Ok, I solved it by just using the value functions that, as it turns out, are available in m_pd.h :)
it all works, but I wanted to expand the object and also make it take symbols, which won't be possible now, but it will be if [value] is expanded to take symbols as well, and there's a PR for it, so I can then annoyingly insist on it instead.
This works better as the external now is perfectly integrated with [value] and can also take values that are set in [expr] for instance.
here's the code, pretty much simpler now as well. Thanks!
// porres 2023
#include "m_pd.h"
static t_class *var_class;
typedef struct _var{
t_object x_obj;
t_int x_n; // number of given vars as arguments
t_symbol **x_sym; // variable names
}t_var;
static void var_bang(t_var *x){
t_atom at[x->x_n];
for(int i = 0; i < x->x_n; i++){
t_float f;
int flag = value_getfloat(x->x_sym[i], &f);
SETFLOAT(at+i, !flag ? f : 0);
}
outlet_list(x->x_obj.ob_outlet, &s_list, x->x_n, at);
}
static void var_list(t_var *x, t_symbol *s, int ac, t_atom *av){
s = NULL;
if(!ac)
var_bang(x);
else for(int i = 0; i < (ac > x->x_n ? x->x_n : ac); i++)
value_setfloat(x->x_sym[i], atom_getfloat(av+i));
}
static void var_free(t_var *x){
for(int i = 0; i < x->x_n; i++)
value_release(x->x_sym[i]);
freebytes(x->x_sym, x->x_n * sizeof(*x->x_sym));
}
static void *var_new(t_symbol *s, int ac, t_atom *av){
s = NULL;
t_var *x = (t_var *)pd_new(var_class);
x->x_sym = getbytes(sizeof(t_symbol) * (x->x_n = (!ac ? 1 : ac)));
if(!ac)
value_get(x->x_sym[0] = &s_);
else for(int i = 0; i < x->x_n; i++)
value_get(x->x_sym[i] = atom_getsymbol(av+i));
outlet_new(&x->x_obj, &s_list);
return(x);
}
void var_setup(void){
var_class = class_new(gensym("var"), (t_newmethod)var_new,
(t_method)var_free, sizeof(t_var), 0, A_GIMME, 0);
class_addbang(var_class, var_bang);
class_addlist(var_class, var_list);
}