update timing improvements

examples/ragdoll.js

@@ -83,7 +83,7 @@ Example.ragdoll = function() {
         lastTime = Common.now();
 
     Events.on(engine, 'afterUpdate', function(event) {
-        var timeScale = event.delta / 1000;
+        var timeScale = timeScale = (event.delta || (1000 / 60)) / 1000;
 
         // tween the timescale for slow-mo
         if (mouse.button === -1) {
@@ -94,7 +94,6 @@ Example.ragdoll = function() {
 
         // every 1.5 sec (real time)
         if (Common.now() - lastTime >= 2000) {
-
             // flip the timescale
             if (timeScaleTarget < 1) {
                 timeScaleTarget = 1;

examples/timescale.js

@@ -65,7 +65,7 @@ Example.timescale = function() {
         lastTime = Common.now();
 
     Events.on(engine, 'afterUpdate', function(event) {
-        var timeScale = event.delta / 1000;
+        var timeScale = timeScale = (event.delta || (1000 / 60)) / 1000;
 
         // tween the timescale for bullet time slow-mo
         engine.timing.timeScale += (timeScaleTarget - engine.timing.timeScale) * 12 * timeScale;

src/collision/Resolver.js

@@ -229,16 +229,9 @@ var Bounds = require('../geometry/Bounds');
         var timeScale = delta / Common._timeUnit,
             timeScale2 = timeScale * timeScale,
             timeScale3 = timeScale2 * timeScale,
-            impulse = Vector._temp[0],
-            tempA = Vector._temp[1],
-            tempB = Vector._temp[2],
-            tempC = Vector._temp[3],
-            tempD = Vector._temp[4],
-            tempE = Vector._temp[5],
-            timeScaleSquared = timeScale * timeScale,
-            restingThresh = Resolver._restingThresh * timeScaleSquared,
+            restingThresh = Resolver._restingThresh * timeScale2,
             frictionNormalMultiplier = Resolver._frictionNormalMultiplier,
-            restingThreshTangent = Resolver._restingThreshTangent * timeScaleSquared,
+            restingThreshTangent = Resolver._restingThreshTangent * timeScale2,
             NumberMaxValue = Number.MAX_VALUE,
             pairsLength = pairs.length,
             tangentImpulse,
@@ -265,7 +258,7 @@ var Bounds = require('../geometry/Bounds');
                 contactsLength = contacts.length,
                 contactShare = 1 / contactsLength,
                 inverseMassTotal = bodyA.inverseMass + bodyB.inverseMass,
-                friction = pair.friction * pair.frictionStatic * frictionNormalMultiplier * timeScaleSquared;
+                friction = pair.friction * pair.frictionStatic * frictionNormalMultiplier * timeScale2;
 
             // update body velocities
             bodyAVelocity.x = bodyA.position.x - bodyA.positionPrev.x;
@@ -297,19 +290,10 @@ var Bounds = require('../geometry/Bounds');
                     tangentVelocity = tangentX * relativeVelocityX + tangentY * relativeVelocityY;
 
                 // coulomb friction
-                // var tangentImpulse = tangentVelocity,
-                //     maxFriction = Infinity;
-
-                // if (tangentSpeed > pair.friction * pair.frictionStatic * normalForce * timeScale3) {
-                //     maxFriction = tangentSpeed * timeScale;
-                //     tangentImpulse = Common.clamp(
-                //         pair.friction * tangentVelocityDirection * timeScale3,
-                //         -maxFriction, maxFriction
-                //     );
                 var normalOverlap = pair.separation + normalVelocity;
                 var normalForce = Math.min(normalOverlap, 1) * timeScale3;
                 normalForce = normalOverlap < 0 ? 0 : normalForce;
-                
+
                 var frictionLimit = normalForce * friction;
 
                 if (tangentVelocity > frictionLimit || -tangentVelocity > frictionLimit) {
@@ -336,7 +320,7 @@ var Bounds = require('../geometry/Bounds');
                 tangentImpulse *= share;
 
                 // handle high velocity and resting collisions separately
-                if (normalVelocity < 0 && normalVelocity * normalVelocity > Resolver._restingThresh * timeScale2) {
+                if (normalVelocity < 0 && normalVelocity * normalVelocity > restingThresh) {
                     // high normal velocity so clear cached contact normal impulse
                     contact.normalImpulse = 0;
                 } else {
@@ -349,7 +333,7 @@ var Bounds = require('../geometry/Bounds');
                 }
 
                 // handle high velocity and resting collisions separately
-                if (tangentVelocity * tangentVelocity > Resolver._restingThreshTangent * timeScale2) {
+                if (tangentVelocity * tangentVelocity > restingThreshTangent) {
                     // high tangent velocity so clear cached contact tangent impulse
                     contact.tangentImpulse = 0;
                 } else {

src/collision/SAT.js

@@ -20,8 +20,6 @@ var deprecated = Common.deprecated;
 
 (function() {
 
-    SAT._reuseMotionThresh = 0.2;
-
     /**
      * Detect collision between two bodies using the Separating Axis Theorem.
      * @deprecated replaced by Collision.collides

src/core/Engine.js

@@ -92,8 +92,8 @@ var Body = require('../body/Body');
         delta *= timing.timeScale;
 
         // increment timestamp
-        timing.timestamp += delta * timing.timeScale;
-        timing.lastDelta = delta * timing.timeScale;
+        timing.timestamp += delta;
+        timing.lastDelta = delta;
 
         // create an event object
         var event = {

src/core/Runner.js

@@ -110,13 +110,6 @@ var Common = require('./Common');
         var timing = engine.timing,
             delta;
 
-        // create an event object
-        var event = {
-            timestamp: timing.timestamp
-        };
-
-        Events.trigger(runner, 'beforeTick', event);
-
         if (runner.isFixed) {
             // fixed timestep
             delta = runner.delta;
@@ -144,7 +137,6 @@ var Common = require('./Common');
         };
 
         Events.trigger(runner, 'beforeTick', event);
-        Events.trigger(engine, 'beforeTick', event); // @deprecated
 
         // fps counter
         runner.frameCounter += 1;

src/core/Sleeping.js

@@ -24,7 +24,9 @@ var Common = require('./Common');
      * @param {number} delta
      */
     Sleeping.update = function(bodies, delta) {
-        var timeScale = delta / Common._timeUnit;
+        var timeScale = delta / Common._timeUnit,
+            timeScale2 = timeScale * timeScale,
+            motionSleepThreshold = Sleeping._motionSleepThreshold * timeScale2;
 
         // update bodies sleeping status
         for (var i = 0; i < bodies.length; i++) {
@@ -43,11 +45,12 @@ var Common = require('./Common');
             // biased average motion estimation between frames
             body.motion = Sleeping._minBias * minMotion + (1 - Sleeping._minBias) * maxMotion;
 
-            if (body.sleepThreshold > 0 && body.motion < Sleeping._motionSleepThreshold * timeScale * timeScale) {
+            if (body.sleepThreshold > 0 && body.motion < motionSleepThreshold) {
                 body.sleepCounter += 1;
 
-                if (body.sleepCounter >= body.sleepThreshold / timeScale)
+                if (body.sleepCounter >= body.sleepThreshold / timeScale) {
                     Sleeping.set(body, true);
+                }
             } else if (body.sleepCounter > 0) {
                 body.sleepCounter -= 1;
             }