screenmodes and how they work (in relation to HD)

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Madmab
Posts: 8
Joined: Wed Oct 20, 2010 3:06 am

screenmodes and how they work (in relation to HD)

Post by Madmab »

I'm trying to get an understanding of how the ScummVM system works in relation to graphics resolution. This is mostly based on the SDL graphics code running on an Xbox.

The xbox is capable of displaying resolutions of 720p, and 1080i. If I set main to start off with a 720p resolution the interface displays at 1280,720 just perfectly.

But I noticed that when, say for example, one starts a game (like Indiana Jones Atlantis) it switches to an (internal?) res of 320x200 which of course the Xbox cant do so it switches to 640x480 and just doubles the res.

I'm just trying to figure out two things.

How can I get it stay at 720p and stretch the image out as needed (aka aspect ratio correct) when a game is started.

The interface also for some reason seems to double in size (CTRL-F5) which seems kinda silly when the hardware is really running at 640x480 (maybe SDL doesn't realize this?). So like the wii version I'd like to also get the Pop-up dialogs/menu to keep their proper size.

Thanks.. any help would be appreciated.
Madmab
Posts: 8
Joined: Wed Oct 20, 2010 3:06 am

Post by Madmab »

ok.. well after sifting thru the sdl.cpp code and thinking about it I did a little experimenting in debug mode.

First thing I did was set USE_SCALERS since I initially had it turned off (little issue with two of the .asm based filters)..

Anywho.. after doing this.. everything became clear. How the scaler is set (1x, 2x, or 3x) pretty much determines the main menu and each games resolution. Where the game depends on what it's native res is (320/200, 640/480, etc).

So when I set the scaler to 3x then the xbox would switch into 720p like I would expect it to. The strange behavior (with the menu and dialog boxes) occured because with no scalers it was essentially running at 1x in 640x480.

Only odd thing is if I set the scaler to 3x and a game uses a res of 640/480 then not so good things happens (pretty much exits out of scumm).

So I think all I have to do is put a check in to prevent that. It'd be nice if the main menu res wasn't so tied in with the rest (so to speak) and have it's own independant setting.

But I think I got a handle on it. I almost feel like I'm talking to myself.. :lol: Which I do alot.. hence the nick.. :P

Anywho back to my little world.
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