I'll go in a little more "in-depth" explanation since I have more time now to explain things than answering discord messages on phone at work !
The 1st thing to understand is : emulators and the system do not run at the same resolution ! Switchres operates with the setting tweaked with the geometry edits, whereas OS resolutions (aka boot resolution) are fixed in the kernel, but we can circumvent that, I'll explain a little later
The 2nd thing to understand, is how swichres works regarding monitor definitions. I encourage you to read
https://gitlab.com/groovyarcade/support/-/wikis/3-Post-Installation-and-Maintenance/3.5-Monitor-Definitions and what a crt_range is, and notice that a tri-sync monitor has at least 3 crt_ranges.
Now we know a little more about some background, let's go a further in depth :
- the geometry tool is meant for a single crt_range. But you have 3 ... eeeek ... so if you want to center your monitor for 3 ranges, it's much more complicated since you have to manually edit the switchres.ini file, then force a single ranged monitor (or manually ste a crt_range), do the geometry thing, sve the resulting crt_range. Once you did this for all the crt_ranges of your monitor preset, add the 3 of them but name them crt_rage0 crt_range1 crt_range2 etc ... Not ideal I must admit, but technologically speaking: as of today, I can't do more without guessing crt_ranges of the monitor_reset, and that would make my code really complicated
- now we can do something to the boot resolution once you're done with geometry tweaking. In gasetup go to gasetup > setup > video setup > boot resolution, select custom, enter the resolution/frequency you want, test it, validate, and it *should* work then. If not (which can happen), we'll need to do some manual edits
-