This means that a tex_t object is passed in instead of just raw bytes
and width and height, but it means the texture can specify whether it's
flipped or uses BGR instead of RGB. This fixes the upside down
screenshots for vulkan.
QFS_NextFilename was renamed to QFS_NextFile to reflect the fact it now
returns a QFile pointer for the newly created file (as well as the
name). This necessitated updating WritePNG to take a file pointer
instead of a file name, with the advantage that WritePNGqfs is no longer
necessary and callers have much more control over the creation of the
file.
This makes QFS_NextFile much more secure against file system race
conditions and attacks (at least in theory). If nothing else, it will
make it more robust in a multi-threaded environment.
For now, the functions check for a null hunk pointer and use the global
hunk (initialized via Memory_Init) if necessary. However, Hunk_Init is
available (and used by Memory_Init) to create a hunk from any arbitrary
memory block. So long as that block is 64-byte aligned, allocations
within the hunk will remain 64-byte aligned.
This makes tex_t more generally useable and probably more portable. The
goal was to be able to use tex_t with data that is in a separate chunk
of memory.
