I'm trying to share pointers between different objects so I can access
data of one object from another one. I thought of creating a pointer
inlet and a pointer outlet and send the pointer of the data structure
out the outlet, receive it in another object through the inlet, and use
the received pointer to access the data. I'm copying/modifying the
simple counter external from IOhannes' pd-externals-HOWTO, but it's not
working.
Here's the code I have so far:
```
#include "m_pd.h"
static t_class *share_pntr_class;
typedef struct _share_pntr {
t_object x_obj;
t_int i_count;
t_gpointer obj_pnt;
t_outlet *count_out, *addr_out;
} t_share_pntr;
void share_pntr_bang(t_share_pntr *x)
{
t_float f=x->i_count;
x->i_count++;
outlet_float(x->count_out, f);
}
void get_pntr_val(t_share_pntr *x)
{
outlet_float(x->count_out, x->obj_pnt.i_count);
}
void get_pntr(t_share_pntr *x)
{
outlet_pointer(x->addr_out, x);
}
void *share_pntr_new(t_floatarg f)
{
t_share_pntr *x = (t_share_pntr *)pd_new(share_pntr_class);
x->i_count=f;
pointerinlet_new(&x->x_obj, &x->obj_pnt);
x->count_out = outlet_new(&x->x_obj, &s_float);
x->addr_out = outlet_new(&x->x_obj, &s_pointer);
return (void *)x;
}
void share_pntr_setup(void) {
share_pntr_class = class_new(gensym("share_pntr"),
(t_newmethod)share_pntr_new,
0, sizeof(t_share_pntr),
CLASS_DEFAULT,
A_DEFFLOAT, 0);
class_addbang(share_pntr_class, share_pntr_bang);
class_addmethod(share_pntr_class, (t_method)get_pntr,
gensym("get_pntr"), 0, 0);
class_addmethod(share_pntr_class, (t_method)get_pntr_val,
gensym("get_pntr_val"), 0, 0);
}
```
This is the error I'm getting:
```
src/share_mem_one.c:21:46: error: ‘t_gpointer’ {aka ‘struct _gpointer’}
has no member named ‘i_count’
21 | outlet_float(x->count_out, x->obj_pnt.i_count);
```
I understand why I get this error, but I can't see how I could share
data between objects. Perhaps there's some other way to do that?
