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#include "primitive_descriptor.h"
typedef raw_vector3d_t vec3;
vec3 add(const vec3& point1, const vec3& point2) { return vec3{point1.x + point2.x, point1.y + point2.y, point1.z + point2.z}; }
vec3 operator+(const vec3& point1, const vec3& point2) { return add(point1, point2); }
vec3 sub(const vec3& point1, const vec3& point2) { return vec3{point1.x - point2.x, point1.y - point2.y, point1.z - point2.z}; }
vec3 operator-(const vec3& point1, const vec3& point2) { return sub(point1, point2); }
vec3 mul(const vec3& vector, const double scalar) { return vec3{vector.x * scalar, vector.y * scalar, vector.z * scalar}; }
vec3 operator*(const vec3& point1, const double scalar) { return mul(point1, scalar); }
vec3 div(const vec3& vector, const double scalar)
{
if (scalar == 0) { throw std::runtime_error("Division by zero error."); }
return vec3{vector.x / scalar, vector.y / scalar, vector.z / scalar};
}
vec3 operator/(const vec3& point1, const double scalar) { return div(point1, scalar); }
double dot(const vec3& vector1, const vec3& vector2)
{
return vector1.x * vector2.x + vector1.y * vector2.y + vector1.z * vector2.z;
}
double dot2(const vec3& vector) { return dot(vector, vector); }
vec3 cross(const vec3& vector1, const vec3& vector2)
{
return vec3{vector1.y * vector2.z - vector1.z * vector2.y,
vector1.z * vector2.x - vector1.x * vector2.z,
vector1.x * vector2.y - vector1.y * vector2.x};
}
double len(const vec3& vector) { return sqrt(dot(vector, vector)); }
double dis(const vec3& point1, const vec3& point2) { return len(sub(point1, point2)); }
double clamp(const double t, const double min, const double max)
{
if (t <= min) { return min; }
if (t >= max) { return max; }
return t;
}
double sign(const double t) { return t >= 0.0 ? 1.0 : -1.0; }
vec3 normalize(const vec3& vector)
{
double temp = len(vector);
if (abs(temp) < 1e-8) { throw std::runtime_error("Cannot normalize a zero-length vector."); }
temp = 1.0 / temp;
return vec3{vector.x * temp, vector.y * temp, vector.z * temp};
}
double evaluate_constant(constant_descriptor_t* desc, raw_vector3d_t point) { return desc->value; }
double evaluate_plane(plane_descriptor_t* desc, raw_vector3d_t point) { return dot(point - desc->point, desc->normal); }
double evaluate_sphere(sphere_descriptor_t* desc, raw_vector3d_t point) { return dis(point, desc->center) - desc->radius; }
double evaluate_cylinder(cylinder_descriptor_t* desc, raw_vector3d_t point)
{
vec3& b = desc->bottom_origion;
vec3 a = b + desc->offset;
vec3& p = point;
double r = desc->radius;
vec3 ba = b - a;
vec3 pa = p - a;
double baba = dot(ba, ba);
double paba = dot(pa, ba);
double x = len(pa * baba - ba * paba) - r * baba;
double y = abs(paba - baba * 0.5) - baba * 0.5;
double x2 = x * x;
double y2 = y * y * baba;
double d = (fmax(x, y) < 0.0) ? -fmin(x2, y2) : (((x > 0.0) ? x2 : 0.0) + ((y > 0.0) ? y2 : 0.0));
return sign(d) * sqrt(abs(d)) / baba;
}
double evaluate_cone(cone_descriptor_t* desc, raw_vector3d_t point)
{
vec3& a = desc->top_point;
vec3& b = desc->bottom_point;
vec3& p = point;
double ra = desc->radius1;
double rb = desc->radius2;
double rba = rb - ra;
double baba = dot(b - a, b - a);
double papa = dot(p - a, p - a);
double paba = dot(p - a, b - a) / baba;
double x = sqrt(papa - paba * paba * baba);
double cax = fmax(0.0, x - ((paba < 0.5) ? ra : rb));
double cay = abs(paba - 0.5) - 0.5;
double k = rba * rba + baba;
double f = clamp((rba * (x - ra) + paba * baba) / k, 0.0, 1.0);
double cbx = x - ra - f * rba;
double cby = paba - f;
double s = (cbx < 0.0 && cay < 0.0) ? -1.0 : 1.0;
return s * sqrt(fmin(cax * cax + cay * cay * baba, cbx * cbx + cby * cby * baba));
}
double evaluate_box(box_descriptor_t* desc, raw_vector3d_t point)
{
// Get the minimum and maximum bounding coordinates of the box
auto min_point = desc->left_bottom_point;
auto max_point = min_point + vec3{desc->length, desc->width, desc->height};
// Point in the box
if (point.x >= min_point.x && point.x <= max_point.x && point.y >= min_point.y && point.y <= max_point.y
&& point.z >= min_point.z && point.z <= max_point.z) {
double min = fmin(point.x - min_point.x, max_point.x - point.x);
min = fmin(min, fmin(point.y - min_point.y, max_point.y - point.y));
min = fmin(min, fmin(point.z - min_point.y, max_point.z - point.z));
return -min;
} else {
// Calculate the closest distance from the point to the border of each dimension of the box
double dx = fmax(fmax(min_point.x - point.x, point.x - max_point.x), 0.0);
double dy = fmax(fmax(min_point.y - point.y, point.y - max_point.y), 0.0);
double dz = fmax(fmax(min_point.z - point.z, point.z - max_point.z), 0.0);
return sqrt(dx * dx + dy * dy + dz * dz);
}
}
double triangle_sdf(const vec3& p, const vec3& a, const vec3& b, const vec3& c)
{
vec3 ba = b - a;
vec3 pa = p - a;
vec3 cb = c - b;
vec3 pb = p - b;
vec3 ac = a - c;
vec3 pc = p - c;
vec3 nor = cross(ba, ac);
return sqrt((sign(dot(cross(ba, nor), pa)) + sign(dot(cross(cb, nor), pb)) + sign(dot(cross(ac, nor), pc)) < 2.0)
? fmin(fmin(dot2(ba * clamp(dot(ba, pa) / dot2(ba), 0.0, 1.0) - pa),
dot2(cb * clamp(dot(cb, pb) / dot2(cb), 0.0, 1.0) - pb)),
dot2(ac * clamp(dot(ac, pc) / dot2(ac), 0.0, 1.0) - pc))
: dot(nor, pa) * dot(nor, pa) / dot2(nor));
}
bool ray_intersects_triangle(const vec3& point, const vec3& dir, const vec3& v0, const vec3& v1, const vec3& v2)
{
vec3 e1 = v1 - v0;
vec3 e2 = v2 - v0;
vec3 s = point - v0;
vec3 s1 = cross(dir, e2);
vec3 s2 = cross(s, e1);
double coeff = 1.0 / dot(s1, e1);
double t = coeff * dot(s2, e2);
double b1 = coeff * dot(s1, s);
double b2 = coeff * dot(s2, dir);
return t >= 0 && b1 >= 0 && b2 >= 0 && (1 - b1 - b2) >= 0;
}
double evaluate_mesh(mesh_descriptor_t* desc, raw_vector3d_t point)
{
// Note: There is no check for out-of-bounds access to points, indexes and faces
auto points = desc->points;
auto indexs = desc->indexs;
auto face = desc->faces;
double min_distance = std::numeric_limits<double>::infinity();
int count = 0;
for (int i = 0; i < desc->face_number; i++) {
int begin_index = face[i][0];
int length = face[i][1];
auto& point0 = points[indexs[begin_index]];
bool flag = false;
for (int j = 1; j < length - 1; j++) {
double temp = triangle_sdf(point, point0, points[indexs[j]], points[indexs[j + 1]]);
min_distance = fmin(min_distance, temp);
if (!flag
&& ray_intersects_triangle(point, vec3{1.0, 0.0, 0.0}, point0, points[indexs[j]], points[indexs[j + 1]])) {
flag = true;
}
}
if (flag) { count++; }
}
if (min_distance < 1e-8) { return 0; }
if (count % 2 == 1) {
return -min_distance;
} else {
return min_distance;
}
}
double evaluate_extrude(extrude_descriptor_t* desc, raw_vector3d_t point)
{
// Note: There is no check for out-of-bounds access to points and bulges
auto points = desc->points;
auto bulges = desc->bulges;
auto extusion = desc->extusion;
double min_distance = std::numeric_limits<double>::infinity();
int count = 0;
// Note: Currently only straight edges are considered, the bottom and top surfaces are polygons
auto& point0 = points[0];
bool flag1 = false;
bool flag2 = false;
for (int i = 1; i < desc->edges_number - 1; i++) {
// Bottom
double temp = triangle_sdf(point, point0, points[i], points[i + 1]);
min_distance = fmin(min_distance, temp);
if (!flag1 && ray_intersects_triangle(point, vec3{1.0, 0.0, 0.0}, point0, points[i], points[i + 1])) { flag1 = true; }
// Top
temp = triangle_sdf(point, point0 + extusion, points[i] + extusion, points[i + 1] + extusion);
min_distance = fmin(min_distance, temp);
if (!flag2
&& ray_intersects_triangle(point,
vec3{1.0, 0.0, 0.0},
point0 + extusion,
points[i] + extusion,
points[i + 1] + extusion)) {
flag2 = true;
}
}
if (flag1) { count++; }
if (flag2) { count++; }
// Side
for (int i = 0; i < desc->edges_number; i++) {
auto& point1 = points[i];
vec3 point2;
if (i + 1 == desc->edges_number) {
point2 = points[0];
} else {
point2 = points[i + 1];
}
auto point3 = point2 + extusion;
auto point4 = point1 + extusion;
auto bulge = bulges[i];
if (abs(bulge) < 1e-8) {
// Straight Edge
bool flag = false;
double temp = triangle_sdf(point, point1, point2, point3);
min_distance = fmin(min_distance, temp);
if (!flag && ray_intersects_triangle(point, vec3{1.0, 0.0, 0.0}, point1, point2, point3)) { flag = true; }
temp = triangle_sdf(point, point1, point3, point4);
min_distance = fmin(min_distance, temp);
if (!flag && ray_intersects_triangle(point, vec3{1.0, 0.0, 0.0}, point1, point3, point4)) { flag = true; }
if (flag) { count++; }
} else {
// Curved Edge
// TODO
}
}
if (count % 2 == 1) {
return -min_distance;
} else {
return min_distance;
}
}