Specifies page rotation, in degrees. Used for routines that set/get the value of a page's Rotate key.

Values:

IG_PDF_ROTATE_0	Zero rotate angle.
IG_PDF_ROTATE_90	Rotate angle is 90 degrees.
IG_PDF_ROTATE_180	Rotate angle is 180 degrees.
IG_PDF_ROTATE_270	Rotate angle is 270 degrees.