captureRenderGraph method

Future<RenderGraphCaptureResult> captureRenderGraph({ int viewIndex = 0, RenderGraphCaptureRequest request = const RenderGraphCaptureRequest(), Duration timeout = const Duration(seconds: 5), })

Captures the next rendered frame of screen view viewIndex: the pass list with CPU timings, the blackboard data flow, and (per request) GPU copies of the textures each pass wrote. Resolves after that frame's graph executes; the caller must ensure a frame renders (schedule one).

Requires debugAllowRenderGraphCapture. A second call before the pending one resolves replaces it, and a capture no frame fulfills within timeout (the view hidden, zero-sized, or the scene not ready) fails instead of hanging its caller; either way the first future completes with an error.

Implementation

Future<RenderGraphCaptureResult> captureRenderGraph({
  int viewIndex = 0,
  RenderGraphCaptureRequest request = const RenderGraphCaptureRequest(),
  Duration timeout = const Duration(seconds: 5),
}) {
  if (!debugAllowRenderGraphCapture) {
    throw StateError(
      'Render graph capture is disabled; set '
      'Scene.debugAllowRenderGraphCapture first.',
    );
  }
  final pending = _pendingGraphCapture;
  if (pending != null) {
    _pendingGraphCapture = null;
    pending.completer.completeError(
      StateError('Superseded by a newer render graph capture'),
    );
  }
  final completer = Completer<RenderGraphCaptureResult>();
  final armed = (
    viewIndex: viewIndex,
    request: request,
    completer: completer,
  );
  _pendingGraphCapture = armed;
  Timer(timeout, () {
    if (!identical(_pendingGraphCapture, armed)) return;
    _pendingGraphCapture = null;
    completer.completeError(
      StateError(
        'Render graph capture timed out; no frame rendered view '
        '$viewIndex (is the viewport visible and the scene ready?)',
      ),
    );
  });
  return completer.future;
}