// Follow an Archimedean spiral, in polar coordinates: r=a+b\theta
Pointfs FillArchimedeanChords::_generate(coord_t min_x, coord_t min_y, coord_t max_x, coord_t max_y)
{
// Radius to achieve.
coordf_t rmax = std::sqrt(coordf_t(max_x)*coordf_t(max_x)+coordf_t(max_y)*coordf_t(max_y)) * std::sqrt(2.) + 1.5;
// Now unwind the spiral.
coordf_t a = 1.;
coordf_t b = 1./(2.*M_PI);
coordf_t theta = 0.;
coordf_t r = 1;
Pointfs out;
//FIXME Vojtech: If used as a solid infill, there is a gap left at the center.
out.push_back(Pointf(0, 0));
out.push_back(Pointf(1, 0));
while (r < rmax) {
theta += 1. / r;
r = a + b * theta;
out.push_back(Pointf(r * cos(theta), r * sin(theta)));
}
return out;
}
Pointfs FillHilbertCurve::_generate(coord_t min_x, coord_t min_y, coord_t max_x, coord_t max_y)
{
// Minimum power of two square to fit the domain.
size_t sz = 2;
size_t pw = 1;
{
size_t sz0 = std::max(max_x + 1 - min_x, max_y + 1 - min_y);
while (sz < sz0) {
sz = sz << 1;
++ pw;
}
}
size_t sz2 = sz * sz;
Pointfs line;
line.reserve(sz2);
for (size_t i = 0; i < sz2; ++ i) {
Point p = hilbert_n_to_xy(i);
line.push_back(Pointf(p.x + min_x, p.y + min_y));
}
return line;
}
Pointfs FillOctagramSpiral::_generate(coord_t min_x, coord_t min_y, coord_t max_x, coord_t max_y)
{
// Radius to achieve.
coordf_t rmax = std::sqrt(coordf_t(max_x)*coordf_t(max_x)+coordf_t(max_y)*coordf_t(max_y)) * std::sqrt(2.) + 1.5;
// Now unwind the spiral.
coordf_t r = 0;
coordf_t r_inc = sqrt(2.);
Pointfs out;
out.push_back(Pointf(0, 0));
while (r < rmax) {
r += r_inc;
coordf_t rx = r / sqrt(2.);
coordf_t r2 = r + rx;
out.push_back(Pointf( r, 0.));
out.push_back(Pointf( r2, rx));
out.push_back(Pointf( rx, rx));
out.push_back(Pointf( rx, r2));
out.push_back(Pointf(0., r));
out.push_back(Pointf(-rx, r2));
out.push_back(Pointf(-rx, rx));
out.push_back(Pointf(-r2, rx));
out.push_back(Pointf(-r, 0.));
out.push_back(Pointf(-r2, -rx));
out.push_back(Pointf(-rx, -rx));
out.push_back(Pointf(-rx, -r2));
out.push_back(Pointf(0., -r));
out.push_back(Pointf( rx, -r2));
out.push_back(Pointf( rx, -rx));
out.push_back(Pointf( r2+r_inc, -rx));
}
return out;
}
