对自定义 WebGL 图层视图的切片支持

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const CustomLayer = Layer.createSubclass({
  tileInfo: TileInfo.create({ size: 512, spatialReference: { wkid: 3857 } }),

  createLayerView(view) {
    if (view.type === "2d") {
      return new CustomLayerView2D({
        view: view,
        layer: this
      });
    }
  }
});

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const CustomLayerView2D = BaseLayerViewGL2D.createSubclass({
  ...

  render(renderParameters) {
    ...

    for (let i = 0; i < this.tiles.length; i++) {
      // Retrieve the current tile and its associated texture.
      const tile = this.tiles[i];

      ...

      // Draw the tile.
      gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_SHORT, 0);
    }
  },

  ...

  tilesChanged() {
    // Respond to a change in the tile screen coverage, for
    // instance by fetching the required data from a server.
  }
});