+++ /dev/null
-
-faust2ck - A FAUST wrapper-generator for ChucK Ugens.
-========
-
-FAUST is a functional language for defining DSP structures that can be
-used for real-time audio computing. It can generate block diagrams
-and also C++ code which will execute the given routine.
-
-This is an ideal way to create unit generators (UGens) for ChucK. The
-ChucK data structures can be a bit weird and the learning curve for
-hacking on ChucK can be a little steap. Using FAUST, you can
-concentrate on the DSP algorithm, and allow faust2ck to take care of
-creating ChucK-compatible C++ code so that you can instantiate your
-new DSP object in a ChucK program.
-
-That said, in order to take advantage of faust2ck, you'll need a
-little C++ knowledge. At least enough to know how to compile ChucK
-and add a line or two to its source code, which is explained in this
-document.
-
-Please see the FAUST websites for more details, online tutorials, and
-even an online compiler that you can try:
-
-http://faust.grame.fr/
-http://sourceforge.net/projects/faudiostream/
-
-This document describes how to use faust2ck.
-
-
-Usage
-=====
-
-Running faust2ck with no parameters will give you a usage string:
-
-$ ./faust2ck
-Usage: faust2ck <filename.dsp.xml>
-
-You can see that it requires a single input, the name of an XML file.
-This XML file can be generated with FAUST by giving it the "-xml"
-parameter:
-
-$ faust -xml filename.dsp
-
-faust2ck will then generate a file called "filename.dsp-wrapper.cpp".
-(Where "filename" is whatever your file is called.)
-
-This program is yet another input for FAUST. It is a C++ file, but it
-has some tags in it that tell FAUST where to put the DSP code. So you
-must run FAUST again, this time telling it to use the wrapper:
-
-$ faust -a filename.dsp-wrapper.cpp -o filename.cpp filename.dsp
-
-This gives you a final C++ file containing the algorithm along with
-routines necessary to plug it in to ChucK.
-
-
-Adding to ChucK
----------------
-
-Unfortunately there are a couple of manual steps necessary here.
-ChucK does not currently support (rightly in my opinion) loadable
-external modules, like other audio programs such as PureData.
-
-So, you need to re-compile ChucK. First, we need to tell it about our
-new C++ file. The first thing to do is create a header file. It only
-needs to contain one line of code, enough to tell ChucK about a single
-function declared in the C++ file.
-
-If your DSP object is called 'mydsp', then your file, mydsp.h, should
-look like this:
-
- #ifndef __MYDSP_H__
- #define __MYDSP_H__
-
- DLL_QUERY mydsp_query( Chuck_DL_Query * QUERY );
-
- #endif // __MYDSP_H__
-
-Put this file in the ChucK source directory. Now you just have to add
-a few lines to the file, 'chuck_compile.cpp'.
-
-At the top of chuck_compile.cpp, add an #include statement for our
-header file:
-
- #include "mydsp.h"
-
-Now, find the function "load_internal_modules()", which should be
-around line 516. Add the necessary code to load your new module,
-which is done by passing ChucK the "mydsp_query" function, where
-"mydsp" is the name of your FAUST object.
-
- EM_log( CK_LOG_SEVERE, "class 'mydsp'..." );
- if( !load_module( env, mydsp_query, "mydsp", "global" ) ) goto error;
-
-That's it!
-
-The last thing to do is to add your C++ file to the makefile so that
-it gets compiled along with ChucK. Depending on which operating
-system you are using, load "makefile.alsa" for Linux, or
-"makefile.win32" for Windows, or "makefile.osx" for OS X, etc.
-
-There is a big list of filenames in a variable called OBJS. You need
-to add "mydsp.o" to this list.
-
-Lastly, you need to add a build target for mydsp.o to the bottom of
-the file:
-
- mydsp.o: mydsp.h mydsp.cpp
- $(CXX) $(FLAGS) mydsp.cpp
-
-Now, run "make", and if all goes well, ChucK will be built with your
-object.
-
-$ make
-
-Time to create a test program! Make a simple ChucK program that looks
-something like the following:
-
- Impulse i => mydsp m => dac;
- 100 => t;
- 1 => i.next;
- while (t>0) {
- <<<m.last()>>>;
- t--;
- samp => now;
- }
-
-This will print the impulse response your object to the console. Good
-luck! Have fun!
-
-If you have any questions you can email me at:
-
-Stephen Sinclair <radarsat1@gmail.com>
-
-
-License
-=======
-
-This code is licensed under the GNU General Public License (GPL) v2 or
-above. Please see COPYING for details, or visit:
-
-http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
-
-
-
-Technical
-=========
-
-You wrote a string parsing and XML reading program
-like this, in 2008, in C ???! Are you mad?
---------------------------------------------------
-
-Yes, a sane person would probably not do such a thing. The FAUST XML
-output is so simple, however, and generally predictable, that I didn't
-feel it was necessary to bring in a lot of external dependencies for
-such a small application. So I ended up basically writing a small,
-inadequate macro replacement parser, which was actually kind of fun.
-Of course, if it ever called for more a complex solution I'd probably
-re-do it in Perl or Python. But this'll do for now, and it means the
-program is tiny and easy to execute on any computer without installing
-huge libraries.
-
-Of course, it does depend on 'sed' to generate the template for
-inclusion in the final program. I wanted to include it right in the
-executable instead of having faust2ck load an external file that would
-always be exactly the same. Unfortunately the C preprocessor doesn't
-make it easy, so sed is just used to wrap lines of the template file
-in double-quotes ("") and backslash-escape a few special characters.
-
-faust2ck is distributed with the template already generated so that it
-can be compiled without needing to have sed around.
-
-
-Why generate the C++ wrapper on demand instead of just writing a
-better wrapper that doesn't need to change?
-----------------------------------------------------------------
-
-If you look at the FAUST wrappers for PureData and Max/MSP, for
-example, they are just a single file where FAUST replaces a certain
-line with the DSP code class.
-
-Unfortunately FAUST doesn't provide much for dynamically generating
-code from the wrapper, other than a single replacement within the file
-where it provides the DSP class. Specifically, for parameters
-(declared in FAUST with "UI" elements like hslider and vslider), it
-calls a function at run-time to inform the UI code about each
-parameter. In the case of PureData and Max/MSP, it's possible to
-instantiate parameters (inlets) at run-time, so this works well. In
-ChucK however, each parameter needs a getter and setting function,
-called "cget" and "ctrl", which must be made available statically at
-compile time. (This isn't strictly true, these functions are "linked
-in" to the rest of ChucK at run-time, but ChucK doesn't provide the
-function with enough information to figure out which parameter it's
-modifying, so each parameter needs its own function.)
-
-Now, before writing faust2ck, I tried very hard to come up with some
-kind of combination of preprocessor macros or C++ templates that would
-do the job of instantiating a cget and ctrl function for each
-parameter, but I just couldn't figure out a way to do it. If anyone
-wants to give it a try, it's a nice challenging problem. In any case,
-I realized I was wasting my time when a quick little program could
-generate the appropriate wrapper easily enough, hence faust2ck.
projects / Faustine.git / blobdiff