zoomOffset from modelMatrix in MultiscaleImageLayer might not be correct?

[jeffpeck10x]

It looks like zoomOffset is coming from the scale of the incoming modelMatrix.

viv/packages/layers/src/multiscale-image-layer/multiscale-image-layer.js

Line 144 in 26e67bf

zoomOffset: Math.round(

This does not work as expected when the scale factor is two-dimensional (i.e. new Matrix4().scale([1, .5]).

But, I am also wondering if this is even necessary. Doesn't the deckgl TileLayer already account for this?

I have not had time to experiment with this, but even just observing the issue of two-dimensional scales, this should at least be updated to defer to whatever the smaller scale is for calculating offset.

[ilan-gold]

@jeffpeck10x Please play around and let me know. If you could share a screenshot that would be great. I actually just made a PR recently here for handling model matrices properly that are like you're describing but I didn't notice anything off at all, and the difference in scaling was much, much worse ([2, 38]). I'll have a think.

[jeffpeck10x]

Ok, I will see what I can find. Unfortunately, I cannot share the screenshots of data that I am noticing issues with this, but once I get a chance to play around, I can try it with something more generic.

What I have found is that it seems to be miscalculating the tiles that need to be rendered when you zoom in. I have noticed it even with [1, .99].

I am starting to wonder if it is indeed the TileLayer that is not working as expected. But, that it is working for you with an extreme scaling like [2, 38] perhaps means that I am doing something differently.

It probably won't be until mid-next week that I dig in further, but I will post here with whatever I find.