code: private float[] calculatePointerPosition(float angle) {
  		float x = (float) (mColorWheelRadius * Math.cos(angle));
  		float y = (float) (mColorWheelRadius * Math.sin(angle));
  
  		return new float[] { x, y };
  	}
docs: Calculate the pointer's coordinates on the color wheel using the supplied
  angle.
  
  @param angle The position of the pointer expressed as angle (in rad).
  
  @return The coordinates of the pointer's center in our internal
  coordinate system.