Type punning like this is undefined behavior. Instead, we use std::memcpy to
copy the necessary data over, which is well defined (as it treats both
the source and destination as unsigned char).
At some point SetCRFieldBit was modified to operate on RSCRATCH, but the
function was only partially changed. As such, setting SO, GT or LT would
write the right bit to cr_field, but then cr_field would just get
overwritten with RSCRATCH, undoing the work.
Behaviorally, this belongs within the netplay client. The server will
always transmit a known RTC value, so it doesn't even need a global for
this. Given the client receives the packet containing said RTC value, we can
store it as a member variable and provide an accessor for reading that
value.
This removes another global variable within the netplay code.
The idea of this code was to not unroll loops, but it was completely broken.
So we've unrolled all loops, but only up to the second iteration.
Honestly, a better check would test if we branch to code which is already in the compiling block. But this is out of scope for now.
But testing shows that this unrolling actually improve the performance. So instead of fixing this bug, this check can be dropped.
Most settings which affect determinism will now be synced on NetPlay.
Additionally, there's a strict sync mode which will sync various
enhancements to prevent desync in games that use EFB reads.
This also adds a check for all players having the IPL.bin file, and
doesn't load it for anyone if someone is missing it. This prevents
desyncs caused by mismatched system fonts.
Additionally, the NetPlay window was getting too wide with checkboxes,
so FlowLayout has been introduced to make the checkboxes take up
multiple rows dynamically. However, there's some minor vertical
centering issues I haven't been able to solve, but it's better than a
ridiculously wide window.
This is accomplished by having SConfig::GetDirectoryForRegion no longer
return nullptr, as doing that was kind silly, considering we never
check for nullptr.
Basically everything here was race conditions in Qt callbacks, so I changed the client/server instances to std::shared_ptr and added null checks. It checks that the object exists in the callback, and the shared_ptr ensures it doesn't get destroyed until we're done with it.
MD5 check would also cause a segfault if you quit without cancelling it first, which was pretty silly.