/**
|
|
* Created by Alex on 2/23/2015.
|
|
*/
|
|
|
|
class CentralGravitySolver {
|
|
constructor(body, physicsBody, options) {
|
|
this.body = body;
|
|
this.physicsBody = physicsBody;
|
|
this.setOptions(options);
|
|
}
|
|
|
|
setOptions(options) {
|
|
this.options = options;
|
|
}
|
|
|
|
solve() {
|
|
var dx, dy, distance, node, i;
|
|
var nodes = this.body.nodes;
|
|
var nodeIndices = this.physicsBody.physicsNodeIndices;
|
|
var forces = this.physicsBody.forces;
|
|
|
|
|
|
var gravity = this.options.centralGravity;
|
|
var gravityForce = 0;
|
|
|
|
for (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);
|
|
|
|
gravityForce = (distance == 0) ? 0 : (gravity / distance);
|
|
forces[nodeId].x = dx * gravityForce;
|
|
forces[nodeId].y = dy * gravityForce;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
export {CentralGravitySolver};
|