true if the two rectangles intersectRect.intersection
bool intersection(graphene.rect.Rect b, out graphene.rect.Rect res)Computes the intersection of the two given rectangles.

The intersection in the image above is the blue outline.
If the two rectangles do not intersect, res will contain a degenerate rectangle with origin in (0, 0) and a size of 0.
Parameters
b | a #graphene_rect_t |
res | return location for a #graphene_rect_t |