Greyscale bars/Display: Difference between revisions
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## Example ## |
## Example ## |
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grayscalesImage(6) # produces image shown in screenshot to the right |
grayscalesImage(6) # produces image shown in screenshot to the right |
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</lang> |
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=={{header|Racket}}== |
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This solution uses the built-in pict library for graphics. |
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[[File:Grayscale-pict.png|thumb|right]] |
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<lang racket> |
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#lang racket/gui |
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(require slideshow/pict) |
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(define-values (*width* *height*) (values 400 40)) |
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(define (shades inc) |
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(for/list ([scale (in-range 0 (+ 1 inc) inc)]) |
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(round (* 255 scale)))) |
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(define (grays increment direction) |
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(define colors (shades increment)) |
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(apply hc-append |
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((if (eq? direction 'right) identity reverse) |
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(for/list ([c colors]) |
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(colorize (filled-rectangle |
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(/ *width* (length colors)) *height*) |
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(make-color c c c)))))) |
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(vc-append (grays 1/8 'right) (grays 1/16 'left) |
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(grays 1/32 'right) (grays 1/64 'left)) |
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</lang> |
</lang> |
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