Hi all, I'm trying to create an external that has one float inlet and a number of signal inlets corresponding to the creation argument. Something like [nfader 4] should have four signal inlets and one float inlet for the interpolation parameter.

Yes, I already found abstract-based solutions but dynamic patching is black magic to me so I'd rather code this in C with which I'm quite comfortable.

The problem is I thought I could have a t_inlet **inlets field in the object's struct and then allocate the inlets with the usual combo of (t_inlet **)malloc(n * sizeof(t_inlet *)) but apparently sizeof does not have access to _inlet (aliased to t_inlet) as it is an externally defined symbol.

Bottom line: all the examples I could think of that have arbitrary amounts of inlets (and outlets for that matter) are bondo from cyclone and pack from vanilla. I tried expr~ but its complexity is not really helping…

… pointers?

@morpheu5 A type agnostic version of [pack] was made for Pd extended.
Here is the source file which should help........ pack.c .....
David.
The help file might be useful to see how arguments are handled......

@whale-av Thanks, it looks just like what I was looking for! It also follows the approach I'm familiar with (array of pointers instead of the pointer to t_atom which I found in expr~) and it turns out that I had to use getbytes instead of plain old malloc.

@morpheu5 That's good. It's largely gobbledegook for me ( Fortran74 at university) but I understand enough to know that it should help someone who knows what they are doing.
David.

@whale-av Of course I'm good enough with C but regularly stumped by PD itself…  I'm currently trying to figure out how to set up the DSP function with all those parameters, but this seems to be a decent resource to start from.

@morpheu5 The source for extended is here...... https://puredata.info/downloads/pd-extended and as it included many externals it should contain something that will help.
Sourceforge has Vanilla sources but vanilla has very few externals so it is probably not helpful.
These might help.....these.zip ..... but if not then there should be something in the Extended tarball.

But also look in your Pd installation doc folder......... \doc\6.externs for an example of creating a dsp object.
David.