OpenEuphoria

Re: Win32Lib: PlaySound parameters

• Posted by David Cuny <dcuny at LANSET.COM> Nov 02, 1999
• 514 views

Dan Moyer wrote:

> I understand almost nothing about the API wrapping, so
> is there anything  that can be done here to make use of
> the PlaySound FUNCTION??

I didn't have any documentation for the PlaySound function, so I just
filched the code from a demo of Robert's. Robert declared the routine as a
procedure, and so that's what I did as well.

The 'A' and 'W' at the end of the function name designate if the routine
takes as ANSI string (1 byte per character) or a Unicode (W=wide=2 bytes per
character). If there is no 'A' or 'W', the 'A' is probably assumed.

In C, all routines return a value - even if it's just NULL. If you don't use
the value returned by the routine; i.e.:

    foo( bar )

then the C compiler just discards the result. So the distinction that
Euphoria makes between a C procedure and function is a bit artificial.

To convert the PlaySound call into a function, use define_c_func() instead
of define_c_proc(), (for Win32Lib, use linkFunc and linkProc) and specify
the type of value the routine returns (C_INT, C_LONG, C_POINTER, etc.). The
prototype would look something like this:

   xPlaySound = linkFunc( winmm, "PlaySoundA", {C_INT, C_INT, C_INT},
C_INT )

Hope this helps!

-- David Cuny