You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
63 lines
1.5 KiB
63 lines
1.5 KiB
/**
|
|
* @class CentralGravitySolver
|
|
*/
|
|
class CentralGravitySolver {
|
|
/**
|
|
*
|
|
* @param {Object} body
|
|
* @param {{physicsNodeIndices: Array, physicsEdgeIndices: Array, forces: {}, velocities: {}}} physicsBody
|
|
* @param {Object} options
|
|
* @constructor CentralGravitySolver
|
|
*/
|
|
constructor(body, physicsBody, options) {
|
|
this.body = body;
|
|
this.physicsBody = physicsBody;
|
|
this.setOptions(options);
|
|
}
|
|
|
|
/**
|
|
*
|
|
* @param {Object} options
|
|
*/
|
|
setOptions(options) {
|
|
this.options = options;
|
|
}
|
|
|
|
/**
|
|
* Calculates forces for each node
|
|
*/
|
|
solve() {
|
|
let dx, dy, distance, node;
|
|
let nodes = this.body.nodes;
|
|
let nodeIndices = this.physicsBody.physicsNodeIndices;
|
|
let forces = this.physicsBody.forces;
|
|
|
|
for (let i = 0; i < nodeIndices.length; i++) {
|
|
let nodeId = nodeIndices[i];
|
|
node = nodes[nodeId];
|
|
dx = -node.x;
|
|
dy = -node.y;
|
|
distance = Math.sqrt(dx * dx + dy * dy);
|
|
|
|
this._calculateForces(distance, dx, dy, forces, node);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Calculate the forces based on the distance.
|
|
* @param {number} distance
|
|
* @param {number} dx
|
|
* @param {number} dy
|
|
* @param {Object<vis.Node.id, vis.Node>} forces
|
|
* @param {vis.Node} node
|
|
* @private
|
|
*/
|
|
_calculateForces(distance, dx, dy, forces, node) {
|
|
let gravityForce = (distance === 0) ? 0 : (this.options.centralGravity / distance);
|
|
forces[node.id].x = dx * gravityForce;
|
|
forces[node.id].y = dy * gravityForce;
|
|
}
|
|
}
|
|
|
|
|
|
export default CentralGravitySolver;
|