Layer texture filtering.

Illustrates various texture filtering modes on layers.

Filter

0% © EOX

index.js

import { LinearFilter, NearestFilter, Vector3 } from "three";
import { MapControls } from "three/examples/jsm/controls/MapControls.js";

import Instance from "@giro3d/giro3d/core/Instance.js";
import Extent from "@giro3d/giro3d/core/geographic/Extent.js";
import ColorLayer from "@giro3d/giro3d/core/layer/ColorLayer.js";
import Map from "@giro3d/giro3d/entities/Map.js";
import Inspector from "@giro3d/giro3d/gui/Inspector.js";
import GeoTIFFSource from "@giro3d/giro3d/sources/GeoTIFFSource.js";

function bindDropDown(id, onChange) {
  const element = document.getElementById(id);
  if (!(element instanceof HTMLSelectElement)) {
    throw new Error(
      "invalid binding element: expected HTMLSelectElement, got: " +
        element.constructor.name,
    );
  }

  element.onchange = () => {
    onChange(element.value);
  };

  const callback = (v) => {
    element.value = v;
    onChange(element.value);
  };

  const setOptions = (options) => {
    const items = options.map(
      (opt) =>
        `<option value=${opt.id} ${opt.selected ? "selected" : ""}>${opt.name}</option>`,
    );
    element.innerHTML = items.join("\n");
  };

  return [callback, element.value, element, setOptions];
}

const extent = new Extent(
  "EPSG:3857",
  1818329.448,
  1987320.77,
  6062229.082,
  6231700.791,
);

const instance = new Instance({
  target: "view",
  crs: extent.crs,
  backgroundColor: "black",
});

const center = new Vector3(1911960, 6130719, 2156);

instance.view.camera.position.set(center.x, center.y, center.z);

const controls = new MapControls(instance.view.camera, instance.domElement);
controls.enableDamping = true;
controls.dampingFactor = 0.2;
controls.target.set(center.x, center.y + 1, 0);
instance.view.setControls(controls);

const map = new Map({ extent, backgroundOpacity: 0 });

instance.add(map);

const source = new GeoTIFFSource({
  url: "https://3d.oslandia.com/giro3d/rasters/TCI-YCbCr-mask.tif",
  crs: extent.crs,
});

let filter = LinearFilter;

function run() {
  map.forEachLayer((layer) => map.removeLayer(layer, { disposeLayer: true }));

  map.addLayer(
    new ColorLayer({
      source,
      minFilter: filter,
      magFilter: filter,
    }),
  );
}

Inspector.attach("inspector", instance);

bindDropDown("filter", (v) => {
  switch (v) {
    case "nearest":
      filter = NearestFilter;
      break;
    case "linear":
      filter = LinearFilter;
      break;
  }

  run();
});

run();

index.html

<!doctype html>
<html lang="en">
  <head>
    <title>Layer texture filtering.</title>
    <meta charset="UTF-8" />
    <meta name="name" content="layer_texture_filter" />
    <meta
      name="description"
      content="Illustrates various texture filtering modes on layers."
    />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />

    <link rel="icon" href="https://giro3d.org/images/favicon.svg" />
    <link
      href="https://giro3d.org/assets/bootstrap-custom.css"
      rel="stylesheet"
    />
    <script src="https://giro3d.org/assets/bootstrap.bundle.min.js"></script>
    <link
      rel="stylesheet"
      type="text/css"
      href="https://giro3d.org/latest/examples/css/example.css"
    />
  </head>

  <body>
    <div id="view" class="m-0 p-0 w-100 h-100"></div>
    <div
      id="inspector"
      class="position-absolute top-0 start-0 mh-100 overflow-auto"
    ></div>

    <div class="side-pane-with-status-bar">
      <div class="card">
        <div class="card-body">
          <div class="input-group">
            <span class="input-group-text flex-grow-1">Filter</span>
            <select
              class="btn btn-outline-primary btn-sm"
              id="filter"
              autocomplete="off"
            >
              <option selected value="linear">Linear filtering</option>
              <option value="nearest">Nearest neighbour</option>
            </select>
          </div>
        </div>
      </div>
    </div>

    <script type="module" src="index.js"></script>
    <script>
      /* activate popovers */
      const popoverTriggerList = [].slice.call(
        document.querySelectorAll('[data-bs-toggle="popover"]'),
      );
      popoverTriggerList.map(
        // bootstrap is used as script in the template, disable warning about undef
        // eslint-disable-next-line no-undef
        (popoverTriggerEl) =>
          new bootstrap.Popover(popoverTriggerEl, {
            trigger: "hover",
            placement: "left",
            content: document.getElementById(
              popoverTriggerEl.getAttribute("data-bs-content"),
            ).innerHTML,
            html: true,
          }),
      );
    </script>
  </body>
</html>

package.json

{
    "name": "layer_texture_filter",
    "dependencies": {
        "@giro3d/giro3d": "0.43.2"
    },
    "devDependencies": {
        "vite": "^3.2.3"
    },
    "scripts": {
        "start": "vite",
        "build": "vite build"
    }
}