Matrix cells reset on zoom/reorder

[Kevin Ulrich]

Describe the bug
Matrix cells reset to the original ordering/clustering (clust/clust for row/col) if you zoom after reordering/reclustering.

To Reproduce
Steps to reproduce the behavior:

1. Select a new ordering, such as "sum"
2. After the heatmap finishes reordering, zoom in -- the matrix cells will reset to their original view

Also:

1. Change column ordering to "sum"
2. Change ordering again, say to var
3. The matrix cells will start from a clust/clust ordering instead of the sum/clust ordering.

[Maximilian Koch]

Do we know a little bit more about this? I had a brief look into this, but wasn’t able to find the exact root cause.

[Kevin Ulrich]

Unfortunately I don't have an answer. It does seem strange that the correct buffers and arrays and everything gets sent to webgl, everything interpolates, and then it snaps back when you zoom or pan.

The best guess I have is that somehow some state is not properly being set (or in the right order) and either the "new" arrs is not overwriting the "ini" arrs or something similar. Or, we might be resetting the state back to default somewhere? I would start from the interactions, since that seems to be "causing" the reset, and then trace it from there, looking carefully at the state with Redux devtools.

[Maximilian Koch]

I wonder, if the reassignments of the state could be a factor for this.
In the reducers, I can see quite regularly things like this:

state = action.payload
return state

This mutates the state, instead of returning a new one.
Instead, it should look like this:
return action.payload

EDIT:

I realised, that createSlice is used, which allows direct access to state's properties. But, I think, state = action.payload should just be return action.payload, as we shouldn't set the state this way.

Also have been looking a bit more into _.merge, which seems to be mutable. Seems like one way to go about this might be merge({}, state, action.payload). Unfortunately, whilst this seems to work, this is slowing down the whole app.

[Maximilian Koch]

The final lead to this seems to be remakeMatrixArgs.

This is part of the camerasManager and is being called when the opacity slider is moved. Moving the opacity slider before zooming/reordering does prevent any strange behaviour.

The remakeMatrixArgs needs to be called in the reorderMatrixArgs for this to work.

I'll create a PR tomorrow morning.