debugCheckLive function

void debugCheckLive(Object handle, String operation)

Asserts that handle — a TextureHandle, GeometryBuffer, StorageBuffer, PipelineHandle, ComputePipelineHandle, QuerySet or RenderBundle — has not been disposed, naming operation when it has.

For a backend, at the point it hands the handle to its API: a bind, a draw, a copy, a readback. A disposed handle reaching a driver is a WebGL error the browser logs, a WebGPU validation error a frame later, and on Impeller (whose handles the collector frees) a picture that still draws, so the one place all four can say the same thing is here, before the call. An assertion: a release build pays nothing.

Anything else, a ShaderHandle among it, passes: a stage is handed out by its library, and a pipeline linked from it keeps drawing after it is disposed (see ShaderHandle.dispose).

Implementation

void debugCheckLive(Object handle, String operation) {
  assert(() {
    final disposed = switch (handle) {
      TextureHandle(:final isDisposed) ||
      GeometryBuffer(:final isDisposed) ||
      StorageBuffer(:final isDisposed) ||
      PipelineHandle(:final isDisposed) ||
      ComputePipelineHandle(:final isDisposed) ||
      QuerySet(:final isDisposed) ||
      RenderBundle(:final isDisposed) => isDisposed,
      _ => false,
    };
    if (disposed) {
      throw StateError(
        '$operation: $handle was disposed. A handle may not be used once '
        'its owner has given it back; make another.',
      );
    }
    return true;
  }());
}