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(assert ... <caller>)

This commit is contained in:
Rolf-Thomas Happe 2003-04-23 17:23:39 +00:00
parent c7e5b8e20a
commit 746040e917
1 changed files with 20 additions and 20 deletions
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40
scsh/image-info/imxize.scm
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@ -2,8 +2,8 @@
; See the file COPYING distributed with the Scheme Untergrund Library
; See the file README for documentation.
;;; since there is no pre-fab lazy-list facility for s48/scsh but a
;;; draft srfi, I don't use what's not there and don't set up a
;;; since there is no pre-fab lazy-list facility for s48/scsh but a
;;; draft srfi, I don't use what's not there and don't set up a
;;; full-fledged facility myself. An ad hoc hack shall do for now.
(define (inport->byte-stream in)
@ -20,7 +20,7 @@
(delay '())))))
(define (segment-byte-stream bs start end)
(assert (<= start end))
(assert (<= start end) segment-byte-stream)
(let* ((bv (make-byte-vector (- end start) 0)))
(let loop ((i 0) (bs bs))
(cond ((< i start)
@ -58,11 +58,11 @@
width/dpi height/dpi)
image-info?
(format image-info:format set-format!)
(depth image-info:depth set-depth!)
(width/pixel image-info:width/pixel set-width/pixel!)
(height/pixel image-info:height/pixel set-height/pixel!)
(width/dpi image-info:width/dpi set-width/dpi!)
(height/dpi image-info:height/dpi set-height/dpi!)
(depth image-info:depth set-depth!)
(width/pixel image-info:width/pixel set-width/pixel!)
(height/pixel image-info:height/pixel set-height/pixel!)
(width/dpi image-info:width/dpi set-width/dpi!)
(height/dpi image-info:height/dpi set-height/dpi!)
)
;; initialize all fields with #f
@ -83,8 +83,8 @@
(if (get r) `((,tag ,(get r))) '()))
;; img : input-port | byte-vector | byte-stream
;; ==> [width height]
@ -103,7 +103,7 @@
(values (image-info:width/pixel info)
(image-info:height/pixel info))
(error "image-dimension : could not extract W x H"))))
;; img : byte-stream
;; ==> info or #f
@ -120,7 +120,7 @@
(= 11 (byte-vector-length bytes))
(= #x47 (byte-vector-ref bytes 0))
(= #x49 (byte-vector-ref bytes 1))
;; magic 8?a
(= #x46 (byte-vector-ref bytes 2))
(= #x38 (byte-vector-ref bytes 3))
@ -182,7 +182,7 @@
(receive (bytes bs) (segment-byte-stream bs 0 6)
(if (< 6 (byte-vector-length bytes)) #f
(get-most!/jpeg info bytes))))
(else
(else
(loop (segment-byte-stream bs (- size 2) (+ size 2))))
))))
)))
@ -207,11 +207,11 @@
(define (cm->inch x)
(floor (/ (* x 254) 100)))
(and ;; app0 id
(= #x4a (byte-vector-ref bv 0))
(= #x46 (byte-vector-ref bv 1))
(= #x49 (byte-vector-ref bv 2))
(= #x46 (byte-vector-ref bv 3))
(= #x00 (byte-vector-ref bv 4))
(= #x4a (byte-vector-ref bv 0))
(= #x46 (byte-vector-ref bv 1))
(= #x49 (byte-vector-ref bv 2))
(= #x46 (byte-vector-ref bv 3))
(= #x00 (byte-vector-ref bv 4))
;; possibly read physical w x h
(cond ((= 1 (byte-vector-ref bv 7))
@ -229,7 +229,7 @@
(set-height/dpi! info
(cm->inch (assemble-bytes
(byte-vector-ref bv 11)
(byte-vector-ref bv 10))))))))
(byte-vector-ref bv 10))))))))
@ -239,7 +239,7 @@
(= 26 (byte-vector-length bytes))
(= #x89 (byte-vector-ref bytes 0))
(= #x50 (byte-vector-ref bytes 1))
;; png magic
(= #x4e (byte-vector-ref bytes 2))
(= #x47 (byte-vector-ref bytes 3))