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Contents
/**
* Created by Alex on 2/10/14.
*/
var hierarchalRepulsionMixin = {
/**
* Calculate the forces the nodes apply on eachother based on a repulsion field.
* This field is linearly approximated.
*
* @private
*/
_calculateNodeForces: function () {
var dx, dy, distance, fx, fy, combinedClusterSize,
repulsingForce, node1, node2, i, j;
var nodes = this.calculationNodes;
var nodeIndices = this.calculationNodeIndices;
// approximation constants
var b = 5;
var a_base = 0.5 * -b;
// repulsing forces between nodes
var nodeDistance = this.constants.physics.hierarchicalRepulsion.nodeDistance;
var minimumDistance = nodeDistance;
// we loop from i over all but the last entree in the array
// j loops from i+1 to the last. This way we do not double count any of the indices, nor i == j
for (i = 0; i < nodeIndices.length - 1; i++) {
node1 = nodes[nodeIndices[i]];
for (j = i + 1; j < nodeIndices.length; j++) {
node2 = nodes[nodeIndices[j]];
dx = node2.x - node1.x;
dy = node2.y - node1.y;
distance = Math.sqrt(dx * dx + dy * dy);
var a = a_base / minimumDistance;
if (distance < 2 * minimumDistance) {
repulsingForce = a * distance + b; // linear approx of 1 / (1 + Math.exp((distance / minimumDistance - 1) * steepness))
// normalize force with
if (distance == 0) {
distance = 0.01;
}
else {
repulsingForce = repulsingForce / distance;
}
fx = dx * repulsingForce;
fy = dy * repulsingForce;
node1.fx -= fx;
node1.fy -= fy;
node2.fx += fx;
node2.fy += fy;
}
}
}
}
};
Version data entries
4 entries across 4 versions & 1 rubygems