Questions regarding D

[Jarrett Billingsley]

On Wed, Jan 14, 2009 at 2:58 PM, William Newbery <wnewbery at hotmail.co.uk> wrote:

> 4)Support for directX: Specificaly I need to  be able to use d3d9, d3dx9, d3d10, d3dx10 and xAudio2.

It's entirely possible.  D natively supports COM interfaces and the
Windows calling convention, so it's really just a matter of porting
the headers from C++.  There are ports of DirectX 9 and possibly 8
(though that doesn't help you..) headers already.  The other small
hurdle is linking against the DirectX DLLs - thankfully MS has put
D3DX in a DLL of its own and you no longer have to deal with the
static linking BS that used to be necessary.  More or less it's a
matter of just using implib (comes with DMC, I think, or DMD) on the
DLL with the /system flag and including the .def file it generates on
the command line when you compile/link your program.

I don't think anyone's taken a shot at porting the DX10 headers, so
you'd be on your own there.

> 5)Support for classes in dynamic libaries, and the ability to dynamicaly load these libaries.

You're on Windows, so no.  Well, for the most part, no.  SOs on Linux
work perfectly.  DLLs on Windows are not sufficient for what D needs
to do proper dynamic linking.  Namely, there are issues with TypeInfo
- the runtime type information that the D runtime uses to perform all
sorts of useful things, like throwing exceptions and sorting arrays
and doing downcasts.  What ends up happening is that the RTTI is
duplicated in both the EXE and the DLL, and the runtime does no
stitching up or removing of redundancy in those situations, leading
to.. odd behavior.  The GC and DLLs also have strange interactions -
it's entirely possible to set up the GC to collect data inside the
DLL, but unloading the DLL sometimes results in a segfault for reasons
behind my understanding.

You do have options.  DDL is a project which aims to perform dynamic
linking on Windows, and it works damn well.  It also has a lot of
useful utility functions to i.e. look up symbols and types by name in
the dynamic library.  There's also another project unrelated to D
called EDLL which more or less does the same things that DDL does; I
don't know if anyone has successfully used it with D.