• Christian Schüler <Christian_member pathlink.com> Apr 18 2005
• "Lynn Allan" <l_d_allan adelphia.net> Apr 19 2005
• Benji Smith <dlanguage xxagg.com> Apr 21 2005
• pragma <pragma_member pathlink.com> Apr 19 2005

Christian Schüler <Christian_member pathlink.com> writes:

Been recently thinking about writing a VST plugin in D.

A VST plugin is a .dll for use with Cubase or other music software.
It has a specially named C function as entry point:

AEffect *main( audioMasterCallback audioMaster );

where AEffect is a struct, and audioMasterCallback is a typedef for a function.


1) How do I get these definitions into D? The VST SDK comes with an "aeffect.h"
that defines these types and some enums.

2) How do I build a dll with D?

3) I need to compile a "main" function with different parameters than just
(argc, argv). VisualC accepts an arbitrary "main" when compiling a .dll, but GCC
does not. Therefore, a common workaround with GCC is to call the entry point
something different, like "main_plugin", and change the export name with a .def
file into "main". Can D do one of these (compile an arbitrary main function or
handle a .def file)?

4) While the VST API is a C-API, in C++ you can derive from the AEffect struct
to add member functions, which helps in organising (instead of having a bunch of
static callback functions floating somewhere). Is this possible in D?

5) A "serious" plugin would need SSE code. I read DMD has it as inline
assembler, but this means writing a complete loop in assembler. SSE-intrinsics
(that is, specially named functions that compile to SSE-instructions) would be
more of a convenience.

Thanks,
Christian

"Lynn Allan" <l_d_allan adelphia.net> writes:

Christian,

This won't help you with D, sorry ...

But I would appreciate hearing about your experience with VST plugin
development. I've been working on a "skin/personality" to the open
source Audacity audio editor that is specialized for speech rather
than music. I would like to learn how to create several plug-ins for
Audacity, and hadn't found any examples or tutorials on how to do that
(didn't look that hard, however)


"Christian Schüler" <Christian_member pathlink.com> wrote in message
news:d41f9m$24c7$1 digitaldaemon.com...
 Been recently thinking about writing a VST plugin in D.

 A VST plugin is a .dll for use with Cubase or other music software.
 It has a specially named C function as entry point:

Benji Smith <dlanguage xxagg.com> writes:

Lynn Allan wrote:
 But I would appreciate hearing about your experience with VST plugin
 development


Yeah, me too. I've been interested in tinkering with some DSP algorithms 
(purely as a learning exercise), and I'd love to read about your 
experience writing VST plugins.

--BenjiSmith

pragma <pragma_member pathlink.com> writes:

In article <d41f9m$24c7$1 digitaldaemon.com>, Christian Schüler says...
Been recently thinking about writing a VST plugin in D.

A VST plugin is a .dll for use with Cubase or other music software.
It has a specially named C function as entry point:

AEffect *main( audioMasterCallback audioMaster );

where AEffect is a struct, and audioMasterCallback is a typedef for a function.


Personally I have no experience in writing plugins for VST, but I used to be an
avid Cubase user.  I still have a copy of version 5 floating around here
someplace. :)

1) How do I get these definitions into D? The VST SDK comes with an "aeffect.h"
that defines these types and some enums.


You'll first want to convert the headers into D code "headers", that will
perform the same task.  The main D page should cover 99% of the things you'll
need to do:

http://www.digitalmars.com/d/ctod.html

Just stay faithful to the byte layout of structs, and the intention of the
preprocessor directives, and you'll do fine.

If you're linking against a provided .obj or .lib file, make sure they're in OMF
format.   You'll know the second it can't link under dmd/optlink. (there is a
conversion utility to cover this problem)

2) How do I build a dll with D?


Again, it's all up on the webpage.

http://www.digitalmars.com/d/dll.html

The first section, "Dlls with a C interface" will apply to your use.

3) I need to compile a "main" function with different parameters than just
(argc, argv). VisualC accepts an arbitrary "main" when compiling a .dll, but GCC
does not. Therefore, a common workaround with GCC is to call the entry point
something different, like "main_plugin", and change the export name with a .def
file into "main". Can D do one of these (compile an arbitrary main function or
handle a .def file)?


DMD uses a .def file which supports an "exports" listing.  The syntax supports
what you're trying to do here.

http://www.digitalmars.com/ctg/ctgDefFiles.html#exports

4) While the VST API is a C-API, in C++ you can derive from the AEffect struct
to add member functions, which helps in organising (instead of having a bunch of
static callback functions floating somewhere). Is this possible in D?


I think you're stuck with structs, callbacks and function pointers.  D does
allow methods on structs, but they're non-virtual.  Fortunately, D does have a
good function pointer syntax, and placing these inside a struct should help you
get the flexibility you crave.

5) A "serious" plugin would need SSE code. I read DMD has it as inline
assembler, but this means writing a complete loop in assembler. SSE-intrinsics
(that is, specially named functions that compile to SSE-instructions) would be
more of a convenience.


I believe that you are correct that D does not have SSE intrinsic support.
You're also correct that the only available workaround in D is to use an asm{}
block and code in things manually.  At least D offers you the 'naked' keyword,
which should help reduce overhead should you write functions to encapsulate
common operations.

Another workaround would be to use a C compiler that has the support you need,
and roll a good SSE library that you could import into D.

- EricAnderton at yahoo