Interfacing the law javascript Zalan Szakacs

• 

  The start...

JavaScript

• 

  2D bobbles

Canvas

First I started with basic beginners JavaScript tutorials and tried to explore the canvas library.

var canvas = document.querySelector('canvas')
	;

canvas.width = window.innerWidth;
canvas.height = window.innerHeight;


var c  = canvas.getContext('2d');

// c.fillStyle = 'rgba(255, 0, 0, 1)';
// c.fillRect(100, 100, 100, 100);
// c.fillStyle = 'rgba(0, 0, 255, 1)';
// c.fillRect(400, 100, 100, 100);
// c.fillStyle = 'rgba(0, 255, 0, 1)';
// c.fillRect(300, 300, 100, 100);
// console.log(canvas);

//Line

// c.beginPath();
// c.moveTo(50,300);
// c.lineTo(300,100);
// c.strokeStyle = 'rgba(0, 0, 255, 1)';
// c.stroke();

//Arc 

//c.beginPath();
//c.arc(300, 300, 30, 0, Math.PI * 2, false);
//c.strokeStyle = 'red';
//c.stroke();

// for (var i = 0; i < 10; i++) {
// 	var x = Math.random() * window.innerWidth;
// 	var y = Math.random() * window.innerHeight;
// 	c.beginPath();
// 	c.arc(x, y, 30, 0,  Math.PI * 2, false);
	
// 	//c.fillStyle = 'rgba(0, 255, 0, 0.5)';
// 	//c.fill();
// 	c.strokeStyle = 'red';
// 	c.stroke();
// }

var mouse = {

	x: undefined,
	y: undefined

}

var maxRadius = 40;
//var minRadius = 2;

var colorArray = [
	'#4166f5',
	'#00bfff',
	'#11ff00',
	'#55dddd',
	'#0d98ba',
];

console.log(colorArray.length);

window.addEventListener('mousemove', function(event) {
	mouse.x = event.x;
	mouse.y = event.y;





})

window.addEventListener('resize', function() 
	{

	canvas.width = window.innerWidth;
	canvas.height = window.innerHeight;

	init();



});

function Circle(x, y, dx, dy, radius) {
	this.x = x;
	this.y = y;
	this.dx = dx;
	this.dy = dy;
	this.radius = radius;
	this.minRadius = radius;
	this.color = colorArray[Math.floor(Math.random() * colorArray.length)];

	this.draw = function() {
		c.beginPath();
	
		c.arc(this.x, this.y, this.radius, 30, 0, Math.PI * 2, false);
		c.fillStyle = this.color;
		c.fill();
		
	}

	this.update = function() {
		if (this.x  + this.radius > innerWidth || this.x - this.radius < 0) {
		this.dx = -this.dx;

	}

	if (this.y + this.radius > innerHeight || this.y - this.radius < 0) {
		this.dy = -this.dy;
	}

	this.x += this.dx;
	this.y += this.dy;

	//interactivity

	if (mouse.x - this.x < 50 && mouse.x - this.x > -50
		&& mouse.y - this.y < 50 && mouse.y - this.y > -50 


		) {
		if (this.radius < maxRadius) {
			this.radius += 1;
		}
		this.radius += 1;
	} else if (this.radius > this.minRadius) {
		this.radius -= 1;
	}



	this.draw();



	}

}



var circleArray =[];



function init() {

	circleArray = [];

	for (var i = 0; i < 1000; i++) {
		var radius = Math.random() * 3 + 1;
		var x = Math.random() * (innerWidth - radius * 2) + radius;
		var y = Math.random() * (innerHeight - radius * 2) + radius;
		var dx = (Math.random() - 0.5); 
		var dy = (Math.random() - 0.5); 

		circleArray.push(new Circle(x, y, dx, dy, radius));


	}


}

function animate() {
	requestAnimationFrame(animate);
	c.clearRect(0,0, innerWidth, innerHeight);


	for (var i = 0; i < circleArray.length; i++) {
		circleArray[i].update();




	}


	
	
	
}

init();

animate();

• 

  The drawing app

Drawing script

var canvas = document.getElementById('canvas');
var context = canvas.getContext('2d');

canvas.width = window.innerWidth;
canvas.height = window.innerHeight;


window.addEventListener('resize', function() 
	{

	

	init();



});
var radius = 5;
var dragging = false;

canvas.width = window.innerWidth;
canvas.height = window.innerHeight;

context.lineWidth = radius*2;

var putPoint = function(e) {
	if(dragging){
		context.lineTo(e.clientX, e.clientY);
		context.strokeStyle = '#55dddd';
		context.stroke();
		context.beginPath();
		context.arc(e.clientX, e.clientY, radius, 8, Math.PI*2);
		context.fillStyle = '#55dddd';
		context.fill();
		context.beginPath();
		context.moveTo(e.clientX, e.clientY);
	}
}

var engage = function(e){
	dragging = true;
	putPoint(e);
}

var disengage = function(){
	dragging = false;
	context.beginPath();

}


canvas.addEventListener('mousedown', engage);
canvas.addEventListener('mousemove', putPoint);
canvas.addEventListener('mouseup', disengage);

ThreeJs

• 

  Scene Graph

To be understand the use of the 3D in JavaScript I had to dive in to some theory of the system how it is build up. Having 3D experience from Cinem4D it helped a bit to get familiar with ThreeJs. Very useful sites were the following ones: theory + tutorial

• 

<!DOCTYPE html>

<html>
<body>
	<script src="three.min.js"></script>
	<script src="TrackballControls.js"></script>

	<script>
		var camera, controls, scene, renderer;

		init();
		animate();

		function init(){

			camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 1000);
			camera.position.z = 500;

			controls = new THREE.TrackballControls( camera );
			controls.addEventListener('change', render);

			scene = new THREE.Scene();

			var geometry = new THREE.CubeGeometry(100, 100, 100);

			var material = new THREE.MeshNormalMaterial();

			var mesh = new THREE.Mesh( geometry, material );
			scene.add(mesh);

			renderer = new THREE.WebGLRenderer();
			renderer.setSize(window.innerWidth,  window.innerHeight);

			document.body.appendChild(renderer.domElement);
		}

		function animate() {
			requestAnimationFrame( animate );
			controls.update();
		}

		function render(){

			renderer.render( scene, camera );

		}

	</script>

</body>
</html>