/**
* 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;
}
/**
* Updates the particle view. This should be called on each draw cycle in order to update the
* positions of all nodes and edges in the viewer. If you need to update the positions of
* particles without drawing it (e.g. to speed up movement, call updateParticles() instead.
*/
public void draw() {
parent.pushStyle();
parent.pushMatrix();
zoomer.transform();
updateCentroid();
centroid.tick();
parent.translate(width / 2, height / 2);
parent.scale(centroid.getZ());
parent.translate(-centroid.getX(), -centroid.getY());
if (!isPaused) {
updateParticles();
}
// Ensure that any selected element is positioned at the mouse location.
if (selectedNode != null) {
Particle p = nodes.get(selectedNode);
p.makeFixed();
float mX = (zoomer.getMouseCoord().x - (width / 2)) / centroid.getZ() + centroid.getX();
float mY = (zoomer.getMouseCoord().y - (height / 2)) / centroid.getZ() + centroid.getY();
p.position().set(mX, mY, 0);
}
// Draw edges if we have positive stroke weight.
if (parent.g.strokeWeight > 0) {
parent.stroke(0, 180);
parent.noFill();
for (Map.Entry<E, Spring> row : edges.entrySet()) {
E edge = row.getKey();
Spring spring = row.getValue();
Vector3D p1 = spring.getOneEnd().position();
Vector3D p2 = spring.getTheOtherEnd().position();
edge.draw(parent, p1.x(), p1.y(), p2.x(), p2.y());
}
}
// Draw nodes.
parent.noStroke();
parent.fill(120, 50, 50, 180);
for (Map.Entry<N, Particle> row : nodes.entrySet()) {
N node = row.getKey();
Vector3D p = row.getValue().position();
node.draw(parent, p.x(), p.y());
}
parent.popMatrix();
parent.popStyle();
}
/**
* Reports the node nearest to the given screen coordinates but within the given radius.
*
* @param x x screen coordinate to query
* @param y y screen coordinate to query
* @param radius Radius within which to search for nodes. If negative, all nodes are searched.
* @return Node nearest to the given screen coordinates or null if no nodes found within the given
* radius of the coordinates.
*/
public N getNearest(float x, float y, float radius) {
float mX = (x - width / 2) / centroid.getZ() + centroid.getX();
float mY = (y - height / 2) / centroid.getZ() + centroid.getY();
float nearestDSq = radius * radius;
N nearestNode = null;
for (Map.Entry<N, Particle> row : nodes.entrySet()) {
N node = row.getKey();
Particle p = row.getValue();
float px = p.position().x();
float py = p.position().y();
float dSq = (px - mX) * (px - mX) + (py - mY) * (py - mY);
if (dSq < nearestDSq) {
nearestDSq = dSq;
nearestNode = node;
}
}
return nearestNode;
}
/** Allows a node to be selected with the mouse. */
public void selectNearestWithMouse() {
if (!zoomer.isMouseCaptured()) {
float mX = (zoomer.getMouseCoord().x - (width / 2)) / centroid.getZ() + centroid.getX();
float mY = (zoomer.getMouseCoord().y - (height / 2)) / centroid.getZ() + centroid.getY();
if (selectedNode == null) {
float nearestDSq = Float.MAX_VALUE;
for (Map.Entry<N, Particle> row : nodes.entrySet()) {
N node = row.getKey();
Particle p = row.getValue();
float px = p.position().x();
float py = p.position().y();
float dSq = (px - mX) * (px - mX) + (py - mY) * (py - mY);
if (dSq < nearestDSq) {
nearestDSq = dSq;
selectedNode = node;
}
}
}
}
}
/** 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);
}
/**
* Tethers the given node to its location with the given strength.
*
* @param node The node to be tethered.
* @param strength Strength of the tether.
* @return True if the viewer contains the given node and it was tethered successfully.
*/
public boolean tether(N node, float strength) {
Particle p1 = nodes.get(node);
if (p1 == null) {
return false;
}
// Grab the tethering stake if it has already been created, otherwise create a new one.
Particle stake = stakes.get(node);
if (stake == null) {
stake = physics.makeParticle(1, node.getLocation().x, node.getLocation().y, 0);
stake.makeFixed();
stakes.put(node, stake);
}
// Grab the tether if it has already been created, otherwise create a new one.
Spring tether = tethers.get(stake);
if (tether == null) {
tether = physics.makeSpring(stake, p1, strength, DAMPING, Float.MIN_VALUE);
tethers.put(stake, tether);
} else {
tether.setStrength(strength);
}
return true;
}