Excess tile loading in animated setView

[hyperknot]

• excess tile usage when zooming in: fixed with e2fbe19
• excess tile usage when setView, {animate:true}

At a given window resolution, a fully loaded map takes 20 requests. Changing the map takes 20 new requests. Zooming out takes 20 requests. Yet, zooming in takes 48 or 56 requests.

Same with detectRetina: switching basemap, zooming out, takes 64 requests. Yet zooming in takes 192 or 208 requests.

This is not related to retina / detectRetina, it happens with non-retina maps as well.

[yohanboniface]

@hyperknot which version, latest master or released beta2? This should be (at least partly) fixed by e2fbe19

[hyperknot]

@yohanboniface I was testing beta2, I've just tested with e2fbe19 and so far it seems to be using equal amount of requests to 0.7!

[hyperknot]

The only scenario where I see excess (around double) tile usage is when jumping to a remote point via setView + {animate:true}. It still uses about 2x the needed tiles, even when no animation should happen (jumping to the other side of the world). When turning animate off, it's not happening.

[yohanboniface]

I've just tested with e2fbe19 and so far it seems to be using equal amount of requests to 0.7!

Good news :)

It still uses about 2x the needed tiles

Just to appreciate whether it's a blocker for the 1.0 release, is this behaviour also with 0.7, or specific to 1.0?

[hyperknot]

I tested it and setView animate behaviour is the same as with 0.7. Should I close this one and open an issue for setView animate tile usage?

[yohanboniface]

Just rename this one :)
Also, if you can provide a minimal test case too, that'd be really helpful :)

[hyperknot]

I'm working on a test case, but it's really hard to replicate, somehow it's not happening in a minimal case.

[hyperknot]

Did a test case here (I get 31 vs. 9 requests, but it's random):
https://output.jsbin.com/wahoxi#
with editor:
https://jsbin.com/wahoxi/edit?html,js,output

After reading Leaflet's code, I believe this is not a bug, this is what animate: true is supposed to do. Actually, animate is acting something like "forceAnimation", where if it's true, it does an animation even to the other end of the world.

Leaflet/src/map/anim/Map.PanAnimation.js

Line 96 in 3fd2d5c

if ((options && options.animate) !== true && !this.getSize().contains(offset)) { return false; }

and

Leaflet/src/map/anim/Map.PanAnimation.js

Line 49 in 3fd2d5c

if (options.animate !== true && !this.getSize().contains(offset)) {

The best/simplest solution would be to allow the user to set the pan animation threshold like zoomAnimationThreshold is done now. I believe constant multiplies of getSize() would be a reasonable unit, so instead of checking for:
this.getSize().contains(offset)
we could check for
this.getSize().multiplyBy(this.options.panAnimationThreshold).contains(offset)

[IvanSanchez]

@hyperknot I'm guessing #4193 might have fixed this already. Can you please check?

[hyperknot]

@IvanSanchez this is still happening. Animated version gets 15-26 tiles, non-animated 9 always.

What do you think is the best solution here? Calculating average speed during panAnimation and disabling animation if the speed is above a given threshold?