This is an issue because a driver may have to maintain two copies of a
texture if it batches all uploads together at the start of a frame.
In the Vulkan backend, we do something similar to avoid breaking out of a
render pass to copy a texture from the streaming buffer to the destination
image.
This was causing issues in the sms-bubbles fifolog, where an EFB copy to
the same address of a previously-used texture caused the previous texture
to be re-used again for a different image later on in the frame, causing
the original contents to be discarded.
Fixes a major preformance regression in Skies of Arcadia during
battle transisions.
I had plans for a more advanced version of this code after 5.0,
but here is a minimal implemenation for now.
This should get Donkey Kong Country Returns characters to be as broken as they should be. They will be fixed in a later pr.
Expected result is:
efbtex: characters are always flickering or invisible, no matter what scaling or IR setting
efb2ram: characters are always working properly at 1xIR, no matter what scaling or IR setting
Approximately three or four times now, the issue of pointers being
in an inconsistent state been an issue in the video backend renderers
with regards to tripping up other developers.
Global (ugh) resources are put into a unique_ptr and will always have a
well-defined state of being - null or not null
Instead of having special case code for efb2tex that ignores hashes,
the only diffence between efb2tex and efb2ram now is that efb2tex
writes zeros to the memory instead of actual texture data.
Though keep in mind, all efb2tex copies will have hashes of zero as
their hash.