Thanks. Please add there as you figure out stuff, don't worry about getting it exactly right, its a wiki, so it can be changed :)
.hc
On Feb 8, 2011, at 4:47 AM, Rich E wrote:
That makes sense, all except the names. :) Nice docs.
On Tue, Feb 8, 2011 at 6:33 AM, Hans-Christoph Steiner hans@at.or.at wrote:
t_canvas is now just a t_glist. a t_glist is a list of objects that represents a patch, here's what I wrote about it a while back:
http://wiki.puredata.info/en/glist
I am pretty sure that t_pd is a generic class pointer, like a pointer to Object in Java.
.hc
On Feb 6, 2011, at 2:15 AM, Rich E wrote:
Update to this: it seems that I can just use t_pd pointers to open and close the patches, although I still need to return the t_pd *x pointer from glob_evalfile(). I don't know which method is best for opening/closing, with t_canvas or t_pd..
The new methods look like this:
t_pd *glob_evalfile(t_pd *ignore, t_symbol *name, t_symbol *dir) { t_pd *x = 0; t_pd *x_loaded = 0;
/* even though binbuf_evalfile appears to take care of dspstate, we have to do it again here, because canvas_startdsp() assumes that all toplevel canvases are visible. LATER check if this is still necessary -- probably not. */
int dspstate = canvas_suspend_dsp(); binbuf_evalfile(name, dir); while ((x != s__X.s_thing) && (x = s__X.s_thing)) {vmess(x, gensym("pop"), "i", 1); x_loaded = x; } pd_doloadbang(); canvas_resume_dsp(dspstate); return x_loaded; }
t_pd *libpd_openfile(const char *basename, const char *dirname) { t_pd *x = glob_evalfile(0, gensym(basename), gensym(dirname));
pd_pushsym(x); int dzero = canvas_getdollarzero(); pd_popsym(x);
return x; }
void libpd_closefile(t_pd *x) { pd_free(x); }
I would appreciate any feedback/suggestions from you guys who know the pd API much, much more thoroughly that myself.
Cheers, Rich
On Sun, Feb 6, 2011 at 4:49 PM, Rich E reakinator@gmail.com wrote: I can't remember, are questions related to pd's C API appropriate for pd-list, or are they better asked here? It seems that everyone who responds to those questions is on this list just as much, anyway.
I have been mucking around with opening and closing pd patches using API calls instead of pd's messaging system. The reason for this is that I would like to be able to manage (open/close) multiple instances of a patch, and be able to send each copy of the patch a unique message via its $0 argument (see http://www.mail-archive.com/pd-list@iem.at/msg41648.html) . So far, the method has been to hack glob_evalfile to look like:
t_canvas *glob_evalfile(t_pd *ignore, t_symbol *name, t_symbol *dir) { t_pd *x = 0; /* even though binbuf_evalfile appears to take care of dspstate, we have to do it again here, because canvas_startdsp() assumes that all toplevel canvases are visible. LATER check if this is still necessary -- probably not. */
t_canvas *x_canvas = 0; int dspstate = canvas_suspend_dsp(); binbuf_evalfile(name, dir);while ((x != s__X.s_thing) && (x = s__X.s_thing)) { x_canvas = canvas_getcurrent(); vmess(x, gensym("pop"), "i", 1); } pd_doloadbang(); canvas_resume_dsp(dspstate); return x_canvas; }
The only addition is that x_canvas is retrieved before x is 'popped' off of pd's global stack, and is then returned, giving me a handle to close that particular patch with something like:
canvas_menuclose(x_canvas, 0);
But I realize that in global_evalfile, t_pd and x_canvas point to the same address space. This leads me to ask, what is the difference between these two pointers? Is t_canvas a t_pd along with variables for its graphical nature?
Mathieu also pointed to me (as I was using the first set of these) that canvas_setcurrent() and canvas_unsetcurrent() are aliases of pd_pushsym() and pd_popsym(). Is there a good reason to use one over the other?
Last question: Does anyone see a way that I could get the value of x in glob_evalfile above without changing the function? I don't think it is a dangerous change (and it looks like I could just hand x.gl_pd to canvas_menuclose, thereby not really needing a t_canvas pointer), but I would of course prefer to not change the API if possible.
Cheers, Rich
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