// Vector arithmetic
// A: current position
// B: target position
// d: distance to travel along the line from A to B
// A_moved = A + |B - A| * d where | | represents 'norm'
public void updateLocation() {
Vector2f currentLoc = new Vector2f((float) getX2(), (float) getY2());
Vector2f update = new Vector2f(target.x, target.y);
update.sub(currentLoc); // B - A
update.normalize(); // |B - A|
update.scale(travelDistance); // |B - A| x dist
currentLoc.add(update); // A + |B - A| x d
setLine(x1, y1, currentLoc.x, currentLoc.y);
}
/** @return Vector2f vector holding the starting location for a Person Node */
public Vector2f pStartLocation() {
// Try to place the new node in a location that won't disrupt the system too much (by being too
// close to another person)
for (int i = 0; i < 100; i++) {
Vector2f testStart = this.randomLocation();
boolean good = true;
for (code_swarm.PersonNode n : code_swarm.getLivingPeople()) {
Vector2f delta = new Vector2f();
delta.sub(n.mPosition, testStart);
if (delta.lengthSquared() < MIN_DISTANCE_SQR) {
good = false;
break;
}
}
if (good) return testStart;
}
return randomLocation();
}
/**
* Method that allows Physics Engine to modify Speed / Position during the relax phase.
*
* @param pNode the node to which the force apply @Note Standard physics is "Position Variation =
* Speed x Duration" with a convention of "Duration=1" between to frames
*/
public void onRelax(code_swarm.PersonNode pNode) {
Vector2f delta = new Vector2f();
// A gentle force to attract pNodes to the center
// NOTE: this should be done prior to attraction/repulsion forces, otherwise
// tends to generate a grid-like pattern
Vector2f midpoint = new Vector2f(code_swarm.width / 2, code_swarm.height / 2);
delta = new Vector2f();
delta.sub(midpoint, pNode.mPosition);
delta.scale(1 / delta.length() * 0.003f);
pNode.mPosition.add(delta);
// All person nodes attract each other, but only to a certain point, then they repel with gentle
// force
for (code_swarm.PersonNode n : code_swarm.getLivingPeople()) {
if (pNode != n) {
delta.sub(pNode.mPosition, n.mPosition);
if (delta.lengthSquared() < MIN_DISTANCE_SQR) {
// This calculation gives a 'stiff spring' affect
float toMove = ((float) Math.sqrt(MIN_DISTANCE_SQR) - delta.length()) / 10.0f;
// This calculation gives a much nicer flow
// float toMove = 0.03f;
delta.scale((1 / delta.length()) * toMove);
n.mPosition.sub(delta);
pNode.mPosition.add(delta);
} else {
float toMove = -0.003f;
delta.scale((1 / delta.length()) * toMove);
n.mPosition.sub(delta);
pNode.mPosition.add(delta);
}
}
}
// place the edited files around the person
Iterator<code_swarm.FileNode> editedFiles = pNode.editing.iterator();
int index = 0;
int radius = 45;
final int node_size = 4;
final int salt = pNode.hashCode(); // used to randomize orientation of circle of nodes
int num_nodes_in_ring = (int) ((2 * radius * Math.PI) / node_size);
while (editedFiles.hasNext()) {
// if we've placed all the nodes in this ring...
if (index == num_nodes_in_ring) {
// start on a new ring
radius += node_size;
num_nodes_in_ring = (int) ((2 * radius * Math.PI) / node_size);
index = 0;
}
index++;
code_swarm.FileNode file = editedFiles.next();
// leave a hole for the null files
if (file == null) continue;
final int place_around_ring = index * num_nodes_in_ring + salt;
int x = (int) (radius * Math.sin(place_around_ring));
int y = (int) (radius * Math.cos(place_around_ring));
delta = new Vector2f();
delta.sub(file.mPosition, new Vector2f(pNode.mPosition.x + x, pNode.mPosition.y + y));
float distance = delta.length();
delta.scale(1 / delta.length() * -0.01f * distance);
file.mPosition.add(delta);
}
}
