<script type="importmap">
  {
    "imports": {
      "three": "https://cdn.jsdelivr.net/npm/three@v0.173.0/build/three.webgpu.js",
      "three/webgpu": "https://cdn.jsdelivr.net/npm/three@v0.173.0/build/three.webgpu.js",
      "three/tsl": "https://cdn.jsdelivr.net/npm/three@v0.173.0/build/three.webgpu.js",
      "three/addons/": "https://cdn.jsdelivr.net/npm/three@v0.173.0/examples/jsm/"
    }
  }
</script>

<div id="courses"><a href="https://niklever.com/courses" target="_blank">niklever.com/courses</a></div>

<style>
			#source {
				position: absolute;
				top: 0;
				left: 0;
				width: 50%;
				height: 100%;
			}
			#result {
				position: absolute;
				top: 0;
				right: 0;
				width: 50%;
				height: 100%;
			}
			#renderer {
				position: absolute;
				bottom: 15px;
				right: calc( 50% + 15px );
				width: 200px;
				height: 200px;
				z-index: 100;
				pointer-events: none;
			}
		</style>

		<div id="source"></div>
		<div id="result"></div>
		<div id="renderer"></div>

body{
  padding: 0;
  margin: 0;
}

#courses{
  font: bold 30px "Arial";
  position: fixed;
  left: 20px;
  top: 20px;
  color: #ffffff;
  text-decoration: none;
}

a:link {
  color: white;
  text-decoration: none;
}

a:hover{
  color: #dddd33;
  text-decoration: underline;
}

a:visited {
  color: white;
  text-decoration: none;
}

import Transpiler from 'three/addons/transpiler/Transpiler.js';
			import GLSLDecoder from 'three/addons/transpiler/GLSLDecoder.js';
			import TSLEncoder from 'three/addons/transpiler/TSLEncoder.js';

			init();

			function init() {

				// editor

				window.require.config( { paths: { 'vs': 'https://cdn.jsdelivr.net/npm/monaco-editor@0.48.0/min/vs' } } );

				require( [ 'vs/editor/editor.main' ], () => {

					let timeout = null;

					const editorDOM = document.getElementById( 'source' );
					const resultDOM = document.getElementById( 'result' );

					const glslCode = `
varying vec2 vUv;

uniform float uTime;
uniform float uContrast;
uniform float uBrightness;
uniform float uFrequency;
uniform vec3 uPhase;
uniform int uCount;

float mandelbrot( vec2 c )
{
    float c2 = dot(c, c);
    // skip computation inside M1 - https://iquilezles.org/articles/mset1bulb
    if( 256.0*c2*c2 - 96.0*c2 + 32.0*c.x - 3.0 < 0.0 ) return 0.0;
    // skip computation inside M2 - https://iquilezles.org/articles/mset2bulb
    if( 16.0*(c2+2.0*c.x+1.0) - 1.0 < 0.0 ) return 0.0;  

    float B = float(uCount);
    float n = 0.0;
    vec2 z  = vec2(0.0);
    for( int i=0; i<uCount; i++ )
    {
        z = vec2( z.x*z.x - z.y*z.y, 2.0*z.x*z.y ) + c;
        if( dot(z,z)>(B*B) ) break;
        n += 1.0;
    }

    if( n>float(uCount - 1) ) return 0.0;
    
    // ------------------------------------------------------

    // optimized smooth interation count
    float sn = n - log2(log2(dot(z,z))) + 4.0;
    
    return sn;
}

void main(  )
{
    vec3 col = vec3(0.0);
    
    int AA = 2;
    float AAsq = float(AA*AA);

    for( int m=0; m<AA; m++ ){
        for( int n=0; n<AA; n++ )
        {
            vec2 p = (-1.0 + 2.0*(vUv+vec2(float(m) * 0.001,float(n) * 0.001)/float(AA)));
            float w = float(AA*m+n);
            float time = uTime + 0.5*(1.0/24.0)*w/AAsq;
        
            float zoo = 0.72 + 0.28*cos(.09*time);
            float theta = 0.05*(1.0-zoo)*time;
            float coa = cos( theta );
            float sia = sin( theta );
            zoo = pow( zoo, 8.0);
            vec2 xy = vec2( p.x*coa-p.y*sia, p.x*sia+p.y*coa);
            //vec2 c = vec2(-.745,.186) + xy*zoo;
            vec2 c = vec2(-0.720,-0.26) + xy*zoo;

            float l = mandelbrot(c);

            //color(t) = a + b ⋅ cos[ 2π(c⋅t+d)]
            //a: contrast
            //b: brightness
            //c: frequency
            //d: phase

            col += (l<0.5) ? vec3(0.0,0.0,0.0) : 
                uContrast + uBrightness*cos( 6.28*(uFrequency*(l/float(uCount)) + uPhase) );
        }
    }
    col /= AAsq;

    gl_FragColor = vec4( col, 1.0 );
}
`;

					const editor = window.monaco.editor.create( editorDOM, {
						value: glslCode,
						language: 'glsl',
						theme: 'vs-dark',
						automaticLayout: true,
						minimap: { enabled: false }
					} );

					const result = window.monaco.editor.create( resultDOM, {
						value: '',
						language: 'javascript',
						theme: 'vs-dark',
						automaticLayout: true,
						readOnly: true,
						minimap: { enabled: false }
					} );

					const showCode = ( code ) => {

						result.setValue( code );
						result.revealLine( 1 );

					};

					const build = () => {

						try {

							const glsl = editor.getValue();

							const decoder = new GLSLDecoder();
							const encoder = new TSLEncoder();

							const transpiler = new Transpiler( decoder, encoder );
							const tsl = transpiler.parse( glsl );

							showCode( tsl );

						} catch ( e ) {

							result.setValue( 'Error: ' + e.message );

						}

					};

					build();

					editor.getModel().onDidChangeContent( () => {

						if ( timeout ) clearTimeout( timeout );

						timeout = setTimeout( build, 1000 );

					} );

				} );

			}