DCM notes for 2026-02-05

[banchan86]

Discussion

• Arrow FrameWriter
• TiffWriter
• HexViewer
• DearImGui 3D plots
• Memory dumps for debugging

[banchan86]

Notes from DCM:

We welcomed @roaldarbol for the first time and discussed proposals for new packages and improvements to Bonsai's debuggability.

• Arrow FrameWriter
  • @bparks13 encountered an issue with using StreamSink, which requires the size of the Mat object to be known before initialization. The issue was resolved by using FileSink instead, which does not have the same limitation.
• TiffWriter
  • Bonsai.Vision.SaveImage supports writing TIFF files, but does not support extended metadata, which is important, for example, in generating TIFF stacks for microscopy
  • @bruno-f-cruz found a .NET wrapper for LibTIFF, which has been working well for generating such stacks.
  • We discussed various options for extending TIFF support in Bonsai using this library, such as including a dedicated TIFF reader/writer in Bonsai.Vision or spinning out a separate Bonsai.LibTIFF package.
• HexViewer
  • @bruno-f-cruz also demonstrated a hexadecimal visualizer he has been working on.
  • This package would be very useful for debugging Harp messages, especially from devices where the interface is still in development.
• DearImGUI 3D plots
  • This discussion arose from a question on Discord by @jonnew about visualizers for Systems.Numerics structs
  • 2D vector visualizations can be done with the RollingGraph operator in Bonsai.Gui.Zedgraph.
  • There is a .NET wrapper for a 3D plot extension for DearImGUI which we could integrate for 3D vectors, but this package is still in pre-release and needs to be tested.
• Memory dumps for debugging
  • Deadlocks/freezes in Bonsai are extremely hard to debug.
  • While a debugger can be attached, sometimes that reduces the frequency of the deadlocks.
  • An alternative is to use memory dumps, which can be viewed with Visual Studio Code, which actually does a good job of reconstructing the stack trace.
  • However, there is still information missing that would be really helpful for interpretation, such as local variable names.
  • We discuss embedding metadata into the expression tree, but it would probably be lost after compilation.
  • It might be possible to apply (reference?) a PDB file on top of the memory dump, which could provide more information, but that needs to be tested.