love (with processing)

I'm publishing my another experiment with processing.
I called it 'love'
The applet and source code are located here.

How t is done
I wanted my heroes in this sketch to have transparent tails. It is not a problem on solid background. To make tails transparent with bitmap background I used following technique.

1. I render my 'souls' to color layer

a 'man' soul:
a 'woman' soul:

2. I render souls as white spots to other layer. I fade that layer to black before rendering.

3. I add my second layer to the first one as alpha channel 4. I render my background which is a bitmap with some simple animation on it

5. Last step is to render image with 'souls' on top of the background. And then I render some effects 'pink hearts' near pairs which are in love.