//https://github.com/mrdoob/three.js/blob/master/examples/webgl_materials_texture_partialupdate.html

// template is blank 
// define your own Three.js World here 


AB.loadCSS ( '/uploads/threeport/main.css' );                             


// use JS to make HTML elements too:

	    AB.newDiv ( "container" );                                 


// template is blank 
// define your own Three.js World here 


import * as THREE from  '/api/threemodule/libs/three.module.js';

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.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 * 3 );
				dataTexture = new THREE.DataTexture( data, width, height, THREE.RGBFormat );

				//

				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() {

				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 * 3;

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

				}

			}