User panel stuff on forum
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Quakeworld HOWTO/FAQ
2009-01-04, 14:21
1329 posts

Apr 2006
This post will answer to that question by investigating situations where the geometry correction is needed. I have already written a widescreen guide over at the QW wiki and one can use that to check the required changes/command when dealing with geometry in QW. So let's get to the main point now.

Question: Do I need geometry or aspect ratio correction in QW?

Answer: Only you can answer that question. If you have played years with certain geometry and have gotten used to it, then probably not. If you are coming from CRT to TFT and feel that the image looks funny, then perhaps.

If the answer to the question above was "no", then there's no need to continue reading the stuff below, unless one cares about information.

Ok I might need the geometry correction, what kind of things affects this?

Let's divide the question in two parts, concerning CRT monitors and TFT monitors. Note that this post only takes QW into account, so if one needs to have more information about other games, I suggest visiting WSGFWiki's game list. The following information is based on the assumption that player has certain type of monitor, and uses the default geometry of vid_conwidth 640 and vid_conheight 480 values (4:3 geometry).

1) Users with CRT monitors (4:3 aspect ratio screens)

With CRT monitors resolution does not affect geometry in QW if the screen size is zoomed and fitted by the monitor controls to fill the whole screen area. For example if you use resolution like 1360*768 (1,77:1) like I do, and adjust the image properly to fill the screen, conwidth/height can remain the same as the physical appearance of the image displayed is 4:3.

Note that due to fitting the image to the screen, some things like crosshair might lose their shape a bit, however their geometry should remain the same. Screenshots don't have proper geometry, since they are shown as their aspect ratio dictates if the image viewer doesn't stretch the image to fill the screen.

2) Users with TFT monitors (non-4:3 aspect ratio screens)

This is where the things get slightly more complicated, but not by that much. TFTs usually have scaling modes that are used when the screen is not in native resolution. Not only that, the native resolution always fills the full screen area, making the image obey TFT monitor's own aspect ratio, which is 5:4, 16:10 or 16:9. Let's see how resolution affects things.

Native resolution:

Always fills all of the screen pixels, making the image the same as the TFT's aspect ratio. This WILL require geometry correcting regardless of the aspect ratio, as long as your TFT isn't actually 4:3.

1:1 pixel mapping:

Only the pixels that fit the resolution will be drawn. This means that if your monitor's native resolution is 1920*1200 and you use resolution 1600*1200, the screen width is not fully used, leaving 320 pixels not being used (black) on the both sides of the image (160 pixels per side).

This also means that the resolution's aspect ratio is carried over to the image, so resolutions like 1600*1200, 1024*768 will have 4:3 geometry and resolutions like 1152*720 and 1680*1050 will have 16:10 geometry. The first example doesn't need geometry correction, but the second one naturally does.

Aspect ratio scaling:

Means that the image is scaled to fill the screen while keeping the aspect ratio of the resolution selected. Because of this you will need geometry correction to your selected resolution: 4:3 resolutions like 1024*768 or 800*600 are fine with the default geometry, but resolutions that don't have 4:3 aspect ratio needs to be geometry corrected.

If the aspect ratio of the selected resolution does not match the aspect ratio of the TFT monitor, there will be unused pixels visible on the screen like with the 1:1 pixel mapping.

Full scaling

Always tries to fill every screen pixel and effectively makes all of the resolutions to match monitor's aspect ratio. Geometry correction is always required regardless of the resolution being used.

That should answer most of the questions regarding this issue, but if not then feel free to ask.
Servers: Troopers
2009-01-04, 14:57
383 posts

Apr 2006
Comprehensive and informative as always, Renzo. gj.
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