29 lines
628 B
CoffeeScript
29 lines
628 B
CoffeeScript
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mandel = (x0, y0, x1, y1, w, h, maxiter) ->
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[dx, dy] = [(x1 - x0) / w, (y1 - y0) / h]
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res = []
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y = y0
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for yc in [0..h-1]
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x = x0
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for xc in [0..w-1]
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[xx, yy] = [x, y]
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c = '*'
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for i in [0..maxiter-1]
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# (xx+i*yy)^2 + (x+i*y) = xx^2 + i*2*xx*yy - yy^2 + x + i*y
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# = (xx^2 - yy^2 + x) + i*(2*xx*yy + y)
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[xx2, yy2] = [xx*xx, yy*yy]
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if xx2 + yy2 >= 4.0
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c = '.'
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break
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[xx, yy] = [xx2 - yy2 + x, 2*xx*yy + y]
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res.push(c)
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x += dx
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res.push('\n')
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y += dy
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print(res.join(''))
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return
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mandel(-2, 2, 2, -2, 200, 100, 1000)
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