fixed more issues with timing.timeScale

liabru · May 4, 2014 · 186d839 · 186d839
1 parent a8d7a40
commit 186d839
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Showing 3 changed files with 16 additions and 13 deletions.
diff --git a/src/body/Body.js b/src/body/Body.js
@@ -168,10 +168,11 @@ var Body = {};
      * @method updateAll
      * @param {body[]} bodies
      * @param {number} deltaTime
+     * @param {number} timeScale
      * @param {number} correction
      * @param {bounds} worldBounds
      */
-    Body.updateAll = function(bodies, deltaTime, correction, worldBounds) {
+    Body.updateAll = function(bodies, deltaTime, timeScale, correction, worldBounds) {
         for (var i = 0; i < bodies.length; i++) {
             var body = bodies[i];
 
@@ -184,7 +185,7 @@ var Body = {};
                 || body.bounds.max.y < worldBounds.min.y || body.bounds.min.y > worldBounds.max.y)
                 continue;
 
-            Body.update(body, deltaTime, correction);
+            Body.update(body, deltaTime, timeScale, correction);
         }
     };
 
@@ -193,13 +194,14 @@ var Body = {};
      * @method update
      * @param {body} body
      * @param {number} deltaTime
+     * @param {number} timeScale
      * @param {number} correction
      */
-    Body.update = function(body, deltaTime, correction) {
-        var deltaTimeSquared = deltaTime * deltaTime * body.timeScale;
+    Body.update = function(body, deltaTime, timeScale, correction) {
+        var deltaTimeSquared = Math.pow(deltaTime * timeScale * body.timeScale, 2);
 
         // from the previous step
-        var frictionAir = 1 - body.frictionAir,
+        var frictionAir = 1 - body.frictionAir * timeScale * body.timeScale,
             velocityPrevX = body.position.x - body.positionPrev.x,
             velocityPrevY = body.position.y - body.positionPrev.y;
 

diff --git a/src/collision/Resolver.js b/src/collision/Resolver.js
@@ -173,8 +173,9 @@ var Resolver = {};
      * @method solveVelocity
      * @param {pair[]} pairs
      */
-    Resolver.solveVelocity = function(pairs) {
-        var impulse = {};
+    Resolver.solveVelocity = function(pairs, timeScale) {
+        var impulse = {},
+            timeScaleSquared = timeScale * timeScale;
 
         for (var i = 0; i < pairs.length; i++) {
             var pair = pairs[i];
@@ -219,8 +220,8 @@ var Resolver = {};
 
                 // coulomb friction
                 var tangentImpulse = tangentVelocity;
-                if (tangentSpeed > normalForce * pair.friction)
-                    tangentImpulse = normalForce * pair.friction * tangentVelocityDirection;
+                if (tangentSpeed > normalForce * pair.friction * timeScaleSquared)
+                    tangentImpulse = normalForce * pair.friction * timeScaleSquared * tangentVelocityDirection;
 
                 // modify impulses accounting for mass, inertia and offset
                 var oAcN = Vector.cross(offsetA, normal),
@@ -230,7 +231,7 @@ var Resolver = {};
                 tangentImpulse *= share;
 
                 // handle high velocity and resting collisions separately
-                if (normalVelocity < 0 && normalVelocity * normalVelocity > _restingThresh) {
+                if (normalVelocity < 0 && normalVelocity * normalVelocity > _restingThresh * timeScaleSquared) {
                     // high velocity so clear cached contact impulse
                     contact.normalImpulse = 0;
                     contact.tangentImpulse = 0;

diff --git a/src/core/Engine.js b/src/core/Engine.js
@@ -191,7 +191,7 @@ var Engine = {};
             i;
 
         // increment timestamp
-        timing.timestamp += delta;
+        timing.timestamp += delta * timing.timeScale;
         timing.correction = correction;
 
         // create an event object
@@ -216,7 +216,7 @@ var Engine = {};
         Body.applyGravityAll(allBodies, world.gravity);
 
         // update all body position and rotation by integration
-        Body.updateAll(allBodies, delta * timing.timeScale, correction, world.bounds);
+        Body.updateAll(allBodies, delta, timing.timeScale, correction, world.bounds);
 
         // update all constraints
         for (i = 0; i < engine.constraintIterations; i++) {
@@ -256,7 +256,7 @@ var Engine = {};
         // iteratively resolve velocity between collisions
         Resolver.preSolveVelocity(pairs.list);
         for (i = 0; i < engine.velocityIterations; i++) {
-            Resolver.solveVelocity(pairs.list);
+            Resolver.solveVelocity(pairs.list, timing.timeScale);
         }
 
         // iteratively resolve position between collisions