others and I have created a ton of widescreen hex patches for Dreamcast games that will allow you to play in full widescreen without artifacts (unlike reicast built it widescreen option) it also works on real hardware check it out here and enjoy Dreamcast games on your switch in full glory
https://assemblergames.com/threads/dreamcast-widescreen-hacks.58620/
How to patch Shenmue to run in 16:9 without load in glitches on the sides of the image (GUI elements will be stretched, so maybe dont replace your original gdis/chds - but just add additional ones).
Extract the gdi using this tool:
https://assemblergames.com/threads/patching-gdi-images.57271/#post-821056
(Read the readme to find out how to do so.)
Open the 1st_read.bin in a hex editor (f.e.
https://www.heise.de/download/product/hxd-50764 ).
Search and replace (select hex in the dropdown menu in replace if you are using HxD from the link above) the following three values:
https://assemblergames.com/threads/dreamcast-widescreen-hacks.58620/page-41#post-932374
(Values for Shenmue 2 are in a previous posting in the same thread.)
Save the file.
Remove the backup file that might have been created.
Repack the .gdi
Optional: Compress the .gdi to a .chd using this tool:
https://forums.launchbox-app.com/to...files-conversion/?tab=comments#comment-292142
In game, disable Widescreen hack, and set horizontal stretch to 134% (checked with ingame assets, its closer to 16:9 than 133%).
Thats it.
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Before you venture into Shenmue, you might want to know that pixel accurate alpha blending would fix the missing polygons in faces, and the notebook.
This might be implemented in future builds, so maybe wait a little before playing the game - or play it in Lakka.
Also - an Overclock of CPU to 1.2 GHz and GPU to 384 Mhz (in portable), solves most of the slowdown issues in game. You might want to set those overclocks with sys-clk