hdc (HDC) - input

Device context handle.

pData (PBYTE) - input

Pointer to data string.

cBits (LONG) - input

Number of bits in row (maximum is 2040).

offRow (ULONG) - input

Row number relative to the current y-position.

Zero is the current position. A value of 1 indicates one row below the current position.

pInstance (PVOID) - input

Pointer to instance data.

lFunction (ULONG) - input

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

rc (LONG) - returns

Return Code.

On completion, the handling routine must return a LONG integer (cHits), indicating whether correlation hits have been 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_BITMAP_NOT_SELECTED PMERR_COORDINATE_OVERFLOW
PMERR_DEV_FUNC_NOT_INSTALLED
PMERR_HDC_BUSY
PMERR_INV_COLOR_DATA
PMERR_INV_COLOR_INDEX
PMERR_INV_COORD_SPACE
PMERR_INV_COORDINATE
PMERR_INV_HDC
PMERR_INV_IMAGE_DATA_LENGTH
PMERR_INV_IN_AREA
PMERR_INV_IN_PATH
PMERR_INV_LENGTH_OR_COUNT
PMERR_INV_PICK_APERTURE_POSN
PMERR_INV_RECT
PMERR_INV_REGION_CONTROL
PMERR_INV_SCAN_START

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