akarpenko.github.io/index.html at main · akarpenko/akarpenko.github.io · GitHub

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<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="
           initial-scale=1.0,
           maximum-scale=1.0,
           user-scalable=no">
  <title>Plasma Globe</title>
  <style>
    html,
    body {
      zoom: 1.06;
      margin: 0;
      padding: 0;
      width: 100%;
      height: 100%;
      overflow: hidden;
      /* disable scrolling */
      display: flex;
      justify-content: center;
      /* horizontal centering */
      align-items: center;
      /* vertical centering */
    }

    canvas {
      display: block;
      /* remove inline whitespace */
      /* you can force it to always cover the screen: */
      width: 100%;
      height: 100%;
      /* or let it size itself, up to you: */
      /* max-width: 100%; max-height: 100%; */
    }

    html,
    body,
    canvas {
      touch-action: none;
      /* disable all default touch gestures (pan/zoom) */
    }
  </style>
</head>

<body>
  <canvas id="glcanvas"></canvas>
  <script type="module">
    //import * as THREE from 'three';
    import * as THREE from 'https://cdn.jsdelivr.net/npm/three@0.152.2/build/three.module.js';


    // 1) Renderer + WebGL canvas
    const canvas = document.getElementById('glcanvas');
    const renderer = new THREE.WebGLRenderer({ canvas });
    renderer.setPixelRatio(window.devicePixelRatio);

    // 2) Scene & camera
    const scene = new THREE.Scene();
    const camera = new THREE.Camera();
    camera.position.z = 1;

    // 3) Geometry
    const geometry = new THREE.PlaneGeometry(2, 2);

    // 4) Uniforms
    const uniforms = {
      iTime: { value: 0.0 },
      iResolution: { value: new THREE.Vector2() },
      iMouse: { value: new THREE.Vector4(0, 0, 0, 0) },
      iChannel0: { value: null }
    };

    const MAX_TOUCHES = 8;
    const touches = new Map();

    uniforms.iTouchCount = { value: 0 };
    uniforms.iTouches = {
      value: Array.from({ length: MAX_TOUCHES }, () => new THREE.Vector2())
    };


    // load a noise texture for iChannel0
    new THREE.TextureLoader().load('noise.png', tex => {
      tex.wrapS = tex.wrapT = THREE.RepeatWrapping;
      tex.generateMipmaps = true;
      tex.minFilter = THREE.LinearMipMapLinearFilter;
      tex.magFilter = THREE.LinearFilter;
      uniforms.iChannel0.value = tex;
    });

    // 5) ShaderMaterial
    const material = new THREE.ShaderMaterial({
      uniforms,
      vertexShader: /* glsl */`
        varying vec2 vUv;
        void main() {
          vUv = uv;
          gl_Position = vec4(position, 1.0);
        }
      `,
      fragmentShader: /* glsl */`
        precision highp float;
        varying vec2 vUv;
        uniform float iTime;
        uniform vec2 iResolution;
        uniform vec4 iMouse;
        uniform int  iTouchCount;
        uniform vec2 iTouches[8];
        uniform sampler2D iChannel0;

        #define ENABLE_MOUSE 1
        #define NUM_RAYS 12.
        #define VOLUMETRIC_STEPS 19
        #define MAX_ITER 35
        #define FAR 6.
        #define time iTime * 1.1

        mat2 mm2(float a){
          float c = cos(a), s = sin(a);
          return mat2(c,-s, s,c);
        }
        float hash(float n){ return fract(sin(n)*43758.5453); }
        float noise(float x){
          return texture2D(iChannel0, vec2(x*0.01, 1.0)).x;
        }
        float noise(vec3 p){
          vec3 ip = floor(p), fp = fract(p);
          fp = fp*fp*(3.0-2.0*fp);
          vec2 tap = (ip.xy + vec2(37.0,17.0)*ip.z) + fp.xy;
          vec2 rg  = texture2D(iChannel0, (tap + 0.5)/256.0).yx;
          return mix(rg.x, rg.y, fp.z);
        }
        mat3 m3 = mat3(
           0.00,  0.80,  0.60,
          -0.80,  0.36, -0.48,
          -0.60, -0.48,  0.64
        );
        float flow(vec3 p, float t){
          float z=2., rz=0.;
          vec3 bp = p;
          for(float i=1.; i<5.; i++){
            p += time*0.1;
            rz += (sin(noise(p + t*0.8)*6.0)*0.5 + 0.5)/z;
            p = mix(bp, p, 0.6);
            z *= 2.0; p *= 2.01; p *= m3;
          }
          return rz;
        }
        float sins(float x){
          float rz=0., z=2.;
          for(float i=0.; i<3.; i++){
            rz += abs(fract(x*1.4)-0.5)/z;
            x  *= 1.3;
            z  *= 1.15;
            x  -= time*0.65*z;
          }
          return rz;
        }
        float segm(vec3 p, vec3 a, vec3 b){
          vec3 pa = p - a, ba = b - a;
          float h = clamp(dot(pa,ba)/dot(ba,ba), 0.0, 1.0);
          return length(pa - ba*h)*0.5;
        }
        vec3 path(float i, float d, vec3 hit){
          vec3 en = vec3(0.,0.,1.);
          float sns2 = sins(d + i*0.5)*0.22;
          float sns  = sins(d + i*0.6)*0.21;
          if(dot(hit,hit)>0.0){
            hit.xz *= mm2(sns2*0.5);
            hit.xy *= mm2(sns*0.3);
            return hit;
          }
          en.xz *= mm2((hash(i*10.569)-0.5)*6.2 + sns2);
          en.xy *= mm2((hash(i*4.732)-0.5)*6.2  + sns);
          return en;
        }
        vec2 map(vec3 p, float i, vec3 hit){
          vec3 bg = vec3(0.0), p0 = p;
          float lp = length(p);
          vec3 en = path(i, lp, hit);
          float ins = smoothstep(0.11,0.46,lp);
          float outs = 0.15 + smoothstep(0.0,0.15,abs(lp-1.0));
          p *= ins*outs;
          float rz = segm(p, bg, en) - 0.011;
          return vec2(rz, ins*outs);
        }
        float march(vec3 ro, vec3 rd, float startf, float maxd, float j, vec3 hit){
          float precis = 0.001, h = 0.5, d = startf;
          for(int i=0; i<MAX_ITER; i++){
            if(abs(h)<precis || d>maxd) break;
            d += h*1.2;
            h  = map(ro + rd*d, j, hit).x;
          }
          return d;
        }
        vec3 vmarch(vec3 ro, vec3 rd, float j, vec3 orig, vec3 hit){
          vec3 p = ro, sum = vec3(0.0);
          for(int i=0; i<VOLUMETRIC_STEPS; i++){
            vec2 r = map(p, j, hit);
            p += rd*0.03;
            float lp = length(p);
            vec3 col = sin(vec3(1.05,2.5,1.52)*3.94 + r.y)*0.85 + 0.4;
            col *= smoothstep(0.0,0.015,-r.x);
            col *= smoothstep(0.04,0.2,abs(lp-1.1));
            col *= smoothstep(0.1,0.34,lp);
            sum += abs(col)*5.0*(1.2 - noise(lp*2.0 + j*13.0 + time*5.0)*1.1)
                   / (log(distance(p,orig)-2.0) + 0.75);
          }
          return sum;
        }
        vec2 iSphere2(vec3 ro, vec3 rd){
          vec3 oc = ro;
          float b = dot(oc,rd), c = dot(oc,oc)-1.0;
          float h = b*b - c;
          if(h<0.0) return vec2(-1.0);
          return vec2((-b - sqrt(h)), (-b + sqrt(h)));
        }

        void main(){
          // normalized pixel coords
          vec2 fragCoord = vUv * iResolution;
          vec2 p = fragCoord / iResolution - 0.5;
          p.x *= iResolution.x / iResolution.y;
          vec2 um = iMouse.xy / iResolution - 0.5;
          um.x *= iResolution.x / iResolution.y;

          // camera
          vec3 ro = vec3(0.0,0.0,5.0);
          vec3 rd = normalize(vec3(p*0.7, -1.5));
          mat2 mx = mm2(time*0.4), my = mm2(time*0.3);
          ro.xz *= mx; rd.xz *= mx;
          ro.xy *= my; rd.xy *= my;
          vec3 bro = ro, brd = rd;
          vec3 col = vec3(0.0125,0.0,0.025);

          // volumetric rays
          for(float j=1.0; j<NUM_RAYS+1.0; j++){
            ro = bro; rd = brd;
            float rz = march(ro, rd, 2.5, FAR, j, vec3(0.0));
            if(rz < FAR){
              vec3 pos = ro + rd*rz;
              col = max(col, vmarch(pos, rd, j, bro, vec3(0.0)));
            }
          }

          #if ENABLE_MOUSE
          for (int ti = 0; ti < 8; ti++) {
            if (ti >= iTouchCount) break;
            // normalized and aspect-corrected touch coord
            vec2 um = iTouches[ti] / iResolution - 0.5;
            um.x *= iResolution.x / iResolution.y;

            // cast a mouse-ray for this touch
            vec3 hit = vec3(0.0);
            vec3 rdm = normalize(vec3(um * 0.7, -1.5));
            rdm.xz *= mx;
            rdm.xy *= my;

            // sphere intersection
            vec2 sph = iSphere2(bro, rdm);
            if (sph.x > 0.0) {
              vec3 hpos = bro + sph.x * rdm;
              float  j   = NUM_RAYS + 1.0 + float(ti);
              ro = bro; rd = brd;
              float rz = march(ro, rd, 2.5, FAR, j, hpos);
              if (rz < FAR) {
                vec3 pos = ro + rd * rz;
                col = max(col, vmarch(pos, rd, j, bro, hpos));
              }
            }
          }
          #endif

          // add reflective sphere flow
          ro = bro; rd = brd;
          vec2 sph = iSphere2(ro, rd);
          if(sph.x>0.0){
            vec3 rf  = reflect(rd, normalize(ro + rd*sph.x));
            vec3 rf2 = reflect(rd, normalize(ro + rd*sph.y));
            float nz  = -log(abs(flow(rf*1.2, time)-0.01));
            float nz2 = -log(abs(flow(rf2*1.2,-time)-0.01));
            col += (0.1*nz*nz*vec3(0.12,0.12,0.5) +
                    0.05*nz2*nz2*vec3(0.55,0.2,0.55))*0.8;
          }

          gl_FragColor = vec4(col*1.3, 1.0);
        }
      `,
    });

    // 6) Mesh + add to scene
    const quad = new THREE.Mesh(geometry, material);
    scene.add(quad);

    // 7) Resize handler
    function onResize() {
      renderer.setSize(window.innerWidth, window.innerHeight);
      uniforms.iResolution.value.set(window.innerWidth, window.innerHeight);
    }
    window.addEventListener('resize', onResize);
    onResize();

    function updateTouches() {
      let idx = 0;
      const H = renderer.domElement.clientHeight;
      for (let [id, pos] of touches) {
        if (idx >= MAX_TOUCHES) break;
        // flip Y to bottom‐origin
        uniforms.iTouches.value[idx].set(pos.x, H - pos.y);
        idx++;
      }
      uniforms.iTouchCount.value = idx;
    }

    canvas.addEventListener('pointerdown', e => {
      touches.set(e.pointerId, { x: e.clientX, y: e.clientY });
      updateTouches();
    });
    canvas.addEventListener('pointermove', e => {
      if (!touches.has(e.pointerId)) return;
      touches.get(e.pointerId).x = e.clientX;
      touches.get(e.pointerId).y = e.clientY;
      updateTouches();
    });
    canvas.addEventListener('pointerup', e => { touches.delete(e.pointerId); updateTouches(); });
    canvas.addEventListener('pointercancel', e => { touches.delete(e.pointerId); updateTouches(); });

    // 9) Animate
    const clock = new THREE.Clock();
    function render() {
      uniforms.iTime.value = clock.getElapsedTime();
      renderer.render(scene, camera);
      requestAnimationFrame(render);
    }
    requestAnimationFrame(render);

    // disable Safari pinch/zoom gestures
    window.addEventListener('gesturestart',  e => e.preventDefault());
    window.addEventListener('gesturechange', e => e.preventDefault());
    window.addEventListener('gestureend',    e => e.preventDefault());
  </script>
</body>

</html>