private bool processRank(Particle p, Rank rank, ref Dictionary<Particle, Rank> ranks)
{
_moveAttempts[p] = true;
bool particleMoved = false;
// Try to move the Particle in its preferred direction
Direction dir = rank.MaxDirection;
int offset = Math.Sign(rank.Pulls[dir]);
bool canMove = canMoveInDirection(p, rank, dir, offset, ref ranks);
if (canMove) {
moveParticle(p, dir, offset);
particleMoved = true;
}
// If unsuccessful, try to move in the other direction
else {
dir = (rank.MaxDirection == Direction.Vertical) ? Direction.Horizontal : Direction.Vertical;
offset = Math.Sign(rank.Pulls[dir]);
canMove = canMoveInDirection(p, rank, dir, offset, ref ranks);
if (canMove) {
moveParticle(p, dir, offset);
particleMoved = true;
}
}
// Either way, this Particle has been processed, so remove it from the Dictionary
ranks.Remove(p);
_moveAttempts[p] = false;
return particleMoved;
}
// HELPER FUNCTIONS
private void initialize()
{
// Add a random number of random particles
for (int p = 0; p < ParticleCount; ++p) {
int atomicNum = _rand.Next(0, ElementCount);
int x, y;
do {
x = _rand.Next(0, Size);
y = _rand.Next(0, Size);
} while (_lattice[x, y] != null);
Particle particle = new Particle(atomicNum, x, y, Temperature);
_lattice[x, y] = particle;
_moveAttempts.Add(particle, false);
}
}
private bool canMoveInDirection(Particle p, Rank rank, Direction dir, int offset, ref Dictionary<Particle, Rank> ranks)
{
int x = p.Position.X;
int y = p.Position.Y;
// If the neighboring position is off the lattice then retun false
bool vertMax = (dir == Direction.Vertical);
if ( ( vertMax && (y + offset < 0 || Size <= y + offset)) ||
(!vertMax && (x + offset < 0 || Size <= x + offset)) )
{
return false;
}
// Otherwise, if the position is open, return true
Particle neighbor = (vertMax ? _lattice[x, y + offset] : _lattice[x + offset, y]);
if (neighbor == null)
return true;
// Recursive case: the position is occupied, so return whether or not the neighbor can move
if (!ranks.ContainsKey(neighbor))
return false;
if (_moveAttempts[p])
return true;
bool neighborCanMove = processRank(neighbor, ranks[neighbor], ref ranks);
return neighborCanMove;
}
private Rank getParticleRank(Particle particle)
{
int x = particle.Position.X;
int y = particle.Position.Y;
// Get the pulls in all directions
double sumLeft = 0d;
for (int px = 0; px < x; ++px) {
Particle other = _lattice[px, y];
double electronegativity = (other?.Electronegativity ?? 1d);
sumLeft += electronegativity / Math.Abs(px - x);
}
double sumRight = 0d;
for (int px = x + 1; px < Size; ++px) {
Particle other = _lattice[px, y];
double electronegativity = (other?.Electronegativity ?? 1d);
sumRight += electronegativity / Math.Abs(px - x);
}
double sumUp = 0d;
for (int py = 0; py < y; ++py) {
Particle other = _lattice[x, py];
double electronegativity = (other?.Electronegativity ?? 1d);
sumUp += electronegativity / Math.Abs(py - y);
}
double sumDown = 0d;
for (int py = y + 1; py < Size; ++py) {
Particle other = _lattice[x, py];
double electronegativity = (other?.Electronegativity ?? 1d);
sumDown += electronegativity / Math.Abs(py - y);
}
// Store the effective pull in each direction
Dictionary<Direction, double> pulls = new Dictionary<Direction, double>() {
{ Direction.Vertical, sumDown - sumUp },
{ Direction.Horizontal, sumRight - sumLeft },
};
// Get the max Direction
double max = 0d;
Direction maxDir = Direction.Vertical;
double absVert = Math.Abs(pulls[Direction.Vertical]);
if (absVert > max) {
max = absVert;
maxDir = Direction.Vertical;
}
double absHorz = Math.Abs(pulls[Direction.Horizontal]);
if (absHorz > max) {
max = absHorz;
maxDir = Direction.Horizontal;
}
// Return the rank for this Particle
Rank r = new Rank() {
Pulls = pulls,
MaxDirection = maxDir,
};
return r;
}
public void moveParticle(Particle p, Direction dir, int offset)
{
int x = p.Position.X;
int y = p.Position.Y;
if (_lattice[x, y].Equals(p))
_lattice[x, y] = null;
bool vertMax = (dir == Direction.Vertical);
if (vertMax) {
_lattice[x, y + offset] = p;
p.Position = new Point(x, y + offset);
}
else {
_lattice[x + offset, y] = p;
p.Position = new Point(x + offset, y);
}
}