SubtractRect function
The SubtractRect function determines the coordinates of a rectangle formed by subtracting one rectangle from another.
Syntax
BOOL SubtractRect( _Out_ LPRECT lprcDst, _In_ const RECT *lprcSrc1, _In_ const RECT *lprcSrc2 );
Parameters
 lprcDst [out]

A pointer to a RECT structure that receives the coordinates of the rectangle determined by subtracting the rectangle pointed to by lprcSrc2 from the rectangle pointed to by lprcSrc1.
 lprcSrc1 [in]

A pointer to a RECT structure from which the function subtracts the rectangle pointed to by lprcSrc2.
 lprcSrc2 [in]

A pointer to a RECT structure that the function subtracts from the rectangle pointed to by lprcSrc1.
Return value
If the resulting rectangle is empty, the return value is zero.
If the resulting rectangle is not empty, the return value is nonzero.
Remarks
The function only subtracts the rectangle specified by lprcSrc2 from the rectangle specified by lprcSrc1 when the rectangles intersect completely in either the x or ydirection. For example, if *lprcSrc1 has the coordinates (10,10,100,100) and *lprcSrc2 has the coordinates (50,50,150,150), the function sets the coordinates of the rectangle pointed to by lprcDst to (10,10,100,100). If *lprcSrc1 has the coordinates (10,10,100,100) and *lprcSrc2 has the coordinates (50,10,150,150), however, the function sets the coordinates of the rectangle pointed to by lprcDst to (10,10,50,100). In other words, the resulting rectangle is the bounding box of the geometric difference.
Because applications can use rectangles for different purposes, the rectangle functions do not use an explicit unit of measure. Instead, all rectangle coordinates and dimensions are given in signed, logical values. The mapping mode and the function in which the rectangle is used determine the units of measure.
Requirements
Minimum supported client  Windows 2000 Professional [desktop apps only] 

Minimum supported server  Windows 2000 Server [desktop apps only] 
Header 

Library 

DLL 

See also