When checked, Fractal! behaves as a MultiFinder friendly application, yielding the processor after rendering 2 polygons. This means that Fractal! can do its rendering in the background while other applications are running. It also allows the user to abort a render by pressing (‚åò-.), or request the current, partially complete image to be displayed in the window by clicking the mouse anywhere within the window. Note that either of these operations will be postponed until after the subdivision phase which, depending upon the processor being used and the level of subdivisions, can be anywhere from a few seconds to a couple of minutes.
If Allow Backgrounding is unselected (the item is unchecked), once a render is started it cannot be aborted or interrupted until it has finished, and no other application will receive processor time. The advantage of turning off backgrounding is that the render operation will proceed much more quickly as the application hogs the entire cpu. It is possible to turn Allow Backgrounding back on again by pressing (‚åò-K). This will switch the program back into the Allow Backgrounding mode and if the progress bar is active, the Cancel button will re-appear.
Note that as the Render menu is the only menu active during a Render operation, it is possible to turn off backgrounding once a render has started via the menu and turn it back on with (‚åò-K) as menus are inactive with Backgrounding turned off.
Also note that because of the possibility of indavertently locking up the cpu for significant amounts of time, this parameter is not saved to the parameter file. In addition, whenever a parameter file is opened, Allow Backgrounding is automatically enabled.
