I wanted to make a ripple effect that distorted the image more realistically. The trick is coming up with the right displacement map. In the displacement map, one color channel controls x-axis displacement and another controls y-axis displacement. Here is an example of what I came up with. This is generated algorithmically.

Download the source code.

Here’s a pretty standard Pixelate Effect made with ActionScript 3. It averages the colors of progressive sizes of squares and than draws the average using fillRect. The trick is each channel must be averaged separately before they are combined back together.

This particular algorithm generates a random maze where there is a unique path between any 2 cells.
Each cell is defined with a 4 bit integer, representing the 4 walls. A fifth bit defines whether a cell has been “visited” or not. Currently there is some redundancy in that each shared wall is defined twice - once in each cell.

One of the ways performance is optimized is by the use of a memory pool for all the particle objects. The emitter object determines how many particles will be on screen at any time and pre-allocates the memory needed. All the particle objects are created and stored in a queue to be used and recycled by the emitter. I used the Arrayed Queue class developed by Michael Baczynski over at Polygonal Labs.