Complex region (more than 1 rectangle)
Possible Errors Detected: When an error is detected, the handling
routine must call WinSetErrorInfo to post the condition. Error codes for
conditions that the handling routine is expected to check include:
PMERR_HRGN_BUSY
PMERR_INSUFFICIENT_MEMORY
PMERR_INV_COORDINATE
PMERR_INV_HRGN
PMERR_INV_LENGTH_OR_COUNT
PMERR_INV_RECT
PMERR_REGION_IS_CLIP_REGION
Refer to the "Error
Explanations" section in the Presentation Manager Programming Reference
for further explanation.