hw5 helper

with orbitControls, XZgrid, info

by zx22516969

HTML

<div id="info">Homework 5 Helper
  <br>Right click to move RED dot<br>
  <button id='reset'>
  Reset
  </button>
</div>
<script src="http://cdnjs.cloudflare.com/ajax/libs/three.js/92/three.min.js"></script>
<script src="https://rawgit.com/mrdoob/three.js/master/examples/js/Detector.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/stats.js/r16/Stats.min.js"></script>
<script src="https://code.jquery.com/jquery-2.1.4.min.js"></script>

CSS

#info {
  position: absolute;
  top: 0px;
  width: 100%;
  padding: 10px;
  text-align: center;
  color: #ffff00
}

body {
  overflow: hidden;
}

JavaScript

$("#reset").click(function() {
  //x[0] = Math.PI/2, x[1] = 0;
  t = 0;
});

var camera, scene, renderer;
var circle, line;
var x = [];  // x0: theta, x1: theta_dot
var mousePoint;
var mouse = new THREE.Vector2();
var stats;
var t, dt;
var g, l;
var lastTime = 0;

init();
animate();

function init() {
    renderer = new THREE.WebGLRenderer({
      antialias: true
    });
	
  // STATS
	stats = new Stats();
	stats.domElement.style.position = 'absolute';
	stats.domElement.style.top = '0px';
	stats.domElement.style.zIndex = 100;
	document.body.appendChild( stats.domElement );	
  
  renderer.setSize(window.innerWidth, window.innerHeight);
 renderer.setClearColor(0x888888);
  document.body.appendChild(renderer.domElement);

	t = 0;
  dt = 0.253;
	
  l = 3;
  g = 10;
  x[0] = Math.PI/6;
  x[1] = 0;
  
  scene = new THREE.Scene();
  camera = new THREE.OrthographicCamera(-5, 5, 7, -3, -10, 100);
  camera.position.z = 10;


	/////////////////////////////
	let grid = new THREE.GridHelper (20,20, 'white','white')
  scene.add (grid)
  grid.rotation.x = Math.PI/2
  
  circle = new THREE.Mesh (new THREE.CircleGeometry (0.5,20), new THREE.MeshBasicMaterial());
  scene.add (circle);
	
  let geometry = new THREE.Geometry();
  geometry.vertices.push (new THREE.Vector3(0,4,0));
  geometry.vertices.push (new THREE.Vector3());
  let material = new THREE.LineDashedMaterial(
  {color:0xffff00,
  gapSize:0.43, dashSize:0.43}
  );
  line = new THREE.Line (geometry, material)
	scene.add (line)
  line.computeLineDistances();
  
	//////////////////////////////////
	window.addEventListener('resize', onWindowResize, false);
  window.addEventListener('mousedown', onDocumentMouseDown, false);
}

function onWindowResize() {
  camera.aspect = window.innerWidth / window.innerHeight;
  camera.updateProjectionMatrix();
  renderer.setSize(window.innerWidth, window.innerHeight);
}

function onDocumentMouseDown(event) {
  event.preventDefault();
  // NDC: [-1,1]x[-1,1]
  mouse.x = (event.clientX /...