[BUG] H2N5 tile source orthoviews misbehaving, possibly due to anisotropic scaling

[clbarnes]

• CATMAID version: 2021.12.21-117-g7510a2cb8
• CATMAID instance: https://neurophyla.mrc-lmb.cam.ac.uk/catmaid/drosophila/l1/igor
• Browser: Chromium
• Operating system: Manjaro linux

Short description

Descending into scale levels with non-power-of-2 downscaling for the first time raises errors if multiple orthoviews are open.

To reproduce

• Navigate to https://neurophyla.mrc-lmb.cam.ac.uk/catmaid/drosophila/l1/igor/?pid=1&zp=0&yp=79035&xp=249595&tool=navigator&sid0=3&s0=7&sid1=2&s1=7&sid2=4&s2=7&sg=2&sgs=7
• Zoom in to scale 2 or below

I've tried lots of combinations of starting with one stack and then adding more before or after zooming for the first time, but can't consistently get it to trigger that way - couldn't detect a pattern.

More information

Note that Igor's N5 stack has isotropic power-of-2 scaling above s3, and scaling as a power of 2 only in XY below that.

After triggering the error for the first time, the viewer is left in a dirty state where more errors are thrown whenever you move.

From the error:

Version: 2021.12.21-117-g7510a2cb8
Error: Cannot read properties of undefined (reading 'position') User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.64 Safari/537.36 Stacktrace: TypeError: Cannot read properties of undefined (reading 'position')
    at PixiTileLayer.redraw (https://neurophyla.mrc-lmb.cam.ac.uk/catmaid/drosophila/l1/igor/static/js/catmaid.1fd00eb70db2.js:26602:14)
    at PixiTileLayer.TileLayer.resize (https://neurophyla.mrc-lmb.cam.ac.uk/catmaid/drosophila/l1/igor/static/js/catmaid.1fd00eb70db2.js:24886:10)
    at PixiTileLayer.resize (https://neurophyla.mrc-lmb.cam.ac.uk/catmaid/drosophila/l1/igor/static/js/catmaid.1fd00eb70db2.js:26684:40)
    at PixiTileLayer.redraw (https://neurophyla.mrc-lmb.cam.ac.uk/catmaid/drosophila/l1/igor/static/js/catmaid.1fd00eb70db2.js:26536:19)
    at StackViewer.redraw (https://neurophyla.mrc-lmb.cam.ac.uk/catmaid/drosophila/l1/igor/static/js/catmaid.1fd00eb70db2.js:9492:15)
    at StackViewer.update (https://neurophyla.mrc-lmb.cam.ac.uk/catmaid/drosophila/l1/igor/static/js/catmaid.1fd00eb70db2.js:9252:10)
    at StackViewer.<anonymous> (https://neurophyla.mrc-lmb.cam.ac.uk/catmaid/drosophila/l1/igor/static/js/catmaid.1fd00eb70db2.js:9614:14)
    at new Promise (<anonymous>)
    at StackViewer.moveToAfterBeforeMoves (https://neurophyla.mrc-lmb.cam.ac.uk/catmaid/drosophila/l1/igor/static/js/catmaid.1fd00eb70db2.js:9613:14)
    at StackViewer.moveTo (https://neurophyla.mrc-lmb.cam.ac.uk/catmaid/drosophila/l1/igor/static/js/catmaid.1fd00eb70db2.js:9649:33)

Workaround

Open a single stack viewer, zoom in to a low scale, then add the other stack viewers. You should be able to move around freely.