//iPhone

//Chrome

//Slackからsketchbookにコピペ



var trianglepointY = [];

var triangleNum;



function setup() {

  createCanvas(windowWidth,

               windowHeight);



  frameRate(10);



  background(0, 0, 0);

  point(0, windowHeight);

  point(windowWidth, windowHeight);



  noFill();

  triangleNum = 50;

  for (var i = 0; i < triangleNum; i = i + 1) {

    trianglepointY[i] = i*50;

  }

}



function draw() {

  strokeWeight(2);



  for (var i = triangleNum - 1; i >= 0; i = i - 1) {

    var R = random(frameCount)  / triangleNum;

    var G = random(frameCount) - i * 20 / triangleNum;

    var B = random(frameCount) - i * 100/ triangleNum;

    stroke(R, G, B);

    triangle(0, windowHeight, windowWidth, windowHeight, windowWidth/2, trianglepointY[i]);

  }

}