Course Vector

Notes: General AS3 Tips

This is the final bit migrated from the Labs Wiki. This is just a short list of quick and easy tips to keep in mind when programming AS3.

• Do not use Objects, if you know which properties will be finally involved. Write a class for it; AS3 seems to register a memory space for them and will have faster access.
• Keep variable names as short as possible. While this doesn’t help a lot, it does help a little.
• Items of 0 alpha are still draw on the stage. Use visible = false to save CPU cycles

Reuse instantiated classes

Create constants for commonly used objects, such as new Point(0,0)

// 100k loops: 75ms
new Point(0,0);

// 100k loops: 8ms
private static const POINT:Point = new Point(0,0);
POINT;

Getters

Store getter properties as local variables when using them more than once in a method (such as .graphics, .transform)

// 100k loops: 202ms
somesprite.graphics.clear();
somesprite.graphics.beginFill(0x000000);
somesprite.graphics.drawRect(0,0,10,10);
somesprite.graphics.endFill();

// 100k loops: 22ms
var n:Graphics = sprite.graphics;
n.clear();
n.beginFill(0x000000);
n.drawRect(0,0,10,10);
n.endFill();

Class Reflection

Create custom reflection methods instead of using: getDefinitionByName(getQualifiedClassName(object))

package {
	public class SomeClass {
		public function get reflect():Class {
			return SomeClass;
		}
	}
}
var someObject:SomeClass = new SomeClass();
var someClass:Class;
var i:int;

// 66ms
for(i=0; i<100000; i++) {
	someclass = getDefinitionByName(getQualifiedClassName(someObject)) as Class;
}

// 28ms
for(i=0; i<100000; i++) {
	someclass = Object(someObject).constructor;
}

// 16ms
for(i=0; i<100000; i++) {
	someclass = someObject.reflect;
}

Constants from other classes

	// This takes 34.08ms to execute
	var tmpVar:int;
	for(var i:Number=0; i<100000; i++) {
		tmpVar = SomeClass.SOME_CONSTANT;
	}

	// This takes 15.8ms to execute
	var tmpVar:int;
	var myConstant:int = SomeClass.SOME_CONSTANT;
	for(var i:Number=0; i<100000; i++) {
		tmpVar = myConstant;
	}

Variable instantiation

	// This takes 46.52ms to execute
	for(var i:int=0; i<100000; i++) {
		var v1:Number=10;
		var v2:Number=10;
		var v3:Number=10;
		var v4:Number=10;
		var v5:Number=10;
	}

	// This takes 19.74ms to execute
	for(var i:int=0; i<100000; i++) {
		var v1:Number=10, v2:Number=10, v3:Number=10, v4:Number=10, v5:Number=10;
	}

Tags: as3

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