"""
FractalBenchmark.cobra - print an image of the Mandelbrot set

See http://www.timestretch.com/FractalBenchmark.html

== History

    2009-03-09 Csaba Urbaniczky
    2009-03-09 Tests
        With float:: 48-128 ms (in SciTE)
        With  float & Try Catch  &:48-128 ms  = same!
        With decimal & Try Catch  6.05 - 6.06 s = very much slower!
        VB.NET 2005 version on the same computer: 175-180 ms
    2009-03-10 Code cleanup by Charles Esterbrook
"""

@number float

class Program

    const bailOut = 16
    const maxIterations = 1_000
    
    def mandelbrot
        for y in -39 : 39
            print
            for x in -39 : 39
                if .calc(x/40, y/40), c = '*'
                else, c = ' '
                print c stop

    def calc(ci as number, y as number) as bool
        cr = y - 0.5
        zr = zi = 0.0
        for i in 0 : .maxIterations
            zr2 = zr * zr
            zi2 = zi * zi
            if zi2 + zr2 > .bailOut, return false
            temp = zr * zi
            zr = zr2 - zi2 + cr
            zi = temp + temp + ci
        return true

    def main
        sw = System.Diagnostics.Stopwatch()
        sw.start
        .mandelbrot
        sw.stop
        print
        print 'Cobra elapsed: [sw.elapsedMilliseconds] ms'