[uv-scroll] create a separate repo

[vincentfretin]

This is a modified version of the uv-scroll.js hubs code that can be used with the aframe material component. Changes required were to use an aframe system and waiting for material to be loaded via the materialtextureloaded event.
Licensed under MPL 2.0

Usage:

• https://hubs.mozilla.com/labs/animating-textures-with-the-uv-scroll-component-pt1/
• https://hubs.mozilla.com/labs/animating-textures-using-the-uv-scroll-component-part-2/ and tweet
• https://hubs.mozilla.com/labs/animating-textures-using-the-uv-scroll-component-part-3/ and tweet

[vincentfretin]

I need to create a new repo in the c-frame organization with some examples how to use it with aframe, and publish to npm.

Here is the full code of the modified version:

/* global AFRAME, THREE */
// This is a modified copy of
// https://github.com/mozilla/hubs/blob/6c49ce303ad7e030c80b301dbc3ce100cac7d9c1/src/components/uv-scroll.js
// to work with an aframe system and waiting for material to be loaded via the materialtextureloaded event.
// @license MPL 2.0 https://github.com/mozilla/hubs/blob/master/LICENSE

const textureToData = new Map();
const registeredTextures = [];

AFRAME.registerSystem("uv-scroll", {
  tick(t, dt) {
    for (let i = 0; i < registeredTextures.length; i++) {
      const map = registeredTextures[i];
      const { offset, instances } = textureToData.get(map);
      const { component } = instances[0];

      offset.addScaledVector(component.data.speed, dt / 1000);

      offset.x = offset.x % 1.0;
      offset.y = offset.y % 1.0;

      const increment = component.data.increment;
      map.offset.x = increment.x ? offset.x - (offset.x % increment.x) : offset.x;
      map.offset.y = increment.y ? offset.y - (offset.y % increment.y) : offset.y;
    }
  },
});

/**
 * Animate the UV offset of a mesh's material
 * @component uv-scroll
 */
AFRAME.registerComponent("uv-scroll", {
  schema: {
    speed: { type: "vec2", default: { x: 0, y: 0 } },
    increment: { type: "vec2", default: { x: 0, y: 0 } },
  },
  play() {
    const mesh = this.el.getObject3D("mesh") || this.el.getObject3D("skinnedmesh");
    const material = mesh && mesh.material;
    if (material) {
      // We store mesh here instead of the material directly because we end up swapping out the material in injectCustomShaderChunks.
      // We need material in the first place because of MobileStandardMaterial
      const instance = { component: this, mesh };

      this.instance = instance;
      this.map = material.map || material.emissiveMap;

      if (this.map && !textureToData.has(this.map)) {
        textureToData.set(this.map, {
          offset: new THREE.Vector2(),
          instances: [instance],
        });
        registeredTextures.push(this.map);
      } else if (!this.map) {
        if (this.el.components.material) {
          // when using material and uv-scroll components
          this.el.addEventListener("materialtextureloaded", () => {
            this.map = material.map || material.emissiveMap;
            if (!textureToData.has(this.map)) {
              textureToData.set(this.map, {
                offset: new THREE.Vector2(),
                instances: [instance],
              });
              registeredTextures.push(this.map);
            }
          });
        } else {
          console.warn(
            "Ignoring uv-scroll added to mesh with no scrollable texture."
          );
        }
      } else {
        console.warn(
          "Multiple uv-scroll instances added to objects sharing a texture, only the speed/increment from the first one will have any effect"
        );
        textureToData.get(this.map).instances.push(instance);
      }
    }
  },

  pause() {
    if (this.map) {
      const instances = textureToData.get(this.map).instances;
      instances.splice(instances.indexOf(this.instance), 1);
      // If this was the last uv-scroll component for a given texture
      if (!instances.length) {
        textureToData.delete(this.map);
        registeredTextures.splice(registeredTextures.indexOf(this.map), 1);
      }
    }
  },
});

[vincentfretin]

Demo: https://aframe-uvscroll.glitch.me
Glitch: https://glitch.com/edit/#!/aframe-uvscroll

<a-entity
  position="0 1.6 -2"
  geometry="primitive:plane;width:0.5;height:0.598"
  material="src:howtousetrigger.jpg;shader:flat;repeat: 0.5 1"
  uv-scroll="increment: 0.5 0; speed: 0.5 0"
></a-entity>

[vincentfretin]

Moved to https://github.com/c-frame/aframe-gltf-model-plus/blob/main/src/components/uv-scroll.js
Some doc and example should be done in the aframe-gltf-model-plus repo.