virtualx-engine/core/math/geometry_3d.cpp
reduz 746dddc067 Replace most uses of Map by HashMap
* Map is unnecessary and inefficient in almost every case.
* Replaced by the new HashMap.
* Renamed Map to RBMap and Set to RBSet for cases that still make sense
  (order matters) but use is discouraged.

There were very few cases where replacing by HashMap was undesired because
keeping the key order was intended.
I tried to keep those (as RBMap) as much as possible, but might have missed
some. Review appreciated!
2022-05-16 10:37:48 +02:00

1022 lines
25 KiB
C++

/*************************************************************************/
/* geometry_3d.cpp */
/*************************************************************************/
/* 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. */
/*************************************************************************/
#include "geometry_3d.h"
#include "core/string/print_string.h"
#include "thirdparty/misc/clipper.hpp"
#include "thirdparty/misc/polypartition.h"
void Geometry3D::MeshData::optimize_vertices() {
HashMap<int, int> vtx_remap;
for (int i = 0; i < faces.size(); i++) {
for (int j = 0; j < faces[i].indices.size(); j++) {
int idx = faces[i].indices[j];
if (!vtx_remap.has(idx)) {
int ni = vtx_remap.size();
vtx_remap[idx] = ni;
}
faces.write[i].indices.write[j] = vtx_remap[idx];
}
}
for (int i = 0; i < edges.size(); i++) {
int a = edges[i].a;
int b = edges[i].b;
if (!vtx_remap.has(a)) {
int ni = vtx_remap.size();
vtx_remap[a] = ni;
}
if (!vtx_remap.has(b)) {
int ni = vtx_remap.size();
vtx_remap[b] = ni;
}
edges.write[i].a = vtx_remap[a];
edges.write[i].b = vtx_remap[b];
}
Vector<Vector3> new_vertices;
new_vertices.resize(vtx_remap.size());
for (int i = 0; i < vertices.size(); i++) {
if (vtx_remap.has(i)) {
new_vertices.write[vtx_remap[i]] = vertices[i];
}
}
vertices = new_vertices;
}
struct _FaceClassify {
struct _Link {
int face = -1;
int edge = -1;
void clear() {
face = -1;
edge = -1;
}
_Link() {}
};
bool valid = false;
int group = -1;
_Link links[3];
Face3 face;
_FaceClassify() {}
};
static bool _connect_faces(_FaceClassify *p_faces, int len, int p_group) {
// Connect faces, error will occur if an edge is shared between more than 2 faces.
// Clear connections.
bool error = false;
for (int i = 0; i < len; i++) {
for (int j = 0; j < 3; j++) {
p_faces[i].links[j].clear();
}
}
for (int i = 0; i < len; i++) {
if (p_faces[i].group != p_group) {
continue;
}
for (int j = i + 1; j < len; j++) {
if (p_faces[j].group != p_group) {
continue;
}
for (int k = 0; k < 3; k++) {
Vector3 vi1 = p_faces[i].face.vertex[k];
Vector3 vi2 = p_faces[i].face.vertex[(k + 1) % 3];
for (int l = 0; l < 3; l++) {
Vector3 vj2 = p_faces[j].face.vertex[l];
Vector3 vj1 = p_faces[j].face.vertex[(l + 1) % 3];
if (vi1.distance_to(vj1) < 0.00001f &&
vi2.distance_to(vj2) < 0.00001f) {
if (p_faces[i].links[k].face != -1) {
ERR_PRINT("already linked\n");
error = true;
break;
}
if (p_faces[j].links[l].face != -1) {
ERR_PRINT("already linked\n");
error = true;
break;
}
p_faces[i].links[k].face = j;
p_faces[i].links[k].edge = l;
p_faces[j].links[l].face = i;
p_faces[j].links[l].edge = k;
}
}
if (error) {
break;
}
}
if (error) {
break;
}
}
if (error) {
break;
}
}
for (int i = 0; i < len; i++) {
p_faces[i].valid = true;
for (int j = 0; j < 3; j++) {
if (p_faces[i].links[j].face == -1) {
p_faces[i].valid = false;
}
}
}
return error;
}
static bool _group_face(_FaceClassify *p_faces, int len, int p_index, int p_group) {
if (p_faces[p_index].group >= 0) {
return false;
}
p_faces[p_index].group = p_group;
for (int i = 0; i < 3; i++) {
ERR_FAIL_INDEX_V(p_faces[p_index].links[i].face, len, true);
_group_face(p_faces, len, p_faces[p_index].links[i].face, p_group);
}
return true;
}
Vector<Vector<Face3>> Geometry3D::separate_objects(Vector<Face3> p_array) {
Vector<Vector<Face3>> objects;
int len = p_array.size();
const Face3 *arrayptr = p_array.ptr();
Vector<_FaceClassify> fc;
fc.resize(len);
_FaceClassify *_fcptr = fc.ptrw();
for (int i = 0; i < len; i++) {
_fcptr[i].face = arrayptr[i];
}
bool error = _connect_faces(_fcptr, len, -1);
ERR_FAIL_COND_V_MSG(error, Vector<Vector<Face3>>(), "Invalid geometry.");
// Group connected faces in separate objects.
int group = 0;
for (int i = 0; i < len; i++) {
if (!_fcptr[i].valid) {
continue;
}
if (_group_face(_fcptr, len, i, group)) {
group++;
}
}
// Group connected faces in separate objects.
for (int i = 0; i < len; i++) {
_fcptr[i].face = arrayptr[i];
}
if (group >= 0) {
objects.resize(group);
Vector<Face3> *group_faces = objects.ptrw();
for (int i = 0; i < len; i++) {
if (!_fcptr[i].valid) {
continue;
}
if (_fcptr[i].group >= 0 && _fcptr[i].group < group) {
group_faces[_fcptr[i].group].push_back(_fcptr[i].face);
}
}
}
return objects;
}
/*** GEOMETRY WRAPPER ***/
enum _CellFlags {
_CELL_SOLID = 1,
_CELL_EXTERIOR = 2,
_CELL_STEP_MASK = 0x1C,
_CELL_STEP_NONE = 0 << 2,
_CELL_STEP_Y_POS = 1 << 2,
_CELL_STEP_Y_NEG = 2 << 2,
_CELL_STEP_X_POS = 3 << 2,
_CELL_STEP_X_NEG = 4 << 2,
_CELL_STEP_Z_POS = 5 << 2,
_CELL_STEP_Z_NEG = 6 << 2,
_CELL_STEP_DONE = 7 << 2,
_CELL_PREV_MASK = 0xE0,
_CELL_PREV_NONE = 0 << 5,
_CELL_PREV_Y_POS = 1 << 5,
_CELL_PREV_Y_NEG = 2 << 5,
_CELL_PREV_X_POS = 3 << 5,
_CELL_PREV_X_NEG = 4 << 5,
_CELL_PREV_Z_POS = 5 << 5,
_CELL_PREV_Z_NEG = 6 << 5,
_CELL_PREV_FIRST = 7 << 5,
};
static inline void _plot_face(uint8_t ***p_cell_status, int x, int y, int z, int len_x, int len_y, int len_z, const Vector3 &voxelsize, const Face3 &p_face) {
AABB aabb(Vector3(x, y, z), Vector3(len_x, len_y, len_z));
aabb.position = aabb.position * voxelsize;
aabb.size = aabb.size * voxelsize;
if (!p_face.intersects_aabb(aabb)) {
return;
}
if (len_x == 1 && len_y == 1 && len_z == 1) {
p_cell_status[x][y][z] = _CELL_SOLID;
return;
}
int div_x = len_x > 1 ? 2 : 1;
int div_y = len_y > 1 ? 2 : 1;
int div_z = len_z > 1 ? 2 : 1;
#define SPLIT_DIV(m_i, m_div, m_v, m_len_v, m_new_v, m_new_len_v) \
if (m_div == 1) { \
m_new_v = m_v; \
m_new_len_v = 1; \
} else if (m_i == 0) { \
m_new_v = m_v; \
m_new_len_v = m_len_v / 2; \
} else { \
m_new_v = m_v + m_len_v / 2; \
m_new_len_v = m_len_v - m_len_v / 2; \
}
int new_x;
int new_len_x;
int new_y;
int new_len_y;
int new_z;
int new_len_z;
for (int i = 0; i < div_x; i++) {
SPLIT_DIV(i, div_x, x, len_x, new_x, new_len_x);
for (int j = 0; j < div_y; j++) {
SPLIT_DIV(j, div_y, y, len_y, new_y, new_len_y);
for (int k = 0; k < div_z; k++) {
SPLIT_DIV(k, div_z, z, len_z, new_z, new_len_z);
_plot_face(p_cell_status, new_x, new_y, new_z, new_len_x, new_len_y, new_len_z, voxelsize, p_face);
}
}
}
#undef SPLIT_DIV
}
static inline void _mark_outside(uint8_t ***p_cell_status, int x, int y, int z, int len_x, int len_y, int len_z) {
if (p_cell_status[x][y][z] & 3) {
return; // Nothing to do, already used and/or visited.
}
p_cell_status[x][y][z] = _CELL_PREV_FIRST;
while (true) {
uint8_t &c = p_cell_status[x][y][z];
if ((c & _CELL_STEP_MASK) == _CELL_STEP_NONE) {
// Haven't been in here, mark as outside.
p_cell_status[x][y][z] |= _CELL_EXTERIOR;
}
if ((c & _CELL_STEP_MASK) != _CELL_STEP_DONE) {
// If not done, increase step.
c += 1 << 2;
}
if ((c & _CELL_STEP_MASK) == _CELL_STEP_DONE) {
// Go back.
switch (c & _CELL_PREV_MASK) {
case _CELL_PREV_FIRST: {
return;
} break;
case _CELL_PREV_Y_POS: {
y++;
ERR_FAIL_COND(y >= len_y);
} break;
case _CELL_PREV_Y_NEG: {
y--;
ERR_FAIL_COND(y < 0);
} break;
case _CELL_PREV_X_POS: {
x++;
ERR_FAIL_COND(x >= len_x);
} break;
case _CELL_PREV_X_NEG: {
x--;
ERR_FAIL_COND(x < 0);
} break;
case _CELL_PREV_Z_POS: {
z++;
ERR_FAIL_COND(z >= len_z);
} break;
case _CELL_PREV_Z_NEG: {
z--;
ERR_FAIL_COND(z < 0);
} break;
default: {
ERR_FAIL();
}
}
continue;
}
int next_x = x, next_y = y, next_z = z;
uint8_t prev = 0;
switch (c & _CELL_STEP_MASK) {
case _CELL_STEP_Y_POS: {
next_y++;
prev = _CELL_PREV_Y_NEG;
} break;
case _CELL_STEP_Y_NEG: {
next_y--;
prev = _CELL_PREV_Y_POS;
} break;
case _CELL_STEP_X_POS: {
next_x++;
prev = _CELL_PREV_X_NEG;
} break;
case _CELL_STEP_X_NEG: {
next_x--;
prev = _CELL_PREV_X_POS;
} break;
case _CELL_STEP_Z_POS: {
next_z++;
prev = _CELL_PREV_Z_NEG;
} break;
case _CELL_STEP_Z_NEG: {
next_z--;
prev = _CELL_PREV_Z_POS;
} break;
default:
ERR_FAIL();
}
if (next_x < 0 || next_x >= len_x) {
continue;
}
if (next_y < 0 || next_y >= len_y) {
continue;
}
if (next_z < 0 || next_z >= len_z) {
continue;
}
if (p_cell_status[next_x][next_y][next_z] & 3) {
continue;
}
x = next_x;
y = next_y;
z = next_z;
p_cell_status[x][y][z] |= prev;
}
}
static inline void _build_faces(uint8_t ***p_cell_status, int x, int y, int z, int len_x, int len_y, int len_z, Vector<Face3> &p_faces) {
ERR_FAIL_INDEX(x, len_x);
ERR_FAIL_INDEX(y, len_y);
ERR_FAIL_INDEX(z, len_z);
if (p_cell_status[x][y][z] & _CELL_EXTERIOR) {
return;
}
#define vert(m_idx) Vector3(((m_idx)&4) >> 2, ((m_idx)&2) >> 1, (m_idx)&1)
static const uint8_t indices[6][4] = {
{ 7, 6, 4, 5 },
{ 7, 3, 2, 6 },
{ 7, 5, 1, 3 },
{ 0, 2, 3, 1 },
{ 0, 1, 5, 4 },
{ 0, 4, 6, 2 },
};
for (int i = 0; i < 6; i++) {
Vector3 face_points[4];
int disp_x = x + ((i % 3) == 0 ? ((i < 3) ? 1 : -1) : 0);
int disp_y = y + (((i - 1) % 3) == 0 ? ((i < 3) ? 1 : -1) : 0);
int disp_z = z + (((i - 2) % 3) == 0 ? ((i < 3) ? 1 : -1) : 0);
bool plot = false;
if (disp_x < 0 || disp_x >= len_x) {
plot = true;
}
if (disp_y < 0 || disp_y >= len_y) {
plot = true;
}
if (disp_z < 0 || disp_z >= len_z) {
plot = true;
}
if (!plot && (p_cell_status[disp_x][disp_y][disp_z] & _CELL_EXTERIOR)) {
plot = true;
}
if (!plot) {
continue;
}
for (int j = 0; j < 4; j++) {
face_points[j] = vert(indices[i][j]) + Vector3(x, y, z);
}
p_faces.push_back(
Face3(
face_points[0],
face_points[1],
face_points[2]));
p_faces.push_back(
Face3(
face_points[2],
face_points[3],
face_points[0]));
}
}
Vector<Face3> Geometry3D::wrap_geometry(Vector<Face3> p_array, real_t *p_error) {
int face_count = p_array.size();
const Face3 *faces = p_array.ptr();
constexpr double min_size = 1.0;
constexpr int max_length = 20;
AABB global_aabb;
for (int i = 0; i < face_count; i++) {
if (i == 0) {
global_aabb = faces[i].get_aabb();
} else {
global_aabb.merge_with(faces[i].get_aabb());
}
}
global_aabb.grow_by(0.01f); // Avoid numerical error.
// Determine amount of cells in grid axis.
int div_x, div_y, div_z;
if (global_aabb.size.x / min_size < max_length) {
div_x = (int)(global_aabb.size.x / min_size) + 1;
} else {
div_x = max_length;
}
if (global_aabb.size.y / min_size < max_length) {
div_y = (int)(global_aabb.size.y / min_size) + 1;
} else {
div_y = max_length;
}
if (global_aabb.size.z / min_size < max_length) {
div_z = (int)(global_aabb.size.z / min_size) + 1;
} else {
div_z = max_length;
}
Vector3 voxelsize = global_aabb.size;
voxelsize.x /= div_x;
voxelsize.y /= div_y;
voxelsize.z /= div_z;
// Create and initialize cells to zero.
uint8_t ***cell_status = memnew_arr(uint8_t **, div_x);
for (int i = 0; i < div_x; i++) {
cell_status[i] = memnew_arr(uint8_t *, div_y);
for (int j = 0; j < div_y; j++) {
cell_status[i][j] = memnew_arr(uint8_t, div_z);
for (int k = 0; k < div_z; k++) {
cell_status[i][j][k] = 0;
}
}
}
// Plot faces into cells.
for (int i = 0; i < face_count; i++) {
Face3 f = faces[i];
for (int j = 0; j < 3; j++) {
f.vertex[j] -= global_aabb.position;
}
_plot_face(cell_status, 0, 0, 0, div_x, div_y, div_z, voxelsize, f);
}
// Determine which cells connect to the outside by traversing the outside and recursively flood-fill marking.
for (int i = 0; i < div_x; i++) {
for (int j = 0; j < div_y; j++) {
_mark_outside(cell_status, i, j, 0, div_x, div_y, div_z);
_mark_outside(cell_status, i, j, div_z - 1, div_x, div_y, div_z);
}
}
for (int i = 0; i < div_z; i++) {
for (int j = 0; j < div_y; j++) {
_mark_outside(cell_status, 0, j, i, div_x, div_y, div_z);
_mark_outside(cell_status, div_x - 1, j, i, div_x, div_y, div_z);
}
}
for (int i = 0; i < div_x; i++) {
for (int j = 0; j < div_z; j++) {
_mark_outside(cell_status, i, 0, j, div_x, div_y, div_z);
_mark_outside(cell_status, i, div_y - 1, j, div_x, div_y, div_z);
}
}
// Build faces for the inside-outside cell divisors.
Vector<Face3> wrapped_faces;
for (int i = 0; i < div_x; i++) {
for (int j = 0; j < div_y; j++) {
for (int k = 0; k < div_z; k++) {
_build_faces(cell_status, i, j, k, div_x, div_y, div_z, wrapped_faces);
}
}
}
// Transform face vertices to global coords.
int wrapped_faces_count = wrapped_faces.size();
Face3 *wrapped_faces_ptr = wrapped_faces.ptrw();
for (int i = 0; i < wrapped_faces_count; i++) {
for (int j = 0; j < 3; j++) {
Vector3 &v = wrapped_faces_ptr[i].vertex[j];
v = v * voxelsize;
v += global_aabb.position;
}
}
// clean up grid
for (int i = 0; i < div_x; i++) {
for (int j = 0; j < div_y; j++) {
memdelete_arr(cell_status[i][j]);
}
memdelete_arr(cell_status[i]);
}
memdelete_arr(cell_status);
if (p_error) {
*p_error = voxelsize.length();
}
return wrapped_faces;
}
Geometry3D::MeshData Geometry3D::build_convex_mesh(const Vector<Plane> &p_planes) {
MeshData mesh;
#define SUBPLANE_SIZE 1024.0
real_t subplane_size = 1024.0; // Should compute this from the actual plane.
for (int i = 0; i < p_planes.size(); i++) {
Plane p = p_planes[i];
Vector3 ref = Vector3(0.0, 1.0, 0.0);
if (ABS(p.normal.dot(ref)) > 0.95f) {
ref = Vector3(0.0, 0.0, 1.0); // Change axis.
}
Vector3 right = p.normal.cross(ref).normalized();
Vector3 up = p.normal.cross(right).normalized();
Vector3 center = p.center();
// make a quad clockwise
Vector<Vector3> vertices = {
center - up * subplane_size + right * subplane_size,
center - up * subplane_size - right * subplane_size,
center + up * subplane_size - right * subplane_size,
center + up * subplane_size + right * subplane_size
};
for (int j = 0; j < p_planes.size(); j++) {
if (j == i) {
continue;
}
Vector<Vector3> new_vertices;
Plane clip = p_planes[j];
if (clip.normal.dot(p.normal) > 0.95f) {
continue;
}
if (vertices.size() < 3) {
break;
}
for (int k = 0; k < vertices.size(); k++) {
int k_n = (k + 1) % vertices.size();
Vector3 edge0_A = vertices[k];
Vector3 edge1_A = vertices[k_n];
real_t dist0 = clip.distance_to(edge0_A);
real_t dist1 = clip.distance_to(edge1_A);
if (dist0 <= 0) { // Behind plane.
new_vertices.push_back(vertices[k]);
}
// Check for different sides and non coplanar.
if ((dist0 * dist1) < 0) {
// Calculate intersection.
Vector3 rel = edge1_A - edge0_A;
real_t den = clip.normal.dot(rel);
if (Math::is_zero_approx(den)) {
continue; // Point too short.
}
real_t dist = -(clip.normal.dot(edge0_A) - clip.d) / den;
Vector3 inters = edge0_A + rel * dist;
new_vertices.push_back(inters);
}
}
vertices = new_vertices;
}
if (vertices.size() < 3) {
continue;
}
// Result is a clockwise face.
MeshData::Face face;
// Add face indices.
for (int j = 0; j < vertices.size(); j++) {
int idx = -1;
for (int k = 0; k < mesh.vertices.size(); k++) {
if (mesh.vertices[k].distance_to(vertices[j]) < 0.001f) {
idx = k;
break;
}
}
if (idx == -1) {
idx = mesh.vertices.size();
mesh.vertices.push_back(vertices[j]);
}
face.indices.push_back(idx);
}
face.plane = p;
mesh.faces.push_back(face);
// Add edge.
for (int j = 0; j < face.indices.size(); j++) {
int a = face.indices[j];
int b = face.indices[(j + 1) % face.indices.size()];
bool found = false;
for (int k = 0; k < mesh.edges.size(); k++) {
if (mesh.edges[k].a == a && mesh.edges[k].b == b) {
found = true;
break;
}
if (mesh.edges[k].b == a && mesh.edges[k].a == b) {
found = true;
break;
}
}
if (found) {
continue;
}
MeshData::Edge edge;
edge.a = a;
edge.b = b;
mesh.edges.push_back(edge);
}
}
return mesh;
}
Vector<Plane> Geometry3D::build_box_planes(const Vector3 &p_extents) {
Vector<Plane> planes = {
Plane(Vector3(1, 0, 0), p_extents.x),
Plane(Vector3(-1, 0, 0), p_extents.x),
Plane(Vector3(0, 1, 0), p_extents.y),
Plane(Vector3(0, -1, 0), p_extents.y),
Plane(Vector3(0, 0, 1), p_extents.z),
Plane(Vector3(0, 0, -1), p_extents.z)
};
return planes;
}
Vector<Plane> Geometry3D::build_cylinder_planes(real_t p_radius, real_t p_height, int p_sides, Vector3::Axis p_axis) {
ERR_FAIL_INDEX_V(p_axis, 3, Vector<Plane>());
Vector<Plane> planes;
const double sides_step = Math_TAU / p_sides;
for (int i = 0; i < p_sides; i++) {
Vector3 normal;
normal[(p_axis + 1) % 3] = Math::cos(i * sides_step);
normal[(p_axis + 2) % 3] = Math::sin(i * sides_step);
planes.push_back(Plane(normal, p_radius));
}
Vector3 axis;
axis[p_axis] = 1.0;
planes.push_back(Plane(axis, p_height * 0.5f));
planes.push_back(Plane(-axis, p_height * 0.5f));
return planes;
}
Vector<Plane> Geometry3D::build_sphere_planes(real_t p_radius, int p_lats, int p_lons, Vector3::Axis p_axis) {
ERR_FAIL_INDEX_V(p_axis, 3, Vector<Plane>());
Vector<Plane> planes;
Vector3 axis;
axis[p_axis] = 1.0;
Vector3 axis_neg;
axis_neg[(p_axis + 1) % 3] = 1.0;
axis_neg[(p_axis + 2) % 3] = 1.0;
axis_neg[p_axis] = -1.0;
const double lon_step = Math_TAU / p_lons;
for (int i = 0; i < p_lons; i++) {
Vector3 normal;
normal[(p_axis + 1) % 3] = Math::cos(i * lon_step);
normal[(p_axis + 2) % 3] = Math::sin(i * lon_step);
planes.push_back(Plane(normal, p_radius));
for (int j = 1; j <= p_lats; j++) {
Vector3 plane_normal = normal.lerp(axis, j / (real_t)p_lats).normalized();
planes.push_back(Plane(plane_normal, p_radius));
planes.push_back(Plane(plane_normal * axis_neg, p_radius));
}
}
return planes;
}
Vector<Plane> Geometry3D::build_capsule_planes(real_t p_radius, real_t p_height, int p_sides, int p_lats, Vector3::Axis p_axis) {
ERR_FAIL_INDEX_V(p_axis, 3, Vector<Plane>());
Vector<Plane> planes;
Vector3 axis;
axis[p_axis] = 1.0;
Vector3 axis_neg;
axis_neg[(p_axis + 1) % 3] = 1.0;
axis_neg[(p_axis + 2) % 3] = 1.0;
axis_neg[p_axis] = -1.0;
const double sides_step = Math_TAU / p_sides;
for (int i = 0; i < p_sides; i++) {
Vector3 normal;
normal[(p_axis + 1) % 3] = Math::cos(i * sides_step);
normal[(p_axis + 2) % 3] = Math::sin(i * sides_step);
planes.push_back(Plane(normal, p_radius));
for (int j = 1; j <= p_lats; j++) {
Vector3 plane_normal = normal.lerp(axis, j / (real_t)p_lats).normalized();
Vector3 position = axis * p_height * 0.5f + plane_normal * p_radius;
planes.push_back(Plane(plane_normal, position));
planes.push_back(Plane(plane_normal * axis_neg, position * axis_neg));
}
}
return planes;
}
Vector<Vector3> Geometry3D::compute_convex_mesh_points(const Plane *p_planes, int p_plane_count) {
Vector<Vector3> points;
// Iterate through every unique combination of any three planes.
for (int i = p_plane_count - 1; i >= 0; i--) {
for (int j = i - 1; j >= 0; j--) {
for (int k = j - 1; k >= 0; k--) {
// Find the point where these planes all cross over (if they
// do at all).
Vector3 convex_shape_point;
if (p_planes[i].intersect_3(p_planes[j], p_planes[k], &convex_shape_point)) {
// See if any *other* plane excludes this point because it's
// on the wrong side.
bool excluded = false;
for (int n = 0; n < p_plane_count; n++) {
if (n != i && n != j && n != k) {
real_t dp = p_planes[n].normal.dot(convex_shape_point);
if (dp - p_planes[n].d > (real_t)CMP_EPSILON) {
excluded = true;
break;
}
}
}
// Only add the point if it passed all tests.
if (!excluded) {
points.push_back(convex_shape_point);
}
}
}
}
}
return points;
}
#define square(m_s) ((m_s) * (m_s))
#define INF 1e20
/* dt of 1d function using squared distance */
static void edt(float *f, int stride, int n) {
float *d = (float *)alloca(sizeof(float) * n + sizeof(int) * n + sizeof(float) * (n + 1));
int *v = reinterpret_cast<int *>(&(d[n]));
float *z = reinterpret_cast<float *>(&v[n]);
int k = 0;
v[0] = 0;
z[0] = -INF;
z[1] = +INF;
for (int q = 1; q <= n - 1; q++) {
float s = ((f[q * stride] + square(q)) - (f[v[k] * stride] + square(v[k]))) / (2 * q - 2 * v[k]);
while (s <= z[k]) {
k--;
s = ((f[q * stride] + square(q)) - (f[v[k] * stride] + square(v[k]))) / (2 * q - 2 * v[k]);
}
k++;
v[k] = q;
z[k] = s;
z[k + 1] = +INF;
}
k = 0;
for (int q = 0; q <= n - 1; q++) {
while (z[k + 1] < q) {
k++;
}
d[q] = square(q - v[k]) + f[v[k] * stride];
}
for (int i = 0; i < n; i++) {
f[i * stride] = d[i];
}
}
#undef square
Vector<uint32_t> Geometry3D::generate_edf(const Vector<bool> &p_voxels, const Vector3i &p_size, bool p_negative) {
uint32_t float_count = p_size.x * p_size.y * p_size.z;
ERR_FAIL_COND_V((uint32_t)p_voxels.size() != float_count, Vector<uint32_t>());
float *work_memory = memnew_arr(float, float_count);
for (uint32_t i = 0; i < float_count; i++) {
work_memory[i] = INF;
}
uint32_t y_mult = p_size.x;
uint32_t z_mult = y_mult * p_size.y;
//plot solid cells
{
const bool *voxr = p_voxels.ptr();
for (uint32_t i = 0; i < float_count; i++) {
bool plot = voxr[i];
if (p_negative) {
plot = !plot;
}
if (plot) {
work_memory[i] = 0;
}
}
}
//process in each direction
//xy->z
for (int i = 0; i < p_size.x; i++) {
for (int j = 0; j < p_size.y; j++) {
edt(&work_memory[i + j * y_mult], z_mult, p_size.z);
}
}
//xz->y
for (int i = 0; i < p_size.x; i++) {
for (int j = 0; j < p_size.z; j++) {
edt(&work_memory[i + j * z_mult], y_mult, p_size.y);
}
}
//yz->x
for (int i = 0; i < p_size.y; i++) {
for (int j = 0; j < p_size.z; j++) {
edt(&work_memory[i * y_mult + j * z_mult], 1, p_size.x);
}
}
Vector<uint32_t> ret;
ret.resize(float_count);
{
uint32_t *w = ret.ptrw();
for (uint32_t i = 0; i < float_count; i++) {
w[i] = uint32_t(Math::sqrt(work_memory[i]));
}
}
memdelete_arr(work_memory);
return ret;
}
Vector<int8_t> Geometry3D::generate_sdf8(const Vector<uint32_t> &p_positive, const Vector<uint32_t> &p_negative) {
ERR_FAIL_COND_V(p_positive.size() != p_negative.size(), Vector<int8_t>());
Vector<int8_t> sdf8;
int s = p_positive.size();
sdf8.resize(s);
const uint32_t *rpos = p_positive.ptr();
const uint32_t *rneg = p_negative.ptr();
int8_t *wsdf = sdf8.ptrw();
for (int i = 0; i < s; i++) {
int32_t diff = int32_t(rpos[i]) - int32_t(rneg[i]);
wsdf[i] = CLAMP(diff, -128, 127);
}
return sdf8;
}