Directional blur PS

Here is small PS i found on MS website… questions also ;]
How to make angel from 0-1 instead of 0-6.350?
Might be any upgrades?.. lol

anyways my 3-d shader dosn’t make me understand HLSL any better ;] cheers

directional blur.rar (589.1 kB)

Here is a quick upgrade, could be more clean but works

Directional_blur_2.fx (3.2 kB)

6,283185307179586476925286766559 ~ 2*Pi