rc (LONG) - returns
This function returns the identifier for the saved DC state (idDC), or it returns GPI_ERROR if an error occurs.
Possible Errors Detected: When an error is detected, the graphics engine calls WinSetErrorInfo to post the condition. Reasons for failure of this function include:
PMERR_BASE_ERROR
PMERR_DEV_FUNC_NOT_INSTALLED
PMERR_EXCEEDS_MAX_SEG_LENGTH
PMERR_HDC_BUSY
PMERR_INSUFFICIENT_MEMORY
PMERR_INV_CODEPAGE
PMERR_INV_COORDINATE
PMERR_INV_DC_TYPE
PMERR_INV_HDC
PMERR_INV_HRGN
PMERR_INV_IN_AREA
PMERR_INV_IN_PATH
PMERR_INV_RECT
PMERR_INV_REGION_CONTROL