added high delta warning to Matter.Engine

src/core/Engine.js

@@ -24,6 +24,8 @@ var Body = require('../body/Body');
 
 (function() {
 
+ Engine._deltaMax = 1000 / 60;
+
  /**
  * Creates a new engine. The options parameter is an object that specifies any properties you wish to override the defaults.
  * All properties have default values, and many are pre-calculated automatically based on other properties.
@@ -88,6 +90,13 @@ var Body = require('../body/Body');
  timestamp = timing.timestamp,
  i;
 
+ // warn if high delta
+ if (delta > Engine._deltaMax) {
+ Common.warnOnce(
+ 'Matter.Engine.update: delta argument is recommended to be less than or equal to', Engine._deltaMax.toFixed(3), 'ms.'
+ );
+ }
+
  delta = typeof delta !== 'undefined' ? delta : Common._baseDelta;
  delta *= timing.timeScale;