Calculates the intersection of two rectangles. It is allowed for
@dest to be the same as either @src1 or @src2. If the rectangles
do not intersect, @dest’s width and height is set to 0 and its x
and y values are undefined. If you are only interested in whether
the rectangles intersect, but not in the intersecting area itself,
pass %NULL for @dest.
Calculates the intersection of two rectangles. It is allowed for @dest to be the same as either @src1 or @src2. If the rectangles do not intersect, @dest’s width and height is set to 0 and its x and y values are undefined. If you are only interested in whether the rectangles intersect, but not in the intersecting area itself, pass %NULL for @dest.