If you haven't already you might want to update ikegami's use of New() to the newer Newx?().

Good idea ... and now done.
In order to have the demo work with older perls that aren't Newx-aware, I've also prefixed the C code with:

/*
Allocate memory with Newx if it's
available - if it's an older perl
that doesn't have Newx then we
resort to using New.
*/
#ifndef Newx
#  define Newx(v,n,t) New(0,v,n,t)
#endif
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Cheers,
Rob