/**
* Cools down the movement on the node.
*
* @param current Node to cool
* @param numOfIterations current state of layout process (heat)
*/
private void calculateNodeCooling(Node current, double numOfIterations) {
/* Check if cooling should start */
if (COOLING_START_DELAY < numOfIterations) {
double coolingFactor = 1 - ((numOfIterations - COOLING_START_DELAY) / COOLING_DIVIDER);
// double coolingFactor = 1 / COOLING_DIVIDER;
coolingFactor = Math.max(COOLING_FACTOR_MINIMUM, coolingFactor);
/* Do some cooling, to stop the mad bouncing */
double vx = current.getVX() * coolingFactor;
double vy = current.getVY() * coolingFactor;
/* if(vx > MIN_VX) {
current.setVX(vx);
}
else {
current.setVX(0);
}
if(vy > MIN_VY) {
current.setVY(vy);
}
else {
current.setVY(0);
}*/
current.setVX(current.getVX() * coolingFactor);
current.setVY(current.getVY() * coolingFactor);
}
}
/**
* This function slows down a node's velocity based on it's weight. So that the heavier the node
* the less it moves.
*
* @param n node to apply friction for.
*/
private void applyNodeFriction(Node n) {
n.setVX(n.getVX() / n.getWeight());
n.setVY(n.getVY() / n.getWeight());
}
/**
* Layout core logic.
*
* <p>This iterates over all the nodes and determines their velocities based on a force directed
* layout approach, performs collision detection/avoidance and then ultimately their new positions
* as they move.
*/
private void doLayout() {
double maxVelocity = 100;
double numOfIterations = 0;
double step = 100;
double skip = step;
int counter = 1;
boolean dividerChanged = false;
// active = true;
while (maxVelocity > 1 && active && (numOfIterations < MAX_NUM_OF_ITERATIONS)) {
counter++;
maxVelocity = 0;
numOfIterations++;
Iterator<Node> outer = controller.getNodeIterator();
startTime = System.currentTimeMillis();
double systemMovement = 0;
double kineticEnergy = 0;
/* Iterate over all nodes and calculate velocity */
while (outer.hasNext()) {
Node current = outer.next();
current.resetVelocity();
current.resetAcceleration();
/*
* If current node is not pinned or selected,
* perform force directed layout calculations here.
*/
if (!((current == controller.getGraphSelected()) || current.isPinned())) {
calculateNodeAttractiveForce(current);
calculateNodeRepulsiveForces(current);
// applyNodeFriction(current);
// if (IS_COOLING) {
// calculateNodeCooling(current, numOfIterations);
// }
// calculate velocities
current.setVX(current.getVX() + current.accelx * TIMESTEP * DAMPING);
current.setVY(current.getVY() + current.accely * TIMESTEP * DAMPING);
double speedSquared =
current.getVX() * current.getVX() + current.getVY() * current.getVY();
kineticEnergy += 0.5 * current.weight * speedSquared;
// cap the velocity
if (current.getVX() >= 0) {
current.setVX(Math.min(current.getVX(), MAX_DIST_PER_MOVE));
} else {
current.setVX(Math.max(current.getVX(), -MAX_DIST_PER_MOVE));
}
if (current.getVY() >= 0) {
current.setVY(Math.min(current.getVY(), MAX_DIST_PER_MOVE));
} else {
current.setVY(Math.max(current.getVY(), -MAX_DIST_PER_MOVE));
}
// System.out.println("vy "+ current.getVY() + ", vx " + current.getVX());
}
}
/* Iterate over all nodes move them after all the velocities are set */
outer = controller.getNodeIterator();
while (outer.hasNext()) {
Node current = outer.next();
int xStart = current.getX();
int yStart = current.getY();
/* update node position */
int xEnd = current.getX() + (int) current.getVX();
int yEnd = current.getY() + (int) current.getVY();
int dX = Math.abs(xStart - xEnd);
int dY = Math.abs(yStart - yEnd);
// systemMovement += dX;
// systemMovement += dY;
// if(dX + dY > 6) {
controller.moveNode(current, xEnd, yEnd);
// }
// controller.moveNode(current, Math.min(current.getX() + (int)
// current.getVX(),MAX_DIST_PER_MOVE), Math.min(current.getY() + (int) current.getVY(),
// MAX_DIST_PER_MOVE));
/* compute maxVelocity for layout iteration */
maxVelocity =
Math.max(
maxVelocity,
Math.sqrt(Math.pow(current.getVX(), 2) + Math.pow(current.getVY(), 2)));
}
if (kineticEnergy < ENERGY_THRESHOLD) {
numOfIterations = MAX_NUM_OF_ITERATIONS;
}
/* Make animation slower */
try {
Thread.sleep(sleepInterval);
} catch (InterruptedException ex) {
}
/* Calculate how long the iteration took */
stopTime = System.currentTimeMillis();
long duration = stopTime - startTime;
if ((duration > MAX_ITERATION_TIME) && (sleepInterval > 5)) {
sleepInterval -= 5;
} else if (duration < MIN_ITERATION_TIME) {
sleepInterval += 5;
}
if (numOfIterations > skip) {
skip += step;
System.out.print('.');
}
}
/* We've reached a stable layout, hold on for now */
stable = true;
// System.out.println("ran in " + numOfIterations + " iterations.");
}