Prevent flickering when adding/removing annotations

[kkaefer]

When adding a new annotation, tiles that contain this annotation are flickering because we are removing the tile, and parsing the new tile may still take a frame or two. Instead of removing the tile, we should reparse the tile and update the bucket as required.

I'm still noticing this for both adding & removing annotations. (iOS)

[incanus]

@jfirebaugh Would you have time to look into this sometime, at least to scope the work required?

[incanus]

This is pretty satisfactory right now. See #1798 (comment).

[parrots]

Regarding comment about #1798 demo seemingly addressing flickering, made a PR to Justin's sample project to show the flickering is still there. See here: incanus/UISyncedMap#1 which just zooms out the map to show the entire user route.

Ideal outcomes, as far as I'd see, besides just "make it faster" which could always still have a visible flicker on old hardware or with enough complex data:

• Find a way to not remove the old drawn layer until the new version can be swapped in so there is 0.1 seconds of stale data vs 0.1 seconds of empty space.
• Only redraw the annotations that were modified.

[mourner]

Find a way to not remove the old drawn layer until the new version can be swapped in so there is 0.1 seconds of stale data vs 0.1 seconds of empty space.

This is what GL JS does currently, which is good enough for use cases like mouse-driven polylines etc.

[pkmital]

We're still experiencing issues with flickering for our use case. We are drawing a polyline of about 100 points, and are constantly removing it and redrawing it with each update, though require updating the polyline so often as we are changing only the last few points of the line.

[maciekish]

We're also experiencing this issue in 294b307. When the user pans our map we reload search results and the experience is horrible. The idea suggested by @mourner sounds like a very good one. cc @Zakay

[incanus]

Going to have to move this from the current iOS milestone as it's non-blocking.