Description GDK provides the GdkPoint, GdkRectangle, GdkRegion and GdkSpan data types for representing pixels and sets of pixels on the screen. GdkPoint is a simple structure containing an x and y coordinate of a point. GdkRectangle is a structure holding the position and size of a rectangle. The intersection of two rectangles can be computed with gdk_rectangle_intersect(). To find the union of two rectangles use gdk_rectangle_union(). GdkRegion is an opaque data type holding a set of arbitrary pixels, and is usually used for clipping graphical operations (see gdk_gc_set_clip_region()). GdkSpan is a structure holding a spanline. A spanline is a horizontal line that is one pixel wide. It is mainly used when rasterizing other graphics primitives. It can be intersected to regions by using gdk_region_spans_intersect_foreach().