This drastically improves stability and prevents all exceptions from leaking into libobs C code, which prevents crashes and unexpected freezes from exception handlers further down the stack.
Additionally minor work was done to further improve the quality and user experience for the filter.
Caching the output of a source is only necessary for really expensive to render sources, so it is disabled by default now. Thanks to that, most Source Mirrors are now "free" instead of requiring two context switches and a texture, while those really expensive can be manually set to cache.
The scaling mode is also set to disabled instead of point when rescaling is off to further improve performance. The previous method would incorrectly cause an extra texture to be used.
Additionally we now have support for debug markers for graphics debugging, allowing us to exactly tell apart improvements in rendering cost for this source.
This class and template should be used to reduce the code clutter from repeatedly doing the same thing. It requires OBS v24.0 or newer since the get_properties2 and get_defaults2 API were fully implemented with it.
This is a massive improvement to stability and safety when using the plugin, as all exceptions should now no longer be leaked into C controlled code, which can't actually handle exceptions at all.
Warnings fixed:
* Potentially throwing exception during library load.
* Possibly throwing function passed to C.
* Statement does nothing.
* Variable is initialized but not referenced.
* Variable overloads variable in parent scope.
It is extremely problematic to throw C++ exceptions into C code, especially because C code usually does not handle C++ exceptions at all. Therefore we have to prevent any exception from leaving the function and define it as noexcept.
The util::event code suffers from the problem that it could call into a class that no longer exists, corrupting memory or even crashing. By tracking lifetime using std::weak_ptr<void> this can be avoided and the dead listeners can be automatically removed.
