lag in 4.2.1

[Sky]

so, here: https://www.youtube.com/watch?v=9Wr7a1RJ8Y8

not the best example, but, look at the mana regenerating. This is me doing a R&[enter]

what is normally a flash, now takes several seconds.

I have plenty of time to cast light, read the message "you are surrounded by light or whatever" and then a couple seconds go by, THEN the room lights up.

[Ingwe Ingweron]

The lag is pretty severe. Just lost a quite promising @ on angband.live due to the lag. Extra keypress. Damnit! Quite frustrating.

[Nick]

The lag is pretty severe. Just lost a quite promising @ on angband.live due to the lag. Extra keypress. Damnit! Quite frustrating.

Do you have any idea whether this was game lag, or internet lag? The first I have some control over (and will look into), the second not so much.

[Sky]

it's offline lag. mine is on my own pc, not on .live

[Ingwe Ingweron]

Do you have any idea whether this was game lag, or internet lag? The first I have some control over (and will look into), the second not so much.

I'm pretty sure it is game lag. It appears indicative only to 4.2.1.

[Nick]

Well, I've filed it as an issue. Any sense of whether it's been in the nightlies for a while, or is recent?

[Cuboideb]

I've noticed the thing with 'R'est for a while, never give it importance until now.

[Nick]

Preliminary investigations lead me to the following conclusions:

• A lot of the real-world time passing during resting is because of the game updating noise and scent, which doesn't actually need updating while the player is not resting. Fixing this speeds things up a bit.
• Shockbolt tiles are a huge overhead, apparently largely due to having to allow for double-height tiles. I timed resting for 3000 turns, with these results:
  • Ascii - 4 seconds
  • Gervais tiles - 4 seconds
  • Shockbolt tiles - 26 seconds
  This is rough, and in fact the time depends on other things - I tested again with less monsters in view, and Shockbolt came down to about 10 seconds. This was all done with the noise update fix in place; without that, it was about 50% longer.
• I was unable to detect any lack of responsiveness to commands, except for when I had the delay factor set high so that things like room-lighting were slow.

[wobbly]

[/LIST][*]I was unable to detect any lack of responsiveness to commands, except for when I had the delay factor set high so that things like room-lighting were slow.[/LIST]

So I tried a bit online & I dropped the delay factor from the default 40 down to 3. It's better, particularly when running down a corridor but I still get a fair bit of lag if I enter a large room with monsters in it. The whole 4.x series is noticeably laggier online then older versions, I haven't played much of 4.2.1 so I'm unsure whether its getting better or worse.

[Nick]

So I tried a bit online & I dropped the delay factor from the default 40 down to 3. It's better, particularly when running down a corridor but I still get a fair bit of lag if I enter a large room with monsters in it. The whole 4.x series is noticeably laggier online then older versions, I haven't played much of 4.2.1 so I'm unsure whether its getting better or worse.

Yes, this is unsurprising. I think there are three main things that account for it, which were deliberate design decisions on my part:

1. More frequent screen updates, so that the player can see monsters moving while they are running or resting;
2. More detailed monster AI, or more precisely less shortcuts in monster AI;
3. Sacrifice of efficiency for readability of code.

All these I deemed to be reasonable on the grounds of improving the game (and its maintainability) at the expense of efficiencies which were no longer required because of increase in computer speeds since Angband was first written.

None of this is to say that efficiencies can't be made (and the noise update one I mentioned is an example), but at a certain point it becomes a trade-off between efficiency and other game features. And I'm a bit reluctant to cut features which improve the quality and immersion of the game for the sake of those who are choosing to use massively inefficient graphical tiles or transmit all their keystrokes halfway around the planet before they have an effect

[Sky]

the lag, i can tell you is not tied to resting, but very likely to mobs sleeping. Because - while the video is of me resting (as i do not know when i'll run into a ton of mobs sleeping, dont want to keep the recording running and then have to trim a 17Gb file) - this mostly happens when there are mobs sleeping nearby. It *also* happens when i rest, but try to enter a vault and you will see. Think, 5 seconds to be able to do 1 move.

[Gwarl]

Yes, this is unsurprising. I think there are three main things that account for it, which were deliberate design decisions on my part:

1. More frequent screen updates, so that the player can see monsters moving while they are running or resting;
2. More detailed monster AI, or more precisely less shortcuts in monster AI;
3. Sacrifice of efficiency for readability of code.

All these I deemed to be reasonable on the grounds of improving the game (and its maintainability) at the expense of efficiencies which were no longer required because of increase in computer speeds since Angband was first written.

None of this is to say that efficiencies can't be made (and the noise update one I mentioned is an example), but at a certain point it becomes a trade-off between efficiency and other game features. And I'm a bit reluctant to cut features which improve the quality and immersion of the game for the sake of those who are choosing to use massively inefficient graphical tiles or transmit all their keystrokes halfway around the planet before they have an effect

I'm of the mind to do some purely abstract numerate hacking, if you can specify the inefficient functions I can give it a try. Particularly if we can decouple it for testing.

I know I should be doing various other stuff but an abstract problem like algorithmic efficiency might be relaxing.

[geoff_tewierik]

I noticed lag recently in my game on my laptop and taking note of others post, I wondered what had triggered it.

Once I moved a bit further down the corridor I came across a pack of hounds, so I wonder whether that was the cause? Were they sleeping?

Sorry, no save file.

[Cuboideb]

And I'm a bit reluctant to cut features which improve the quality and immersion of the game for the sake of those who are choosing to use massively inefficient graphical tiles or transmit all their keystrokes halfway around the planet before they have an effect

It's okay. The shockbolt tiles are very resource-intensive. For android I had to break the tileset into 8 smaller pages, storing the tiles in a secondary less-recently-used cache to load and resize just what is needed.

I've noticed that the game do more refreshs when the size of the tiles is greater than 1 (more chance to have garbage on the screen). And... shockbolt has double sized tiles. That's a lot of overhead.

[Sideways]

All these I deemed to be reasonable on the grounds of improving the game (and its maintainability) at the expense of efficiencies which were no longer required because of increase in computer speeds since Angband was first written.

Old V had many efficiencies, but also many efficiency options for turning them on or off as needed and desired; and while AI or code modifications are a bit hard to just toggle on or off, that solution would still work for screen update frequency.