spark/examples/glsl/index.html

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<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>Spark • GLSL Shaders</title>
  <style>
    body {
      margin: 0;
    }
    canvas {
      touch-action: none;
    }
  </style>
</head>

<body>
  <script type="importmap">
    {
      "imports": {
        "three": "/examples/js/vendor/three/build/three.module.js",
        "@sparkjsdev/spark": "/dist/spark.module.js"
      }
    }
  </script>
  <script type="module">
    import * as THREE from "three";
    import { SparkControls, SplatMesh, dyno } from "@sparkjsdev/spark";
    import { getAssetFileURL } from "/examples/js/get-asset-url.js";

    const scene = new THREE.Scene();
    const camera = new THREE.PerspectiveCamera(60, window.innerWidth / window.innerHeight, 0.1, 1000);
    const renderer = new THREE.WebGLRenderer();
    renderer.setSize(window.innerWidth, window.innerHeight);
    document.body.appendChild(renderer.domElement);

    window.addEventListener('resize', onWindowResize, false);
    function onWindowResize() {
      camera.aspect = window.innerWidth / window.innerHeight;
      camera.updateProjectionMatrix();
      renderer.setSize(window.innerWidth, window.innerHeight);
    }

    const splatURL = await getAssetFileURL("butterfly.spz");
    const butterfly = new SplatMesh({ url: splatURL });
    butterfly.quaternion.set(1, 0, 0, 0);
    butterfly.position.set(0, 0, -1.5);
    scene.add(butterfly);

    // A Gsplat type is defined in GLSL in src/dyno/splats.ts as follows:
    // struct Gsplat {
    //   vec3 center;
    //   uint flags;
    //   vec3 scales;
    //   int index;
    //   vec4 quaternion;
    //   vec4 rgba;
    // };
    // const uint GSPLAT_FLAG_ACTIVE = 1u << 0u;

    // Inject GLSL color shader into world-space SplatMesh modifier
    butterfly.worldModifier = new dyno.Dyno({
      inTypes: { gsplat: dyno.Gsplat },
      outTypes: { gsplat: dyno.Gsplat },
      globals: () => [dyno.unindent(`
        vec3 waveRgb(vec3 pos) {
          return vec3(
            0.6 + 0.4 * sin(pos.x * 56.0),
            0.6 + 0.4 * sin(pos.y * 78.0),
            0.6 + 0.4 * cos(pos.z * 90.0)
          );
        }
      `)],
      statements: ({ inputs, outputs }) => dyno.unindentLines(`
        ${outputs.gsplat} = ${inputs.gsplat};
        ${outputs.gsplat}.rgba.rgb *= waveRgb(${inputs.gsplat}.center);
      `),
    });

    // Inject DynoBlock with embedded GLSL shader that uses an external
    // uniform value animateT to control motion. Any GLSL statements can only
    // uses references provided in inputs + outputs, so we create a DynoBlock
    // that allows us to get `t` as an input parameter to our GLSL block.
    const animateT = dyno.dynoFloat(0);

    butterfly.objectModifier = dyno.dynoBlock(
      { gsplat: dyno.Gsplat },
      { gsplat: dyno.Gsplat },
      ({ gsplat }) => {
        // Create an inline GLSL block that has all the inputs we need
        const d = new dyno.Dyno({
          inTypes: { gsplat: dyno.Gsplat, t: "float" },
          outTypes: { gsplat: dyno.Gsplat },
          globals: () => [
            dyno.unindent(`
              float warpRadial(float r, float t) {
                return r * (1.0 + 0.1 * sin(r * 15.0 + t * 3.0));
              }
              vec3 warp(vec3 pos, float t) {
                float r = length(pos);
                float newR = warpRadial(r, t);
                return pos * (newR / r);
              }
            `)
          ],
          statements: ({ inputs, outputs }) => dyno.unindentLines(`
            ${outputs.gsplat} = ${inputs.gsplat};
            ${outputs.gsplat}.center = warp(${inputs.gsplat}.center, ${inputs.t});
          `),
        });
        // Apply the GLSL block with appropriate inputs and return the output
        gsplat = d.apply({ gsplat, t: animateT }).gsplat;
        return { gsplat };
      },
    );

    // Make sure to update the generator after updating modifiers
    butterfly.updateGenerator();

    const controls = new SparkControls({ canvas: renderer.domElement });
    renderer.setAnimationLoop(function animate(time) {
      animateT.value = time / 1000;
      butterfly.updateVersion();

      controls.update(camera);
      renderer.render(scene, camera);
    });
  </script>
</body>

</html>