http://www.directfb.org
index.html
DirectFB Reference Manual
IDirectFBSurface.html
IDirectFBSurface
GetSubSurface
Get an interface to a sub area of this surface.
GetSubSurface (
IDirectFBSurface.html
IDirectFBSurface
*
thiz,
const
types.html#DFBRectangle
DFBRectangle
*
rect,
IDirectFBSurface.html
IDirectFBSurface
**
ret_interface
);
No image data is duplicated, this is a clipped graphics within the original surface. This is very helpful for lightweight components in a GUI toolkit.  The new surface's state (color, drawingflags, etc.) is independent from this one. So it's a handy graphics context.  If no rectangle is specified, the whole surface (or a part if this surface is a subsurface itself) is represented by the new one.
