vector<Particle> Lightcone::getSegment(Snapshot& snap, double rMax,
double rMin) {
printf("Generating segment (rMax, rMin) (%.0f, %.0f) . . . \n", rMax, rMin);
vector<Particle> inSegment;
// First find the observer collision box
// Define the 8 points that enclose the lightcone in rotated reference frame
vector<Particle> points;
double d = rMax * tan(mOpening);
// // correction to d
// if (d > rMax) {
// d = rMax;
// }
double dp = rMin * sin(mOpening);
double rp = rMin * cos(mOpening);
//printf("d:d':r' (%.0f:%.0f:%.0f)\n", d, dp, rp);
points.push_back(Particle(-d, -d, rMax));
points.push_back(Particle(-d, d, rMax));
points.push_back(Particle(d, -d, rMax));
points.push_back(Particle(d, d, rMax));
points.push_back(Particle(-dp, -dp, rp));
points.push_back(Particle(-dp, dp, rp));
points.push_back(Particle(dp, -dp, rp));
points.push_back(Particle(dp, dp, rp));
reverseRotation(points);
shiftPointsByObserver(points, true);
Box obsBox = makeBoxFromParticles(points);
// Full sky map
if (mOpening > M_PI / 2) {
obsBox = Box(mObserver.x - rMax, mObserver.y - rMax, mObserver.z - rMax,
2 * rMax);
}
printf(
"Original Observer box at [%.2f, %.2f, %.2f] with size [%.2f, %.2f, %.2f], ",
obsBox.x, obsBox.y, obsBox.z, obsBox.w, obsBox.h, obsBox.d);
// Calculate the offset range need in each direction
int xOffMin, xOffMax, yOffMin, yOffMax, zOffMin, zOffMax;
xOffMin = (obsBox.x / BOX_WIDTH) - 1;
xOffMax = ((obsBox.x + obsBox.w) / BOX_WIDTH) + 1;
// printf("x Offset (Min:Max)(%d:%d) \n", xOffMin, xOffMax);
yOffMin = (obsBox.y / BOX_WIDTH) - 1;
yOffMax = ((obsBox.y + obsBox.h) / BOX_WIDTH) + 1;
// printf("y Offset (Min:Max)(%d:%d) \n", yOffMin, yOffMax);
zOffMin = (obsBox.z / BOX_WIDTH) - 1;
zOffMax = ((obsBox.z + obsBox.d) / BOX_WIDTH) + 1;
// printf("z Offset (Min:Max)(%d:%d) \n", zOffMin, zOffMax);
// Create snapshot boxes from offset and test if they collide with segment
vector<Particle> validOffsets;
for (int i = xOffMin; i <= xOffMax; i++) {
for (int j = yOffMin; j <= yOffMax; j++) {
for (int k = zOffMin; k <= zOffMax; k++) {
// Create the box
Box virtualSnap = Box(i * BOX_WIDTH, j * BOX_WIDTH,
k * BOX_WIDTH, BOX_WIDTH);
if (collide(obsBox, virtualSnap)) {
validOffsets.push_back(Particle(i, j, k));
}
}
}
}
printf("%lu boxes are required.\n", validOffsets.size());
// Check lightcone
inSegment = snap.getCone(rMax, rMin, mTheta, mPhi, mOpening, mObserver,
validOffsets);
if (inSegment.size() == 0) {
printf("[Error] Segment returns 0 particles!\n");
}
printf(" Segment Size: %lu\n", inSegment.size());
return inSegment;
}
