Re: [QUIZ][SOLUTION] Circle Drawing (#166)

My solution follows....

Regards,

Bill


# Ruby Quiz #166
#
# This draws a circle of the specified radius, modified
# by an optional aspect ratio and thickness factor.
#
# implementation notes:
# - for the fun of it, i forbade use of sqrt() and trancendentals
# - the circle is not drawn into a buffer before being printed
# - some values are empirically derived (thickness factor, in parciular)
#
# bugs:
# - the thickness factor causes bloat in small circles

ARGV.length >= 1 or abort("usage: #$0 radius [aspect] [thickness]")

radius = ARGV.shift.to_f
radius > 0 or abort("please provide radius of circle")

aspect = ARGV.shift.to_f
aspect > 0 or aspect = 1.0

thick = ARGV.shift.to_f
thick > 0 or thick = 1.0

hradius = (radius * aspect).ceil + (thick/2.0).round
vradius = radius.ceil + (thick/2.0).round

def get_radius_ch(rsq, dsq, tfactor)
(rsq - dsq).abs <= tfactor ? "*" : " "
end

tfactor = (thick * 4.0) + 2.5
rsq = radius**2
(-vradius).upto(vradius) do |y|
(-hradius).upto(hradius) do |x|
print(get_radius_ch(rsq, (x * (1.0/aspect))**2 + y**2, tfactor))
end
puts
end


# example: radius 7.0, aspect 1.0, thickness 1.0
#
# $ ruby 166_circle.rb 7 1 1
#
# *****
# ** **
# * *
# * *
# * *
# * *
# * *
# * *
# * *
# * *
# * *
# * *
# * *
# ** **
# *****
#
#
# example: radius 10.0, aspect 2.0, thickness 5.0
#
# $ ruby 166_circle.rb 10 2 5
#
#
# *****
# *******************
# *************************
# ******** ********
# ******* *******
# ****** ******
# ***** *****
# ***** *****
# ***** *****
# **** ****
# ***** *****
# ***** *****
# ***** *****
# **** ****
# ***** *****
# ***** *****
# ***** *****
# ****** ******
# ******* *******
# ******** ********
# *************************
# *******************
# *****
#



.

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