omino pixel blog

download: ==> omino staragon 32 <== a pixel bender filter

Just recently, Dale Bradshaw posted a rounded-rect pixel bender plugin. Pretty nifty!

It got me thinking, What about other rounded-corner polygons? It was a bit of a puzzle. As with all Pixel Bender plugins, the question is, What color is this pixel? How does a given pixel know if it’s inside a rounded-corner pentagon or not?

I stuck to regular and stellated polygons to start. One solution goes like so:

• Divide the plane into pie-slices, one for each edge of the polygon.
• For each point, decide which slice you’re in.
• Decide if you’re inside or outside the edge.
• For the rounding… decide which corner you’re nearest
• Are you in the arc of that corner? If so, decide if you’re inside the rounding-radius.

Well, that was a bit of obsessive fun. Here’s a screen shot, including the parameter controls:

And here’s a little demo of it.

download: ==> omino staragon 32 <== a pixel bender filter