// 场景、相机、光源定义定义
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000000);
camera.up.set(0,0,1);
var light = new THREE.AmbientLight(0xffffff);
scene.add(light);

// 渲染器定义
var canvas = document.createElement( 'canvas' );
canvas.id = 'model';
var context = canvas.getContext( 'webgl2', {antialias: true, preserveDrawingBuffer: true});
var renderer = new THREE.WebGLRenderer({canvas: canvas, context: context, logarithmicDepthBuffer: true});
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.setClearColor(0xffffff);
document.body.appendChild(renderer.domElement);

// 加载模型数据
const loader = new THREE.FileLoader();
loader.load(
    '/demo/res/single-demo.json',
    function(data)
    {
        var bimScene = BIMLoader(JSON.parse(data));
        var box = new THREE.Box3();
        box.expandByObject(bimScene);
        box.expandByScalar(10000);
        var cameraPos = new THREE.Vector3(box.min.x, box.min.y, box.max.z);
        camera.position.copy(cameraPos);
        camera.lookAt(box.getCenter());
        camera.updateMatrixWorld();
        scene.add(bimScene);
    },
    function(xhr)
    {
        console.log((xhr.loaded / xhr.total * 100) + '% loaded');   
    },
    function(err)
    {
        console.error('An error happened');
    }
)

function animate() {
    requestAnimationFrame( animate );
    renderer.render( scene, camera );
}

 animate();