23 lines
545 B
Racket
23 lines
545 B
Racket
#lang racket/base
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(require racket/class
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racket/gui/base)
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(define w 50)
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(define h 50)
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(define on (make-bitmap w h))
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(define off (make-bitmap w h))
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(send (send on make-dc) draw-rectangle 5 5 (- w 10) (- h 10))
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(send
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(for/fold ([prev-f #f]) ([i (in-range 10)])
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(define f (new frame% [label "GC Blit"] [width 100] [height 100]))
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(define c (new canvas% [parent f]))
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(register-collecting-blit c 0 0 w h on off)
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(send f show #t)
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(collect-garbage)
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(yield (system-idle-evt))
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(when prev-f (send prev-f show #f))
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f)
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show #f)
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