return function applyEdgeAttraction(edge) {
var na = edge.source;
var nb = edge.target;
vec2.sub(v, na.position, nb.position);
var d = vec2.len(v);
var w;
if (this.edgeWeightInfluence === 0) {
w = 1;
} else if (this.edgeWeightInfluence == 1) {
w = edge.weight;
} else {
w = Math.pow(edge.weight, this.edgeWeightInfluence);
}
var factor;
if (this.preventOverlap) {
d = d - na.size - nb.size;
if (d <= 0) {
// No attraction
return;
}
}
var factor = -w * d / this._k;
vec2.scaleAndAdd(na.force, na.force, v, factor);
vec2.scaleAndAdd(nb.force, nb.force, v, -factor);
};
return function(node) {
// PENDING Move to centerOfMass or [0, 0] ?
// vec2.sub(v, this._rootRegion.centerOfMass, node.position);
// vec2.negate(v, node.position);
vec2.sub(v, this.center, node.position);
var d = vec2.len(v);
vec2.scaleAndAdd(node.force, node.force, v, this.gravity * node.mass / (d + 1));
}
return function(node) {
// PENDING Move to centerOfMass or [0, 0] ?
// vec2.sub(v, this._rootRegion.centerOfMass, node.position);
// vec2.negate(v, node.position);
vec2.sub(v, this.center, node.position);
if (this.width > this.height) {
// Stronger gravity on y axis
v[1] *= this.width / this.height;
} else {
// Stronger gravity on x axis
v[0] *= this.height / this.width;
}
var d = vec2.len(v) / 100;
if (this.strongGravity) {
vec2.scaleAndAdd(node.force, node.force, v, d * this.gravity * node.mass);
} else {
vec2.scaleAndAdd(node.force, node.force, v, this.gravity * node.mass / (d + 1));
}
};
return function (pointSet, p0, p1, out) {
// Limit the max turning angle
var maxTurningAngleCos = Math.cos(this.maxTurningAngle);
var maxTurningAngleTan = Math.tan(this.maxTurningAngle);
vec2.sub(v10, p0, p1);
vec2.normalize(v10, v10);
// Simply copy the centroid point if no need to turn the angle
vec2.copy(out, p0);
var maxMovement = 0;
for (var i = 0; i < pointSet.length; i++) {
var p = pointSet[i];
vec2.sub(vTmp, p, p0);
var len = vec2.len(vTmp);
vec2.scale(vTmp, vTmp, 1 / len);
var turningAngleCos = vec2.dot(vTmp, v10);
// Turning angle is to large
if (turningAngleCos < maxTurningAngleCos) {
// Calculat p's project point on vector p1-p0
// and distance to the vector
vec2.scaleAndAdd(
project, p0, v10, len * turningAngleCos
);
var distance = v2Dist(project, p);
// Use the max turning angle to calculate the new meet point
var d = distance / maxTurningAngleTan;
vec2.scaleAndAdd(tmpOut, project, v10, -d);
var movement = v2DistSquare(tmpOut, p0);
if (movement > maxMovement) {
maxMovement = movement;
vec2.copy(out, tmpOut);
}
}
}
};
ForceLayout.prototype.update = function() {
var nNodes = this.nodes.length;
this.updateBBox();
this._k = 0.4 * this.scaling * Math.sqrt(this.width * this.height / nNodes);
if (this.barnesHutOptimize) {
this._rootRegion.setBBox(
this.bbox[0], this.bbox[1],
this.bbox[2], this.bbox[3]
);
this._rootRegion.beforeUpdate();
for (var i = 0; i < nNodes; i++) {
this._rootRegion.addNode(this.nodes[i]);
}
this._rootRegion.afterUpdate();
} else {
// Update center of mass of whole graph
var mass = 0;
var centerOfMass = this._rootRegion.centerOfMass;
vec2.set(centerOfMass, 0, 0);
for (var i = 0; i < nNodes; i++) {
var node = this.nodes[i];
mass += node.mass;
vec2.scaleAndAdd(centerOfMass, centerOfMass, node.position, node.mass);
}
vec2.scale(centerOfMass, centerOfMass, 1 / mass);
}
// Reset forces
for (var i = 0; i < nNodes; i++) {
var node = this.nodes[i];
vec2.copy(node.forcePrev, node.force);
vec2.copy(node.speedPrev, node.speed);
vec2.set(node.force, 0, 0);
}
// Compute forces
// Repulsion
for (var i = 0; i < nNodes; i++) {
var na = this.nodes[i];
if (this.barnesHutOptimize) {
this.applyRegionToNodeRepulsion(this._rootRegion, na);
} else {
for (var j = i + 1; j < nNodes; j++) {
var nb = this.nodes[j];
this.applyNodeToNodeRepulsion(na, nb, false);
}
}
// Gravity
if (this.gravity > 0) {
this.applyNodeGravity(na);
}
}
// Attraction
for (var i = 0; i < this.edges.length; i++) {
this.applyEdgeAttraction(this.edges[i]);
}
// Apply forces
// var speed = vec2.create();
var v = vec2.create();
for (var i = 0; i < nNodes; i++) {
var node = this.nodes[i];
var speed = node.speed;
// var swing = vec2.dist(node.force, node.forcePrev);
// // var swing = 30;
// vec2.scale(node.force, node.force, 1 / (1 + Math.sqrt(swing)));
vec2.scale(node.force, node.force, 1 / 30);
// contraint force
var df = vec2.len(node.force) + 0.1;
var scale = Math.min(df, 500.0) / df;
vec2.scale(node.force, node.force, scale);
vec2.add(speed, speed, node.force);
vec2.scale(speed, speed, this.temperature);
// Prevent swinging
// Limited the increase of speed up to 100% each step
// TODO adjust by nodes number
vec2.sub(v, speed, node.speedPrev);
var swing = vec2.len(v);
if (swing > 0) {
vec2.scale(v, v, 1 / swing);
var base = vec2.len(node.speedPrev);
if (base > 0) {
swing = Math.min(swing / base, this.maxSpeedIncrease) * base;
vec2.scaleAndAdd(speed, node.speedPrev, v, swing);
}
}
// constraint speed
var ds = vec2.len(speed);
var scale = Math.min(ds, 100.0) / (ds + 0.1);
vec2.scale(speed, speed, scale);
vec2.add(node.position, node.position, speed);
}
};
return function(node) {
// vec2.negate(v, node.position);
vec2.sub(v, this.center, node.position);
var d = vec2.len(v) / 100;
vec2.scaleAndAdd(node.force, node.force, v, d * this.gravity * node.mass);
}