fix: Ensure we reset state when changing sources in MultiCOGLayer (#414)

Author: kylebarron

packages/deck.gl-geotiff/src/multi-cog-layer.ts

@@ -307,8 +307,19 @@ export class MultiCOGLayer extends CompositeLayer<MultiCOGLayerProps> {
     });
   }
 
-  override updateState({ changeFlags }: UpdateParameters<this>): void {
-    if (changeFlags.dataChanged || changeFlags.propsChanged) {
+  override updateState({
+    changeFlags,
+    props,
+    oldProps,
+  }: UpdateParameters<this>): void {
+    if (changeFlags.dataChanged || props.sources !== oldProps.sources) {
+      // Reset state so renderLayers() returns null while we re-open COGs.
+      // Without this, the TileLayer renders with new props but stale state,
+      // caching tiles with the wrong bands.
+      this.setState({
+        sources: null,
+        multiDescriptor: null,
+      });
       this._parseAllSources();
     }
   }
@@ -494,6 +505,10 @@ export class MultiCOGLayer extends CompositeLayer<MultiCOGLayerProps> {
       0,
     );
 
+    console.log(
+      `Tile (${x}, ${y}, ${z}): fetched bands [${[...bands.keys()].join(", ")}], total byte length: ${byteLength}`,
+    );
+
     return {
       bands,
       forwardTransform,