I wish it would be just that, then at least I could easily write a patcher for it;P. The result is same, but actually the reason is slightly different.
Full story - the adress storing value which game reads to apply proportions is always same, but the game engine patches it constantly(and unfortunately faster than 1ms - if it was slower then no problem;], couse it could still be patched normally) to default value. It's changed by instructions passed by GS which memory changes by each run or any other thing which restarts GS(like loading a savestate in pcsx2). That also cannot be easily found as it doesn't have any good pattern or rather same pattern constantly repeats itself all the time and only register values change and basically I do find that code by checking for an register which points to the widescreen adress.
I generally know that at least fair amount of the most interesting patches/cheats for PS2 games are using code caves in EE memory to put own assembly code there to do something normally impossible in the game, soo maybe it could still be patched somehow. The problem is such assembly code needs to be activated somehow, jumped to from going through original code and after doing itself continuing with the old code. Meaning it must start from some known adress at first and GS memory is probably impossible, or at least my experience lacks a way to do that such way;3. Maybe someone who has more experience in true "hacking" ps2 could do it, surely not me, I only tried few times things like that for PC games, which in generally are harder to cheat, but at least doing stuff like that feels easier there with pointers which I guess cannot be used here;3.
I tried to trace from where the initial default value was taken from, but it leads me to too many opcodes at completely unknown(for me) area of pcsx2 memory, I only can guess it's IOP which means the value probably originates from disc, which ultimately leads to another guess that the game iso could be patched instead of patching the memory;3(and here's a chance to make it "easily" working even at ps2), but trying to search through whole iso in hex editor lead to soo many 0.75 floats, that finding the correct one will surely not be made by me;3. Maybe some code in IOP do points to that somehow, maybe it's easy way to find it using some ps2 debugger or something like that, but I completely lack any experience with it and don't feel like gaining it couse it rather seem like a labor work and not something interesting;]. Feel free to try it yourself. If it really could be found there, it would be as easy as rewriting one byte there to set default value to 16:9/10.
Sorry if most of that post is hard to understand, I just feel that the more info I pass over here, at least something of it could be used by someone for this or similar project;3. I see loads of people patching games with by simply changing values, but we can also put our own code and do other silly stuff with some knowledge, guess it's worth mentioning
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