>SDL is composed of eight subsystems - Audio, CDROM, Event Handling, File I/O, Joystick Handling, Threading, Timers and Video. Before you can use any of these subsystems they must be initialized by calling <A
> must be called before any other SDL function. It automatically initializes the Event Handling, File I/O and Threading subsystems and it takes a parameter specifying which other subsystems to initialize. So, to initialize the default subsystems and the Video subsystems you would call:
<PRE
CLASS="PROGRAMLISTING"
> SDL_Init ( SDL_INIT_VIDEO );</PRE
>
To initialize the default subsystems, the Video subsystem and the Timers subsystem you would call:
> shuts down all subsystems, including the default ones. It should always be called before a SDL application exits.</P
><P
>With <TT
CLASS="FUNCTION"
>SDL_Init</TT
> and <TT
CLASS="FUNCTION"
>SDL_Quit</TT
> firmly embedded in your programmers toolkit you can write your first and most basic SDL application. However, we must be prepare to handle errors. Many SDL functions return a value and indicates whether the function has succeeded or failed, <TT
CLASS="FUNCTION"
>SDL_Init</TT
>, for instance, returns -1 if it could not initialize a subsystem. SDL provides a useful facility that allows you to determine exactly what the problem was, every time an error occurs within SDL an error message is stored which can be retrieved using <TT
CLASS="FUNCTION"
>SDL_GetError</TT
>. Use this often, you can never know too much about an error.</P
