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33 lines
949 B
Racket
33 lines
949 B
Racket
#lang racket/base
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(require
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"helper.rkt"
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racket/class
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racket/contract
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"jpeg.rkt"
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"png.rkt")
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(provide PDFImage-open)
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#;(define PDFImage
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(class object%
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(super-new)
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(as-methods
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)))
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(define/contract (PDFImage-open src label)
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(any/c any/c . -> . (or/c (is-a?/c PNG) (is-a?/c JPEG)))
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(define data (cond
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[(bytes? src) src]
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;;else if src instanceof ArrayBuffer
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;;data = new Buffer(new Uint8Array(src))
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[(regexp-match #rx"^data:.+;base64,(.*)$" src)
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(void)] ;; base64 ; todo
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[else (open-input-file src)]))
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(cond
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[(equal? (peek-bytes 2 0 data) (bytes #xff #xd8))
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(make-object JPEG data label)]
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[(equal? (peek-bytes 4 0 data) (apply bytes (cons #x89 (map char->integer '(#\P #\N #\G)))))
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(make-object PNG data label)]
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[else (raise-argument-error 'PDFImage-open "valid image format" src)]))
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