//ported from threejs examples
//https://threejs.org/examples/#webgl_geometry_terrain
//https://github.com/mrdoob/three.js/blob/master/examples/webgl_geometry_terrain.html


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

// path edits:

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

            import Stats from '/uploads/threeport/stats.module.js';

			import { FirstPersonControls } from '/uploads/threejs/FirstPersonControls.js';
			import { ImprovedNoise } from '/uploads/threejs/ImprovedNoise.js';

			let container, stats;
			let camera, controls, scene, renderer;
			let mesh, texture;

			const worldWidth = 256, worldDepth = 256;
			const clock = new THREE.Clock();

			init();
			animate();

			function init() {

				container = document.getElementById( 'container' );

				camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 1, 10000 );

				scene = new THREE.Scene();
				scene.background = new THREE.Color( 0xefd1b5 );
				scene.fog = new THREE.FogExp2( 0xefd1b5, 0.0025 );

				const data = generateHeight( worldWidth, worldDepth );

				camera.position.set( 100, 800, - 800 );
				camera.lookAt( - 100, 810, - 800 );

				const geometry = new THREE.PlaneGeometry( 7500, 7500, worldWidth - 1, worldDepth - 1 );
				geometry.rotateX( - Math.PI / 2 );

				const vertices = geometry.attributes.position.array;

				for ( let i = 0, j = 0, l = vertices.length; i < l; i ++, j += 3 ) {

					vertices[ j + 1 ] = data[ i ] * 10;

				}

				texture = new THREE.CanvasTexture( generateTexture( data, worldWidth, worldDepth ) );
				texture.wrapS = THREE.ClampToEdgeWrapping;
				texture.wrapT = THREE.ClampToEdgeWrapping;

				mesh = new THREE.Mesh( geometry, new THREE.MeshBasicMaterial( { map: texture } ) );
				scene.add( mesh );

				renderer = new THREE.WebGLRenderer();
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );
				container.appendChild( renderer.domElement );

				controls = new FirstPersonControls( camera, renderer.domElement );
				controls.movementSpeed = 150;
				controls.lookSpeed = 0.1;

				stats = new Stats();
				container.appendChild( stats.dom );


				//

				window.addEventListener( 'resize', onWindowResize );

			}

			function onWindowResize() {

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

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

				controls.handleResize();

			}

			function generateHeight( width, height ) {

				let seed = Math.PI / 4;
				window.Math.random = function () {

					const x = Math.sin( seed ++ ) * 10000;
					return x - Math.floor( x );

				};

				const size = width * height, data = new Uint8Array( size );
				const perlin = new ImprovedNoise(), z = Math.random() * 100;

				let quality = 1;

				for ( let j = 0; j < 4; j ++ ) {

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

						const x = i % width, y = ~ ~ ( i / width );
						data[ i ] += Math.abs( perlin.noise( x / quality, y / quality, z ) * quality * 1.75 );

					}

					quality *= 5;

				}

				return data;

			}

			function generateTexture( data, width, height ) {

				let context, image, imageData, shade;

				const vector3 = new THREE.Vector3( 0, 0, 0 );

				const sun = new THREE.Vector3( 1, 1, 1 );
				sun.normalize();

				const canvas = document.createElement( 'canvas' );
				canvas.width = width;
				canvas.height = height;

				context = canvas.getContext( '2d' );
				context.fillStyle = '#000';
				context.fillRect( 0, 0, width, height );

				image = context.getImageData( 0, 0, canvas.width, canvas.height );
				imageData = image.data;

				for ( let i = 0, j = 0, l = imageData.length; i < l; i += 4, j ++ ) {

					vector3.x = data[ j - 2 ] - data[ j + 2 ];
					vector3.y = 2;
					vector3.z = data[ j - width * 2 ] - data[ j + width * 2 ];
					vector3.normalize();

					shade = vector3.dot( sun );

					imageData[ i ] = ( 96 + shade * 128 ) * ( 0.5 + data[ j ] * 0.007 );
					imageData[ i + 1 ] = ( 32 + shade * 96 ) * ( 0.5 + data[ j ] * 0.007 );
					imageData[ i + 2 ] = ( shade * 96 ) * ( 0.5 + data[ j ] * 0.007 );

				}

				context.putImageData( image, 0, 0 );

				// Scaled 4x

				const canvasScaled = document.createElement( 'canvas' );
				canvasScaled.width = width * 4;
				canvasScaled.height = height * 4;

				context = canvasScaled.getContext( '2d' );
				context.scale( 4, 4 );
				context.drawImage( canvas, 0, 0 );

				image = context.getImageData( 0, 0, canvasScaled.width, canvasScaled.height );
				imageData = image.data;

				for ( let i = 0, l = imageData.length; i < l; i += 4 ) {

					const v = ~ ~ ( Math.random() * 5 );

					imageData[ i ] += v;
					imageData[ i + 1 ] += v;
					imageData[ i + 2 ] += v;

				}

				context.putImageData( image, 0, 0 );

				return canvasScaled;

			}

			//

			function animate() {

				requestAnimationFrame( animate );

				render();
				stats.update();

			}


			function render() {

				controls.update( clock.getDelta() );
				renderer.render( scene, camera );

			}