These are chat archives for openseadragon/openseadragon

25th
Oct 2018
Kampenuss
@Kampenuss_twitter
Oct 25 2018 16:43
While we were working on the osd fabricjs overlay (here is their demo http://altert.github.io/OpenseadragonFabricjsOverlay/demo.html) I noticed that when I drag the image the drag animation has become "framed", it feels like rendering frame rate has gotten reduced compared to the osd source demo (https://openseadragon.github.io/). As I was messing around with the source demo, I noticed that the drag also gets "framed" when the new tiles are being loaded. After all tiles are loaded, then the drag becomes smooth. Question: my assumption is that there is no way to improve the osd behavior, but is there any trick that we could try so that fabricjs overlay does not mess up osd canvas? It pretty bad, my eyes get dizzy..
Ian Gilman
@iangilman
Oct 25 2018 16:47
So you're experiencing poor performance when you add the Fabric overlay? I don't know, but it certainly seems possible that something could be done!
One thing might be to try the other overlays like canvas and SVG to see how they perform.
Ian Gilman
@iangilman
Oct 25 2018 17:05
@Kampenuss_twitter ^
On another topic (for general discussion): Should we add support for flipping individual images, or is the existing support for flipping the whole viewer enough? openseadragon/openseadragon#1553
Kampenuss
@Kampenuss_twitter
Oct 25 2018 20:32
I gave my input under the issue.
Ian Gilman
@iangilman
Oct 25 2018 20:33
Thanks! :)
Kampenuss
@Kampenuss_twitter
Oct 25 2018 20:33
I tried different overlays (https://openseadragon.github.io/examples/ui-overlays/) and some of them feel better than others.
Which feel better?
Kampenuss
@Kampenuss_twitter
Oct 25 2018 20:38
svg-overlay is absolutely better. The animation gets framed only when the rectangle is visible on the screen.
Ian Gilman
@iangilman
Oct 25 2018 20:39
Cool, but sounds like it's still not ideal.
Is your target machine kind of low powered?
How complicated is your overlay? Just a rectangle?
Kampenuss
@Kampenuss_twitter
Oct 25 2018 20:40
MacBook Pro (Retina, 13-inch, Early 2013)
I am messing around only with the demos. And now I am getting confused. When I said that svg-ovelay is better, I tried for multiple minutes to figure out what is going on, because sometimes it "framed" and sometimes not. Now when I drag at the bottom of the image so that rectangle is not visible, it still "frames". Maybe I have to close all tabs and clear the cache and try again. Do you notice that the animation sometimes is not smooth and that it fells like the animations jumps forward incrementally?
When I'm testing, I am zooming in
Ian Gilman
@iangilman
Oct 25 2018 20:46
I haven't noticed these performance issues, but I'm on a faster computer, so that may account for the difference.
Of course we want it to be fast on every computer if we can!
Kampenuss
@Kampenuss_twitter
Oct 25 2018 22:03
Initially I tested on osd github without maximizing the canvas, and that is when I got a feeling that it is "framing" only until new tiles are loaded. When I tested the sv-overlay demo and altert demo, I did not hit full screen, but the canvas in the demo are maximized already, so the comparison was not fair. Now when I am testing the osd github demo I also have the "framing" on the full screen even after all the tiles are loaded. I recorded a video with my phone to show what is going on, but it is useless, because the video frame rate is too low, it looks like the animation is "framing" all the time :). This happens both on MacOS Chrome and Firfox, and Safari. I am surprised because it has 8GB of RAM. Surprising is that sometimes it gets smooth without opening/ closing browser tabs or applications. I tested this on another PC and all demos are smooth. It has to be the issue with the machine!