_vertices[1].y * p_vertices[2].x;
return det < p_vertex_snap2;
}
inline static bool are_segements_parallel(const Vector2 p_segment1_points[2], const Vector2 p_segment2_points[2], float p_vertex_snap2) {
Vector2 segment1 = p_segment1_points[1] - p_segment1_points[0];
Vector2 segment2 = p_segment2_points[1] - p_segment2_points[0];
real_t segment1_length2 = segment1.dot(segment1);
real_t segment2_length2 = segment2.dot(segment2);
real_t segment_onto_segment = segment2.dot(segment1);
if (segment1_length2 < p_vertex_snap2 || segment2_length2 < p_vertex_snap2) {
return true;
}
real_t max_separation2;
if (segment1_length2 > segment2_length2) {
max_separation2 = segment2_length2 - segment_onto_segment * segment_onto_segment / segment1_length2;
} else {
max_separation2 = segment1_length2 - segment_onto_segment * segment_onto_segment / segment2_length2;
}
return max_separation2 < p_vertex_snap2;
}
// CSGBrush
void CSGBrush::_regen_face_aabbs() {
for (int i = 0; i < faces.size(); i++) {
faces.write[i].aabb = AABB();
faces.write[i].aabb.position = faces[i].vertices[0];
faces.write[i].aabb.expand_to(faces[i].vertices[1]);
faces.write[i].aabb.expand_to(faces[i].vertices[2]);
}
}
void CSGBrush::build_from_faces(const PoolVector<Vector3> &p_vertices, const PoolVector<Vector2> &p_uvs, const PoolVector<bool> &p_smooth, const PoolVector<Ref<Material>> &p_materials, const PoolVector<bool> &p_invert_faces) {
faces.clear();
int vc = p_vertices.size();
ERR_FAIL_COND((vc % 3) != 0);
PoolVector<Vector3>::Read rv = p_vertices.read();
int uvc = p_uvs.size();
PoolVector<Vector2>::Read ruv = p_uvs.read();
int sc = p_smooth.size();
PoolVector<bool>::Read rs = p_smooth.read();
int mc = p_materials.size();
PoolVector<Ref<Material>>::Read rm = p_materials.read();
int ic = p_invert_faces.size();
PoolVector<bool>::Read ri = p_invert_faces.read();
Map<Ref<Material>, int> material_map;
faces.resize(p_vertices.size() / 3);
for (int i = 0; i < faces.size(); i++) {
Face &f = faces.write[i];
f.vertices[0] = rv[i * 3 + 0];
f.vertices[1] = rv[i * 3 + 1];
f.vertices[2] = rv[i * 3 + 2];
if (uvc == vc) {
f.uvs[0] = ruv[i * 3 + 0];
f.uvs[1] = ruv[i * 3 + 1];
f.uvs[2] = ruv[i * 3 + 2];
}
if (sc == vc / 3) {
f.smooth = rs[i];
} else {
f.smooth = false;
}
if (ic == vc / 3) {
f.invert = ri[i];
} else {
f.invert = false;
}
if (mc == vc / 3) {
Ref<Material> mat = rm[i];
if (mat.is_valid()) {
const Map<Ref<Material>, int>::Element *E = material_map.find(mat);
if (E) {
f.material = E->get();
} else {
f.material = material_map.size();
material_map[mat] = f.material;
}
} else {
f.material = -1;
}
}
}
materials.resize(material_map.size());
for (Map<Ref<Material>, int>::Element *E = material_map.front(); E; E = E->next()) {
materials.write[E->get()] = E->key();
}
_regen_face_aabbs();
}
void CSGBrush::copy_from(const CSGBrush &p_brush, const Transform &p_xform) {
faces = p_brush.faces;
materials = p_brush.materials;
for (int i = 0; i < faces.size(); i++) {
for (int j = 0; j < 3; j++) {
faces.write[i].vertices[j] = p_xform.xform(p_brush.faces[i].vertices[j]);
}
}
_regen_face_aabbs();
}
// CSGBrushOperation
void CSGBrushOperation::merge_brushes(Operation p_operation, const CSGBrush &p_brush_a, const CSGBrush &p_brush_b, CSGBrush &r_merged_brush, float p_vertex_snap) {
// Check for face collisions and add necessary faces.
Build2DFaceCollection build2DFaceCollection;
for (int i = 0; i < p_brush_a.faces.size(); i++) {
for (int j = 0; j < p_brush_b.faces.size(); j++) {
if (p_brush_a.faces[i].aabb.intersects_inclusive(p_brush_b.faces[j].aabb)) {
update_faces(p_brush_a, i, p_brush_b, j, build2DFaceCollection, p_vertex_snap);
}
}
}
// Add faces to MeshMerge.
MeshMerge mesh_merge;
mesh_merge.vertex_snap = p_vertex_snap;
for (int i = 0; i < p_brush_a.faces.size(); i++) {
Ref<Material> material;
if (p_brush_a.faces[i].material != -1) {
material = p_brush_a.materials[p_brush_a.faces[i].material];
}
if (build2DFaceCollection.build2DFacesA.has(i)) {
build2DFaceCollection.build2DFacesA[i].addFacesToMesh(mesh_merge, p_brush_a.faces[i].smooth, p_brush_a.faces[i].invert, material, false);
} else {
Vector3 points[3];
Vector2 uvs[3];
for (int j = 0; j < 3; j++) {
points[j] = p_brush_a.faces[i].vertices[j];
uvs[j] = p_brush_a.faces[i].uvs[j];
}
mesh_merge.add_face(points, uvs, p_brush_a.faces[i].smooth, p_brush_a.faces[i].invert, material, false);
}
}
for (int i = 0; i < p_brush_b.faces.size(); i++) {
Ref<Material> material;
if (p_brush_b.faces[i].material != -1) {
material = p_brush_b.materials[p_brush_b.faces[i].material];
}
if (build2DFaceCollection.build2DFacesB.has(i)) {
build2DFaceCollection.build2DFacesB[i].addFacesToMesh(mesh_merge, p_brush_b.faces[i].smooth, p_brush_b.faces[i].invert, material, true);
} else {
Vector3 points[3];
Vector2 uvs[3];
for (int j = 0; j < 3; j++) {
points[j] = p_brush_b.faces[i].vertices[j];
uvs[j] = p_brush_b.faces[i].uvs[j];
}
mesh_merge.add_face(points, uvs, p_brush_b.faces[i].smooth, p_brush_b.faces[i].invert, material, true);
}
}
// Mark faces that ended up inside the intersection.
mesh_merge.mark_inside_faces();
// Create new brush and fill with new faces.
r_merged_brush.faces.clear();
switch (p_operation) {
case OPERATION_UNION: {
int outside_count = 0;
for (int i = 0; i < mesh_merge.faces.size(); i++) {
if (mesh_merge.faces[i].inside) {
continue;
}
outside_count++;
}
r_merged_brush.faces.resize(outside_count);
outside_count = 0;
for (int i = 0; i < mesh_merge.faces.size(); i++) {
if (mesh_merge.faces[i].inside) {
continue;
}
for (int j = 0; j < 3; j++) {
r_merged_brush.faces.write[outside_count].vertices[j] = mesh_merge.points[mesh_merge.faces[i].points[j]];
r_merged_brush.faces.write[outside_count].uvs[j] = mesh_merge.faces[i].uvs[j];
}
r_merged_brush.faces.write[outside_count].smooth = mesh_merge.faces[i].smooth;
r_merged_brush.faces.write[outside_count].invert = mesh_merge.faces[i].invert;
r_merged_brush.faces.write[outside_count].material = mesh_merge.faces[i].material_idx;
outside_count++;
}
r_merged_brush._regen_face_aabbs();
} break;
case OPERATION_INTERSECTION: {
int inside_count = 0;
for (int i = 0; i < mesh_merge.faces.size(); i++) {
if (!mesh_merge.faces[i].inside) {
continue;
}
inside_count++;
}
r_merged_brush.faces.resize(inside_count);
inside_count = 0;
for (int i = 0; i < mesh_merge.faces.size(); i++) {
if (!mesh_merge.faces[i].inside) {
continue;
}
for (int j = 0; j < 3; j++) {
r_merged_brush.faces.write[inside_count].vertices[j] = mesh_merge.points[mesh_merge.faces[i].points[j]];
r_merged_brush.faces.write[inside_count].uvs[j] = mesh_merge.faces[i].uvs[j];
}
r_merged_brush.faces.write[inside_count].smooth = mesh_merge.faces[i].smooth;
r_merged_brush.faces.write[inside_count].invert = mesh_merge.faces[i].invert;
r_merged_brush.faces.write[inside_count].material = mesh_merge.faces[i].material_idx;
inside_count++;
}
r_merged_brush._regen_face_aabbs();
} break;
case OPERATION_SUBSTRACTION: {
int face_count = 0;
for (int i = 0; i < mesh_merge.faces.size(); i++) {
if (mesh_merge.faces[i].from_b && !mesh_merge.faces[i].inside) {
continue;
}
if (!mesh_merge.faces[i].from_b && mesh_merge.faces[i].inside) {
continue;
}
face_count++;
}
r_merged_brush.faces.resize(face_count);
face_count = 0;
for (int i = 0; i < mesh_merge.faces.size(); i++) {
if (mesh_merge.faces[i].from_b && !mesh_merge.faces[i].inside) {
continue;
}
if (!mesh_merge.faces[i].from_b && mesh_merge.faces[i].inside) {
continue;
}
for (int j = 0; j < 3; j++) {
r_merged_brush.faces.write[face_count].vertices[j] = mesh_merge.points[mesh_merge.faces[i].points[j]];
r_merged_brush.faces.write[face_count].uvs[j] = mesh_merge.faces[i].uvs[j];
}
if (mesh_merge.faces[i].from_b) {
//invert facing of insides of B
SWAP(r_merged_brush.faces.write[face_count].vertices[1], r_merged_brush.faces.write[face_count].vertices[2]);
SWAP(r_merged_brush.faces.write[face_count].uvs[1], r_merged_brush.faces.write[face_count].uvs[2]);
}
r_merged_brush.faces.write[face_count].smooth = mesh_merge.faces[i].smooth;
r_merged_brush.faces.write[face_count].invert = mesh_merge.faces[i].invert;
r_merged_brush.faces.write[face_count].material = mesh_merge.faces[i].material_idx;
face_count++;
}
r_merged_brush._regen_face_aabbs();
} break;
}
// Update the list of materials.
r_merged_brush.materials.resize(mesh_merge.materials.size());
for (const Map<Ref<Material>, int>::Element *E = mesh_merge.materials.front(); E; E = E->next()) {
r_merged_brush.materials.write[E->get()] = E->key();
}
}
// CSGBrushOperation::MeshMerge
// Use a limit to speed up bvh and limit the depth.
#define BVH_LIMIT 8
int CSGBrushOperation::MeshMerge::_create_bvh(FaceBVH *facebvhptr, FaceBVH **facebvhptrptr, int p_from, int p_size, int p_depth, int &r_max_depth, int &r_max_alloc) {
if (p_depth > r_max_depth) {
r_max_depth = p_depth;
}
if (p_size == 0) {
return -1;
}
if (p_size <= BVH_LIMIT) {
for (int i = 0; i < p_size - 1; i++) {
facebvhptrptr[p_from + i]->next = facebvhptrptr[p_from + i + 1] - facebvhptr;
}
return facebvhptrptr[p_from] - facebvhptr;
}
AABB aabb;
aabb = facebvhptrptr[p_from]->aabb;
for (int i = 1; i < p_size; i++) {
aabb.merge_with(facebvhptrptr[p_from + i]->aabb);
}
int li = aabb.get_longest_axis_index();
switch (li) {
case Vector3::AXIS_X: {
SortArray<FaceBVH *, FaceBVHCmpX> sort_x;
sort_x.nth_element(0, p_size, p_size / 2, &facebvhptrptr[p_from]);
//sort_x.sort(&p_bb[p_from],p_size);
} break;
case Vector3::AXIS_Y: {
SortArray<FaceBVH *, FaceBVHCmpY> sort_y;
sort_y.nth_element(0, p_size, p_size / 2, &facebvhptrptr[p_from]);
//sort_y.sort(&p_bb[p_from],p_size);
} break;
case Vector3::AXIS_Z: {
SortArray<FaceBVH *, FaceBVHCmpZ> sort_z;
sort_z.nth_element(0, p_size, p_size / 2, &facebvhptrptr[p_from]);
//sort_z.sort(&p_bb[p_from],p_size);
} break;
}
int left = _create_bvh(facebvhptr, facebvhptrptr, p_from, p_size / 2, p_depth + 1, r_max_depth, r_max_alloc);
int right = _create_bvh(facebvhptr, facebvhptrptr, p_from + p_size / 2, p_size - p_size / 2, p_depth + 1, r_max_depth, r_max_alloc);
int index = r_max_alloc++;
FaceBVH *_new = &facebvhptr[index];
_new->aabb = aabb;
_new->center = aabb.position + aabb.size * 0.5;
_new->face = -1;
_new->left = left;
_new->right = right;
_new->next = -1;
return index;
}
void CSGBrushOperation::MeshMerge::_add_distance(List<real_t> &r_intersectionsA, List<real_t> &r_intersectionsB, bool p_from_B, real_t p_distance) const {
List<real_t> &intersections = p_from_B ? r_intersectionsB : r_intersectionsA;
// Check if distance exists.
for (const List<real_t>::Element *E = intersections.front(); E; E = E->next()) {
if (Math::is_equal_approx(**E, p_distance)) {
return;
}
}
intersections.push_back(p_distance);
}
bool CSGBrushOperation::MeshMerge::_bvh_inside(FaceBVH *facebvhptr, int p_max_depth, int p_bvh_first, int p_face_idx) const {
Face face = faces[p_face_idx];
Vector3 face_points[3] = {
points[face.points[0]],
points[face.points[1]],
points[face.points[2]]
};
Vector3 face_center = (face_points[0] + face_points[1] + face_points[2]) / 3.0;
Vector3 face_normal = Plane(face_points[0], face_points[1], face_points[2]).normal;
uint32_t *stack = (uint32_t *)alloca(sizeof(int) * p_max_depth);
enum {
TEST_AABB_BIT = 0,
VISIT_LEFT_BIT = 1,
VISIT_RIGHT_BIT = 2,
VISIT_DONE_BIT = 3,
VISITED_BIT_SHIFT = 29,
NODE_IDX_MASK = (1 << VISITED_BIT_SHIFT) - 1,
VISITED_BIT_MASK = ~NODE_IDX_MASK
};
List<real_t> intersectionsA;
List<real_t> intersectionsB;
int level = 0;
int pos = p_bvh_first;
stack[0] = pos;
while (true) {
uint32_t node = stack[level] & NODE_IDX_MASK;
const FaceBVH *current_facebvhptr = &(facebvhptr[node]);
bool done = false;
switch (stack[level] >> VISITED_BIT_SHIFT) {
case TEST_AABB_BIT: {
if (current_facebvhptr->face >= 0) {
while (current_facebvhptr) {
if (p_face_idx != current_facebvhptr->face &&
current_facebvhptr->aabb.intersects_ray(face_center, face_normal)) {
const Face &current_face = faces[current_facebvhptr->face];
Vector3 current_points[3] = {
points[current_face.points[0]],
points[current_face.points[1]],
points[current_face.points[2]]
};
Vector3 current_normal = Plane(current_points[0], current_points[1], current_points[2]).normal;
Vector3 intersection_point;
// Check if faces are co-planar.
if ((current_normal - face_normal).length_squared() < CMP_EPSILON2 &&
is_point_in_triangle(face_center, current_points)) {
// Only add an intersection if not a B face.
if (!face.from_b) {
_add_distance(intersectionsA, intersectionsB, current_face.from_b, 0);
}
} else if (ray_intersects_triangle(face_center, face_normal, current_points, CMP_EPSILON, intersection_point)) {
real_t distance = (intersection_point - face_center).length();
_add_distance(intersectionsA, intersectionsB, current_face.from_b, distance);
}
}
if (current_facebvhptr->next != -1) {
current_facebvhptr = &facebvhptr[current_facebvhptr->next];
} else {
current_facebvhptr = nullptr;
}
}
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
bool valid = current_facebvhptr->aabb.intersects_ray(face_center, face_normal);
if (!valid) {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
} else {
stack[level] = (VISIT_LEFT_BIT << VISITED_BIT_SHIFT) | node;
}
}
continue;
}
case VISIT_LEFT_BIT: {
stack[level] = (VISIT_RIGHT_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = current_facebvhptr->left | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_RIGHT_BIT: {
stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node;
stack[level + 1] = current_facebvhptr->right | TEST_AABB_BIT;
level++;
continue;
}
case VISIT_DONE_BIT: {
if (level == 0) {
done = true;
break;
} else {
level--;
}
continue;
}
}
if (done) {
break;
}
}
// Inside if face normal intersects other faces an odd number of times.
return (intersectionsA.size() + intersectionsB.size()) & 1;
}
void CSGBrushOperation::MeshMerge::mark_inside_faces() {
// Mark faces that are inside. This helps later do the boolean ops when merging.
// This approach is very brute force with a bunch of optimizations,
// such as BVH and pre AABB intersection test.
Vector<FaceBVH> bvhvec;
bvhvec.resize(faces.size() * 3); // Will never be larger than this (TODO: Make better)
FaceBVH *facebvh = bvhvec.ptrw();
AABB aabb_a;
AABB aabb_b;
bool first_a = true;
bool first_b = true;
for (int i = 0; i < faces.size(); i++) {
facebvh[i].left = -1;
facebvh[i].right = -1;
facebvh[i].face = i;
facebvh[i].aabb.position = points[faces[i].points[0]];
facebvh[i].aabb.expand_to(points[faces[i].points[1]]);
facebvh[i].aabb.expand_to(points[faces[i].points[2]]);
facebvh[i].center = facebvh[i].aabb.position + facebvh[i].aabb.size * 0.5;
facebvh[i].aabb.grow_by(vertex_snap);
facebvh[i].next = -1;
if (faces[i].from_b) {
if (first_b) {
aabb_b = facebvh[i].aabb;
first_b = false;
} else {
aabb_b.merge_with(facebvh[i].aabb);
}
} else {
if (first_a) {
aabb_a = facebvh[i].aabb;
first_a = false;
} else {
aabb_a.merge_with(facebvh[i].aabb);
}
}
}
AABB intersection_aabb = aabb_a.intersection(aabb_b);
// Check if shape AABBs intersect.
if (intersection_aabb.size == Vector3()) {
return;
}
Vector<FaceBVH *> bvhtrvec;
bvhtrvec.resize(faces.size());
FaceBVH **bvhptr = bvhtrvec.ptrw();
for (int i = 0; i < faces.size(); i++) {
bvhptr[i] = &facebvh[i];
}
int max_depth = 0;
int max_alloc = faces.size();
_create_bvh(facebvh, bvhptr, 0, faces.size(), 1, max_depth, max_alloc);
for (int i = 0; i < faces.size(); i++) {
// Check if face AABB intersects the intersection AABB.
if (!intersection_aabb.intersects_inclusive(facebvh[i].aabb)) {
continue;
}
if (_bvh_inside(facebvh, max_depth, max_alloc - 1, i)) {
faces.write[i].inside = true;
}
}
}
void CSGBrushOperation::MeshMerge::add_face(const Vector3 p_points[], const Vector2 p_uvs[], bool p_smooth, bool p_invert, const Ref<Material> &p_material, bool p_from_b) {
int indices[3];
for (int i = 0; i < 3; i++) {
VertexKey vk;
vk.x = int((double(p_points[i].x) + double(vertex_snap) * 0.31234) / double(vertex_snap));
vk.y = int((double(p_points[i].y) + double(vertex_snap) * 0.31234) / double(vertex_snap));
vk.z = int((double(p_points[i].z) + double(vertex_snap) * 0.31234) / double(vertex_snap));
int res;
if (snap_cache.lookup(vk, res)) {
indices[i] = res;
} else {
indices[i] = points.size();
points.push_back(p_points[i]);
snap_cache.set(vk, indices[i]);
}
}
// Don't add degenerate faces.
if (indices[0] == indices[2] || indices[0] == indices[1] || indices[1] == indices[2]) {
return;
}
MeshMerge::Face face;
face.from_b = p_from_b;
face.inside = false;
face.smooth = p_smooth;
face.invert = p_invert;
if (p_material.is_valid()) {
if (!materials.has(p_material)) {
face.material_idx = materials.size();
materials[p_material] = face.material_idx;
} else {
face.material_idx = materials[p_material];
}
} else {
face.material_idx = -1;
}
for (int k = 0; k < 3; k++) {
face.points[k] = indices[k];
face.uvs[k] = p_uvs[k];
}
faces.push_back(face);
}
// CSGBrushOperation::Build2DFaces
int CSGBrushOperation::Build2DFaces::_get_point_idx(const Vector2 &p_point) {
for (int vertex_idx = 0; vertex_idx < vertices.size(); ++vertex_idx) {
if ((p_point - vertices[vertex_idx].point).length_squared() < vertex_snap2) {
return vertex_idx;
}
}
return -1;
}
int CSGBrushOperation::Build2DFaces::_add_vertex(const Vertex2D &p_vertex) {
// Check if vertex exists.
int vertex_id = _get_point_idx(p_vertex.point);
if (vertex_id != -1) {
return vertex_id;
}
vertices.push_back(p_vertex);
return vertices.size() - 1;
}
void CSGBrushOperation::Build2DFaces::_add_vertex_idx_sorted(Vector<int> &r_vertex_indices, int p_new_vertex_index) {
if (p_new_vertex_index >= 0 && r_vertex_indices.find(p_new_vertex_index) == -1) {
ERR_FAIL_COND_MSG(p_new_vertex_index >= vertices.size(), "Invalid vertex index.");
// The first vertex.
if (r_vertex_indices.size() == 0) {
// Simply add it.
r_vertex_indices.push_back(p_new_vertex_index);
return;
}
// The second vertex.
if (r_vertex_indices.size() == 1) {
Vector2 first_point = vertices[r_vertex_indices[0]].point;
Vector2 new_point = vertices[p_new_vertex_index].point;
// Sort along the axis with the greatest difference.
int axis = 0;
if (Math::abs(new_point.x - first_point.x) < Math::abs(new_point.y - first_point.y)) {
axis = 1;
}
// Add it to the beginning or the end appropriately.
if (new_point[axis] < first_point[axis]) {
r_vertex_indices.insert(0, p_new_vertex_index);
} else {
r_vertex_indices.push_back(p_new_vertex_index);
}
return;
}
// Third or later vertices.
Vector2 first_point = vertices[r_vertex_indices[0]].point;
Vector2 last_point = vertices[r_vertex_indices[r_vertex_indices.size() - 1]].point;
Vector2 new_point = vertices[p_new_vertex_index].point;
// Determine axis being sorted against i.e. the axis with the greatest difference.
int axis = 0;
if (Math::abs(last_point.x - first_point.x) < Math::abs(last_point.y - first_point.y)) {
axis = 1;
}
// Insert the point at the appropriate index.
for (int insert_idx = 0; insert_idx < r_vertex_indices.size(); ++insert_idx) {
Vector2 insert_point = vertices[r_vertex_indices[insert_idx]].point;
if (new_point[axis] < insert_point[axis]) {
r_vertex_indices.insert(insert_idx, p_new_vertex_index);
return;
}
}
// New largest, add it to the end.
r_vertex_indices.push_back(p_new_vertex_index);
}
}
void CSGBrushOperation::Build2DFaces::_merge_faces(const Vector<int> &p_segment_indices) {
int segments = p_segment_indices.size() - 1;
if (segments < 2) {
return;
}
// Faces around an inner vertex are merged by moving the inner vertex to the first vertex.
for (int sorted_idx = 1; sorted_idx < segments; ++sorted_idx) {
int closest_idx = 0;
int inner_idx = p_segment_indices[sorted_idx];
if (sorted_idx > segments / 2) {
// Merge to other segment end.
closest_idx = segments;
// Reverse the merge order.
inner_idx = p_segment_indices[segments + segments / 2 - sorted_idx];
}
// Find the mergeable faces.
Vector<int> merge_faces_idx;
Vector<Face2D> merge_faces;
Vector<int> merge_faces_inner_vertex_idx;
for (int face_idx = 0; face_idx < faces.size(); ++face_idx) {
for (int face_vertex_idx = 0; face_vertex_idx < 3; ++face_vertex_idx) {
if (faces[face_idx].vertex_idx[face_vertex_idx] == inner_idx) {
merge_faces_idx.push_back(face_idx);
merge_faces.push_back(faces[face_idx]);
merge_faces_inner_vertex_idx.push_back(face_vertex_idx);
}
}
}
Vector<int> degenerate_points;
// Create the new faces.
for (int merge_idx = 0; merge_idx < merge_faces.size(); ++merge_idx) {
int outer_edge_idx[2];
outer_edge_idx[0] = merge_faces[merge_idx].vertex_idx[(merge_faces_inner_vertex_idx[merge_idx] + 1) % 3];
outer_edge_idx[1] = merge_faces[merge_idx].vertex_idx[(merge_faces_inner_vertex_idx[merge_idx] + 2) % 3];
// Skip flattened faces.
if (outer_edge_idx[0] == p_segment_indices[closest_idx] ||
outer_edge_idx[1] == p_segment_indices[closest_idx]) {
continue;
}
//Don't create degenerate triangles.
Vector2 edge1[2] = {
vertices[outer_edge_idx[0]].point,
vertices[p_segment_indices[closest_idx]].point
};
Vector2 edge2[2] = {
vertices[outer_edge_idx[1]].point,
vertices[p_segment_indices[closest_idx]].point
};
if (are_segements_parallel(edge1, edge2, vertex_snap2)) {
if (!degenerate_points.find(outer_edge_idx[0])) {
degenerate_points.push_back(outer_edge_idx[0]);
}
if (!degenerate_points.find(outer_edge_idx[1])) {
degenerate_points.push_back(outer_edge_idx[1]);
}
continue;
}
// Create new faces.
Face2D new_face;
new_face.vertex_idx[0] = p_segment_indices[closest_idx];
new_face.vertex_idx[1] = outer_edge_idx[0];
new_face.vertex_idx[2] = outer_edge_idx[1];
faces.push_back(new_face);
}
// Delete the old faces in reverse index order.
merge_faces_idx.sort();
merge_faces_idx.invert();
for (int i = 0; i < merge_faces_idx.size(); ++i) {
faces.remove(merge_faces_idx[i]);
}
if (degenerate_points.size() == 0) {
continue;
}
// Split faces using degenerate points.
for (int face_idx = 0; face_idx < faces.size(); ++face_idx) {
Face2D face = faces[face_idx];
Vertex2D face_vertices[3] = {
vertices[face.vertex_idx[0]],
vertices[face.vertex_idx[1]],
vertices[face.vertex_idx[2]]
};
Vector2 face_points[3] = {
face_vertices[0].point,
face_vertices[1].point,
face_vertices[2].point
};
for (int point_idx = 0; point_idx < degenerate_points.size(); ++point_idx) {
int degenerate_idx = degenerate_points[point_idx];
Vector2 point_2D = vertices[degenerate_idx].point;
// Check if point is existing face vertex.
bool existing = false;
for (int i = 0; i < 3; ++i) {
if ((point_2D - face_vertices[i].point).length_squared() < vertex_snap2) {
existing = true;
break;
}
}
if (existing) {
continue;
}
// Check if point is on an each edge.
for (int face_edge_idx = 0; face_edge_idx < 3; ++face_edge_idx) {
Vector2 edge_points[2] = {
face_points[face_edge_idx],
face_points[(face_edge_idx + 1) % 3]
};
Vector2 closest_point = Geometry::get_closest_point_to_segment_2d(point_2D, edge_points);
if ((closest_point - point_2D).length_squared() < vertex_snap2) {
int opposite_vertex_idx = face.vertex_idx[(face_edge_idx + 2) % 3];
// If new vertex snaps to degenerate vertex, just delete this face.
if (degenerate_idx == opposite_vertex_idx) {
faces.remove(face_idx);
// Update index.
--face_idx;
break;
}
// Create two new faces around the new edge and remove this face.
// The new edge is the last edge.
Face2D left_face;
left_face.vertex_idx[0] = degenerate_idx;
left_face.vertex_idx[1] = face.vertex_idx[(face_edge_idx + 1) % 3];
left_face.vertex_idx[2] = opposite_vertex_idx;
Face2D right_face;
right_face.vertex_idx[0] = opposite_vertex_idx;
right_face.vertex_idx[1] = face.vertex_idx[face_edge_idx];
right_face.vertex_idx[2] = degenerate_idx;
faces.remove(face_idx);
faces.insert(face_idx, right_face);
faces.insert(face_idx, left_face);
// Don't check against the new faces.
++face_idx;
// No need to check other edges.
break;
}
}
}
}
}
}
void CSGBrushOperation::Build2DFaces::_find_edge_intersections(const Vector2 p_segment_points[2], Vector<int> &r_segment_indices) {
// For each face.
for (int face_idx = 0; face_idx < faces.size(); ++face_idx) {
Face2D face = faces[face_idx];
Vertex2D face_vertices[3] = {
vertices[face.vertex_idx[0]],
vertices[face.vertex_idx[1]],
vertices[face.vertex_idx[2]]
};
// Check each edge.
for (int face_edge_idx = 0; face_edge_idx < 3; ++face_edge_idx) {
Vector2 edge_points[2] = {
face_vertices[face_edge_idx].point,
face_vertices[(face_edge_idx + 1) % 3].point
};
Vector2 edge_uvs[2] = {
face_vertices[face_edge_idx].uv,
face_vertices[(face_edge_idx + 1) % 3].uv
};
Vector2 intersection_point;
// First check if the ends of the segment are on the edge.
bool on_edge = false;
for (int edge_point_idx = 0; edge_point_idx < 2; ++edge_point_idx) {
intersection_point = Geometry::get_closest_point_to_segment_2d(p_segment_points[edge_point_idx], edge_points);
if ((intersection_point - p_segment_points[edge_point_idx]).length_squared() < vertex_snap2) {
on_edge = true;
break;
}
}
// Else check if the segment intersects the edge.
if (on_edge || Geometry::segment_intersects_segment_2d(p_segment_points[0], p_segment_points[1], edge_points[0], edge_points[1], &intersection_point)) {
// Check if intersection point is an edge point.
if ((intersection_point - edge_points[0]).length_squared() < vertex_snap2 ||
(intersection_point - edge_points[1]).length_squared() < vertex_snap2) {
continue;
}
// Check if edge exists, by checking if the intersecting segment is parallel to the edge.
if (are_segements_parallel(p_segment_points, edge_points, vertex_snap2)) {
continue;
}
// Add the intersection point as a new vertex.
Vertex2D new_vertex;
new_vertex.point = intersection_point;
new_vertex.uv = interpolate_segment_uv(edge_points, edge_uvs, intersection_point);
int new_vertex_idx = _add_vertex(new_vertex);
int opposite_vertex_idx = face.vertex_idx[(face_edge_idx + 2) % 3];
_add_vertex_idx_sorted(r_segment_indices, new_vertex_idx);
// If new vertex snaps to opposite vertex, just delete this face.
if (new_vertex_idx == opposite_vertex_idx) {
faces.remove(face_idx);
// Update index.
--face_idx;
break;
}
// If opposite point is on the segemnt, add its index to segment indices too.
Vector2 closest_point = Geometry::get_closest_point_to_segment_2d(vertices[opposite_vertex_idx].point, p_segment_points);
if ((closest_point - vertices[opposite_vertex_idx].point).length_squared() < vertex_snap2) {
_add_vertex_idx_sorted(r_segment_indices, opposite_vertex_idx);
}
// Create two new faces around the new edge and remove this face.
// The new edge is the last edge.
Face2D left_face;
left_face.vertex_idx[0] = new_vertex_idx;
left_face.vertex_idx[1] = face.vertex_idx[(face_edge_idx + 1) % 3];
left_face.vertex_idx[2] = opposite_vertex_idx;
Face2D right_face;
right_face.vertex_idx[0] = opposite_vertex_idx;
right_face.vertex_idx[1] = face.vertex_idx[face_edge_idx];
right_face.vertex_idx[2] = new_vertex_idx;
faces.remove(face_idx);
faces.insert(face_idx, right_face);
faces.insert(face_idx, left_face);
// Check against the new faces.
--face_idx;
break;
}
}
}
}
int CSGBrushOperation::Build2DFaces::_insert_point(const Vector2 &p_point) {
int new_vertex_idx = -1;
for (int face_idx = 0; face_idx < faces.size(); ++face_idx) {
Face2D face = faces[face_idx];
Vertex2D face_vertices[3] = {
vertices[face.vertex_idx[0]],
vertices[face.vertex_idx[1]],
vertices[face.vertex_idx[2]]
};
Vector2 points[3] = {
face_vertices[0].point,
face_vertices[1].point,
face_vertices[2].point
};
Vector2 uvs[3] = {
face_vertices[0].uv,
face_vertices[1].uv,
face_vertices[2].uv
};
// Skip degenerate triangles.
if (is_triangle_degenerate(points, vertex_snap2)) {
continue;
}
// Check if point is existing face vertex.
for (int i = 0; i < 3; ++i) {
if ((p_point - face_vertices[i].point).length_squared() < vertex_snap2) {
return face.vertex_idx[i];
}
}
// Check if point is on an each edge.
bool on_edge = false;
for (int face_edge_idx = 0; face_edge_idx < 3; ++face_edge_idx) {
Vector2 edge_points[2] = {
points[face_edge_idx],
points[(face_edge_idx + 1) % 3]
};
Vector2 edge_uvs[2] = {
uvs[face_edge_idx],
uvs[(face_edge_idx + 1) % 3]
};
Vector2 closest_point = Geometry::get_closest_point_to_segment_2d(p_point, edge_points);
if ((closest_point - p_point).length_squared() < vertex_snap2) {
on_edge = true;
// Add the point as a new vertex.
Vertex2D new_vertex;
new_vertex.point = p_point;
new_vertex.uv = interpolate_segment_uv(edge_points, edge_uvs, p_point);
new_vertex_idx = _add_vertex(new_vertex);
int opposite_vertex_idx = face.vertex_idx[(face_edge_idx + 2) % 3];
// If new vertex snaps to opposite vertex, just delete this face.
if (new_vertex_idx == opposite_vertex_idx) {
faces.remove(face_idx);
// Update index.
--face_idx;
break;
}
// Don't create degenerate triangles.
Vector2 split_edge1[2] = { vertices[new_vertex_idx].point, edge_points[0] };
Vector2 split_edge2[2] = { vertices[new_vertex_idx].point, edge_points[1] };
Vector2 new_edge[2] = { vertices[new_vertex_idx].point, vertices[opposite_vertex_idx].point };
if (are_segements_parallel(split_edge1, new_edge, vertex_snap2) &&
are_segements_parallel(split_edge2, new_edge, vertex_snap2)) {
break;
}
// Create two new faces around the new edge and remove this face.
// The new edge is the last edge.
Face2D left_face;
left_face.vertex_idx[0] = new_vertex_idx;
left_face.vertex_idx[1] = face.vertex_idx[(face_edge_idx + 1) % 3];
left_face.vertex_idx[2] = opposite_vertex_idx;
Face2D right_face;
right_face.vertex_idx[0] = opposite_vertex_idx;
right_face.vertex_idx[1] = face.vertex_idx[face_edge_idx];
right_face.vertex_idx[2] = new_vertex_idx;
faces.remove(face_idx);
faces.insert(face_idx, right_face);
faces.insert(face_idx, left_face);
// Don't check against the new faces.
++face_idx;
// No need to check other edges.
break;
}
}
// If not on an edge, check if the point is inside the face.
if (!on_edge && Geometry::is_point_in_triangle(p_point, face_vertices[0].point, face_vertices[1].point, face_vertices[2].point)) {
// Add the point as a new vertex.
Vertex2D new_vertex;
new_vertex.point = p_point;
new_vertex.uv = interpolate_triangle_uv(points, uvs, p_point);
new_vertex_idx = _add_vertex(new_vertex);
// Create three new faces around this point and remove this face.
// The new vertex is the last vertex.
for (int i = 0; i < 3; ++i) {
// Don't create degenerate triangles.
Vector2 new_points[3] = { points[i], points[(i + 1) % 3], vertices[new_vertex_idx].point };
if (is_triangle_degenerate(new_points, vertex_snap2)) {
continue;
}
Face2D new_face;
new_face.vertex_idx[0] = face.vertex_idx[i];
new_face.vertex_idx[1] = face.vertex_idx[(i + 1) % 3];
new_face.vertex_idx[2] = new_vertex_idx;
faces.push_back(new_face);
}
faces.remove(face_idx);
// No need to check other faces.
break;
}
}
return new_vertex_idx;
}
void CSGBrushOperation::Build2DFaces::insert(const CSGBrush &p_brush, int p_face_idx) {
// Find edge points that cross the plane and face points that are in the plane.
// Map those points to 2D.
// Create new faces from those points.
Vector2 points_2D[3];
int points_count = 0;
for (int i = 0; i < 3; i++) {
Vector3 point_3D = p_brush.faces[p_face_idx].vertices[i];
if (plane.has_point(point_3D)) {
// Point is in the plane, add it.
Vector3 point_2D = plane.project(point_3D);
point_2D = to_2D.xform(point_2D);
points_2D[points_count++] = Vector2(point_2D.x, point_2D.y);
} else {
Vector3 next_point_3D = p_brush.faces[p_face_idx].vertices[(i + 1) % 3];
if (plane.has_point(next_point_3D)) {
continue; // Next point is in plane, it will be added separately.
}
if (plane.is_point_over(point_3D) == plane.is_point_over(next_point_3D)) {
continue; // Both points on the same side of the plane, ignore.
}
// Edge crosses the plane, find and add the intersection point.
Vector3 point_2D;
if (plane.intersects_segment(point_3D, next_point_3D, &point_2D)) {
point_2D = to_2D.xform(point_2D);
points_2D[points_count++] = Vector2(point_2D.x, point_2D.y);
}
}
}
Vector<int> segment_indices;
Vector2 segment[2];
int inserted_index[3] = { -1, -1, -1 };
// Insert points.
for (int i = 0; i < points_count; ++i) {
inserted_index[i] = _insert_point(points_2D[i]);
}
if (points_count == 2) {
// Insert a single segment.
segment[0] = points_2D[0];
segment[1] = points_2D[1];
_find_edge_intersections(segment, segment_indices);
for (int i = 0; i < 2; ++i) {
_add_vertex_idx_sorted(segment_indices, inserted_index[i]);
}
_merge_faces(segment_indices);
}
if (points_count == 3) {
// Insert three segments.
for (int edge_idx = 0; edge_idx < 3; ++edge_idx) {
segment[0] = points_2D[edge_idx];
segment[1] = points_2D[(edge_idx + 1) % 3];
_find_edge_intersections(segment, segment_indices);
for (int i = 0; i < 2; ++i) {
_add_vertex_idx_sorted(segment_indices, inserted_index[(edge_idx + i) % 3]);
}
_merge_faces(segment_indices);
segment_indices.clear();
}
}
}
void CSGBrushOperation::Build2DFaces::addFacesToMesh(MeshMerge &r_mesh_merge, bool p_smooth, bool p_invert, const Ref<Material> &p_material, bool p_from_b) {
for (int face_idx = 0; face_idx < faces.size(); ++face_idx) {
Face2D face = faces[face_idx];
Vertex2D fv[3] = {
vertices[face.vertex_idx[0]],
vertices[face.vertex_idx[1]],
vertices[face.vertex_idx[2]]
};
// Convert 2D vertex points to 3D.
Vector3 points_3D[3];
Vector2 uvs[3];
for (int i = 0; i < 3; ++i) {
Vector3 point_2D(fv[i].point.x, fv[i].point.y, 0);
points_3D[i] = to_3D.xform(point_2D);
uvs[i] = fv[i].uv;
}
r_mesh_merge.add_face(points_3D, uvs, p_smooth, p_invert, p_material, p_from_b);
}
}
CSGBrushOperation::Build2DFaces::Build2DFaces(const CSGBrush &p_brush, int p_face_idx, float p_vertex_snap2) :
vertex_snap2(p_vertex_snap2 * p_vertex_snap2) {
// Convert 3D vertex points to 2D.
Vector3 points_3D[3] = {
p_brush.faces[p_face_idx].vertices[0],
p_brush.faces[p_face_idx].vertices[1],
p_brush.faces[p_face_idx].vertices[2],
};
plane = Plane(points_3D[0], points_3D[1], points_3D[2]);
to_3D.origin = points_3D[0];
to_3D.basis.set_axis(2, plane.normal);
to_3D.basis.set_axis(0, (points_3D[1] - points_3D[2]).normalized());
to_3D.basis.set_axis(1, to_3D.basis.get_axis(0).cross(to_3D.basis.get_axis(2)).normalized());
to_2D = to_3D.affine_inverse();
Face2D face;
for (int i = 0; i < 3; i++) {
Vertex2D vertex;
Vector3 point_2D = to_2D.xform(points_3D[i]);
vertex.point.x = point_2D.x;
vertex.point.y = point_2D.y;
vertex.uv = p_brush.faces[p_face_idx].uvs[i];
vertices.push_back(vertex);
face.vertex_idx[i] = i;
}
faces.push_back(face);
}
void CSGBrushOperation::update_faces(const CSGBrush &p_brush_a, const int p_face_idx_a, const CSGBrush &p_brush_b, const int p_face_idx_b, Build2DFaceCollection &p_collection, float p_vertex_snap) {
Vector3 vertices_a[3] = {
p_brush_a.faces[p_face_idx_a].vertices[0],
p_brush_a.faces[p_face_idx_a].vertices[1],
p_brush_a.faces[p_face_idx_a].vertices[2],
};
Vector3 vertices_b[3] = {
p_brush_b.faces[p_face_idx_b].vertices[0],
p_brush_b.faces[p_face_idx_b].vertices[1],
p_brush_b.faces[p_face_idx_b].vertices[2],
};
// Don't use degenerate faces.
bool has_degenerate = false;
if (is_snapable(vertices_a[0], vertices_a[1], p_vertex_snap) ||
is_snapable(vertices_a[0], vertices_a[2], p_vertex_snap) ||
is_snapable(vertices_a[1], vertices_a[2], p_vertex_snap)) {
p_collection.build2DFacesA[p_face_idx_a] = Build2DFaces();
has_degenerate = true;
}
if (is_snapable(vertices_b[0], vertices_b[1], p_vertex_snap) ||
is_snapable(vertices_b[0], vertices_b[2], p_vertex_snap) ||
is_snapable(vertices_b[1], vertices_b[2], p_vertex_snap)) {
p_collection.build2DFacesB[p_face_idx_b] = Build2DFaces();
has_degenerate = true;
}
if (has_degenerate) {
return;
}
// Ensure B has points either side of or in the plane of A.
int in_plane_count = 0, over_count = 0, under_count = 0;
Plane plane_a(vertices_a[0], vertices_a[1], vertices_a[2]);
ERR_FAIL_COND_MSG(plane_a.normal == Vector3(), "Couldn't form plane from Brush A face.");
for (int i = 0; i < 3; i++) {
if (plane_a.has_point(vertices_b[i])) {
in_plane_count++;
} else if (plane_a.is_point_over(vertices_b[i])) {
over_count++;
} else {
under_count++;
}
}
// If all points under or over the plane, there is no intesection.
if (over_count == 3 || under_count == 3) {
return;
}
// Ensure A has points either side of or in the plane of B.
in_plane_count = 0;
over_count = 0;
under_count = 0;
Plane plane_b(vertices_b[0], vertices_b[1], vertices_b[2]);
ERR_FAIL_COND_MSG(plane_b.normal == Vector3(), "Couldn't form plane from Brush B face.");
for (int i = 0; i < 3; i++) {
if (plane_b.has_point(vertices_a[i])) {
in_plane_count++;
} else if (plane_b.is_point_over(vertices_a[i])) {
over_count++;
} else {
under_count++;
}
}
// If all points under or over the plane, there is no intesection.
if (over_count == 3 || under_count == 3) {
return;
}
// Check for intersection using the SAT theorem.
{
// Edge pair cross product combinations.
for (int i = 0; i < 3; i++) {
Vector3 axis_a = (vertices_a[i] - vertices_a[(i + 1) % 3]).normalized();
for (int j = 0; j < 3; j++) {
Vector3 axis_b = (vertices_b[j] - vertices_b[(j + 1) % 3]).normalized();
Vector3 sep_axis = axis_a.cross(axis_b);
if (sep_axis == Vector3()) {
continue; //colineal
}
sep_axis.normalize();
real_t min_a = 1e20, max_a = -1e20;
real_t min_b = 1e20, max_b = -1e20;
for (int k = 0; k < 3; k++) {
real_t d = sep_axis.dot(vertices_a[k]);
min_a = MIN(min_a, d);
max_a = MAX(max_a, d);
d = sep_axis.dot(vertices_b[k]);
min_b = MIN(min_b, d);
max_b = MAX(max_b, d);
}
min_b -= (max_a - min_a) * 0.5;
max_b += (max_a - min_a) * 0.5;
real_t dmin = min_b - (min_a + max_a) * 0.5;
real_t dmax = max_b - (min_a + max_a) * 0.5;
if (dmin > CMP_EPSILON || dmax < -CMP_EPSILON) {
return; // Does not contain zero, so they don't overlap.
}
}
}
}
// If we're still here, the faces probably intersect, so add new faces.
if (!p_collection.build2DFacesA.has(p_face_idx_a)) {
p_collection.build2DFacesA[p_face_idx_a] = Build2DFaces(p_brush_a, p_face_idx_a, p_vertex_snap);
}
p_collection.build2DFacesA[p_face_idx_a].insert(p_brush_b, p_face_idx_b);
if (!p_collection.build2DFacesB.has(p_face_idx_b)) {
p_collection.build2DFacesB[p_face_idx_b] = Build2DFaces(p_brush_b, p_face_idx_b, p_vertex_snap);
}
p_collection.build2DFacesB[p_face_idx_b].insert(p_brush_a, p_face_idx_a);
}
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