Wandering Astroid

script.js

/* Copy of Bees and Bombs' sketch
https://twitter.com/beesandbombs/status/881857295008882689
*/
var b = 0; //counter for rotation
var sz = 500; //size of triangle
var linelist = [];
var side = 1; //side that's being drawn

function setup(){
  createCanvas(600,600);
  noFill();
  colorMode(HSB);
}

function draw(){
  frameRate(15);
  background(0);//black
  translate(width/2,height/2); //go to center of screen
  //create the vertices of the big triangle
  var pt1 = createVector(sz/2,sz/(2*sqrt(3)));
  var pt2 = createVector(-sz/2,sz/(2*sqrt(3)));
  var pt3 = createVector(0,-sz/sqrt(3));
  //call the triangle fractal
  astroid1 = tri1(pt1,pt2,pt3,3,b);
  //draw a line between p4 and p5
    //add line to list
    
  linelist.push(astroid1);
  
  
  for (var i=0; i<linelist.length; i++){
    linelist[i].display();
  }
  
  //increment b
  b += 0.05; 
  //b can only be between 0 and 1
  if (b > 1.0){
    b = 0.0;
    if (side == 1){
      side = 2;
    } else if (side == 2){
      side = 3;
    } else {
      side = 1;
    }
  }
  if (linelist.length > 20){
    linelist.splice(0,1);
  }
}

function tri1(p1,p2,p3,level,b){
    strokeWeight(1);
    stroke(200,300,300) //color
    //draw the main triangle
    triangle(p1.x,p1.y,p2.x,p2.y,p3.x,p3.y);
    //the rotated points are linear interpolations of the 
    //vertices of the triangle
    var p4 = createVector(lerp(p1.x,p2.x,b),lerp(p1.y,p2.y,b));
    var p5 = createVector(lerp(p2.x,p3.x,b),lerp(p2.y,p3.y,b));
    var p6 = createVector(lerp(p3.x,p1.x,b),lerp(p3.y,p1.y,b));
    
    if(side == 1){
    return new AstroidLine(p4,p5,b);
    } else if(side == 2){
    return new AstroidLine(p5,p6,b);
    } else {
      return new AstroidLine(p6,p4,b);
    }
    
    //make a triangle fractal of those points
    //tri1(p4,p5,p6,level+1,b);
  
}

function AstroidLine(p1,p2,b){
  this.p1 = p1;
  this.p2 = p2;
  this.b = b;
  //lineList.push(this.p1,this.p2);
  
  this.display = function(){
   stroke(360-this.b*350,300,300) //color
    line(this.p1.x,this.p1.y,this.p2.x,this.p2.y)
    
  }
  
  
}

scripts

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wandering-astroid.markdown

Wandering Astroid

A Pen by Peter Farrell on CodePen.

License.