At Sat, 9 Jun 2012 02:42:43 -0400, Vince Kuyatt wrote: > While working on the Rhipmunk FFI, I ran into a definition called > "NOT_GRABABLE_MASK", which as far as I can tell, is defined as: > #define GRABABLE_MASK (1<<31) > #define NOT_GRABABLE_MASK (~GRABABLE_MASK) > > The problem with this, is that when I do the same operations: > (define GRABABLE_MASK (int->uint (arithmetic-shift 1 31))) > (define NOT_GRABABLE_MASK (bitwise-not GRABABLE_MASK)) > > I get an error thrown back at me when I use it in one of the Chipmunk > functions: > Scheme->C: expects argument of type <uint32>; given -2147483649 > > How can I coerce the definitions of those two masks so that they will be a > uint32 that I can pass to the Chipmunk API?
I think you want (define (sint32->uint32 v) (bitwise-and #xFFFFFFFF v)) ____________________ Racket Users list: http://lists.racket-lang.org/users
