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.
794 lines
23 KiB
794 lines
23 KiB
var BarnesHutSolver = require('./components/physics/BarnesHutSolver').default;
|
|
var Repulsion = require('./components/physics/RepulsionSolver').default;
|
|
var HierarchicalRepulsion = require('./components/physics/HierarchicalRepulsionSolver').default;
|
|
var SpringSolver = require('./components/physics/SpringSolver').default;
|
|
var HierarchicalSpringSolver = require('./components/physics/HierarchicalSpringSolver').default;
|
|
var CentralGravitySolver = require('./components/physics/CentralGravitySolver').default;
|
|
var ForceAtlas2BasedRepulsionSolver = require('./components/physics/FA2BasedRepulsionSolver').default;
|
|
var ForceAtlas2BasedCentralGravitySolver = require('./components/physics/FA2BasedCentralGravitySolver').default;
|
|
var util = require('../../util');
|
|
var EndPoints = require('./components/edges/util/EndPoints').default; // for debugging with _drawForces()
|
|
|
|
|
|
/**
|
|
* The physics engine
|
|
*/
|
|
class PhysicsEngine {
|
|
/**
|
|
* @param {Object} body
|
|
*/
|
|
constructor(body) {
|
|
this.body = body;
|
|
this.physicsBody = {physicsNodeIndices:[], physicsEdgeIndices:[], forces: {}, velocities: {}};
|
|
|
|
this.physicsEnabled = true;
|
|
this.simulationInterval = 1000 / 60;
|
|
this.requiresTimeout = true;
|
|
this.previousStates = {};
|
|
this.referenceState = {};
|
|
this.freezeCache = {};
|
|
this.renderTimer = undefined;
|
|
|
|
// parameters for the adaptive timestep
|
|
this.adaptiveTimestep = false;
|
|
this.adaptiveTimestepEnabled = false;
|
|
this.adaptiveCounter = 0;
|
|
this.adaptiveInterval = 3;
|
|
|
|
this.stabilized = false;
|
|
this.startedStabilization = false;
|
|
this.stabilizationIterations = 0;
|
|
this.ready = false; // will be set to true if the stabilize
|
|
|
|
// default options
|
|
this.options = {};
|
|
this.defaultOptions = {
|
|
enabled: true,
|
|
barnesHut: {
|
|
theta: 0.5,
|
|
gravitationalConstant: -2000,
|
|
centralGravity: 0.3,
|
|
springLength: 95,
|
|
springConstant: 0.04,
|
|
damping: 0.09,
|
|
avoidOverlap: 0
|
|
},
|
|
forceAtlas2Based: {
|
|
theta: 0.5,
|
|
gravitationalConstant: -50,
|
|
centralGravity: 0.01,
|
|
springConstant: 0.08,
|
|
springLength: 100,
|
|
damping: 0.4,
|
|
avoidOverlap: 0
|
|
},
|
|
repulsion: {
|
|
centralGravity: 0.2,
|
|
springLength: 200,
|
|
springConstant: 0.05,
|
|
nodeDistance: 100,
|
|
damping: 0.09,
|
|
avoidOverlap: 0
|
|
},
|
|
hierarchicalRepulsion: {
|
|
centralGravity: 0.0,
|
|
springLength: 100,
|
|
springConstant: 0.01,
|
|
nodeDistance: 120,
|
|
damping: 0.09
|
|
},
|
|
maxVelocity: 50,
|
|
minVelocity: 0.75, // px/s
|
|
solver: 'barnesHut',
|
|
stabilization: {
|
|
enabled: true,
|
|
iterations: 1000, // maximum number of iteration to stabilize
|
|
updateInterval: 50,
|
|
onlyDynamicEdges: false,
|
|
fit: true
|
|
},
|
|
timestep: 0.5,
|
|
adaptiveTimestep: true
|
|
};
|
|
util.extend(this.options, this.defaultOptions);
|
|
this.timestep = 0.5;
|
|
this.layoutFailed = false;
|
|
|
|
this.bindEventListeners();
|
|
}
|
|
|
|
/**
|
|
* Binds event listeners
|
|
*/
|
|
bindEventListeners() {
|
|
this.body.emitter.on('initPhysics', () => {this.initPhysics();});
|
|
this.body.emitter.on('_layoutFailed', () => {this.layoutFailed = true;});
|
|
this.body.emitter.on('resetPhysics', () => {this.stopSimulation(); this.ready = false;});
|
|
this.body.emitter.on('disablePhysics', () => {this.physicsEnabled = false; this.stopSimulation();});
|
|
this.body.emitter.on('restorePhysics', () => {
|
|
this.setOptions(this.options);
|
|
if (this.ready === true) {
|
|
this.startSimulation();
|
|
}
|
|
});
|
|
this.body.emitter.on('startSimulation', () => {
|
|
if (this.ready === true) {
|
|
this.startSimulation();
|
|
}
|
|
});
|
|
this.body.emitter.on('stopSimulation', () => {this.stopSimulation();});
|
|
this.body.emitter.on('destroy', () => {
|
|
this.stopSimulation(false);
|
|
this.body.emitter.off();
|
|
});
|
|
this.body.emitter.on("_dataChanged", () => {
|
|
// Nodes and/or edges have been added or removed, update shortcut lists.
|
|
this.updatePhysicsData();
|
|
});
|
|
|
|
// debug: show forces
|
|
// this.body.emitter.on("afterDrawing", (ctx) => {this._drawForces(ctx);});
|
|
}
|
|
|
|
|
|
/**
|
|
* set the physics options
|
|
* @param {Object} options
|
|
*/
|
|
setOptions(options) {
|
|
if (options !== undefined) {
|
|
if (options === false) {
|
|
this.options.enabled = false;
|
|
this.physicsEnabled = false;
|
|
this.stopSimulation();
|
|
}
|
|
else if (options === true) {
|
|
this.options.enabled = true;
|
|
this.physicsEnabled = true;
|
|
this.startSimulation();
|
|
}
|
|
else {
|
|
this.physicsEnabled = true;
|
|
util.selectiveNotDeepExtend(['stabilization'], this.options, options);
|
|
util.mergeOptions(this.options, options, 'stabilization');
|
|
|
|
if (options.enabled === undefined) {
|
|
this.options.enabled = true;
|
|
}
|
|
|
|
if (this.options.enabled === false) {
|
|
this.physicsEnabled = false;
|
|
this.stopSimulation();
|
|
}
|
|
|
|
// set the timestep
|
|
this.timestep = this.options.timestep;
|
|
}
|
|
}
|
|
this.init();
|
|
}
|
|
|
|
|
|
/**
|
|
* configure the engine.
|
|
*/
|
|
init() {
|
|
var options;
|
|
if (this.options.solver === 'forceAtlas2Based') {
|
|
options = this.options.forceAtlas2Based;
|
|
this.nodesSolver = new ForceAtlas2BasedRepulsionSolver(this.body, this.physicsBody, options);
|
|
this.edgesSolver = new SpringSolver(this.body, this.physicsBody, options);
|
|
this.gravitySolver = new ForceAtlas2BasedCentralGravitySolver(this.body, this.physicsBody, options);
|
|
}
|
|
else if (this.options.solver === 'repulsion') {
|
|
options = this.options.repulsion;
|
|
this.nodesSolver = new Repulsion(this.body, this.physicsBody, options);
|
|
this.edgesSolver = new SpringSolver(this.body, this.physicsBody, options);
|
|
this.gravitySolver = new CentralGravitySolver(this.body, this.physicsBody, options);
|
|
}
|
|
else if (this.options.solver === 'hierarchicalRepulsion') {
|
|
options = this.options.hierarchicalRepulsion;
|
|
this.nodesSolver = new HierarchicalRepulsion(this.body, this.physicsBody, options);
|
|
this.edgesSolver = new HierarchicalSpringSolver(this.body, this.physicsBody, options);
|
|
this.gravitySolver = new CentralGravitySolver(this.body, this.physicsBody, options);
|
|
}
|
|
else { // barnesHut
|
|
options = this.options.barnesHut;
|
|
this.nodesSolver = new BarnesHutSolver(this.body, this.physicsBody, options);
|
|
this.edgesSolver = new SpringSolver(this.body, this.physicsBody, options);
|
|
this.gravitySolver = new CentralGravitySolver(this.body, this.physicsBody, options);
|
|
}
|
|
|
|
this.modelOptions = options;
|
|
}
|
|
|
|
|
|
/**
|
|
* initialize the engine
|
|
*/
|
|
initPhysics() {
|
|
if (this.physicsEnabled === true && this.options.enabled === true) {
|
|
if (this.options.stabilization.enabled === true) {
|
|
this.stabilize();
|
|
}
|
|
else {
|
|
this.stabilized = false;
|
|
this.ready = true;
|
|
this.body.emitter.emit('fit', {}, this.layoutFailed); // if the layout failed, we use the approximation for the zoom
|
|
this.startSimulation();
|
|
}
|
|
}
|
|
else {
|
|
this.ready = true;
|
|
this.body.emitter.emit('fit');
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Start the simulation
|
|
*/
|
|
startSimulation() {
|
|
if (this.physicsEnabled === true && this.options.enabled === true) {
|
|
this.stabilized = false;
|
|
|
|
// when visible, adaptivity is disabled.
|
|
this.adaptiveTimestep = false;
|
|
|
|
// this sets the width of all nodes initially which could be required for the avoidOverlap
|
|
this.body.emitter.emit("_resizeNodes");
|
|
if (this.viewFunction === undefined) {
|
|
this.viewFunction = this.simulationStep.bind(this);
|
|
this.body.emitter.on('initRedraw', this.viewFunction);
|
|
this.body.emitter.emit('_startRendering');
|
|
}
|
|
}
|
|
else {
|
|
this.body.emitter.emit('_redraw');
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* Stop the simulation, force stabilization.
|
|
* @param {boolean} [emit=true]
|
|
*/
|
|
stopSimulation(emit = true) {
|
|
this.stabilized = true;
|
|
if (emit === true) {
|
|
this._emitStabilized();
|
|
}
|
|
if (this.viewFunction !== undefined) {
|
|
this.body.emitter.off('initRedraw', this.viewFunction);
|
|
this.viewFunction = undefined;
|
|
if (emit === true) {
|
|
this.body.emitter.emit('_stopRendering');
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* The viewFunction inserts this step into each render loop. It calls the physics tick and handles the cleanup at stabilized.
|
|
*
|
|
*/
|
|
simulationStep() {
|
|
// check if the physics have settled
|
|
var startTime = Date.now();
|
|
this.physicsTick();
|
|
var physicsTime = Date.now() - startTime;
|
|
|
|
// run double speed if it is a little graph
|
|
if ((physicsTime < 0.4 * this.simulationInterval || this.runDoubleSpeed === true) && this.stabilized === false) {
|
|
this.physicsTick();
|
|
|
|
// this makes sure there is no jitter. The decision is taken once to run it at double speed.
|
|
this.runDoubleSpeed = true;
|
|
}
|
|
|
|
if (this.stabilized === true) {
|
|
this.stopSimulation();
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* trigger the stabilized event.
|
|
*
|
|
* @param {number} [amountOfIterations=this.stabilizationIterations]
|
|
* @private
|
|
*/
|
|
_emitStabilized(amountOfIterations = this.stabilizationIterations) {
|
|
if (this.stabilizationIterations > 1 || this.startedStabilization === true) {
|
|
setTimeout(() => {
|
|
this.body.emitter.emit('stabilized', {iterations: amountOfIterations});
|
|
this.startedStabilization = false;
|
|
this.stabilizationIterations = 0;
|
|
}, 0);
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* Calculate the forces for one physics iteration and move the nodes.
|
|
* @private
|
|
*/
|
|
physicsStep() {
|
|
this.gravitySolver.solve();
|
|
this.nodesSolver.solve();
|
|
this.edgesSolver.solve();
|
|
this.moveNodes();
|
|
}
|
|
|
|
|
|
/**
|
|
* Make dynamic adjustments to the timestep, based on current state.
|
|
*
|
|
* Helper function for physicsTick().
|
|
* @private
|
|
*/
|
|
adjustTimeStep() {
|
|
const factor = 1.2; // Factor for increasing the timestep on success.
|
|
|
|
// we compare the two steps. if it is acceptable we double the step.
|
|
if (this._evaluateStepQuality() === true) {
|
|
this.timestep = factor * this.timestep;
|
|
}
|
|
else {
|
|
// if not, we decrease the step to a minimum of the options timestep.
|
|
// if the decreased timestep is smaller than the options step, we do not reset the counter
|
|
// we assume that the options timestep is stable enough.
|
|
if (this.timestep/factor < this.options.timestep) {
|
|
this.timestep = this.options.timestep;
|
|
}
|
|
else {
|
|
// if the timestep was larger than 2 times the option one we check the adaptivity again to ensure
|
|
// that large instabilities do not form.
|
|
this.adaptiveCounter = -1; // check again next iteration
|
|
this.timestep = Math.max(this.options.timestep, this.timestep/factor);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* A single simulation step (or 'tick') in the physics simulation
|
|
*
|
|
* @private
|
|
*/
|
|
physicsTick() {
|
|
this._startStabilizing(); // this ensures that there is no start event when the network is already stable.
|
|
if (this.stabilized === true) return;
|
|
|
|
// adaptivity means the timestep adapts to the situation, only applicable for stabilization
|
|
if (this.adaptiveTimestep === true && this.adaptiveTimestepEnabled === true) {
|
|
// timestep remains stable for "interval" iterations.
|
|
let doAdaptive = (this.adaptiveCounter % this.adaptiveInterval === 0);
|
|
|
|
if (doAdaptive) {
|
|
// first the big step and revert.
|
|
this.timestep = 2 * this.timestep;
|
|
this.physicsStep();
|
|
this.revert(); // saves the reference state
|
|
|
|
// now the normal step. Since this is the last step, it is the more stable one and we will take this.
|
|
this.timestep = 0.5 * this.timestep;
|
|
|
|
// since it's half the step, we do it twice.
|
|
this.physicsStep();
|
|
this.physicsStep();
|
|
|
|
this.adjustTimeStep();
|
|
}
|
|
else {
|
|
this.physicsStep(); // normal step, keeping timestep constant
|
|
}
|
|
|
|
this.adaptiveCounter += 1;
|
|
}
|
|
else {
|
|
// case for the static timestep, we reset it to the one in options and take a normal step.
|
|
this.timestep = this.options.timestep;
|
|
this.physicsStep();
|
|
}
|
|
|
|
if (this.stabilized === true) this.revert();
|
|
this.stabilizationIterations++;
|
|
}
|
|
|
|
|
|
/**
|
|
* Nodes and edges can have the physics toggles on or off. A collection of indices is created here so we can skip the check all the time.
|
|
*
|
|
* @private
|
|
*/
|
|
updatePhysicsData() {
|
|
this.physicsBody.forces = {};
|
|
this.physicsBody.physicsNodeIndices = [];
|
|
this.physicsBody.physicsEdgeIndices = [];
|
|
let nodes = this.body.nodes;
|
|
let edges = this.body.edges;
|
|
|
|
// get node indices for physics
|
|
for (let nodeId in nodes) {
|
|
if (nodes.hasOwnProperty(nodeId)) {
|
|
if (nodes[nodeId].options.physics === true) {
|
|
this.physicsBody.physicsNodeIndices.push(nodes[nodeId].id);
|
|
}
|
|
}
|
|
}
|
|
|
|
// get edge indices for physics
|
|
for (let edgeId in edges) {
|
|
if (edges.hasOwnProperty(edgeId)) {
|
|
if (edges[edgeId].options.physics === true) {
|
|
this.physicsBody.physicsEdgeIndices.push(edges[edgeId].id);
|
|
}
|
|
}
|
|
}
|
|
|
|
// get the velocity and the forces vector
|
|
for (let i = 0; i < this.physicsBody.physicsNodeIndices.length; i++) {
|
|
let nodeId = this.physicsBody.physicsNodeIndices[i];
|
|
this.physicsBody.forces[nodeId] = {x:0,y:0};
|
|
|
|
// forces can be reset because they are recalculated. Velocities have to persist.
|
|
if (this.physicsBody.velocities[nodeId] === undefined) {
|
|
this.physicsBody.velocities[nodeId] = {x:0,y:0};
|
|
}
|
|
}
|
|
|
|
// clean deleted nodes from the velocity vector
|
|
for (let nodeId in this.physicsBody.velocities) {
|
|
if (nodes[nodeId] === undefined) {
|
|
delete this.physicsBody.velocities[nodeId];
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* Revert the simulation one step. This is done so after stabilization, every new start of the simulation will also say stabilized.
|
|
*/
|
|
revert() {
|
|
var nodeIds = Object.keys(this.previousStates);
|
|
var nodes = this.body.nodes;
|
|
var velocities = this.physicsBody.velocities;
|
|
this.referenceState = {};
|
|
|
|
for (let i = 0; i < nodeIds.length; i++) {
|
|
let nodeId = nodeIds[i];
|
|
if (nodes[nodeId] !== undefined) {
|
|
if (nodes[nodeId].options.physics === true) {
|
|
this.referenceState[nodeId] = {
|
|
positions: {x:nodes[nodeId].x, y:nodes[nodeId].y}
|
|
};
|
|
velocities[nodeId].x = this.previousStates[nodeId].vx;
|
|
velocities[nodeId].y = this.previousStates[nodeId].vy;
|
|
nodes[nodeId].x = this.previousStates[nodeId].x;
|
|
nodes[nodeId].y = this.previousStates[nodeId].y;
|
|
}
|
|
}
|
|
else {
|
|
delete this.previousStates[nodeId];
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This compares the reference state to the current state
|
|
*
|
|
* @returns {boolean}
|
|
* @private
|
|
*/
|
|
_evaluateStepQuality() {
|
|
let dx, dy, dpos;
|
|
let nodes = this.body.nodes;
|
|
let reference = this.referenceState;
|
|
let posThreshold = 0.3;
|
|
|
|
for (let nodeId in this.referenceState) {
|
|
if (this.referenceState.hasOwnProperty(nodeId) && nodes[nodeId] !== undefined) {
|
|
dx = nodes[nodeId].x - reference[nodeId].positions.x;
|
|
dy = nodes[nodeId].y - reference[nodeId].positions.y;
|
|
|
|
dpos = Math.sqrt(Math.pow(dx,2) + Math.pow(dy,2))
|
|
|
|
if (dpos > posThreshold) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* move the nodes one timestep and check if they are stabilized
|
|
*/
|
|
moveNodes() {
|
|
var nodeIndices = this.physicsBody.physicsNodeIndices;
|
|
var maxNodeVelocity = 0;
|
|
var averageNodeVelocity = 0;
|
|
|
|
// the velocity threshold (energy in the system) for the adaptivity toggle
|
|
var velocityAdaptiveThreshold = 5;
|
|
|
|
for (let i = 0; i < nodeIndices.length; i++) {
|
|
let nodeId = nodeIndices[i];
|
|
let nodeVelocity = this._performStep(nodeId);
|
|
// stabilized is true if stabilized is true and velocity is smaller than vmin --> all nodes must be stabilized
|
|
maxNodeVelocity = Math.max(maxNodeVelocity, nodeVelocity);
|
|
averageNodeVelocity += nodeVelocity;
|
|
}
|
|
|
|
// evaluating the stabilized and adaptiveTimestepEnabled conditions
|
|
this.adaptiveTimestepEnabled = (averageNodeVelocity/nodeIndices.length) < velocityAdaptiveThreshold;
|
|
this.stabilized = maxNodeVelocity < this.options.minVelocity;
|
|
}
|
|
|
|
|
|
/**
|
|
* Calculate new velocity for a coordinate direction
|
|
*
|
|
* @param {number} v velocity for current coordinate
|
|
* @param {number} f regular force for current coordinate
|
|
* @param {number} m mass of current node
|
|
* @returns {number} new velocity for current coordinate
|
|
* @private
|
|
*/
|
|
calculateComponentVelocity(v,f, m) {
|
|
let df = this.modelOptions.damping * v; // damping force
|
|
let a = (f - df) / m; // acceleration
|
|
|
|
v += a * this.timestep;
|
|
|
|
// Put a limit on the velocities if it is really high
|
|
let maxV = this.options.maxVelocity || 1e9;
|
|
if (Math.abs(v) > maxV) {
|
|
v = ((v > 0) ? maxV: -maxV);
|
|
}
|
|
|
|
return v;
|
|
}
|
|
|
|
|
|
/**
|
|
* Perform the actual step
|
|
*
|
|
* @param {Node.id} nodeId
|
|
* @returns {number} the new velocity of given node
|
|
* @private
|
|
*/
|
|
_performStep(nodeId) {
|
|
let node = this.body.nodes[nodeId];
|
|
let force = this.physicsBody.forces[nodeId];
|
|
let velocity = this.physicsBody.velocities[nodeId];
|
|
|
|
// store the state so we can revert
|
|
this.previousStates[nodeId] = {x:node.x, y:node.y, vx:velocity.x, vy:velocity.y};
|
|
|
|
if (node.options.fixed.x === false) {
|
|
velocity.x = this.calculateComponentVelocity(velocity.x, force.x, node.options.mass);
|
|
node.x += velocity.x * this.timestep;
|
|
}
|
|
else {
|
|
force.x = 0;
|
|
velocity.x = 0;
|
|
}
|
|
|
|
if (node.options.fixed.y === false) {
|
|
velocity.y = this.calculateComponentVelocity(velocity.y, force.y, node.options.mass);
|
|
node.y += velocity.y * this.timestep;
|
|
}
|
|
else {
|
|
force.y = 0;
|
|
velocity.y = 0;
|
|
}
|
|
|
|
let totalVelocity = Math.sqrt(Math.pow(velocity.x,2) + Math.pow(velocity.y,2));
|
|
return totalVelocity;
|
|
}
|
|
|
|
|
|
/**
|
|
* When initializing and stabilizing, we can freeze nodes with a predefined position.
|
|
* This greatly speeds up stabilization because only the supportnodes for the smoothCurves have to settle.
|
|
*
|
|
* @private
|
|
*/
|
|
_freezeNodes() {
|
|
var nodes = this.body.nodes;
|
|
for (var id in nodes) {
|
|
if (nodes.hasOwnProperty(id)) {
|
|
if (nodes[id].x && nodes[id].y) {
|
|
let fixed = nodes[id].options.fixed;
|
|
this.freezeCache[id] = {x:fixed.x, y:fixed.y};
|
|
fixed.x = true;
|
|
fixed.y = true;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* Unfreezes the nodes that have been frozen by _freezeDefinedNodes.
|
|
*
|
|
* @private
|
|
*/
|
|
_restoreFrozenNodes() {
|
|
var nodes = this.body.nodes;
|
|
for (var id in nodes) {
|
|
if (nodes.hasOwnProperty(id)) {
|
|
if (this.freezeCache[id] !== undefined) {
|
|
nodes[id].options.fixed.x = this.freezeCache[id].x;
|
|
nodes[id].options.fixed.y = this.freezeCache[id].y;
|
|
}
|
|
}
|
|
}
|
|
this.freezeCache = {};
|
|
}
|
|
|
|
/**
|
|
* Find a stable position for all nodes
|
|
*
|
|
* @param {number} [iterations=this.options.stabilization.iterations]
|
|
*/
|
|
stabilize(iterations = this.options.stabilization.iterations) {
|
|
if (typeof iterations !== 'number') {
|
|
iterations = this.options.stabilization.iterations;
|
|
console.log('The stabilize method needs a numeric amount of iterations. Switching to default: ', iterations);
|
|
}
|
|
|
|
if (this.physicsBody.physicsNodeIndices.length === 0) {
|
|
this.ready = true;
|
|
return;
|
|
}
|
|
|
|
// enable adaptive timesteps
|
|
this.adaptiveTimestep = true && this.options.adaptiveTimestep;
|
|
|
|
// this sets the width of all nodes initially which could be required for the avoidOverlap
|
|
this.body.emitter.emit("_resizeNodes");
|
|
|
|
this.stopSimulation(); // stop the render loop
|
|
this.stabilized = false;
|
|
|
|
// block redraw requests
|
|
this.body.emitter.emit('_blockRedraw');
|
|
this.targetIterations = iterations;
|
|
|
|
// start the stabilization
|
|
if (this.options.stabilization.onlyDynamicEdges === true) {
|
|
this._freezeNodes();
|
|
}
|
|
this.stabilizationIterations = 0;
|
|
|
|
setTimeout(() => this._stabilizationBatch(),0);
|
|
}
|
|
|
|
|
|
/**
|
|
* If not already stabilizing, start it and emit a start event.
|
|
*
|
|
* @returns {boolean} true if stabilization started with this call
|
|
* @private
|
|
*/
|
|
_startStabilizing() {
|
|
if (this.startedStabilization === true) return false;
|
|
|
|
this.body.emitter.emit('startStabilizing');
|
|
this.startedStabilization = true;
|
|
return true;
|
|
}
|
|
|
|
|
|
/**
|
|
* One batch of stabilization
|
|
* @private
|
|
*/
|
|
_stabilizationBatch() {
|
|
var running = () => (this.stabilized === false && this.stabilizationIterations < this.targetIterations);
|
|
|
|
var sendProgress = () => {
|
|
this.body.emitter.emit('stabilizationProgress', {
|
|
iterations: this.stabilizationIterations,
|
|
total: this.targetIterations
|
|
});
|
|
};
|
|
|
|
if (this._startStabilizing()) {
|
|
sendProgress(); // Ensure that there is at least one start event.
|
|
}
|
|
|
|
var count = 0;
|
|
while (running() && count < this.options.stabilization.updateInterval) {
|
|
this.physicsTick();
|
|
count++;
|
|
}
|
|
|
|
sendProgress();
|
|
|
|
if (running()) {
|
|
setTimeout(this._stabilizationBatch.bind(this),0);
|
|
}
|
|
else {
|
|
this._finalizeStabilization();
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* Wrap up the stabilization, fit and emit the events.
|
|
* @private
|
|
*/
|
|
_finalizeStabilization() {
|
|
this.body.emitter.emit('_allowRedraw');
|
|
if (this.options.stabilization.fit === true) {
|
|
this.body.emitter.emit('fit');
|
|
}
|
|
|
|
if (this.options.stabilization.onlyDynamicEdges === true) {
|
|
this._restoreFrozenNodes();
|
|
}
|
|
|
|
this.body.emitter.emit('stabilizationIterationsDone');
|
|
this.body.emitter.emit('_requestRedraw');
|
|
|
|
if (this.stabilized === true) {
|
|
this._emitStabilized();
|
|
}
|
|
else {
|
|
this.startSimulation();
|
|
}
|
|
|
|
this.ready = true;
|
|
}
|
|
|
|
|
|
//--------------------------- DEBUGGING BELOW ---------------------------//
|
|
|
|
|
|
/**
|
|
* Debug function that display arrows for the forces currently active in the network.
|
|
*
|
|
* Use this when debugging only.
|
|
*
|
|
* @param {CanvasRenderingContext2D} ctx
|
|
* @private
|
|
*/
|
|
_drawForces(ctx) {
|
|
for (var i = 0; i < this.physicsBody.physicsNodeIndices.length; i++) {
|
|
let index = this.physicsBody.physicsNodeIndices[i];
|
|
let node = this.body.nodes[index];
|
|
let force = this.physicsBody.forces[index];
|
|
let factor = 20;
|
|
let colorFactor = 0.03;
|
|
let forceSize = Math.sqrt(Math.pow(force.x,2) + Math.pow(force.x,2));
|
|
|
|
let size = Math.min(Math.max(5,forceSize),15);
|
|
let arrowSize = 3*size;
|
|
|
|
let color = util.HSVToHex((180 - Math.min(1,Math.max(0,colorFactor*forceSize))*180) / 360,1,1);
|
|
|
|
let point = {
|
|
x: node.x + factor*force.x,
|
|
y: node.y + factor*force.y
|
|
};
|
|
|
|
ctx.lineWidth = size;
|
|
ctx.strokeStyle = color;
|
|
ctx.beginPath();
|
|
ctx.moveTo(node.x,node.y);
|
|
ctx.lineTo(point.x, point.y);
|
|
ctx.stroke();
|
|
|
|
let angle = Math.atan2(force.y, force.x);
|
|
ctx.fillStyle = color;
|
|
EndPoints.draw(ctx, {type: 'arrow', point: point, angle: angle, length: arrowSize});
|
|
ctx.fill();
|
|
|
|
}
|
|
}
|
|
}
|
|
|
|
export default PhysicsEngine;
|