Question

For e.g.

function showIt():void {
   something.visible = true;
}

function init():void {

  time1 = flash.utils.getTimer();
  showIt();
  time2 = flash.utils.getTimer();

}

<mx:st id="something" visible="false"/>
<mx:Button click="init()"/>

In the above code, I want to measure the time taken to display st on screen.
Is it enough to compute time2 – time1?
Or should I put an event handler on render?
Or some other way?

Answer 1

You should try out Grant Skinner’s AS3 Performance Test Harness.

Here’s a simple demo of it in action (from his blog):

––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––
performancetests.GraphicsTests (5 iterations)
Testing different approaches for drawing.                               
––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––
method...................................................ttl ms...avg ms
tare [3]                                                      2     0.40
drawPath                                                    242    48.40
drawPathShort                                               171    34.20
fullPath                                                    182    36.40
reference                                                   127    25.40
shortReference                                              129    25.80
withGraphics                                               1154   230.80
––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

In the download he has a class called “RenderTest.as”, which he describes with:

Represents a render test, which times how long it takes to draw a specified DisplayObject to a BitmapData instance.

I use it all the time, it’s great.

Hope that helps,
Lance