ggi_graphtype specifies the graphic type:
Number of significant bits (e.g. bits representing the actual color or some other property of the pixel)
Applications can use GT_AUTO in any of these fields to get a 'recommended' setting.
The four aspects of a graphic type above are packed into a ggi_graphtype. See ggi/types.h for details about the possible schemes and subschemes.
There are also macros which represent some common ggi_graphtypes, mainly for compatibility:
equivalent to the GGI_AUTO (see next section) for graphic types. It indincates that any default value may be taken. Where possible this is currently a graphics mode, often the highest.
text modes with word- and longword-aligned characters and attributes.
(these modes use a palette.)
graphics modes with the respective bits per pixel. Note that for 32-bit modes, only the size (bits per pixel) is 32-bits, the depth (significant bits) is 24-bit.