// Задача: Направете топки да се пързалят напряко
// по улей до затихване. Улеят също го направете.			

var renderer = new THREE.WebGLRenderer({antialias:true});
renderer.setSize( window.innerWidth, window.innerHeight );
renderer.setAnimationLoop( drawFrame );
document.body.appendChild( renderer.domElement );

renderer.shadowMap.enabled = true;
renderer.shadowMap.type = THREE.PCFSoftShadowMap;

var scene = new THREE.Scene();
scene.background = new THREE.Color( 'skyblue' );

var aspect = window.innerWidth/window.innerHeight;
var camera = new THREE.PerspectiveCamera( 30, aspect );
camera.position.set( 0, 120, 300 );
camera.lookAt( new THREE.Vector3( 0, -10, 0 ) );


var n = 3; // брой топки
var r = 15; // радиус на топка
var balls = [];
var colors = [ 0x907000, 0x2040A0, 0xA02040 ]; // фиксирани цветове

// създаване на трите топки
for( var i=0; i<n; i++ )
{
	balls[i] = new THREE.Mesh(
		new THREE.SphereGeometry( r, 32, 32 ),
		new THREE.MeshPhongMaterial( {shininess: 100 } )
	);
	balls[i].castShadow = true;
	balls[i].material.color.set( colors[i] );
	balls[i].material.emissive.set( colors[i] );
	balls[i].position.set( -50+50*i, 0, 0 );
	balls[i].v = 1.5+1*Math.random(); // скорост
	balls[i].o = 2*Math.PI*Math.random(); // отместване
	scene.add( balls[i] );
}

// улей (не все още)
var ground = new THREE.Mesh(
	new THREE.BoxGeometry( 200, 50, 140 ),
	new THREE.MeshPhongMaterial()
);
var hole = new THREE.Mesh(new THREE.CylinderGeometry(r * 2, r * 2, 200, 32));
hole.rotation.z = Math.PI / 2;
hole.position.y = r;
var csg = new CSG();
csg.subtract([ground, hole]);
ground = csg.toMesh();
ground.position.y = -r;
ground.receiveShadow = true;
scene.add( ground );

// светлина
var light = new THREE.PointLight( 'white', 0.5 );
light.position.set( 0, 40, 0 );
light.castShadow = false;
scene.add( light );

// и още една
var light = new THREE.PointLight();
light.position.set( 0, 100, 0 );
light.castShadow = true;
scene.add( light );

scene.rotation.y = Math.PI / 2;
var frame = 0;
function drawFrame()
{
	// scene.rotation.y += 0.003;
	for (var i = 0; i < n; i++) {
		var coef = balls[i].v * 7 * Math.sin(frame/10) * Math.exp(-frame / 100);
		balls[i].position.set(balls[i].position.x, r * Math.sin(coef / (8 * balls[i].v) * balls[i].o / 2 - Math.PI / 2), r * Math.cos(coef / (8 * balls[i].v) * balls[i].o / 2 - Math.PI / 2));
	}
	
	renderer.render( scene, camera );
	frame++;
}