;;;; vim:ft=lisp
;;;; Touched: <10-Oct-03 05:34:56 IST, madhu>
;;;;
;;;; (CLISP and WIN32)
(in-package pdf)

#+pdf-compress
(ffi:def-call-out zlib-compress-string 
  (:name "compress")
  (:library "c:/windows/system/zlib.dll")
  (:arguments (dest ffi:c-pointer :in)
              (destlen (ffi:c-ptr ffi:ulong) :in-out)
              (source ffi:c-string)
              (sourcelen ffi:ulong))
  (:return-type ffi:int)
  (:language :stdc))

;; whats the idea in making this a symbol-macro place?
#+pdf-compress
(setf custom:*foreign-encoding* +external-format+)
;; if it were a global special I can shadow it when calling compress-string
;; instead of setting it globally

#+pdf-compress
(defun compress-string (source) 
  "Compress the string SOURCE. Returns an array of bytes
representing the compressed data."
  (let* ((sourcelen (length source))
         (destlen (+ 12 (ceiling (* sourcelen 1.05)))))
    ;; Using CLISP's symbol-macro based interface
    (ffi:with-c-var (dest `(ffi:c-array ffi:uint8 ,destlen)) ; no init
      (multiple-value-bind (status actual)
          (zlib-compress-string (ffi:c-var-address dest) destlen source sourcelen)
        (if (zerop status)
            ;;(subseq dest 0 actual)
            ;;ffi:cast not usable because of different size...
            (ffi:offset dest 0 `(ffi:c-array ffi:uint8 ,actual))
          (error "zlib error, code ~d" status))))))