Author Topic: Mouse jittery?  (Read 5468 times)

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Offline 607

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Mouse jittery?
« on: February 21, 2016, 05:33:36 PM »
Hello!
I copied over my Lemmings and DOSBox files, to play Lemmings on my new, Windows 10 pc. But now the mouse movement seems to be much less smooth.
Does anyone else recognise this problem?
I can't make very precise movements as easily now, and it just feels less smooth.

Offline namida

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Re: Mouse jittery?
« Reply #1 on: February 21, 2016, 10:57:24 PM »
That's normal. It's becuase DOS Lemmings only has a resolution of 320x200. So, a move by in-game coordinates of 1 pixel will be equivalent to, on a modern screen - let's say 1080p - a move of about 5 pixels.

The only workaround is to use a clone engine instead of the official game. Lemmix (the regular one, not NeoLemmix) tries to be as close as possible to DOS in terms of game physics, but it does not have the jittery mouse issue. It does have most of the same fine-control features NeoLemmix has, but of course, no one's forcing you to use them.
My Lemmings projects
2D Lemmings: NeoLemmix (engine) | Lemmings Plus Series (level packs) | Doomsday Lemmings (level pack)
3D Lemmings: Loap (engine) | L3DEdit (level / graphics editor) | L3DUtils (replay / etc utility) | Lemmings Plus 3D (level pack)

Offline Simon

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Re: Mouse jittery?
« Reply #2 on: February 22, 2016, 06:31:22 AM »
Do you experience this in other Dos games than Lemmings run inside Dosbox?

Does the mouse move equally smooth horizontally as it does vertically?

Do you have the most recent version of Dosbox installed?

Are you using a much bigger monitor than before?

This reeks like Icho's mouse problem with C++ Lix. What I saw at Icho's was not "less smooth", but horribly unplayable. Unfortunately, "less smooth" can't be measured. Icho has a high-precision mouse, and my code did workarounds with an outdated library. I know Dosbox relies on SDL 1.2, which is getting outdated too.

@namida: The issue at hand is: (Mouse in Lemmings/Dosbox on Win 10) is less smooth than (mouse in Lemmings/Dosbox on the old machine). This isn't normal. If the low internal resolution of the game were a problem, the issue should have been on the old machine already.

-- Simon
« Last Edit: February 22, 2016, 06:46:25 AM by Simon »

Offline 607

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Re: Mouse jittery?
« Reply #3 on: February 22, 2016, 07:08:03 AM »
Ah, of course, should've realised this, thanks for the replies.
I did actually get a new monitor. I'll try setting it to my old resolution and see what I prefer.
I'm not sure why I didn't think of that earlier >.<

Offline Simon

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Re: Mouse jittery?
« Reply #4 on: February 22, 2016, 07:29:24 AM »
I still doubt the problem comes from the monitor resolution. Nonetheless, try different resolutions, and let us know what happens. I'm willing to learn. :P

<SimonN> namida42: have you already seen Dosbox/Lemmings mouse failure on large monitors? It wouldn't have been my first hunch
<namida42> it doesn't fail, but the jerkiness becomes extremely noticable


607: Do you have the problem when Dosbox is windowed/fullscreen?

-- Simon
« Last Edit: February 22, 2016, 10:11:57 AM by Simon »

Offline 607

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Re: Mouse jittery?
« Reply #5 on: February 22, 2016, 06:51:28 PM »
Okay, so... I found out that when I select "For High Performance PCs" instead of "For PC compatibles" the problem is fixed.
Windowed mode or a different resolution didn't change the way it worked.
Edit: I tried the other options: "For an IBM PS2 Machine" makes it work perfectly, and the Amstrad option makes it jittery again, and much worse, makes the mouse buttons not work. But that might be intended, I never used any other options than the first two.

Offline ccexplore

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Re: Mouse jittery?
« Reply #6 on: February 22, 2016, 11:20:29 PM »
The mouse cursor in DOS Lemmings is drawn entirely by the game itself, and as I vaguely recall, the game only updates the display like 17 times a second, a far cry from 30 and 60 fps that are expected nowadays.  It's possible that some of the other modes have higher frequency screen refreshes.

Given the low-resolution nature of the game itself though, I would expect that you can still target the mouse precisely enough for gameplay purposes, even if the cursor movements don't look smooth compared to outside the game.

Offline Simon

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Re: Mouse jittery?
« Reply #7 on: February 23, 2016, 02:30:38 AM »
Okay, so... I found out that when I select "For High Performance PCs" instead of "For PC compatibles" the problem is fixed.
Windowed mode or a different resolution didn't change the way it worked.
Edit: I tried the other options: [...]

Awesome, thanks for the good testing report!

-- Simon