Handle masks in GeoTIFFs

test/rendering/cases/cog-masked/main.js

@@ -0,0 +1,22 @@
+import GeoTIFF from '../../../../src/ol/source/GeoTIFF.js';
+import Map from '../../../../src/ol/Map.js';
+import TileLayer from '../../../../src/ol/layer/WebGLTile.js';
+
+const source = new GeoTIFF({
+  convertToRGB: true,
+  sources: [{url: '/data/raster/masked.tif'}],
+});
+
+new Map({
+  layers: [
+    new TileLayer({
+      source: source,
+    }),
+  ],
+  target: 'map',
+  view: source.getView(),
+});
+
+render({
+  message: 'works with geotiffs that include a mask',
+});