int octsect_active(const Region R, const MathTree* tree, Region* const out)
{
out[0] = R;
uint8_t bits = 1;
const uint8_t active = active_axes(tree);
if (R.nk > 1 && (active & 1)) {
bisect_z(out[0], out, out+1);
bits |= (bits << 1);
}
if (R.nj > 1 && (active & 2)) {
if (bits & (1 << 0))
bisect_y(out[0], out, out+2);
if (bits & (1 << 1))
bisect_y(out[1], out+1, out+3);
bits |= (bits << 2);
}
if (R.ni > 1 && (active & 4)) {
if (bits & (1 << 0))
bisect_x(out[0], out, out+4);
if (bits & (1 << 1))
bisect_x(out[1], out+1, out+5);
if (bits & (1 << 2))
bisect_x(out[2], out+2, out+6);
if (bits & (1 << 3))
bisect_x(out[3], out+3, out+7);
bits |= (bits << 4);
}
return bits;
}
// Splits a region into up to 8 sections, returning
// a bitfield with bits set where a region was stored.
uint8_t octsect(const Region R, Region* const out)
{
out[0] = R;
uint8_t bits = 1;
if (R.nk > 1) {
bisect_z(out[0], out, out+1);
bits |= (bits << 1);
}
if (R.nj > 1) {
if (bits & (1 << 0))
bisect_y(out[0], out, out+2);
if (bits & (1 << 1))
bisect_y(out[1], out+1, out+3);
bits |= (bits << 2);
}
if (R.ni > 1) {
if (bits & (1 << 0))
bisect_x(out[0], out, out+4);
if (bits & (1 << 1))
bisect_x(out[1], out+1, out+5);
if (bits & (1 << 2))
bisect_x(out[2], out+2, out+6);
if (bits & (1 << 3))
bisect_x(out[3], out+3, out+7);
bits |= (bits << 4);
}
return bits;
}
// Splits a region into up to 8 sections, returning
// a bitfield with bits set where a region was stored.
uint8_t octsect_merged(const Region R, const ASDF* const asdf,
Region* const out)
{
out[0] = R;
uint8_t bits = 1;
if (asdf->branches[1] && R.nk > 1) {
bisect_z(out[0], out, out+1);
bits |= (bits << 1);
}
if (asdf->branches[2] && R.nj > 1) {
if (bits & (1 << 0))
bisect_y(out[0], out, out+2);
if (bits & (1 << 1))
bisect_y(out[1], out+1, out+3);
bits |= (bits << 2);
}
if (asdf->branches[4] && R.ni > 1) {
if (bits & (1 << 0))
bisect_x(out[0], out, out+4);
if (bits & (1 << 1))
bisect_x(out[1], out+1, out+5);
if (bits & (1 << 2))
bisect_x(out[2], out+2, out+6);
if (bits & (1 << 3))
bisect_x(out[3], out+3, out+7);
bits |= (bits << 4);
}
return bits;
}
// Splits a region in two along its longest axis. Returns 1
// if the region is of volume 1 and cannot be split.
int bisect(const Region r, Region* const A, Region* const B)
{
if (r.ni * r.nj * r.nk == 1) {
*A = r;
return 1;
}
if (r.ni >= r.nj && r.ni >= r.nk)
bisect_x(r, A, B);
else if (r.nj >= r.nk)
bisect_y(r, A, B);
else
bisect_z(r, A, B);
return 0;
}