An improvement upon the previous experiment. Two alternating concatenation rules (X
and Y
) are used to make the spiral grow alternatively clockwise and counterclockwise. Due to the fact that less segments are aligned, the worst aspect ratio of this layout is 1/4 like for the Hilbert spiral layout (the former experiment gave 1/6).
Last active
August 29, 2015 14:03
-
-
Save nitaku/e0f1b570161875b27fc9 to your computer and use it in GitHub Desktop.
FASS spiral II (L-system)
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
`// noprotect` | |
### compute a Lindenmayer system given an axiom, a number of steps and rules ### | |
fractalize = (config) -> | |
input = config.axiom | |
for i in [0...config.steps] | |
output = '' | |
for char in input | |
if char of config.rules | |
output += config.rules[char] | |
else | |
output += char | |
input = output | |
return output | |
### convert a Lindenmayer string into an SVG path string ### | |
svg_path = (config) -> | |
angle = 0.0 | |
path = 'M0 0' | |
for char in config.fractal | |
if char == '+' | |
angle += config.angle | |
else if char == '-' | |
angle -= config.angle | |
else if char == 'F' | |
path += "l#{config.side * Math.cos(angle)} #{config.side * Math.sin(angle)}" | |
return path | |
### animate the path ### | |
### from Mike Bostock's stroke dash interpolation example http://bl.ocks.org/mbostock/5649592 ### | |
tweenDash = () -> | |
l = this.getTotalLength() | |
i = d3.interpolateString('0,' + l, l + ',' + l) | |
return (t) -> i(t) | |
transition = (path) -> | |
path.transition() | |
.duration(20000) | |
.attrTween('stroke-dasharray', tweenDash) | |
curve = fractalize | |
axiom: 'FX' | |
steps: 4 | |
rules: | |
X: 'Y-LFL-FRF-LFLFL-FRFR+F' | |
Y: 'X+RFR+FLF+RFRFR+FLFL-F' | |
L: 'LF+RFR+FL-F-LFLFL-FRFR+' | |
R: '-LFLF+RFRFR+F+RF-LFL-FR' | |
d = svg_path | |
fractal: curve | |
side: 5 | |
angle: Math.PI/2 | |
width = 960 | |
height = 500 | |
vis = d3.select('body').append('svg') | |
.attr | |
width: width | |
height: height | |
.append('g') | |
.attr | |
transform: "translate(#{width/2},#{height/2})" | |
vis.append('path') | |
.attr('class', 'curve shadow') | |
.attr('d', d) | |
vis.append('path') | |
.attr('class', 'curve') | |
.attr('d', d) | |
.call(transition) | |
vis.append('circle') | |
.attr | |
r: 2 | |
fill: 'red' | |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
svg { | |
background: white; | |
} | |
.curve { | |
fill: none; | |
stroke: black; | |
stroke-width: 1px; | |
shape-rendering: crispEdges; | |
} | |
.shadow { | |
opacity: 0.1; | |
} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
<!DOCTYPE html> | |
<html> | |
<head> | |
<meta charset="utf-8"> | |
<meta name="description" content="FASS spiral II (L-system)" /> | |
<title>FASS spiral II (L-system)</title> | |
<link rel="stylesheet" href="index.css"> | |
<script src="http://d3js.org/d3.v3.min.js"></script> | |
</head> | |
<body> | |
<script src="index.js"></script> | |
</body> | |
</html> |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
(function() { | |
// noprotect; | |
/* compute a Lindenmayer system given an axiom, a number of steps and rules | |
*/ | |
var curve, d, fractalize, height, svg_path, transition, tweenDash, vis, width; | |
fractalize = function(config) { | |
var char, i, input, output, _i, _j, _len, _ref; | |
input = config.axiom; | |
for (i = _i = 0, _ref = config.steps; 0 <= _ref ? _i < _ref : _i > _ref; i = 0 <= _ref ? ++_i : --_i) { | |
output = ''; | |
for (_j = 0, _len = input.length; _j < _len; _j++) { | |
char = input[_j]; | |
if (char in config.rules) { | |
output += config.rules[char]; | |
} else { | |
output += char; | |
} | |
} | |
input = output; | |
} | |
return output; | |
}; | |
/* convert a Lindenmayer string into an SVG path string | |
*/ | |
svg_path = function(config) { | |
var angle, char, path, _i, _len, _ref; | |
angle = 0.0; | |
path = 'M0 0'; | |
_ref = config.fractal; | |
for (_i = 0, _len = _ref.length; _i < _len; _i++) { | |
char = _ref[_i]; | |
if (char === '+') { | |
angle += config.angle; | |
} else if (char === '-') { | |
angle -= config.angle; | |
} else if (char === 'F') { | |
path += "l" + (config.side * Math.cos(angle)) + " " + (config.side * Math.sin(angle)); | |
} | |
} | |
return path; | |
}; | |
/* animate the path | |
*/ | |
/* from Mike Bostock's stroke dash interpolation example http://bl.ocks.org/mbostock/5649592 | |
*/ | |
tweenDash = function() { | |
var i, l; | |
l = this.getTotalLength(); | |
i = d3.interpolateString('0,' + l, l + ',' + l); | |
return function(t) { | |
return i(t); | |
}; | |
}; | |
transition = function(path) { | |
return path.transition().duration(20000).attrTween('stroke-dasharray', tweenDash); | |
}; | |
curve = fractalize({ | |
axiom: 'FX', | |
steps: 4, | |
rules: { | |
X: 'Y-LFL-FRF-LFLFL-FRFR+F', | |
Y: 'X+RFR+FLF+RFRFR+FLFL-F', | |
L: 'LF+RFR+FL-F-LFLFL-FRFR+', | |
R: '-LFLF+RFRFR+F+RF-LFL-FR' | |
} | |
}); | |
d = svg_path({ | |
fractal: curve, | |
side: 5, | |
angle: Math.PI / 2 | |
}); | |
width = 960; | |
height = 500; | |
vis = d3.select('body').append('svg').attr({ | |
width: width, | |
height: height | |
}).append('g').attr({ | |
transform: "translate(" + (width / 2) + "," + (height / 2) + ")" | |
}); | |
vis.append('path').attr('class', 'curve shadow').attr('d', d); | |
vis.append('path').attr('class', 'curve').attr('d', d).call(transition); | |
vis.append('circle').attr({ | |
r: 2, | |
fill: 'red' | |
}); | |
}).call(this); |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment