[plt-scheme] Binding C-Structs Containing Fixed-Size Arrays with the FFI

From: Henk Boom (lunarc.lists at gmail.com)
Date: Mon Jan 26 13:30:28 EST 2009

2009/1/26 Matthew Flatt <mflatt at cs.utah.edu>:
> I would define `dVector3' as a structure:
>  (define _dReal _float)
>  (define-cstruct _dVector3 ([v0 _dReal] [v1 _dReal]
>                            [v2 _dReal] [v3 _dReal]))
> Defining a cstruct type doesn't work well for large arrays, but I bet
> it will work well in this case.

Thanks for the reply! That would work well in this case, but perhaps I
should have thrown out the tougher problem first:

typedef dReal dMatrix3[4*3];
struct dMass {
  dReal mass;
  dVector4 c;
  dMatrix3 I;

It would be awkward to define and use dMatrix3 as a struct in this
case, and with my limited C implementation knowledge it's not clear to
me that the alignment would be the same.


Posted on the users mailing list.