IntersectClipRect info Overview Group

The IntersectClipRect function creates a new clipping region from the intersection of the current clipping region and the specified rectangle.

int IntersectClipRect(

HDC hdc,	// handle of device context
int nLeftRect,	// x-coordinate of upper-left corner of rectangle
int nTopRect,	// y-coordinate of upper-left corner of rectangle
int nRightRect,	// x-coordinate of lower-right corner of rectangle
int nBottomRect	// y-coordinate of lower-right corner of rectangle
);

Parameters

hdc: Identifies the device context.
nLeftRect: Specifies the logical x-coordinate of the upper-left corner of the rectangle.
nTopRect: Specifies the logical y-coordinate of the upper-left corner of the rectangle.
nRightRect: Specifies the logical x-coordinate of the lower-right corner of the rectangle.
nBottomRect: Specifies the logical y-coordinate of the lower-right corner of the rectangle.

The return value specifies the new clipping region’s type and can be any one of the following values:

Value	Meaning
NULLREGION	Region is empty.
SIMPLEREGION	Region is a single rectangle.
COMPLEXREGION	Region is more than one rectangle.
ERROR	An error occurred. (The current clipping region is unaffected.)

The lower and rightmost edges of the given rectangle are excluded from the clipping region.