diff --git a/build/fireworks-bundle.js b/build/fireworks-bundle.js
index 2464403..6d9ac3e 100644
--- a/build/fireworks-bundle.js
+++ b/build/fireworks-bundle.js
@@ -167,12 +167,12 @@ Fireworks.Emitter	= function(opts){
 
 Fireworks.Emitter.prototype.destroy	= function()
 {
-	this._effects.forEach(function(effect){
-		effect.destroy();
-	});
-	this._particles.forEach(function(particle){
-		particle.destroy();
-	});
+	for(var i=0;i<this._effects.length;i++){
+		this._effects[i].destroy()
+	}
+	for(var i=0;i<this._particles.length;i++){
+		this._particles[i].destroy()
+	}
 }
 
 
@@ -225,10 +225,11 @@ Fireworks.Emitter.prototype.intensity	= function(value){
 	// update the value
 	this._intensity	= value;
 	// notify all effects
-	this._effects.forEach(function(effect){
-		if( !effect.onIntensityChange )	return;
-		effect.onIntensityChange(this._intensity, oldValue);			
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onIntensityChange){
+			this._effects[i].onIntensityChange(this._intensity, oldValue);
+		}
+	}
 	return this;	// for chained API
 }
 
@@ -272,12 +273,13 @@ Fireworks.Emitter.prototype.start	= function()
 	this._started		= true;
 
 	// onCreate on all particles
-	this._effects.forEach(function(effect){
-		if( !effect.onCreate )	return;
-		this._particles.forEach(function(particle, particleIdx){
-			effect.onCreate(particle, particleIdx);			
-		})
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onCreate){
+			for(var j=0;j<this._particles.length;j++){
+				this._effects[i].onCreate(this._particles[j], j);
+			}
+		}
+	}
 	// set the intensity to 1
 	this.intensity(1)
 
@@ -288,35 +290,40 @@ Fireworks.Emitter.prototype.update	= function(deltaTime){
 	// bound the deltaTime to this._maxDeltaTime
 	deltaTime	= Math.min(this._maxDeltaTime, deltaTime)
 	// honor effect.onPreUpdate
-	this._effects.forEach(function(effect){
-		if( !effect.onPreUpdate )	return;
-		effect.onPreUpdate(deltaTime);			
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onPreUpdate){
+			this._effects[i].onPreUpdate(deltaTime);
+		}
+	}
 	// update each particles
-	this._effects.forEach(function(effect){
-		if( !effect.onUpdate )	return;
-		this._liveParticles.forEach(function(particle){
-			effect.onUpdate(particle, deltaTime);			
-		})
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onUpdate){
+			for(var j=0;j<this._liveParticles.length;j++){
+				this._effects[i].onUpdate(this._liveParticles[j], deltaTime);			
+			}
+		}
+	}
 	return this;	// for chained API
 }
 
 Fireworks.Emitter.prototype.render	= function(){
-	this._effects.forEach(function(effect){
-		if( !effect.onPreRender )	return;
-		effect.onPreRender();			
-	}.bind(this));
-	this._effects.forEach(function(effect){
-		if( !effect.onRender )	return;
-		this._liveParticles.forEach(function(particle){
-			effect.onRender(particle);			
-		})
-	}.bind(this));
-	this._effects.forEach(function(effect){
-		if( !effect.onPostRender )	return;
-		effect.onPostRender();			
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onPreRender){
+			this._effects[i].onPreRender();
+		}
+	}
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onRender){
+			for(var j=0;j<this._liveParticles.length;j++){
+				this._effects[i].onRender(this._liveParticles[j]);
+			}
+		}
+	}
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onPostRender){
+			this._effects[i].onPostRender();
+		}
+	}
 	return this;	// for chained API
 }
 
@@ -335,9 +342,9 @@ Fireworks.Emitter.prototype.killParticle	= function(particle)
 	this._liveParticles.splice(idx, 1)
 	this._deadParticles.push(particle);
 	// do the death on all effects
-	this.effects().forEach(function(effect){
-		effect.onDeath && effect.onDeath(particle);			
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		this._effects[i].onDeath && this._effects[i].onDeath(particle);
+	}
 }
 
 /**
@@ -350,9 +357,9 @@ Fireworks.Emitter.prototype.spawnParticle	= function(){
 	var particle	= this.deadParticles().pop();
 	this.liveParticles().push(particle);
 	// do the birth on all effects
-	this.effects().forEach(function(effect){
-		effect.onBirth && effect.onBirth(particle);			
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		this._effects[i].onBirth && this._effects[i].onBirth(particle);
+	}
 }
 Fireworks.createLinearGradient	= function(opts){
 	var LinearGradient	= new Fireworks.LinearGradient(opts);
diff --git a/build/fireworks-bundle.min.js b/build/fireworks-bundle.min.js
index 6e4be03..980f401 100644
--- a/build/fireworks-bundle.min.js
+++ b/build/fireworks-bundle.min.js
@@ -1,16 +1,16 @@
 var Fireworks={debug:!0,EffectsStackBuilder:function(a){this._emitter=a}};Fireworks.EffectsStackBuilder.prototype.emitter=function(){return this._emitter};Fireworks.EffectsStackBuilder.prototype.back=function(){return this._emitter};Fireworks.EffectsStackBuilder.prototype.createEffect=function(a,b){var c=Fireworks.createEffect(a,b).pushTo(this._emitter).back(this);c.effect().emitter(this._emitter);return c};
 Fireworks.createEffect=function(a,b){"object"===typeof a&&(b=a,a=void 0);var c=new Fireworks.Effect;c.opts=b;c.name=a;c.back=null;var d={onCreate:function(a){c.onCreate=a;return d},onBirth:function(a){c.onBirth=a;return d},onUpdate:function(a){c.onUpdate=a;return d},onDeath:function(a){c.onDeath=a;return d},onPreUpdate:function(a){c.onPreUpdate=a;return d},onPreRender:function(a){c.onPreRender=a;return d},onRender:function(a){c.onRender=a;return d},onPostRender:function(a){c.onPostRender=a;return d},
 onIntensityChange:function(a){c.onIntensityChange=a;return d},pushTo:function(a){a.effects().push(c);return d},back:function(a){if(void 0===a)return c.back;c.back=a;return d},effect:function(){return c}};return d};Fireworks.Effect=function(){this._emitter=null};Fireworks.Effect.prototype.destroy=function(){};Fireworks.Effect.prototype.emitter=function(a){if(void 0===a)return this._emitter;this._emitter=a;return this};Fireworks.createEmitter=function(a){return new Fireworks.Emitter(a)};
-Fireworks.Emitter=function(a){this._nParticles=void 0!==a.nParticles?a.nParticles:100;this._particles=[];this._effects=[];this._started=!1;this._onUpdated=null;this._intensity=0;this._maxDeltaTime=1/3;this._effectsStackBuilder=new Fireworks.EffectsStackBuilder(this)};Fireworks.Emitter.prototype.destroy=function(){this._effects.forEach(function(a){a.destroy()});this._particles.forEach(function(a){a.destroy()})};Fireworks.Emitter.prototype.effects=function(){return this._effects};
+Fireworks.Emitter=function(a){this._nParticles=void 0!==a.nParticles?a.nParticles:100;this._particles=[];this._effects=[];this._started=!1;this._onUpdated=null;this._intensity=0;this._maxDeltaTime=1/3;this._effectsStackBuilder=new Fireworks.EffectsStackBuilder(this)};Fireworks.Emitter.prototype.destroy=function(){for(var a=0;a<this._effects.length;a++)this._effects[a].destroy();for(a=0;a<this._particles.length;a++)this._particles[a].destroy()};Fireworks.Emitter.prototype.effects=function(){return this._effects};
 Fireworks.Emitter.prototype.effect=function(a){for(var b=0;b<this._effects.length;b++){var c=this._effects[b];if(c.name===a)return c}return null};Fireworks.Emitter.prototype.particles=function(){return this._particles};Fireworks.Emitter.prototype.liveParticles=function(){return this._liveParticles};Fireworks.Emitter.prototype.deadParticles=function(){return this._deadParticles};Fireworks.Emitter.prototype.nParticles=function(){return this._nParticles};
 Fireworks.Emitter.prototype.effectsStackBuilder=function(){return this._effectsStackBuilder};
-Fireworks.Emitter.prototype.intensity=function(a){if(void 0===a)return this._intensity;if(a===this._intensity)return this;Fireworks.debug&&console.assert(0<=a,"Fireworks.Emitter.intensity: invalid value.",a);Fireworks.debug&&console.assert(1>=a,"Fireworks.Emitter.intensity: invalid value.",a);var b=this._intensity;this._intensity=a;this._effects.forEach(function(a){if(a.onIntensityChange)a.onIntensityChange(this._intensity,b)}.bind(this));return this};
+Fireworks.Emitter.prototype.intensity=function(a){if(void 0===a)return this._intensity;if(a===this._intensity)return this;Fireworks.debug&&console.assert(0<=a,"Fireworks.Emitter.intensity: invalid value.",a);Fireworks.debug&&console.assert(1>=a,"Fireworks.Emitter.intensity: invalid value.",a);var b=this._intensity;this._intensity=a;for(a=0;a<this._effects.length;a++)if(this._effects[a].onIntensityChange)this._effects[a].onIntensityChange(this._intensity,b);return this};
 Fireworks.Emitter.prototype.maxDeltaTime=function(a){if(void 0===a)return this._maxDeltaTime;this._maxDeltaTime=a;return this};Fireworks.Emitter.prototype.setParticleData=function(a,b,c){a[b]=c};Fireworks.Emitter.prototype.getParticleData=function(a,b){return a[b]};
-Fireworks.Emitter.prototype.start=function(){console.assert(0<this._effects.length,"At least one effect MUST be set");console.assert(!1===this._started);this._particles=Array(this._nParticles);for(var a=0;a<this._nParticles;a++)this._particles[a]=new Fireworks.Particle;this._liveParticles=[];this._deadParticles=this._particles.slice(0);this._started=!0;this._effects.forEach(function(a){a.onCreate&&this._particles.forEach(function(c,d){a.onCreate(c,d)})}.bind(this));this.intensity(1);return this};
-Fireworks.Emitter.prototype.update=function(a){a=Math.min(this._maxDeltaTime,a);this._effects.forEach(function(b){if(b.onPreUpdate)b.onPreUpdate(a)}.bind(this));this._effects.forEach(function(b){b.onUpdate&&this._liveParticles.forEach(function(c){b.onUpdate(c,a)})}.bind(this));return this};
-Fireworks.Emitter.prototype.render=function(){this._effects.forEach(function(a){if(a.onPreRender)a.onPreRender()}.bind(this));this._effects.forEach(function(a){a.onRender&&this._liveParticles.forEach(function(b){a.onRender(b)})}.bind(this));this._effects.forEach(function(a){if(a.onPostRender)a.onPostRender()}.bind(this));return this};
-Fireworks.Emitter.prototype.killParticle=function(a){var b=this._liveParticles.indexOf(a);Fireworks.debug&&console.assert(-1!==b);this._liveParticles.splice(b,1);this._deadParticles.push(a);this.effects().forEach(function(b){b.onDeath&&b.onDeath(a)}.bind(this))};
-Fireworks.Emitter.prototype.spawnParticle=function(){Fireworks.debug&&console.assert(1<=this._deadParticles.length,"no more particle available");var a=this.deadParticles().pop();this.liveParticles().push(a);this.effects().forEach(function(b){b.onBirth&&b.onBirth(a)}.bind(this))};Fireworks.createLinearGradient=function(a){return new Fireworks.LinearGradient(a)};Fireworks.LinearGradient=function(){this._keyPoints=[]};
+Fireworks.Emitter.prototype.start=function(){console.assert(0<this._effects.length,"At least one effect MUST be set");console.assert(!1===this._started);this._particles=Array(this._nParticles);for(var a=0;a<this._nParticles;a++)this._particles[a]=new Fireworks.Particle;this._liveParticles=[];this._deadParticles=this._particles.slice(0);this._started=!0;for(a=0;a<this._effects.length;a++)if(this._effects[a].onCreate)for(var b=0;b<this._particles.length;b++)this._effects[a].onCreate(this._particles[b],
+b);this.intensity(1);return this};Fireworks.Emitter.prototype.update=function(a){a=Math.min(this._maxDeltaTime,a);for(var b=0;b<this._effects.length;b++)if(this._effects[b].onPreUpdate)this._effects[b].onPreUpdate(a);for(b=0;b<this._effects.length;b++)if(this._effects[b].onUpdate)for(var c=0;c<this._liveParticles.length;c++)this._effects[b].onUpdate(this._liveParticles[c],a);return this};
+Fireworks.Emitter.prototype.render=function(){for(var a=0;a<this._effects.length;a++)if(this._effects[a].onPreRender)this._effects[a].onPreRender();for(a=0;a<this._effects.length;a++)if(this._effects[a].onRender)for(var b=0;b<this._liveParticles.length;b++)this._effects[a].onRender(this._liveParticles[b]);for(a=0;a<this._effects.length;a++)if(this._effects[a].onPostRender)this._effects[a].onPostRender();return this};
+Fireworks.Emitter.prototype.killParticle=function(a){var b=this._liveParticles.indexOf(a);Fireworks.debug&&console.assert(-1!==b);this._liveParticles.splice(b,1);this._deadParticles.push(a);for(b=0;b<this._effects.length;b++)this._effects[b].onDeath&&this._effects[b].onDeath(a)};
+Fireworks.Emitter.prototype.spawnParticle=function(){Fireworks.debug&&console.assert(1<=this._deadParticles.length,"no more particle available");var a=this.deadParticles().pop();this.liveParticles().push(a);for(var b=0;b<this._effects.length;b++)this._effects[b].onBirth&&this._effects[b].onBirth(a)};Fireworks.createLinearGradient=function(a){return new Fireworks.LinearGradient(a)};Fireworks.LinearGradient=function(){this._keyPoints=[]};
 Fireworks.LinearGradient.prototype.push=function(a,b){this._keyPoints.push({x:a,y:b});return this};Fireworks.LinearGradient.prototype.get=function(a){for(var b=0;b<this._keyPoints.length&&!(a<=this._keyPoints[b].x);b++);if(0===b)return this._keyPoints[0].y;Fireworks.debug&&console.assert(b<this._keyPoints.length);var c=this._keyPoints[b-1],b=this._keyPoints[b];return c.y+(a-c.x)/(b.x-c.x)*(b.y-c.y)};Fireworks.Particle=function(){};
 Fireworks.Particle.prototype.set=function(a,b){Fireworks.debug&&console.assert(void 0===this[a],"key already defined: "+a);this[a]=b;return this[a]};Fireworks.Particle.prototype.get=function(a){Fireworks.debug&&console.assert(void 0!==this[a],"key undefined: "+a);return this[a]};Fireworks.Particle.prototype.has=function(a){return void 0!==this[a]?!0:!1};Fireworks.Shape=function(){};Fireworks.createVector=function(a,b,c){return new Fireworks.Vector(a,b,c)};
 Fireworks.Vector=function(a,b,c){this.x=a||0;this.y=b||0;this.z=c||0};
diff --git a/build/fireworks.js b/build/fireworks.js
index 311851c..4ec1c9b 100644
--- a/build/fireworks.js
+++ b/build/fireworks.js
@@ -166,12 +166,12 @@ Fireworks.Emitter	= function(opts){
 
 Fireworks.Emitter.prototype.destroy	= function()
 {
-	this._effects.forEach(function(effect){
-		effect.destroy();
-	});
-	this._particles.forEach(function(particle){
-		particle.destroy();
-	});
+	for(var i=0;i<this._effects.length;i++){
+		this._effects[i].destroy()
+	}
+	for(var i=0;i<this._particles.length;i++){
+		this._particles[i].destroy()
+	}
 }
 
 
@@ -224,10 +224,11 @@ Fireworks.Emitter.prototype.intensity	= function(value){
 	// update the value
 	this._intensity	= value;
 	// notify all effects
-	this._effects.forEach(function(effect){
-		if( !effect.onIntensityChange )	return;
-		effect.onIntensityChange(this._intensity, oldValue);			
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onIntensityChange){
+			this._effects[i].onIntensityChange(this._intensity, oldValue);
+		}
+	}
 	return this;	// for chained API
 }
 
@@ -271,12 +272,13 @@ Fireworks.Emitter.prototype.start	= function()
 	this._started		= true;
 
 	// onCreate on all particles
-	this._effects.forEach(function(effect){
-		if( !effect.onCreate )	return;
-		this._particles.forEach(function(particle, particleIdx){
-			effect.onCreate(particle, particleIdx);			
-		})
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onCreate){
+			for(var j=0;j<this._particles.length;j++){
+				this._effects[i].onCreate(this._particles[j], j);
+			}
+		}
+	}
 	// set the intensity to 1
 	this.intensity(1)
 
@@ -287,35 +289,40 @@ Fireworks.Emitter.prototype.update	= function(deltaTime){
 	// bound the deltaTime to this._maxDeltaTime
 	deltaTime	= Math.min(this._maxDeltaTime, deltaTime)
 	// honor effect.onPreUpdate
-	this._effects.forEach(function(effect){
-		if( !effect.onPreUpdate )	return;
-		effect.onPreUpdate(deltaTime);			
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onPreUpdate){
+			this._effects[i].onPreUpdate(deltaTime);
+		}
+	}
 	// update each particles
-	this._effects.forEach(function(effect){
-		if( !effect.onUpdate )	return;
-		this._liveParticles.forEach(function(particle){
-			effect.onUpdate(particle, deltaTime);			
-		})
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onUpdate){
+			for(var j=0;j<this._liveParticles.length;j++){
+				this._effects[i].onUpdate(this._liveParticles[j], deltaTime);			
+			}
+		}
+	}
 	return this;	// for chained API
 }
 
 Fireworks.Emitter.prototype.render	= function(){
-	this._effects.forEach(function(effect){
-		if( !effect.onPreRender )	return;
-		effect.onPreRender();			
-	}.bind(this));
-	this._effects.forEach(function(effect){
-		if( !effect.onRender )	return;
-		this._liveParticles.forEach(function(particle){
-			effect.onRender(particle);			
-		})
-	}.bind(this));
-	this._effects.forEach(function(effect){
-		if( !effect.onPostRender )	return;
-		effect.onPostRender();			
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onPreRender){
+			this._effects[i].onPreRender();
+		}
+	}
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onRender){
+			for(var j=0;j<this._liveParticles.length;j++){
+				this._effects[i].onRender(this._liveParticles[j]);
+			}
+		}
+	}
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onPostRender){
+			this._effects[i].onPostRender();
+		}
+	}
 	return this;	// for chained API
 }
 
@@ -334,9 +341,9 @@ Fireworks.Emitter.prototype.killParticle	= function(particle)
 	this._liveParticles.splice(idx, 1)
 	this._deadParticles.push(particle);
 	// do the death on all effects
-	this.effects().forEach(function(effect){
-		effect.onDeath && effect.onDeath(particle);			
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		this._effects[i].onDeath && this._effects[i].onDeath(particle);
+	}
 }
 
 /**
@@ -349,9 +356,9 @@ Fireworks.Emitter.prototype.spawnParticle	= function(){
 	var particle	= this.deadParticles().pop();
 	this.liveParticles().push(particle);
 	// do the birth on all effects
-	this.effects().forEach(function(effect){
-		effect.onBirth && effect.onBirth(particle);			
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		this._effects[i].onBirth && this._effects[i].onBirth(particle);
+	}
 }
 Fireworks.createLinearGradient	= function(opts){
 	var LinearGradient	= new Fireworks.LinearGradient(opts);
diff --git a/build/fireworks.min.js b/build/fireworks.min.js
index bbc5281..a52fe9e 100644
--- a/build/fireworks.min.js
+++ b/build/fireworks.min.js
@@ -1,16 +1,16 @@
 var Fireworks={debug:!0,EffectsStackBuilder:function(a){this._emitter=a}};Fireworks.EffectsStackBuilder.prototype.emitter=function(){return this._emitter};Fireworks.EffectsStackBuilder.prototype.back=function(){return this._emitter};Fireworks.EffectsStackBuilder.prototype.createEffect=function(a,b){var c=Fireworks.createEffect(a,b).pushTo(this._emitter).back(this);c.effect().emitter(this._emitter);return c};
 Fireworks.createEffect=function(a,b){"object"===typeof a&&(b=a,a=void 0);var c=new Fireworks.Effect;c.opts=b;c.name=a;c.back=null;var d={onCreate:function(a){c.onCreate=a;return d},onBirth:function(a){c.onBirth=a;return d},onUpdate:function(a){c.onUpdate=a;return d},onDeath:function(a){c.onDeath=a;return d},onPreUpdate:function(a){c.onPreUpdate=a;return d},onPreRender:function(a){c.onPreRender=a;return d},onRender:function(a){c.onRender=a;return d},onPostRender:function(a){c.onPostRender=a;return d},
 onIntensityChange:function(a){c.onIntensityChange=a;return d},pushTo:function(a){a.effects().push(c);return d},back:function(a){if(void 0===a)return c.back;c.back=a;return d},effect:function(){return c}};return d};Fireworks.Effect=function(){this._emitter=null};Fireworks.Effect.prototype.destroy=function(){};Fireworks.Effect.prototype.emitter=function(a){if(void 0===a)return this._emitter;this._emitter=a;return this};Fireworks.createEmitter=function(a){return new Fireworks.Emitter(a)};
-Fireworks.Emitter=function(a){this._nParticles=void 0!==a.nParticles?a.nParticles:100;this._particles=[];this._effects=[];this._started=!1;this._onUpdated=null;this._intensity=0;this._maxDeltaTime=1/3;this._effectsStackBuilder=new Fireworks.EffectsStackBuilder(this)};Fireworks.Emitter.prototype.destroy=function(){this._effects.forEach(function(a){a.destroy()});this._particles.forEach(function(a){a.destroy()})};Fireworks.Emitter.prototype.effects=function(){return this._effects};
+Fireworks.Emitter=function(a){this._nParticles=void 0!==a.nParticles?a.nParticles:100;this._particles=[];this._effects=[];this._started=!1;this._onUpdated=null;this._intensity=0;this._maxDeltaTime=1/3;this._effectsStackBuilder=new Fireworks.EffectsStackBuilder(this)};Fireworks.Emitter.prototype.destroy=function(){for(var a=0;a<this._effects.length;a++)this._effects[a].destroy();for(a=0;a<this._particles.length;a++)this._particles[a].destroy()};Fireworks.Emitter.prototype.effects=function(){return this._effects};
 Fireworks.Emitter.prototype.effect=function(a){for(var b=0;b<this._effects.length;b++){var c=this._effects[b];if(c.name===a)return c}return null};Fireworks.Emitter.prototype.particles=function(){return this._particles};Fireworks.Emitter.prototype.liveParticles=function(){return this._liveParticles};Fireworks.Emitter.prototype.deadParticles=function(){return this._deadParticles};Fireworks.Emitter.prototype.nParticles=function(){return this._nParticles};
 Fireworks.Emitter.prototype.effectsStackBuilder=function(){return this._effectsStackBuilder};
-Fireworks.Emitter.prototype.intensity=function(a){if(void 0===a)return this._intensity;if(a===this._intensity)return this;Fireworks.debug&&console.assert(0<=a,"Fireworks.Emitter.intensity: invalid value.",a);Fireworks.debug&&console.assert(1>=a,"Fireworks.Emitter.intensity: invalid value.",a);var b=this._intensity;this._intensity=a;this._effects.forEach(function(a){if(a.onIntensityChange)a.onIntensityChange(this._intensity,b)}.bind(this));return this};
+Fireworks.Emitter.prototype.intensity=function(a){if(void 0===a)return this._intensity;if(a===this._intensity)return this;Fireworks.debug&&console.assert(0<=a,"Fireworks.Emitter.intensity: invalid value.",a);Fireworks.debug&&console.assert(1>=a,"Fireworks.Emitter.intensity: invalid value.",a);var b=this._intensity;this._intensity=a;for(a=0;a<this._effects.length;a++)if(this._effects[a].onIntensityChange)this._effects[a].onIntensityChange(this._intensity,b);return this};
 Fireworks.Emitter.prototype.maxDeltaTime=function(a){if(void 0===a)return this._maxDeltaTime;this._maxDeltaTime=a;return this};Fireworks.Emitter.prototype.setParticleData=function(a,b,c){a[b]=c};Fireworks.Emitter.prototype.getParticleData=function(a,b){return a[b]};
-Fireworks.Emitter.prototype.start=function(){console.assert(0<this._effects.length,"At least one effect MUST be set");console.assert(!1===this._started);this._particles=Array(this._nParticles);for(var a=0;a<this._nParticles;a++)this._particles[a]=new Fireworks.Particle;this._liveParticles=[];this._deadParticles=this._particles.slice(0);this._started=!0;this._effects.forEach(function(a){a.onCreate&&this._particles.forEach(function(c,d){a.onCreate(c,d)})}.bind(this));this.intensity(1);return this};
-Fireworks.Emitter.prototype.update=function(a){a=Math.min(this._maxDeltaTime,a);this._effects.forEach(function(b){if(b.onPreUpdate)b.onPreUpdate(a)}.bind(this));this._effects.forEach(function(b){b.onUpdate&&this._liveParticles.forEach(function(c){b.onUpdate(c,a)})}.bind(this));return this};
-Fireworks.Emitter.prototype.render=function(){this._effects.forEach(function(a){if(a.onPreRender)a.onPreRender()}.bind(this));this._effects.forEach(function(a){a.onRender&&this._liveParticles.forEach(function(b){a.onRender(b)})}.bind(this));this._effects.forEach(function(a){if(a.onPostRender)a.onPostRender()}.bind(this));return this};
-Fireworks.Emitter.prototype.killParticle=function(a){var b=this._liveParticles.indexOf(a);Fireworks.debug&&console.assert(-1!==b);this._liveParticles.splice(b,1);this._deadParticles.push(a);this.effects().forEach(function(b){b.onDeath&&b.onDeath(a)}.bind(this))};
-Fireworks.Emitter.prototype.spawnParticle=function(){Fireworks.debug&&console.assert(1<=this._deadParticles.length,"no more particle available");var a=this.deadParticles().pop();this.liveParticles().push(a);this.effects().forEach(function(b){b.onBirth&&b.onBirth(a)}.bind(this))};Fireworks.createLinearGradient=function(a){return new Fireworks.LinearGradient(a)};Fireworks.LinearGradient=function(){this._keyPoints=[]};
+Fireworks.Emitter.prototype.start=function(){console.assert(0<this._effects.length,"At least one effect MUST be set");console.assert(!1===this._started);this._particles=Array(this._nParticles);for(var a=0;a<this._nParticles;a++)this._particles[a]=new Fireworks.Particle;this._liveParticles=[];this._deadParticles=this._particles.slice(0);this._started=!0;for(a=0;a<this._effects.length;a++)if(this._effects[a].onCreate)for(var b=0;b<this._particles.length;b++)this._effects[a].onCreate(this._particles[b],
+b);this.intensity(1);return this};Fireworks.Emitter.prototype.update=function(a){a=Math.min(this._maxDeltaTime,a);for(var b=0;b<this._effects.length;b++)if(this._effects[b].onPreUpdate)this._effects[b].onPreUpdate(a);for(b=0;b<this._effects.length;b++)if(this._effects[b].onUpdate)for(var c=0;c<this._liveParticles.length;c++)this._effects[b].onUpdate(this._liveParticles[c],a);return this};
+Fireworks.Emitter.prototype.render=function(){for(var a=0;a<this._effects.length;a++)if(this._effects[a].onPreRender)this._effects[a].onPreRender();for(a=0;a<this._effects.length;a++)if(this._effects[a].onRender)for(var b=0;b<this._liveParticles.length;b++)this._effects[a].onRender(this._liveParticles[b]);for(a=0;a<this._effects.length;a++)if(this._effects[a].onPostRender)this._effects[a].onPostRender();return this};
+Fireworks.Emitter.prototype.killParticle=function(a){var b=this._liveParticles.indexOf(a);Fireworks.debug&&console.assert(-1!==b);this._liveParticles.splice(b,1);this._deadParticles.push(a);for(b=0;b<this._effects.length;b++)this._effects[b].onDeath&&this._effects[b].onDeath(a)};
+Fireworks.Emitter.prototype.spawnParticle=function(){Fireworks.debug&&console.assert(1<=this._deadParticles.length,"no more particle available");var a=this.deadParticles().pop();this.liveParticles().push(a);for(var b=0;b<this._effects.length;b++)this._effects[b].onBirth&&this._effects[b].onBirth(a)};Fireworks.createLinearGradient=function(a){return new Fireworks.LinearGradient(a)};Fireworks.LinearGradient=function(){this._keyPoints=[]};
 Fireworks.LinearGradient.prototype.push=function(a,b){this._keyPoints.push({x:a,y:b});return this};Fireworks.LinearGradient.prototype.get=function(a){for(var b=0;b<this._keyPoints.length&&!(a<=this._keyPoints[b].x);b++);if(0===b)return this._keyPoints[0].y;Fireworks.debug&&console.assert(b<this._keyPoints.length);var c=this._keyPoints[b-1],b=this._keyPoints[b];return c.y+(a-c.x)/(b.x-c.x)*(b.y-c.y)};Fireworks.Particle=function(){};
 Fireworks.Particle.prototype.set=function(a,b){Fireworks.debug&&console.assert(void 0===this[a],"key already defined: "+a);this[a]=b;return this[a]};Fireworks.Particle.prototype.get=function(a){Fireworks.debug&&console.assert(void 0!==this[a],"key undefined: "+a);return this[a]};Fireworks.Particle.prototype.has=function(a){return void 0!==this[a]?!0:!1};Fireworks.Shape=function(){};Fireworks.createVector=function(a,b,c){return new Fireworks.Vector(a,b,c)};
 Fireworks.Vector=function(a,b,c){this.x=a||0;this.y=b||0;this.z=c||0};
diff --git a/src/emitter.js b/src/emitter.js
index 9683887..4c6f53b 100644
--- a/src/emitter.js
+++ b/src/emitter.js
@@ -19,12 +19,12 @@ Fireworks.Emitter	= function(opts){
 
 Fireworks.Emitter.prototype.destroy	= function()
 {
-	this._effects.forEach(function(effect){
-		effect.destroy();
-	});
-	this._particles.forEach(function(particle){
-		particle.destroy();
-	});
+	for(var i=0;i<this._effects.length;i++){
+		this._effects[i].destroy()
+	}
+	for(var i=0;i<this._particles.length;i++){
+		this._particles[i].destroy()
+	}
 }
 
 
@@ -77,10 +77,11 @@ Fireworks.Emitter.prototype.intensity	= function(value){
 	// update the value
 	this._intensity	= value;
 	// notify all effects
-	this._effects.forEach(function(effect){
-		if( !effect.onIntensityChange )	return;
-		effect.onIntensityChange(this._intensity, oldValue);			
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onIntensityChange){
+			this._effects[i].onIntensityChange(this._intensity, oldValue);
+		}
+	}
 	return this;	// for chained API
 }
 
@@ -124,12 +125,13 @@ Fireworks.Emitter.prototype.start	= function()
 	this._started		= true;
 
 	// onCreate on all particles
-	this._effects.forEach(function(effect){
-		if( !effect.onCreate )	return;
-		this._particles.forEach(function(particle, particleIdx){
-			effect.onCreate(particle, particleIdx);			
-		})
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onCreate){
+			for(var j=0;j<this._particles.length;j++){
+				this._effects[i].onCreate(this._particles[j], j);
+			}
+		}
+	}
 	// set the intensity to 1
 	this.intensity(1)
 
@@ -140,35 +142,40 @@ Fireworks.Emitter.prototype.update	= function(deltaTime){
 	// bound the deltaTime to this._maxDeltaTime
 	deltaTime	= Math.min(this._maxDeltaTime, deltaTime)
 	// honor effect.onPreUpdate
-	this._effects.forEach(function(effect){
-		if( !effect.onPreUpdate )	return;
-		effect.onPreUpdate(deltaTime);			
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onPreUpdate){
+			this._effects[i].onPreUpdate(deltaTime);
+		}
+	}
 	// update each particles
-	this._effects.forEach(function(effect){
-		if( !effect.onUpdate )	return;
-		this._liveParticles.forEach(function(particle){
-			effect.onUpdate(particle, deltaTime);			
-		})
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onUpdate){
+			for(var j=0;j<this._liveParticles.length;j++){
+				this._effects[i].onUpdate(this._liveParticles[j], deltaTime);			
+			}
+		}
+	}
 	return this;	// for chained API
 }
 
 Fireworks.Emitter.prototype.render	= function(){
-	this._effects.forEach(function(effect){
-		if( !effect.onPreRender )	return;
-		effect.onPreRender();			
-	}.bind(this));
-	this._effects.forEach(function(effect){
-		if( !effect.onRender )	return;
-		this._liveParticles.forEach(function(particle){
-			effect.onRender(particle);			
-		})
-	}.bind(this));
-	this._effects.forEach(function(effect){
-		if( !effect.onPostRender )	return;
-		effect.onPostRender();			
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onPreRender){
+			this._effects[i].onPreRender();
+		}
+	}
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onRender){
+			for(var j=0;j<this._liveParticles.length;j++){
+				this._effects[i].onRender(this._liveParticles[j]);
+			}
+		}
+	}
+	for(var i=0;i<this._effects.length;i++){
+		if(this._effects[i].onPostRender){
+			this._effects[i].onPostRender();
+		}
+	}
 	return this;	// for chained API
 }
 
@@ -187,9 +194,9 @@ Fireworks.Emitter.prototype.killParticle	= function(particle)
 	this._liveParticles.splice(idx, 1)
 	this._deadParticles.push(particle);
 	// do the death on all effects
-	this.effects().forEach(function(effect){
-		effect.onDeath && effect.onDeath(particle);			
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		this._effects[i].onDeath && this._effects[i].onDeath(particle);
+	}
 }
 
 /**
@@ -202,7 +209,7 @@ Fireworks.Emitter.prototype.spawnParticle	= function(){
 	var particle	= this.deadParticles().pop();
 	this.liveParticles().push(particle);
 	// do the birth on all effects
-	this.effects().forEach(function(effect){
-		effect.onBirth && effect.onBirth(particle);			
-	}.bind(this));
+	for(var i=0;i<this._effects.length;i++){
+		this._effects[i].onBirth && this._effects[i].onBirth(particle);
+	}
 }