Difference between revisions of "HOWTO-Backends"

HOWTO-Backends (view source)

195 bytes added , 21:44, 3 April 2006

Now backends have to instatiate OSystem

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 # Subclass OSystem. You could copy the content of <tt>backends/null/null.cpp</tt> to <tt>backends/foobar/foobar.cpp</tt> to get a skeleton. As you progress, it might be helpful to look at other backends to learn how they do things.
 # Make sure to provide the <tt>main</tt> function in your backend (the actual main function of ScummVM is <tt>scummvm_main</tt>, which your backend must invoke at some point).
+# Instantiate OSystem class and assign it to <tt>g_system</tt>, do that before calling <tt>scumm_main</tt> i.e.:
+  g_system = new OSystem_SDL();
+  assert(g_system);
+  scummvm_main(argc, argv);
 # If appropriate, edit <tt>configure</tt> to add your backend (this is only necessary if you are going to use the "./configure && make" build system).
 # Modify <tt>common/system.cpp</tt> and <tt>backends/intern.h</tt> to make it aware of your backend. Mostly, this means telling it about your OSystem factory function (I'll leave the code there to document itself, if you don't understand it, ask us on IRC or on our mailing list).
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 That's it. The difficult part is of course writing the OSystem subclass. More on that in the next section!
 === Subclassing OSystem ===