Since it's now possible in HWA, I've ported Photoshop's blend modes, except for:
- Darker Color, Lighter Color
- Hue, Saturation, Saturation, Color, Luminosity
The last 4 ones aren't possible in PS 2.0, too many instructions.
I don't know what Dissolve, Darker and Lighter Color do.
Thanks to http://www.nathanm.com/photoshop-blending-math/ for the algorithms, and thanks to http://www.northlite.net/ps/blend.htm for the descriptions.
Just copy the /Photoshop/ directory into your /Effects/ folder.
Note that currently, these won't work at runtime, but they will in the next HWA build.
None of the shaders has parameters.
EDIT: If you experience problems with alpha channels, tell me. Some blend modes seem to ignore it, like Vivid Light.
Have fun looking at them in the frame editor !