     space arbiters>>
     [ num>> ] [ arr>> swap <direct-void*-array> ] bi [
         cpArbiter memory>struct
-        [ numContacts>> ] [ contacts>> swap <direct-cpContact-array> ] bi [
+        [ numContacts>> ] [ contacts>> >c-ptr swap <direct-cpContact-array> ] bi [
             p>> [ x>> ] [ y>> ] bi glVertex2f
         ] each
     ] each

        open-window
    ] with-ui ;


                x image-width 2 / - 0.05 0.0 1.0 uniform-random-float * + 2 *
                image-height 2 / y - 0.05 0.0 1.0 uniform-random-float * + 2 *
                make-ball :> shape
                space shape shape>> body>> cpSpaceAddBody drop
                space shape cpSpaceAddShape drop
            ] when
        ] each
