//Objeto cena é quem gerencia tudo que deve existir em uma cena
var cena = new THREE.Scene();

//Camera é uma config sbore como e de que posicao iremos observar a cena
var camera = new THREE.PerspectiveCamera(50, window.innerWidth / window.innerHeight, 0.1, 1000);
var render = new THREE.WebGLRenderer();

//Sombra
render.shadowMap.enabled = true;
render.shadowMap.type = THREE.PCFSoftShadowMap; // default THREE.PCFShadowMap

render.setSize(window.innerWidth, window.innerHeight);

//O canvas será construido pelo renderizador
var canvas = render.domElement;
document.body.appendChild(canvas);

var materialLinha = new THREE.LineBasicMaterial({color: 0xFFFFFF});
var geometriaLinha = new THREE.Geometry();

//Luz ambiente
var luzAmbiente = new THREE.AmbientLight(0x111111);
cena.add(luzAmbiente);

//Luz pontual
var luzPonto = new THREE.PointLight(0xcccccc);
luzPonto.position.set(2, 0, 4);
luzPonto.castShadow = true;
cena.add(luzPonto);

//Luz pontual 2
var luzPonto2 = new THREE.PointLight(0xcccccc);
luzPonto2.position.set(-2, 0, 4);
luzPonto2.castShadow = true;
cena.add(luzPonto2);

////Luz pontual 3
//var luzPonto3 = new THREE.PointLight(0xcccccc);
//luzPonto3.position.set(0, 2, 4);
//luzPonto3.castShadow = true;
//cena.add(luzPonto3);

////Luz pontual 4
//var luzPonto4 = new THREE.PointLight(0xcccccc);
//luzPonto4.position.set(0, -2, 4);
//luzPonto4.castShadow = true;
//cena.add(luzPonto4);


var posicaoCameraX = 0;
var posicaoCameraY = 0;
var posicaoCameraZ = 5;



camera.position.x = posicaoCameraX;
camera.position.y = posicaoCameraY;
camera.position.z = posicaoCameraZ;


cena.rotation.x = -1.2;

var curva = new THREE.CatmullRomCurve3([

    new THREE.Vector3(0,0,0),
    new THREE.Vector3(1,1,0),
    new THREE.Vector3(2,0,0),
    new THREE.Vector3(1,-1,0),
    new THREE.Vector3(0,0,0),
    new THREE.Vector3(-1,1,0),
    new THREE.Vector3(-2,0,0),
    new THREE.Vector3(-1,-1,0),
    new THREE.Vector3(0,0,0),

]);

var caminho = new THREE.Path(curva.getPoints(200));
var geometriaLinha = caminho.createPointsGeometry(200);


var materialPonto = new THREE.PointsMaterial({size: 10, sizeAttenuation: false});

for (let p of curva.points) {
    var geometriaPonto = new THREE.Geometry();
    geometriaPonto.vertices.push(new THREE.Vector3( p.x, p.y, p.z));
    var ponto = new THREE.Points(geometriaPonto, materialPonto);
    cena.add(ponto);
}

var linha = new THREE.Line(geometriaLinha, materialLinha);
cena.add(linha);

var geometriaCarro = new THREE.BoxGeometry(0.4,0.2,0.2);

var materialCarro = new THREE.MeshPhongMaterial();

var carro = new THREE.Mesh(geometriaCarro, materialCarro);
carro.material.color.setHex(0xFF0000);

//Sombra
carro.castShadow = true; //default is false
carro.receiveShadow = false; //default

cena.add(carro);

var contadorCarro = 0;

/* Floor  */
var geometry = new THREE.PlaneGeometry( 100000, 100000, 0, 0 );
var material = new THREE.MeshPhongMaterial( { color: 0x444444 } );
var floor = new THREE.Mesh( geometry, material );
floor.material.side = THREE.DoubleSide;
floor.position.z = -0.2;
floor.receiveShadow = true;
cena.add( floor );

function desenhar() {

    carro.geometry.verticesNeedUpdate = true;
    var pontoAtual = linha.geometry.vertices[contadorCarro];

    carro.position.x = pontoAtual.x;
    carro.position.y = pontoAtual.y;
	carro.position.z = pontoAtual.z;

    contadorCarro++;
    if(contadorCarro == linha.geometry.vertices.length - 1) {
        var proximoPonto = linha.geometry.vertices[contadorCarro];
        contadorCarro = 0;
    }else{
        var proximoPonto = linha.geometry.vertices[contadorCarro+1];
    }


    var angulo = Math.atan2(proximoPonto.y - pontoAtual.y, proximoPonto.x - pontoAtual.x)
    carro.rotation.z = angulo;

    var pos = new THREE.Vector3(
        carro.position.x,
        carro.position.y,
        carro.position.z
        );
        camera.lookAt(pos);

    render.render(cena, camera);
    requestAnimationFrame(desenhar);

}

requestAnimationFrame(desenhar);

canvas.addEventListener("mousedown", function (e){
    xi = e.offsetX;
    yi = e.offsetY;
}, false);

//Evento de movimento do mouse (se há botão pressionado)
canvas.addEventListener("mousemove", function(e) {
    if(e.buttons > 0){
        camera.position.x = 15 * (xi - e.offsetX) / canvas.width;
        camera.position.y = 2 * (e.offsetY - yi) / canvas.height;
    }
}, false);