Strange AngleParam value

Anyone know if there's some special way to handle an AngleParam?

Currently I'm having to divide the value by some ridiculous number (about 3753600) to make it usable as degrees.

Here's the function I'm feeding it into (as "rot"):

static PF_PixelFloat rotateY(PF_FpLong rot, PF_PixelFloat inVec){

  PF_FpLong tmpX = inVec.red;

  PF_FpLong tmpZ = inVec.blue;

  inVec.red = tmpX*cosf(rot) + tmpZ*sinf(rot);

  inVec.blue = tmpZ*cosf(rot) - tmpX*sinf(rot);

  return inVec;

}

I figured it would just be a matter of converting degrees to radians, but apparently not.