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jrtechs-vis
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first step to modularize the physics engine

flowchartTest
Alex de Mulder 9 years ago
parent
093cb73de5
commit
b91757fabf
10 changed files with 603 additions and 569 deletions
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  1. +1
    -2
      dist/vis.js
  2. +1
    -1
      lib/network/Network.js
  3. +1
    -1
      lib/network/modules/Clustering.js
  4. +25
    -23
      lib/network/modules/PhysicsEngine.js
  5. +0
    -409
      lib/network/modules/components/BarnesHutSolver.js
  6. +0
    -32
      lib/network/modules/components/CentralGravitySolver.js
  7. +0
    -101
      lib/network/modules/components/SpringSolver.js
  8. +434
    -0
      lib/network/modules/components/physics/BarnesHutSolver.js
  9. +32
    -0
      lib/network/modules/components/physics/CentralGravitySolver.js
  10. +109
    -0
      lib/network/modules/components/physics/SpringSolver.js

+ 1
- 2
dist/vis.js View File

@ -23120,8 +23120,8 @@ return /******/ (function(modules) { // webpackBootstrap
}
var me = this;
// this event will trigger a rebuilding of the cache of colors, nodes etc.
this.on("_dataChanged", function () {
console.log("here");
me._updateNodeIndexList();
me._updateCalculationNodes();
me._markAllEdgesAsDirty();
@ -34441,7 +34441,6 @@ return /******/ (function(modules) { // webpackBootstrap
var ClusterEngine = (function () {
function ClusterEngine(body) {
var options = arguments[1] === undefined ? {} : arguments[1];
_classCallCheck(this, ClusterEngine);
this.body = body;

+ 1
- 1
lib/network/Network.js View File

@ -374,8 +374,8 @@ function Network (container, data, options) {
}
var me = this;
// this event will trigger a rebuilding of the cache of colors, nodes etc.
this.on("_dataChanged", function () {
console.log("here")
me._updateNodeIndexList();
me._updateCalculationNodes();
me._markAllEdgesAsDirty();

+ 1
- 1
lib/network/modules/Clustering.js View File

@ -5,7 +5,7 @@
var util = require("../../util");
class ClusterEngine {
constructor(body, options={}) {
constructor(body) {
this.body = body;
this.clusteredNodes = {};
}

+ 25
- 23
lib/network/modules/PhysicsEngine.js View File

@ -2,32 +2,34 @@
* Created by Alex on 2/23/2015.
*/
var BarnesHut = require("./compontents/BarnesHutSolver")
var SpringSolver = require("./compontents/SpringSolver")
var CentralGravitySolver = require("./compontents/CentralGravitySolver")
import {BarnesHut} from "./components/physics/BarnesHutSolver";
import {SpringSolver} from "./components/physics/SpringSolver";
import {CentralGravitySolver} from "./components/physics/CentralGravitySolver";
function PhysicsEngine(body, options) {
this.body = body;
class PhysicsEngine {
constructor(body, options) {
this.body = body;
this.nodesSolver = new BarnesHut(body, options);
this.edgesSolver = new SpringSolver(body, options);
this.gravitySolver = new CentralGravitySolver(body, options);
}
this.nodesSolver = new BarnesHut(body, options);
this.edgesSolver = new SpringSolver(body, options);
this.gravitySolver = new CentralGravitySolver(body, options);
}
PhysicsEngine.prototype.calculateField = function () {
this.nodesSolver.solve();
};
calculateField() {
this.nodesSolver.solve();
};
PhysicsEngine.prototype.calculateSprings = function () {
this.edgesSolver.solve();
};
calculateSprings() {
this.edgesSolver.solve();
};
PhysicsEngine.prototype.calculateCentralGravity = function () {
this.gravitySolver.solve();
};
calculateCentralGravity() {
this.gravitySolver.solve();
};
PhysicsEngine.prototype.calculate = function () {
this.calculateCentralGravity();
this.calculateField();
this.calculateSprings();
};
calculate() {
this.calculateCentralGravity();
this.calculateField();
this.calculateSprings();
};
}

+ 0
- 409
lib/network/modules/components/BarnesHutSolver.js View File

@ -1,409 +0,0 @@
/**
* Created by Alex on 2/23/2015.
*/
function BarnesHutSolver(body, options) {
this.body = body;
this.options = options;
}
/**
* This function calculates the forces the nodes apply on eachother based on a gravitational model.
* The Barnes Hut method is used to speed up this N-body simulation.
*
* @private
*/
BarnesHutSolver.prototype.solve = function() {
if (this.options.gravitationalConstant != 0) {
var node;
var nodes = this.body.calculationNodes;
var nodeIndices = this.body.calculationNodeIndices;
var nodeCount = nodeIndices.length;
var barnesHutTree = this._formBarnesHutTree(nodes,nodeIndices);
// place the nodes one by one recursively
for (var i = 0; i < nodeCount; i++) {
node = nodes[nodeIndices[i]];
if (node.options.mass > 0) {
// starting with root is irrelevant, it never passes the BarnesHutSolver condition
this._getForceContribution(barnesHutTree.root.children.NW,node);
this._getForceContribution(barnesHutTree.root.children.NE,node);
this._getForceContribution(barnesHutTree.root.children.SW,node);
this._getForceContribution(barnesHutTree.root.children.SE,node);
}
}
}
};
/**
* This function traverses the barnesHutTree. It checks when it can approximate distant nodes with their center of mass.
* If a region contains a single node, we check if it is not itself, then we apply the force.
*
* @param parentBranch
* @param node
* @private
*/
BarnesHutSolver.prototype._getForceContribution = function(parentBranch,node) {
// we get no force contribution from an empty region
if (parentBranch.childrenCount > 0) {
var dx,dy,distance;
// get the distance from the center of mass to the node.
dx = parentBranch.centerOfMass.x - node.x;
dy = parentBranch.centerOfMass.y - node.y;
distance = Math.sqrt(dx * dx + dy * dy);
// BarnesHutSolver condition
// original condition : s/d < thetaInverted = passed === d/s > 1/theta = passed
// calcSize = 1/s --> d * 1/s > 1/theta = passed
if (distance * parentBranch.calcSize > this.options.thetaInverted) {
// duplicate code to reduce function calls to speed up program
if (distance == 0) {
distance = 0.1*Math.random();
dx = distance;
}
var gravityForce = this.options.gravitationalConstant * parentBranch.mass * node.options.mass / (distance * distance * distance);
var fx = dx * gravityForce;
var fy = dy * gravityForce;
node.fx += fx;
node.fy += fy;
}
else {
// Did not pass the condition, go into children if available
if (parentBranch.childrenCount == 4) {
this._getForceContribution(parentBranch.children.NW,node);
this._getForceContribution(parentBranch.children.NE,node);
this._getForceContribution(parentBranch.children.SW,node);
this._getForceContribution(parentBranch.children.SE,node);
}
else { // parentBranch must have only one node, if it was empty we wouldnt be here
if (parentBranch.children.data.id != node.id) { // if it is not self
// duplicate code to reduce function calls to speed up program
if (distance == 0) {
distance = 0.5*Math.random();
dx = distance;
}
var gravityForce = this.options.gravitationalConstant * parentBranch.mass * node.options.mass / (distance * distance * distance);
var fx = dx * gravityForce;
var fy = dy * gravityForce;
node.fx += fx;
node.fy += fy;
}
}
}
}
};
/**
* This function constructs the barnesHut tree recursively. It creates the root, splits it and starts placing the nodes.
*
* @param nodes
* @param nodeIndices
* @private
*/
BarnesHutSolver.prototype._formBarnesHutTree = function(nodes,nodeIndices) {
var node;
var nodeCount = nodeIndices.length;
var minX = Number.MAX_VALUE,
minY = Number.MAX_VALUE,
maxX =-Number.MAX_VALUE,
maxY =-Number.MAX_VALUE;
// get the range of the nodes
for (var i = 0; i < nodeCount; i++) {
var x = nodes[nodeIndices[i]].x;
var y = nodes[nodeIndices[i]].y;
if (nodes[nodeIndices[i]].options.mass > 0) {
if (x < minX) { minX = x; }
if (x > maxX) { maxX = x; }
if (y < minY) { minY = y; }
if (y > maxY) { maxY = y; }
}
}
// make the range a square
var sizeDiff = Math.abs(maxX - minX) - Math.abs(maxY - minY); // difference between X and Y
if (sizeDiff > 0) {minY -= 0.5 * sizeDiff; maxY += 0.5 * sizeDiff;} // xSize > ySize
else {minX += 0.5 * sizeDiff; maxX -= 0.5 * sizeDiff;} // xSize < ySize
var minimumTreeSize = 1e-5;
var rootSize = Math.max(minimumTreeSize,Math.abs(maxX - minX));
var halfRootSize = 0.5 * rootSize;
var centerX = 0.5 * (minX + maxX), centerY = 0.5 * (minY + maxY);
// construct the barnesHutTree
var barnesHutTree = {
root:{
centerOfMass: {x:0, y:0},
mass:0,
range: {
minX: centerX-halfRootSize,maxX:centerX+halfRootSize,
minY: centerY-halfRootSize,maxY:centerY+halfRootSize
},
size: rootSize,
calcSize: 1 / rootSize,
children: { data:null},
maxWidth: 0,
level: 0,
childrenCount: 4
}
};
this._splitBranch(barnesHutTree.root);
// place the nodes one by one recursively
for (i = 0; i < nodeCount; i++) {
node = nodes[nodeIndices[i]];
if (node.options.mass > 0) {
this._placeInTree(barnesHutTree.root,node);
}
}
// make global
return barnesHutTree
};
/**
* this updates the mass of a branch. this is increased by adding a node.
*
* @param parentBranch
* @param node
* @private
*/
BarnesHutSolver.prototype._updateBranchMass = function(parentBranch, node) {
var totalMass = parentBranch.mass + node.options.mass;
var totalMassInv = 1/totalMass;
parentBranch.centerOfMass.x = parentBranch.centerOfMass.x * parentBranch.mass + node.x * node.options.mass;
parentBranch.centerOfMass.x *= totalMassInv;
parentBranch.centerOfMass.y = parentBranch.centerOfMass.y * parentBranch.mass + node.y * node.options.mass;
parentBranch.centerOfMass.y *= totalMassInv;
parentBranch.mass = totalMass;
var biggestSize = Math.max(Math.max(node.height,node.radius),node.width);
parentBranch.maxWidth = (parentBranch.maxWidth < biggestSize) ? biggestSize : parentBranch.maxWidth;
};
/**
* determine in which branch the node will be placed.
*
* @param parentBranch
* @param node
* @param skipMassUpdate
* @private
*/
BarnesHutSolver.prototype._placeInTree = function(parentBranch,node,skipMassUpdate) {
if (skipMassUpdate != true || skipMassUpdate === undefined) {
// update the mass of the branch.
this._updateBranchMass(parentBranch,node);
}
if (parentBranch.children.NW.range.maxX > node.x) { // in NW or SW
if (parentBranch.children.NW.range.maxY > node.y) { // in NW
this._placeInRegion(parentBranch,node,"NW");
}
else { // in SW
this._placeInRegion(parentBranch,node,"SW");
}
}
else { // in NE or SE
if (parentBranch.children.NW.range.maxY > node.y) { // in NE
this._placeInRegion(parentBranch,node,"NE");
}
else { // in SE
this._placeInRegion(parentBranch,node,"SE");
}
}
};
/**
* actually place the node in a region (or branch)
*
* @param parentBranch
* @param node
* @param region
* @private
*/
BarnesHutSolver.prototype._placeInRegion = function(parentBranch,node,region) {
switch (parentBranch.children[region].childrenCount) {
case 0: // place node here
parentBranch.children[region].children.data = node;
parentBranch.children[region].childrenCount = 1;
this._updateBranchMass(parentBranch.children[region],node);
break;
case 1: // convert into children
// if there are two nodes exactly overlapping (on init, on opening of cluster etc.)
// we move one node a pixel and we do not put it in the tree.
if (parentBranch.children[region].children.data.x == node.x &&
parentBranch.children[region].children.data.y == node.y) {
node.x += Math.random();
node.y += Math.random();
}
else {
this._splitBranch(parentBranch.children[region]);
this._placeInTree(parentBranch.children[region],node);
}
break;
case 4: // place in branch
this._placeInTree(parentBranch.children[region],node);
break;
}
};
/**
* this function splits a branch into 4 sub branches. If the branch contained a node, we place it in the subbranch
* after the split is complete.
*
* @param parentBranch
* @private
*/
BarnesHutSolver.prototype._splitBranch = function(parentBranch) {
// if the branch is shaded with a node, replace the node in the new subset.
var containedNode = null;
if (parentBranch.childrenCount == 1) {
containedNode = parentBranch.children.data;
parentBranch.mass = 0; parentBranch.centerOfMass.x = 0; parentBranch.centerOfMass.y = 0;
}
parentBranch.childrenCount = 4;
parentBranch.children.data = null;
this._insertRegion(parentBranch,"NW");
this._insertRegion(parentBranch,"NE");
this._insertRegion(parentBranch,"SW");
this._insertRegion(parentBranch,"SE");
if (containedNode != null) {
this._placeInTree(parentBranch,containedNode);
}
};
/**
* This function subdivides the region into four new segments.
* Specifically, this inserts a single new segment.
* It fills the children section of the parentBranch
*
* @param parentBranch
* @param region
* @param parentRange
* @private
*/
BarnesHutSolver.prototype._insertRegion = function(parentBranch, region) {
var minX,maxX,minY,maxY;
var childSize = 0.5 * parentBranch.size;
switch (region) {
case "NW":
minX = parentBranch.range.minX;
maxX = parentBranch.range.minX + childSize;
minY = parentBranch.range.minY;
maxY = parentBranch.range.minY + childSize;
break;
case "NE":
minX = parentBranch.range.minX + childSize;
maxX = parentBranch.range.maxX;
minY = parentBranch.range.minY;
maxY = parentBranch.range.minY + childSize;
break;
case "SW":
minX = parentBranch.range.minX;
maxX = parentBranch.range.minX + childSize;
minY = parentBranch.range.minY + childSize;
maxY = parentBranch.range.maxY;
break;
case "SE":
minX = parentBranch.range.minX + childSize;
maxX = parentBranch.range.maxX;
minY = parentBranch.range.minY + childSize;
maxY = parentBranch.range.maxY;
break;
}
parentBranch.children[region] = {
centerOfMass:{x:0,y:0},
mass:0,
range:{minX:minX,maxX:maxX,minY:minY,maxY:maxY},
size: 0.5 * parentBranch.size,
calcSize: 2 * parentBranch.calcSize,
children: {data:null},
maxWidth: 0,
level: parentBranch.level+1,
childrenCount: 0
};
};
/**
* This function is for debugging purposed, it draws the tree.
*
* @param ctx
* @param color
* @private
*/
BarnesHutSolver.prototype._drawTree = function(ctx,color) {
if (this.barnesHutTree !== undefined) {
ctx.lineWidth = 1;
this._drawBranch(this.barnesHutTree.root,ctx,color);
}
};
/**
* This function is for debugging purposes. It draws the branches recursively.
*
* @param branch
* @param ctx
* @param color
* @private
*/
BarnesHutSolver.prototype._drawBranch = function(branch,ctx,color) {
if (color === undefined) {
color = "#FF0000";
}
if (branch.childrenCount == 4) {
this._drawBranch(branch.children.NW,ctx);
this._drawBranch(branch.children.NE,ctx);
this._drawBranch(branch.children.SE,ctx);
this._drawBranch(branch.children.SW,ctx);
}
ctx.strokeStyle = color;
ctx.beginPath();
ctx.moveTo(branch.range.minX,branch.range.minY);
ctx.lineTo(branch.range.maxX,branch.range.minY);
ctx.stroke();
ctx.beginPath();
ctx.moveTo(branch.range.maxX,branch.range.minY);
ctx.lineTo(branch.range.maxX,branch.range.maxY);
ctx.stroke();
ctx.beginPath();
ctx.moveTo(branch.range.maxX,branch.range.maxY);
ctx.lineTo(branch.range.minX,branch.range.maxY);
ctx.stroke();
ctx.beginPath();
ctx.moveTo(branch.range.minX,branch.range.maxY);
ctx.lineTo(branch.range.minX,branch.range.minY);
ctx.stroke();
/*
if (branch.mass > 0) {
ctx.circle(branch.centerOfMass.x, branch.centerOfMass.y, 3*branch.mass);
ctx.stroke();
}
*/
};
module.exports = BarnesHutSolver;

+ 0
- 32
lib/network/modules/components/CentralGravitySolver.js View File

@ -1,32 +0,0 @@
/**
* Created by Alex on 2/23/2015.
*/
function CentralGravitySolver(body, options) {
this.body = body;
this.options = options;
}
CentralGravitySolver.prototype.solve = function () {
var dx, dy, distance, node, i;
var nodes = this.body.calculationNodes;
var gravity = this.options.centralGravity;
var gravityForce = 0;
for (i = 0; i < this.body.calculationNodeIndices.length; i++) {
node = nodes[this.body.calculationNodeIndices[i]];
node.damping = this.options.damping; // possibly add function to alter damping properties of clusters.
dx = -node.x;
dy = -node.y;
distance = Math.sqrt(dx * dx + dy * dy);
gravityForce = (distance == 0) ? 0 : (gravity / distance);
node.fx = dx * gravityForce;
node.fy = dy * gravityForce;
}
};
module.exports = CentralGravitySolver;

+ 0
- 101
lib/network/modules/components/SpringSolver.js View File

@ -1,101 +0,0 @@
/**
* Created by Alex on 2/23/2015.
*/
function SpringSolver(body, options) {
this.body = body;
this.options = options;
}
/**
* this function calculates the effects of the springs in the case of unsmooth curves.
*
* @private
*/
SpringSolver.prototype._calculateSpringForces = function () {
var edgeLength, edge, edgeId;
var edges = this.edges;
// forces caused by the edges, modelled as springs
for (edgeId in edges) {
if (edges.hasOwnProperty(edgeId)) {
edge = edges[edgeId];
if (edge.connected === true) {
// only calculate forces if nodes are in the same sector
if (this.nodes.hasOwnProperty(edge.toId) && this.nodes.hasOwnProperty(edge.fromId)) {
edgeLength = edge.physics.springLength;
this._calculateSpringForce(edge.from, edge.to, edgeLength);
}
}
}
}
};
/**
* This function calculates the springforces on the nodes, accounting for the support nodes.
*
* @private
*/
SpringSolver.prototype._calculateSpringForcesWithSupport = function () {
var edgeLength, edge, edgeId;
var edges = this.edges;
// forces caused by the edges, modelled as springs
for (edgeId in edges) {
if (edges.hasOwnProperty(edgeId)) {
edge = edges[edgeId];
if (edge.connected === true) {
// only calculate forces if nodes are in the same sector
if (this.nodes.hasOwnProperty(edge.toId) && this.nodes.hasOwnProperty(edge.fromId)) {
if (edge.via != null) {
var node1 = edge.to;
var node2 = edge.via;
var node3 = edge.from;
edgeLength = edge.physics.springLength;
this._calculateSpringForce(node1, node2, 0.5 * edgeLength);
this._calculateSpringForce(node2, node3, 0.5 * edgeLength);
}
}
}
}
}
};
/**
* This is the code actually performing the calculation for the function above. It is split out to avoid repetition.
*
* @param node1
* @param node2
* @param edgeLength
* @private
*/
SpringSolver.prototype._calculateSpringForce = function (node1, node2, edgeLength) {
var dx, dy, fx, fy, springForce, distance;
dx = (node1.x - node2.x);
dy = (node1.y - node2.y);
distance = Math.sqrt(dx * dx + dy * dy);
distance = distance == 0 ? 0.01 : distance;
// the 1/distance is so the fx and fy can be calculated without sine or cosine.
springForce = this.options.springConstant * (edgeLength - distance) / distance;
fx = dx * springForce;
fy = dy * springForce;
node1.fx += fx;
node1.fy += fy;
node2.fx -= fx;
node2.fy -= fy;
};
module.exports = SpringSolver;

+ 434
- 0
lib/network/modules/components/physics/BarnesHutSolver.js View File

@ -0,0 +1,434 @@
/**
* Created by Alex on 2/23/2015.
*/
class BarnesHutSolver {
constructor(body, options) {
this.body = body;
this.options = options;
}
/**
* This function calculates the forces the nodes apply on eachother based on a gravitational model.
* The Barnes Hut method is used to speed up this N-body simulation.
*
* @private
*/
solve() {
if (this.options.gravitationalConstant != 0) {
var node;
var nodes = this.body.calculationNodes;
var nodeIndices = this.body.calculationNodeIndices;
var nodeCount = nodeIndices.length;
var barnesHutTree = this._formBarnesHutTree(nodes, nodeIndices);
// place the nodes one by one recursively
for (var i = 0; i < nodeCount; i++) {
node = nodes[nodeIndices[i]];
if (node.options.mass > 0) {
// starting with root is irrelevant, it never passes the BarnesHutSolver condition
this._getForceContribution(barnesHutTree.root.children.NW, node);
this._getForceContribution(barnesHutTree.root.children.NE, node);
this._getForceContribution(barnesHutTree.root.children.SW, node);
this._getForceContribution(barnesHutTree.root.children.SE, node);
}
}
}
}
/**
* This function traverses the barnesHutTree. It checks when it can approximate distant nodes with their center of mass.
* If a region contains a single node, we check if it is not itself, then we apply the force.
*
* @param parentBranch
* @param node
* @private
*/
_getForceContribution(parentBranch, node) {
// we get no force contribution from an empty region
if (parentBranch.childrenCount > 0) {
var dx, dy, distance;
// get the distance from the center of mass to the node.
dx = parentBranch.centerOfMass.x - node.x;
dy = parentBranch.centerOfMass.y - node.y;
distance = Math.sqrt(dx * dx + dy * dy);
// BarnesHutSolver condition
// original condition : s/d < thetaInverted = passed === d/s > 1/theta = passed
// calcSize = 1/s --> d * 1/s > 1/theta = passed
if (distance * parentBranch.calcSize > this.options.thetaInverted) {
// duplicate code to reduce function calls to speed up program
if (distance == 0) {
distance = 0.1 * Math.random();
dx = distance;
}
var gravityForce = this.options.gravitationalConstant * parentBranch.mass * node.options.mass / (distance * distance * distance);
var fx = dx * gravityForce;
var fy = dy * gravityForce;
node.fx += fx;
node.fy += fy;
}
else {
// Did not pass the condition, go into children if available
if (parentBranch.childrenCount == 4) {
this._getForceContribution(parentBranch.children.NW, node);
this._getForceContribution(parentBranch.children.NE, node);
this._getForceContribution(parentBranch.children.SW, node);
this._getForceContribution(parentBranch.children.SE, node);
}
else { // parentBranch must have only one node, if it was empty we wouldnt be here
if (parentBranch.children.data.id != node.id) { // if it is not self
// duplicate code to reduce function calls to speed up program
if (distance == 0) {
distance = 0.5 * Math.random();
dx = distance;
}
var gravityForce = this.options.gravitationalConstant * parentBranch.mass * node.options.mass / (distance * distance * distance);
var fx = dx * gravityForce;
var fy = dy * gravityForce;
node.fx += fx;
node.fy += fy;
}
}
}
}
}
/**
* This function constructs the barnesHut tree recursively. It creates the root, splits it and starts placing the nodes.
*
* @param nodes
* @param nodeIndices
* @private
*/
_formBarnesHutTree(nodes, nodeIndices) {
var node;
var nodeCount = nodeIndices.length;
var minX = Number.MAX_VALUE,
minY = Number.MAX_VALUE,
maxX = -Number.MAX_VALUE,
maxY = -Number.MAX_VALUE;
// get the range of the nodes
for (var i = 0; i < nodeCount; i++) {
var x = nodes[nodeIndices[i]].x;
var y = nodes[nodeIndices[i]].y;
if (nodes[nodeIndices[i]].options.mass > 0) {
if (x < minX) {
minX = x;
}
if (x > maxX) {
maxX = x;
}
if (y < minY) {
minY = y;
}
if (y > maxY) {
maxY = y;
}
}
}
// make the range a square
var sizeDiff = Math.abs(maxX - minX) - Math.abs(maxY - minY); // difference between X and Y
if (sizeDiff > 0) {
minY -= 0.5 * sizeDiff;
maxY += 0.5 * sizeDiff;
} // xSize > ySize
else {
minX += 0.5 * sizeDiff;
maxX -= 0.5 * sizeDiff;
} // xSize < ySize
var minimumTreeSize = 1e-5;
var rootSize = Math.max(minimumTreeSize, Math.abs(maxX - minX));
var halfRootSize = 0.5 * rootSize;
var centerX = 0.5 * (minX + maxX), centerY = 0.5 * (minY + maxY);
// construct the barnesHutTree
var barnesHutTree = {
root: {
centerOfMass: {x: 0, y: 0},
mass: 0,
range: {
minX: centerX - halfRootSize, maxX: centerX + halfRootSize,
minY: centerY - halfRootSize, maxY: centerY + halfRootSize
},
size: rootSize,
calcSize: 1 / rootSize,
children: {data: null},
maxWidth: 0,
level: 0,
childrenCount: 4
}
};
this._splitBranch(barnesHutTree.root);
// place the nodes one by one recursively
for (i = 0; i < nodeCount; i++) {
node = nodes[nodeIndices[i]];
if (node.options.mass > 0) {
this._placeInTree(barnesHutTree.root, node);
}
}
// make global
return barnesHutTree
}
/**
* this updates the mass of a branch. this is increased by adding a node.
*
* @param parentBranch
* @param node
* @private
*/
_updateBranchMass(parentBranch, node) {
var totalMass = parentBranch.mass + node.options.mass;
var totalMassInv = 1 / totalMass;
parentBranch.centerOfMass.x = parentBranch.centerOfMass.x * parentBranch.mass + node.x * node.options.mass;
parentBranch.centerOfMass.x *= totalMassInv;
parentBranch.centerOfMass.y = parentBranch.centerOfMass.y * parentBranch.mass + node.y * node.options.mass;
parentBranch.centerOfMass.y *= totalMassInv;
parentBranch.mass = totalMass;
var biggestSize = Math.max(Math.max(node.height, node.radius), node.width);
parentBranch.maxWidth = (parentBranch.maxWidth < biggestSize) ? biggestSize : parentBranch.maxWidth;
}
/**
* determine in which branch the node will be placed.
*
* @param parentBranch
* @param node
* @param skipMassUpdate
* @private
*/
_placeInTree(parentBranch, node, skipMassUpdate) {
if (skipMassUpdate != true || skipMassUpdate === undefined) {
// update the mass of the branch.
this._updateBranchMass(parentBranch, node);
}
if (parentBranch.children.NW.range.maxX > node.x) { // in NW or SW
if (parentBranch.children.NW.range.maxY > node.y) { // in NW
this._placeInRegion(parentBranch, node, "NW");
}
else { // in SW
this._placeInRegion(parentBranch, node, "SW");
}
}
else { // in NE or SE
if (parentBranch.children.NW.range.maxY > node.y) { // in NE
this._placeInRegion(parentBranch, node, "NE");
}
else { // in SE
this._placeInRegion(parentBranch, node, "SE");
}
}
}
/**
* actually place the node in a region (or branch)
*
* @param parentBranch
* @param node
* @param region
* @private
*/
_placeInRegion(parentBranch, node, region) {
switch (parentBranch.children[region].childrenCount) {
case 0: // place node here
parentBranch.children[region].children.data = node;
parentBranch.children[region].childrenCount = 1;
this._updateBranchMass(parentBranch.children[region], node);
break;
case 1: // convert into children
// if there are two nodes exactly overlapping (on init, on opening of cluster etc.)
// we move one node a pixel and we do not put it in the tree.
if (parentBranch.children[region].children.data.x == node.x &&
parentBranch.children[region].children.data.y == node.y) {
node.x += Math.random();
node.y += Math.random();
}
else {
this._splitBranch(parentBranch.children[region]);
this._placeInTree(parentBranch.children[region], node);
}
break;
case 4: // place in branch
this._placeInTree(parentBranch.children[region], node);
break;
}
}
/**
* this function splits a branch into 4 sub branches. If the branch contained a node, we place it in the subbranch
* after the split is complete.
*
* @param parentBranch
* @private
*/
_splitBranch(parentBranch) {
// if the branch is shaded with a node, replace the node in the new subset.
var containedNode = null;
if (parentBranch.childrenCount == 1) {
containedNode = parentBranch.children.data;
parentBranch.mass = 0;
parentBranch.centerOfMass.x = 0;
parentBranch.centerOfMass.y = 0;
}
parentBranch.childrenCount = 4;
parentBranch.children.data = null;
this._insertRegion(parentBranch, "NW");
this._insertRegion(parentBranch, "NE");
this._insertRegion(parentBranch, "SW");
this._insertRegion(parentBranch, "SE");
if (containedNode != null) {
this._placeInTree(parentBranch, containedNode);
}
}
/**
* This function subdivides the region into four new segments.
* Specifically, this inserts a single new segment.
* It fills the children section of the parentBranch
*
* @param parentBranch
* @param region
* @param parentRange
* @private
*/
_insertRegion(parentBranch, region) {
var minX, maxX, minY, maxY;
var childSize = 0.5 * parentBranch.size;
switch (region) {
case "NW":
minX = parentBranch.range.minX;
maxX = parentBranch.range.minX + childSize;
minY = parentBranch.range.minY;
maxY = parentBranch.range.minY + childSize;
break;
case "NE":
minX = parentBranch.range.minX + childSize;
maxX = parentBranch.range.maxX;
minY = parentBranch.range.minY;
maxY = parentBranch.range.minY + childSize;
break;
case "SW":
minX = parentBranch.range.minX;
maxX = parentBranch.range.minX + childSize;
minY = parentBranch.range.minY + childSize;
maxY = parentBranch.range.maxY;
break;
case "SE":
minX = parentBranch.range.minX + childSize;
maxX = parentBranch.range.maxX;
minY = parentBranch.range.minY + childSize;
maxY = parentBranch.range.maxY;
break;
}
parentBranch.children[region] = {
centerOfMass: {x: 0, y: 0},
mass: 0,
range: {minX: minX, maxX: maxX, minY: minY, maxY: maxY},
size: 0.5 * parentBranch.size,
calcSize: 2 * parentBranch.calcSize,
children: {data: null},
maxWidth: 0,
level: parentBranch.level + 1,
childrenCount: 0
};
}
//--------------------------- DEBUGGING BELOW ---------------------------//
/**
* This function is for debugging purposed, it draws the tree.
*
* @param ctx
* @param color
* @private
*/
_drawTree(ctx, color) {
if (this.barnesHutTree !== undefined) {
ctx.lineWidth = 1;
this._drawBranch(this.barnesHutTree.root, ctx, color);
}
}
/**
* This function is for debugging purposes. It draws the branches recursively.
*
* @param branch
* @param ctx
* @param color
* @private
*/
_drawBranch(branch, ctx, color) {
if (color === undefined) {
color = "#FF0000";
}
if (branch.childrenCount == 4) {
this._drawBranch(branch.children.NW, ctx);
this._drawBranch(branch.children.NE, ctx);
this._drawBranch(branch.children.SE, ctx);
this._drawBranch(branch.children.SW, ctx);
}
ctx.strokeStyle = color;
ctx.beginPath();
ctx.moveTo(branch.range.minX, branch.range.minY);
ctx.lineTo(branch.range.maxX, branch.range.minY);
ctx.stroke();
ctx.beginPath();
ctx.moveTo(branch.range.maxX, branch.range.minY);
ctx.lineTo(branch.range.maxX, branch.range.maxY);
ctx.stroke();
ctx.beginPath();
ctx.moveTo(branch.range.maxX, branch.range.maxY);
ctx.lineTo(branch.range.minX, branch.range.maxY);
ctx.stroke();
ctx.beginPath();
ctx.moveTo(branch.range.minX, branch.range.maxY);
ctx.lineTo(branch.range.minX, branch.range.minY);
ctx.stroke();
/*
if (branch.mass > 0) {
ctx.circle(branch.centerOfMass.x, branch.centerOfMass.y, 3*branch.mass);
ctx.stroke();
}
*/
}
}
export {BarnesHutSolver};

+ 32
- 0
lib/network/modules/components/physics/CentralGravitySolver.js View File

@ -0,0 +1,32 @@
/**
* Created by Alex on 2/23/2015.
*/
class CentralGravitySolver {
constructor(body, options) {
this.body = body;
this.options = options;
}
solve() {
var dx, dy, distance, node, i;
var nodes = this.body.calculationNodes;
var gravity = this.options.centralGravity;
var gravityForce = 0;
var calculationNodeIndices = this.body.calculationNodeIndices;
for (i = 0; i < calculationNodeIndices.length; i++) {
node = nodes[calculationNodeIndices[i]];
dx = -node.x;
dy = -node.y;
distance = Math.sqrt(dx * dx + dy * dy);
gravityForce = (distance == 0) ? 0 : (gravity / distance);
node.fx = dx * gravityForce;
node.fy = dy * gravityForce;
}
}
}
export {CentralGravitySolver};

+ 109
- 0
lib/network/modules/components/physics/SpringSolver.js View File

@ -0,0 +1,109 @@
/**
* Created by Alex on 2/23/2015.
*/
class SpringSolver {
constructor(body, options) {
this.body = body;
this.options = options;
}
solve() {
if (this.options.smoothCurves.enabled == true && this.options.smoothCurves.dynamic == true) {
this._calculateSpringForcesWithSupport();
}
else {
this._calculateSpringForces();
}
}
/**
* this function calculates the effects of the springs in the case of unsmooth curves.
*
* @private
*/
_calculateSpringForces() {
var edgeLength, edge, edgeId;
var edges = this.edges;
// forces caused by the edges, modelled as springs
for (edgeId in edges) {
if (edges.hasOwnProperty(edgeId)) {
edge = edges[edgeId];
if (edge.connected === true) {
// only calculate forces if nodes are in the same sector
if (this.nodes.hasOwnProperty(edge.toId) && this.nodes.hasOwnProperty(edge.fromId)) {
edgeLength = edge.physics.springLength;
this._calculateSpringForce(edge.from, edge.to, edgeLength);
}
}
}
}
}
/**
* This function calculates the springforces on the nodes, accounting for the support nodes.
*
* @private
*/
_calculateSpringForcesWithSupport() {
var edgeLength, edge, edgeId;
var edges = this.edges;
// forces caused by the edges, modelled as springs
for (edgeId in edges) {
if (edges.hasOwnProperty(edgeId)) {
edge = edges[edgeId];
if (edge.connected === true) {
// only calculate forces if nodes are in the same sector
if (this.nodes.hasOwnProperty(edge.toId) && this.nodes.hasOwnProperty(edge.fromId)) {
if (edge.via != null) {
var node1 = edge.to;
var node2 = edge.via;
var node3 = edge.from;
edgeLength = edge.physics.springLength;
this._calculateSpringForce(node1, node2, 0.5 * edgeLength);
this._calculateSpringForce(node2, node3, 0.5 * edgeLength);
}
}
}
}
}
}
/**
* This is the code actually performing the calculation for the function above. It is split out to avoid repetition.
*
* @param node1
* @param node2
* @param edgeLength
* @private
*/
_calculateSpringForce(node1, node2, edgeLength) {
var dx, dy, fx, fy, springForce, distance;
dx = (node1.x - node2.x);
dy = (node1.y - node2.y);
distance = Math.sqrt(dx * dx + dy * dy);
distance = distance == 0 ? 0.01 : distance;
// the 1/distance is so the fx and fy can be calculated without sine or cosine.
springForce = this.options.springConstant * (edgeLength - distance) / distance;
fx = dx * springForce;
fy = dy * springForce;
node1.fx += fx;
node1.fy += fy;
node2.fx -= fx;
node2.fy -= fy;
}
}
export {SpringSolver};

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