pdfPrintSetRotate
Set the page rotation.
void pdfPrintSetRotate(PDFHandle pdf, int angle)
This function sets the page rotation. Allowed rotation values are 0,
90, 180, and 270 degrees.
pdfPrintResetParams
resets this to its default value, which is to
print portrait-mode pages with a rotation of 0 and landscape pages
with a rotation of 90.
C:
pdfPrintSetRotate(pdf, 180);