path_from_function_2

_.md

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config.json

{"description":"path_from_function_2","endpoint":"","display":"svg","public":true,"require":[],"fileconfigs":{"inlet.js":{"default":true,"vim":false,"emacs":false,"fontSize":12},"_.md":{"default":true,"vim":false,"emacs":false,"fontSize":12},"config.json":{"default":true,"vim":false,"emacs":false,"fontSize":12}},"tab":"edit","display_percent":0.36369165867866515,"play":false,"loop":false,"restart":false,"autoinit":true,"pause":true,"loop_type":"period","bv":false,"nclones":15,"clone_opacity":0.4,"duration":3000,"ease":"linear","dt":0.01,"hidepanel":false}

inlet.js

var svg = d3.select("svg");

// paths visit http://www.w3.org/TR/SVG11/paths.html


// variables
var bend = 60,						// angle to twist (degrees)
    iterations = 2,					// number of rewrites
	F = 60 / iterations,			// arm distance
	angle_offset = to_rad(bend);	// angle as radian

// converting from resulting string to svg path commands ---------------

function to_rad(degrees){
  return degrees * (2*Math.PI) / 360
}

function get_xy(angle_rad){
  return {x: Math.cos(angle_rad) * F,
          y: Math.sin(angle_rad) * F}
}

function command_from_rad(angle_rad){
  var c = get_xy(angle_rad);
  return " l " + c.x + " " + c.y
}

function make_path(input_string){
  var angle_rad = 0;
  var token = "";
  var path_string = "M " + 33 + "," + 150;
  for (i in d3.range(input_string.length)){
      token = input_string[i]
      if (token === '-') angle_rad += angle_offset
      if (token === '+') angle_rad -= angle_offset
      if (token === 'F') path_string += command_from_rad(angle_rad)
  }
  return path_string
}

function draw_path(path){  
  svg.append("path")
    .attr("d", path)
    .style("fill", "none")
    .style("stroke", "#0033FF")
    .style("stroke-width", 1)
}

var path = 	make_path("F+F--F+F");
//var path = 	make_path("F+F--F+F+F+F--F+F--F+F--F+F+F+F--F+F+F+F--F+F+F+F--F+F--F+F--F+F+F+F--F+F--F+F--F+F+F+F--F+F--F+F--F+F+F+F--F+F+F+F--F+F+F+F--F+F--F+F--F+F+F+F--F+F")
draw_path(path)