Castle Paradox

Bagne · Posted: Wed Dec 23, 2009 11:58 am Post subject: Scrolling

While playing my game, I've been noticing something about the camera scrolling that has been bothering me.

As I walk, the camera scrolls with the hero's movement, but I've noticed that the scrolling isn't smooth.
If I track a maptile feature as I walk, it seems to sporadically "catch", kind of like pushing a rubber sole shoe across a gym floor.

I've done some experimenting, comparing the WIP to werewaffle: the difference is like night and day.
While werewaffle doesn't scroll completely smoothly, it looks far better.

I've observed the catching on both my family computer and my laptop.
I'm using gfx_fb on both.
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TMC · Posted: Wed Dec 23, 2009 7:59 pm Post subject:

I see what you mean, and I know what the problem is. It was introduced in the nightlies a few days ago. Thanks for spotting that.

Also, the screen tearing annoys me greatly. Luckily, we now have a solution to screen tearing: the new gfx_directx backend supports vsync! (People with compositing window managers like in Vista should not have seen screen tearing anyway) For some reason, even the jumping doesn't occur when using gfx_directx, even though it should.
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Bagne · Posted: Wed Dec 23, 2009 11:06 pm Post subject:

Really?
Cool!

I'm not sure what you mean by a "few days ago", but I've been seeing this happen for at least half a month now.

I was going to report it, but I first wanted to make sure it wasn't just my computer. I waited until the holidays so that I could try and see it happen on my family's computer.
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TMC · Posted: Thu Dec 24, 2009 12:14 am Post subject:

There seem to be multiple things going on here. 7 days ago a change to the fps regulation made things much jerkier. However, even after fixing that I can still see a difference between werewaffle and the nightlies. It seems to be a problem with gfx_fb:

You can press ctrl+~ to see the fps display. Normally it should be steady at 18.2, and vary by just 0.1 or 0.2. However, when using a gfx_fb nightly build and holding down a button, the fps starts jumping up and down, by over 0.5 for me. I don't know what's causing it, or when it started.

EDIT: It seems to have started in the Nov 25th nightly. The problem is extremely bad in that nightly, and has since gotten much milder.
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Bagne · Posted: Fri Dec 25, 2009 8:39 am Post subject:

Is it just me, or does even werewaffle have the occasional hiccup?

Btw, is this problem what you call "tearing"?
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TMC · Posted: Sun Dec 27, 2009 7:21 pm Post subject:

Tearing occurs when a new frame is drawn while screen is being refreshed. Part of the previous frame is seen, then below some point onscreen, the nw frame starts. It's really noticeable when there's a vertical line is moving left or right - it appears to be torn at some random point many times each second.

vsync - vertical retrace synchronisation - waits until the monitor is not drawing anything before changing the onscreen image.
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"It is so great it is insanely great."

Bagne · Posted: Tue Jan 05, 2010 4:10 pm Post subject:

Wut wut!
Scrolling is way smoother now!

I can't try it on full screen yet though... I need to turn off my alt-tab hot key, but don't know how.
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Working on rain and cloud formation

TMC · Posted: Wed Jan 06, 2010 3:48 am Post subject:

That's because the graphics backend was changed to gfx_sdl. I forgot all about the gfx_fb problem, better go file a bug to remind myself.

Try out gfx_directx!