a744958fd5
currently the support is limited to images that can only report their sizes and pinholes and where equal? signals an error unless the arguments are eq?.
37 lines
1.0 KiB
Racket
37 lines
1.0 KiB
Racket
#lang racket/base
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(require racket/class)
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(provide fetch image<%>
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get-shape set-shape get-bb get-pinhole
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get-normalized? set-normalized get-normalized-shape)
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(define-local-member-name
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get-shape set-shape get-bb get-pinhole
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get-normalized? set-normalized get-normalized-shape)
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(define image<%>
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(interface ()
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get-shape set-shape get-bb get-pinhole
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get-normalized? get-normalized-shape))
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(define (fetch bytes)
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(let* ([str
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(and bytes
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(with-handlers ((exn:fail? (λ (x) #f)))
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(bytes->string/utf-8 bytes)))]
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[lst (and str
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(with-handlers ((exn:fail:read? (λ (x) #f)))
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(racket/base:read
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(open-input-string
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str))))])
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(cond
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[(and (list? lst)
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(= 2 (length lst)))
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;; backwards compatibility for saved images that didn't have a pinhole
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(list (list-ref lst 0)
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(list-ref lst 1)
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#f)]
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[else
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lst])))
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(define racket/base:read read)
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