Swingpant's Game Lab

The AS3 Magnifying Glass is a lense refraction class employing PixelBender. The class is an encapsulated method that takes a source image, a position and radius and returns a refracted result in sprite form.

I needed to represent a spy glass in my current project, and was looking for a very efficient method to achieve this. PixelBender seemed the obvious route and I’m pretty impressed by the speeds I am getting. I have max-ed out the frame rate and am still getting full (120) fps.

The MagnifyingGlass effect is the resultant class. The class embeds a pixelbender filter that spherizes it’s input and returns this as a sprite.

When using the class, the source image should be sent to the MagnifyingGlass full size, and be displayed to the user at a reduced size. This helps to preserve the integrity of the refracted image.

Usage:

//refraction: 0=Lots, 1 =None
//radius: The radius of the magnifying glass
//position_point: The position of the magnifying glass on the source image
//source_pic: BitmapData of the source picture
magnifying_glass = new MagnifyingGlass(refraction,radius, posn_point, source_pic)

magnifying_glass.magnifyingGlassPosition=posn_point
magnifying_glass.update()

The AS3 MagnifyingGlass Class

I have set up a quick demo that shows the class at work on 3 different images. Press any key to change the image.

Image#1: Have a look around a bit of England & Wales. Enjoy.
Image#2: Hundreds of cartoon characters. See if you can find Quagmire! – Gigity.
Image#3: There is a sheep in there somewhere.

NOTE: The PixelBender filter used here is based on Joa Ebert’s Spherize Filter originally built in Hydra – the forerunner of PixelBender.

NOTE: This requires Flash Player 10 and above.

Demo: Magnifying Glass Class Demo
Source: MagnifyingGlass.zip