vis.js is a dynamic, browser-based visualization library
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import BarnesHutSolver from "./BarnesHutSolver"
/**
* @class ForceAtlas2BasedRepulsionSolver
* @extends BarnesHutSolver
*/
class ForceAtlas2BasedRepulsionSolver extends BarnesHutSolver {
/**
* @param {Object} body
* @param {{physicsNodeIndices: Array, physicsEdgeIndices: Array, forces: {}, velocities: {}}} physicsBody
* @param {Object} options
* @constructor ForceAtlas2BasedRepulsionSolver
* @extends BarnesHutSolver
*/
constructor(body, physicsBody, options) {
super(body, physicsBody, options);
}
/**
* Calculate the forces based on the distance.
*
* @param {number} distance
* @param {number} dx
* @param {number} dy
* @param {vis.Node} node
* @param {Object} parentBranch
* @private
*/
_calculateForces(distance, dx, dy, node, parentBranch) {
if (distance === 0) {
distance = 0.1 * Math.random();
dx = distance;
}
if (this.overlapAvoidanceFactor < 1 && node.shape.radius) {
distance = Math.max(0.1 + (this.overlapAvoidanceFactor * node.shape.radius), distance - node.shape.radius);
}
let degree = (node.edges.length + 1);
// the dividing by the distance cubed instead of squared allows us to get the fx and fy components without sines and cosines
// it is shorthand for gravityforce with distance squared and fx = dx/distance * gravityForce
let gravityForce = this.options.gravitationalConstant * parentBranch.mass * node.options.mass * degree / Math.pow(distance,2);
let fx = dx * gravityForce;
let fy = dy * gravityForce;
this.physicsBody.forces[node.id].x += fx;
this.physicsBody.forces[node.id].y += fy;
}
}
export default ForceAtlas2BasedRepulsionSolver;