Declare Function IntersectRect Lib "user32.dll" (lpDestRect As RECT, lpSrc1Rect As RECT, lpSrc2Rect As RECT) As Long
Platforms: Win 32s, Win 95/98, Win NT
IntersectRect creates a rectangle based on the intersecting part of two other rectangles. The rectangular region where the two source rectangles overlap is the intersection rectangle. If one or both of the source rectangles are empty or there is no intersection, the function returns 0 and the lpDestRect rectangle is set to (0,0)-(0,0). If the source rectangles do overlap, the intersection is put into lpDestRect and the function returns 1.
Example:
' Determine if windows Form1 and Form2 are overlapping on the
' screen. If they don't the intersection rectangle will be empty.
Dim intrect As RECT ' receives the intersection rectangle
Dim window1 As RECT, window2 As RECT ' receive rectangles of Form1 and Form2
Dim result As Long ' will be set to 0 if no intersection, 1 if there is intersection
Dim retval As Long ' return value for other functions
retval = GetWindowRect(Form1.hWnd, window1) ' get Form1's rectangle
retval = GetWindowRect(Form2.hWnd, window2) ' get Form2's rectangle
result = IntersectRect(intrect, window1, window2) ' determine the intersection rectangle
If result = 0 ' in this case, intrect will also be empty
Debug.Print "Windows Form1 and Form2 are not overlapping on the screen."
Else
Debug.Print "Windows Form1 and Form2 are overlapping on the screen."
End IfSee Also: SubtractRect, UnionRect
Category: Rectangles
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