The new status quo is simple: all messages coming from libplacebo are
marked "vo/gpu{-next}/libplacebo", regardless of the backend API (vulkan
vs opengl/d3d11).
Messages coming from mpv's internal vulkan code will continue to come
from "vo/gpu{-next}/vulkan", and messages coming from the vo module
itself will be marked "vo/gpu{-next}".
This is significantly better than the old status quo of vulkan messages
coming from "vo/gpu{-next}/vulkan/libplacebo" whereas opengl/d3d11
messages simply came from "vo/gpu{-next}", even when those messages
originated from libplacebo.
(It's worth noting that the the destructor for the log is redundant
because it's attached to the ctx which is freed on uninit anyway)
Facing down the multitude of ways to somehow wrangle the get_fn pointer
out of the GL environment and into libplacebo, I decided the easiest is
to just store it inside the GL struct itself.
The lifetime of this get_fn function is a bit murky, since it's not
clear on whether or not it survives the VO init call (especially in the
case of the GL render API, which explicitly states that parameters do
not need to survive the call they're passed to), so just add a
disclaimer.
(It's fine for us to use like this because `gpu_ctx_create` is still
part of VO init)
Closes https://code.videolan.org/videolan/libplacebo/-/issues/216
There are two major ways of going about this:
1. Expose the native ra_gl/ra_pl/ra_d3d11 objects to the pre-existing
hwdec mappers, and then add code in vo_gpu_next to rewrap those
ra_tex objects into pl_tex.
2. Wrap the underlying pl_opengl/pl_d3d11 into a ra_pl object and expose
it to the hwdec mappers, then directly use the resulting pl_tex.
I ultimately opted for approach 1 because it enables compatibility with
more hardware decoders, specifically including ones that use native
OpenGL calls currently. The second approach only really works with
cuda_vk and vaapi_pl.
By receiving the graphics API-specific contexts from the generic
pl_gpu instance, it is not necessary to store them separately.
As the current priv struct stores nothing else, this allows its
removal. This removal cleans up related compiler warnings regarding
unused variables in case of opengl and d3d11 being disabled in
mpv/libplacebo.
Functions to receive the underlying vulkan,gl,d3d11 structure were
added in libplacebo version 4.182. Our current requirement for
gpu-next is 4.190, and thus we can freely utilize these helper
functions.
This is done to avoid cluttering vo_gpu_next.c with more ifdeffery and context-specific code
when additional backends are added in the near future.
Eventually gpu_ctx is intended to take the place of ra_ctx to further separate gpu and gpu_next.