decodeAtlas method
Decodes atlasPixels into the GPU-sampled atlas image. rgba8888 via decodeImageFromPixels is byte-exact (M0-verified); asynchronous, so the strip device defers all drawing to its finish() replay.
Implementation
Future<void> decodeAtlas() {
final completer = Completer<void>();
ui.decodeImageFromPixels(
atlasPixels, atlasWidth, atlasHeight, ui.PixelFormat.rgba8888,
(image) {
atlas = image;
completer.complete();
});
return completer.future;
}