Getting the resolution of a source is very expensive in libOBS, as libOBS does not cache it and instead always calls into the filters and sources to determine the actual source. This also leads to potential lockups due to the filter list mutex being locked for the target source.
Therefore instead of calling it multiple times, cache the result of the call, if that result is even necessary. This reduces the need to synchronize lightly parallelized work (UI and libOBS code) and helps against the potential race condition in libOBS.
Prevents the use of get() and reset() where not actually needed and forces us to actually implement all of the methods needed to interface with the object, leading to cleaner and safer code.
These two wrap the underlying gs_epass and gs_effect_technique objects, to allow direct and improved access to them without relying on the libobs API to provide this access for us. Additionally these make it safe for us to use them instead of relying on C-like code to deal with it.
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.
