/**
* Adds the given edge to those to be displayed in the viewer. Note that the edge must connect
* nodes that have already been added to the viewer. This version will use the locations of the
* two nodes to calculate their distance of separation.
*
* @param edge Edge to add to the display.
* @return True if edge was added successfully. False if edge contains nodes that have not been
* added to the viewer.
*/
public boolean addEdge(E edge) {
Particle p1 = nodes.get(edge.getNode1());
if (p1 == null) {
System.err.println("Warning: Node1 not found when creating edge.");
return false;
}
Particle p2 = nodes.get(edge.getNode2());
if (p2 == null) {
System.err.println("Warning: Node2 not found when creating edge.");
return false;
}
// Only add edge if it does not already exist in the collection
if (!edges.containsKey(edge)) {
float x1 = p1.position().x();
float y1 = p1.position().y();
float x2 = p2.position().x();
float y2 = p2.position().y();
// Strength, damping, reset length
edges.put(
edge,
physics.makeSpring(
p1,
p2,
EDGE_STRENGTH,
DAMPING,
(float) Math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2))));
}
return true;
}
/** Centres the particle view on the currently visible nodes. */
private void updateCentroid() {
float xMax = Float.NEGATIVE_INFINITY,
xMin = Float.POSITIVE_INFINITY,
yMin = Float.POSITIVE_INFINITY,
yMax = Float.NEGATIVE_INFINITY;
for (int i = 0; i < physics.getNumParticles(); ++i) {
Particle p = physics.getParticle(i);
xMax = Math.max(xMax, p.position().x());
xMin = Math.min(xMin, p.position().x());
yMin = Math.min(yMin, p.position().y());
yMax = Math.max(yMax, p.position().y());
}
float xRange = xMax - xMin;
float yRange = yMax - yMin;
if ((xRange == 0) && (yRange == 0)) {
xRange = Math.max(1, xMax);
yRange = Math.max(1, yMax);
}
float zScale = (float) Math.min(height / (yRange * 1.2), width / (xRange * 1.2));
centroid.setTarget(xMin + 0.5f * xRange, yMin + 0.5f * yRange, zScale);
}