import * as THREE from 'three';
const {
performance,
  document,
	window,
	HTMLCanvasElement,
	requestAnimationFrame,
	cancelAnimationFrame,
core,
	Event,
  Event0
} = THREE .DHTML
var requestId
Page({
	onUnload() {
		cancelAnimationFrame(requestId, this.canvas)
		this.worker && this.worker.terminate()
if(this.canvas) this.canvas = null
		setTimeout(() => {
			if (this.renderer instanceof THREE.WebGLRenderer) {
				this.renderer.dispose()
				this.renderer.forceContextLoss()
				this.renderer.context = null
				this.renderer.domElement = null
				this.renderer = null
			}
		}, 10)
	},
  webgl_touch(e){
		const web_e = (window.platform=="devtools"?Event:Event0).fix(e)
		this.canvas.dispatchEvent(web_e)
  },
  onLoad() {
		document.createElementAsync("canvas", "webgl2",this).then(canvas => {
      this.canvas = canvas
      this.body_load(canvas).then()
    })
  },
  async body_load(canvas3d) {

    let camera, scene, renderer, clock, dataTexture, diffuseMap;

    let last = 0;
    const position = new THREE.Vector2();
    const color = new THREE.Color();

    init();

    function init() {

      camera = new THREE.PerspectiveCamera( 70, window.innerWidth / window.innerHeight, 0.01, 10 );
      camera.position.z = 2;

      scene = new THREE.Scene();

      clock = new THREE.Clock();

      const loader = new THREE.TextureLoader();
      diffuseMap = loader.load( 'textures/floors/FloorsCheckerboard_S_Diffuse.jpg', animate );
      diffuseMap.colorSpace = THREE.SRGBColorSpace;
      diffuseMap.minFilter = THREE.LinearFilter;
      diffuseMap.generateMipmaps = false;

      const geometry = new THREE.PlaneGeometry( 2, 2 );
      const material = new THREE.MeshBasicMaterial( { map: diffuseMap } );

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

      //

      const width = 32;
      const height = 32;

      const data = new Uint8Array( width * height * 4 );
      dataTexture = new THREE.DataTexture( data, width, height );

      //

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

      //

      window.addEventListener( 'resize', onWindowResize );

    }

    function onWindowResize() {

      camera.aspect = window.innerWidth / window.innerHeight;
      camera.updateProjectionMatrix();

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

    }

    function animate() {

      requestId = requestAnimationFrame( animate );

      const elapsedTime = clock.getElapsedTime();

      if ( elapsedTime - last > 0.1 ) {

        last = elapsedTime;

        position.x = ( 32 * THREE.MathUtils.randInt( 1, 16 ) ) - 32;
        position.y = ( 32 * THREE.MathUtils.randInt( 1, 16 ) ) - 32;

        // generate new color data

        updateDataTexture( dataTexture );

        // perform copy from src to dest texture to a random position

        renderer.copyTextureToTexture( position, dataTexture, diffuseMap );

      }

      renderer.render( scene, camera );

    }

    function updateDataTexture( texture ) {

      const size = texture.image.width * texture.image.height;
      const data = texture.image.data;

      // generate a random color and update texture data

      color.setHex( Math.random() * 0xffffff );

      const r = Math.floor( color.r * 255 );
      const g = Math.floor( color.g * 255 );
      const b = Math.floor( color.b * 255 );

      for ( let i = 0; i < size; i ++ ) {

        const stride = i * 4;

        data[ stride ] = r;
        data[ stride + 1 ] = g;
        data[ stride + 2 ] = b;
        data[ stride + 3 ] = 1;

      }

    }

  }
})