Lara Croft & The Guardian Of Light -
Edit the registry as follows at your own risk be very careful you do not delete or change the wrong setting: Also make a note of the old settings before changing these.
HKEY_CURRENT_USER\Software\Crystal Dynamics\Lara Croft: GoL\Graphics\AspectRatio=23703 (Decimal)
HKEY_CURRENT_USER\Software\Crystal Dynamics\Lara Croft: GoL\Graphics\FullScreenModeID=3c438A00 (Hex)
The formula is:
AspectRatio (decimal) = Width Divided by Height x 10000
FullScreenModeID (hexadecimal) = a complex key that includes refresh rate, height and width
Example: 2560x1080 (21:9), 60 Hz
Dec >>> Hex
60 >>> 3C
1080 >>> 438
2560 >>> A00
So the registry values would be:
AspectRatio 23703 (2560 divided by 1080=2.37037037037037 x 10000= 23703
FullScreenModeID 3c438A00
Formula came from this webpage here:
http://www.wsgf.org/dr/lara-croft-and-guardian-light
Aspect Ratio still looks slightly wrong to me ingame & many elements are 16:9 stretched/squashed so this older title only has partial 21:9 support IMO & the sequel is out next week using the same game engine lets see if that is any better as Tomb Raider 2013 had native 21:9 support.