Solved:
(defmd gnc-point ()
(x (c-in 0))
(y (c-in 0))
(z (c-in 0))
(foreign-ptr (c-in (fgn-alloc 'glInt 3 :gnc-point))))
(defobserver x ((self gnc-point))
(with-integrity (:change self)
(let ((ptr (^foreign-ptr)))
(if ptr
(setf (eltgli ptr 0) (^x))
(error "OBSERVER X OF ~S: FOREIGN-PTR is NIL (Foreign memory
not available)" self)))))
(defobserver y ((self gnc-point))
(with-integrity (:change self)
(let ((ptr (^foreign-ptr)))
(if ptr
(setf (eltgli ptr 1) (^y))
(error "OBSERVER Y OF ~S: FOREIGN-PTR is NIL (Foreign memory
not available)" self)))))
(defobserver z ((self gnc-point))
(with-integrity (:change self)
(let ((ptr (^foreign-ptr)))
(if ptr
(setf (eltgli ptr 2) (^z))
(error "OBSERVER Z OF ~S: FOREIGN-PTR is NIL (Foreign memory
not available)" self)))))
... A bit more complex but works ;-) Frank Am 29.08.2007 um 21:50 schrieb Frank Goenninger:
* PGP Signed: 08/29/07 at 21:50:08 Correct problem case:I defined the foreign-ptr cell as lazy (as :until-asked) for a reason ... ->0> 7612 calculating cell ~a appears in call stack: ~a dirty=0/ foreign-ptr/gnc-point0] dirty=0/foreign-ptr/gnc-point0](dirty=0/foreign-ptr/gnc-point0]) ... landing in a (break) ...Ok. So I am basically looking for an idiom on how to avoid the circularity. I sense there is a simple solution but ...Oh my. It's been a long day ;-) Frank Am 29.08.2007 um 21:35 schrieb Frank Goenninger:> Old Signed: 08/29/07 at 21:35:14 Hi Kenny (and all on the list): I have a simple defmd: (defmd gnc-point () (x (c-in 0)) (y (c-in 0)) (z (c-in 0))(foreign-ptr (c_? (let ((ptr (or (^foreign-ptr) (fgn-alloc 'glInt 3 :gnc-point))))(when ptr (setf (eltgli ptr 0) (^x)) (setf (eltgli ptr 1) (^y)) (setf (eltgli ptr 2) (^z))) ptr))))This is a model for a point ( x | y | z ) and a foreign object pointer. The pointer shall be set to a an FFI memory pointer (via CFFI) when the instance is created. Also, the elements of the memory array (which is 3 glInt, this being three OpenGL Integers) shall be updated when any of the coordinates x y z is changed...I get x, y, and z updated but the foreign-ptr remains NIL ... What am I doing wrong ???Thx! Frank * Frank Goenninger<[EMAIL PROTECTED]> * 0xED320F02:0x05AE0907 _______________________________________________ cells-devel site list [email protected] http://common-lisp.net/mailman/listinfo/cells-devel > Old Signed: 08/29/07 at 21:35:14 * text/plain body * Frank Goenninger<[EMAIL PROTECTED]> * 0xED320F02:0x05AE0907* Frank Goenninger<[EMAIL PROTECTED]> * 0xED320F02:0x05AE0907 _______________________________________________ cells-devel site list [email protected] http://common-lisp.net/mailman/listinfo/cells-devel * PGP Signed: 08/29/07 at 21:50:08 * text/plain body * Frank Goenninger<[EMAIL PROTECTED]> * 0xED320F02:0x05AE0907
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