hdc (HDC) - input

Device context handle.

prclRect (PRECTL) - input

Pointer to rectangle in world or screen coordinates.

RECTL structure:

xLeft

Minimum x-coordinate of rectangle
yBottom
Minimum y-coordinate
xRight
Maximum x-coordinate of rectangle
yTop
Maximum y-coordinate
The prclRect parameter is a NULL rectangle when the value of xRight is less than xLeft, and yTop is less than yBottom.

pInstance (PVOID) - input

Pointer to instance data.

lFunction (ULONG) - input

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

rc (LONG) - returns

Return codes.

This function returns an integer (lComplexity) indicating the complexity of the resultant "clipping region", which is defined as the intersection of all clipping (that is, the clip path, viewing limits, graphics field, clip region, and visible region).

RGN_ERROR

Error
RGN_NULL
Null region
RGN_RECT
Rectangular region
RGN_COMPLEX
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_COORDINATE_OVERFLOW PMERR_DEV_FUNC_NOT_INSTALLED
PMERR_HDC_BUSY
PMERR_INV_COORD_SPACE
PMERR_INV_HDC
PMERR_INV_LENGTH_OR_COUNT
PMERR_INV_RECT

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