hdc (HDC) - input

Device context handle.

paptlPoint (PPOINTL) - input

Pointer to points array.

An array of (cPoints) (X,Y) pairs that contain the (X,Y) coordinates of the markers.

cPoints (LONG) - input

Number of markers to be drawn.

When this is passed as NULL, the handling routine takes no action except to return Successful.

pInstance (PVOID) - input

Pointer to instance data.

lFunction (ULONG) - input

High-order WORD=flags; low-order WORD=NGrePolyMarker.

rc (LONG) - returns

Return Code.

On completion, the handling routine must return an integer (cHits) indicating, where appropriate, whether correlation hits were detected:

GPI_OK

Successful
GPI_HITS
Successful with correlate hit (returned by display drivers when the correlate flag is ON, and a hit is detected)
GPI_ERROR
Error
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_BASE_ERROR PMERR_COORDINATE_OVERFLOW
PMERR_EXCEEDS_MAX_SEG_LENGTH
PMERR_HDC_BUSY
PMERR_HRGN_BUSY
PMERR_HUGE_FONTS_NOT_SUPPORTED
PMERR_INSUFFICIENT_MEMORY
PMERR_INV_IN_AREA
PMERR_INV_MARKER_SYMBOL_ATTR
PMERR_PATH_LIMIT_EXCEEDED
PMERR_UNSUPPORTED_ATTR
PMERR_UNSUPPORTED_ATTR_VALUE

Refer to the "Error Explanations" section in the Presentation Manager Programming Reference for further explanation.