#---------------------------------------------------------------------#
Program : Fractals (Ruby Q. #125)
Author : David T.
Date : 2007-05-30
Blog : http://davidtran.doublegifts.com/blog/?p=48
Reference : Perpendicular Vector -- from Wolfram MathWorld
Note : Using vector calculation to compute each level’s
points. The first level line can be in any direction.
#---------------------------------------------------------------------#
require ‘enumerator’
require ‘RMagick’
LEVEL_0 = [[0, 0], [350, 200]]
def next_level(polylines)
polylines.enum_cons(2).inject([polylines.first]) do |array, (p1, p2)|
x1, y1 = p1
x2, y2 = p2
a = (x2 - x1) / 3.0
b = (y2 - y1) / 3.0
array << [x1+a, y1+b] << [x1+a-b, y1+b+a] <<
[x1+2a-b, y1+2b+a] << [x1+2a, y1+2b] << p2
end
end
exit unless FILE == $0
imageList = Magick::ImageList.new
level = LEVEL_0
(ARGV[0].to_i + 1).times do |i|
level = next_level(level) if i > 0
image = Magick::Image.new(400, 300)
image.delay = 100
draw = Magick::Draw.new
draw.fill_opacity(0)
draw.stroke(‘black’)
draw.polyline(*level)
draw.text(300,100,“level #{i}”)
draw.draw(image)
imageList << image
end
imageList.write(File.basename($0) + “.gif”)