Count of features in view is inconsistent

[matthew-white]

something's wrong, either with “Showing x of x” points or the “zoom to fit all data” button, or with the pin count on the map. Perhaps the pins in the cluster are being summed incorrectly?

https://jam.dev/c/9fb1f447-330d-4bc5-9be2-28f1c50cc21b

Originally posted by @srujner in #1152

[matthew-white]

Ah good one. I think part of the problem has to do with the initial count. It says "Showing 10,000 of 10,000", but it's just saying that. It doesn't actually check that all 10,000 are visible. It just assumes that all features are initially in view. I think the 6,303 number that's shown later in the video is the more accurate one. The "Showing" number is calculated/checked whenever the center of the map is moved or the zoom level is changed. I don't think clicking the "fit all data" button will recalculate the number unless it causes the center of the map or the zoom level to change.

In terms of why all 10,000 aren't actually in view, I'm assuming that's due to the 85.0 latitude issue. Does that sound right? If no features on the map are beyond 85.0/-85.0, is the count correct/consistent?

Perhaps the pins in the cluster are being summed incorrectly?

I don't think this is the issue, but there is a subtlety in summing clusters that you might find interesting. If a cluster point is in view, then all features within the cluster are included in the sum even if some of the features lie offscreen. That case is most likely when a cluster is close to the edge. In that case, the center point of the cluster is in view, but some of the features within the cluster away from its center point may lie offscreen. I set it up that way because I think it'd be confusing if the sum of the numbers shown within the clusters don't add up to the total "Showing" number.

Originally posted by @matthew-white in #1152

[matthew-white]

@srujner, this should now be fixed. For this form, the map still won't show all features at once. However, it at least won't pretend that it's showing everything. The count should now be accurate. Let me know if you see any cases where the count isn't accurate.

@ktuite tells me that it's expected that it might not be possible for the map to show all features at once. That happens based on:

• How widely distributed around the globe the features are
• The aspect ratio of the map shown in the browser
• The fact that you can no longer move around the map in such a way that panning clones the map. Like you might not even be able to zoom out to see the whole globe at once. That's due to the fix for feat(#305): support select one from map web-forms#491 (comment), which has now been added to the Central map.