void gdk_rectangle_union ( const GdkRectangle* src1, const GdkRectangle* src2, GdkRectangle* dest )
Calculates the union of two rectangles.
The union of rectangles
src2 is the smallest rectangle which
src2 within it. It is allowed for
dest to be
the same as either
Note that this function does not ignore ‘empty’ rectangles (ie. with zero width or height).