@JohnnyWalker2001: Yes, by 'native resolution' I meant a resolution that Windows supports, e.g. my optimal one is 1366x768, common ones are 640x480, 800x600, 1024x768, 1280x960, 1680x1050 etc., it all depends on the display device really. About knowing the native resolution, I think that's an SDL thing. E.G. I can run a 4000x4000 window if I'd like, but not fullscreen. Maybe it's just a simple check to see if the height/width that you're trying to achieve is bigger than the one your display supports.
Just as an example, here
's a 5333x4000 image (4k x 1.333AR), ran it fine in a window, not able to run it fullscreen.
@somaen: Yes, I do get noticeable skewing, but I get that either way when I go fullscreen, even with no upscaling at 640x480. Here are some images below, all of which are taken at my optimal fullscreen resolution ( 1366x768 ):
Gotta love the way how even the textures look better.
P.S.: I couldn't find a method to take screenshots, is there one? Prtscr doesn't work when fullscreen, I guess because of the GL. I took these with some SDL Surface Scale code I put in.
P.P.S.: On today's machines, the upped resolution, the recreated textures, recreated backgrounds ( with some patience ), and the deluxe models could really lead to the game looking as good as today's games.
The only limitations I see currently are recreation of the videos (which is highly doable from an animator's point of view, the animations aren't that hard as the characters are skeletons, and there wouldn't be too much skinning / weight painting ), and the hierarchy of the models, which makes the models chopped up in different pieces, so we get the effect of arms being separate from body, etc. If only they made animations to be handled by polygon groups or something...
And to think that only two years later, EMI uses skeletal animations and morphing.