This is done in several steps:
1. refactor MPGLContext -> struct ra_ctx
2. move GL-specific stuff in vo_opengl into opengl/context.c
3. generalize context creation to support other APIs, and add --gpu-api
4. rename all of the --opengl- options that are no longer opengl-specific
5. move all of the stuff from opengl/* that isn't GL-specific into gpu/
(note: opengl/gl_utils.h became opengl/utils.h)
6. rename vo_opengl to vo_gpu
7. to handle window screenshots, the short-term approach was to just add
it to ra_swchain_fns. Long term (and for vulkan) this has to be moved to
ra itself (and vo_gpu altered to compensate), but this was a stop-gap
measure to prevent this commit from getting too big
8. move ra->fns->flush to ra_gl_ctx instead
9. some other minor changes that I've probably already forgotten
Note: This is one half of a major refactor, the other half of which is
provided by rossy's following commit. This commit enables support for
all linux platforms, while his version enables support for all non-linux
platforms.
Note 2: vo_opengl_cb.c also re-uses ra_gl_ctx so it benefits from the
--opengl- options like --opengl-early-flush, --opengl-finish etc. Should
be a strict superset of the old functionality.
Disclaimer: Since I have no way of compiling mpv on all platforms, some
of these ports were done blindly. Specifically, the blind ports included
context_mali_fbdev.c and context_rpi.c. Since they're both based on
egl_helpers, the port should have gone smoothly without any major
changes required. But if somebody complains about a compile error on
those platforms (assuming anybody actually uses them), you know where to
complain.
This starts work on moving OpenGL-specific code out of the general
renderer code, so that we can support other other GPU APIs. This is in
a very early stage and it's only a proof of concept. It's unknown
whether this will succeed or result in other backends.
For now, the GL rendering API ("ra") and its only provider (ra_gl) does
texture creation/upload/destruction only. And it's used for the main
video texture only. All other code is still hardcoded to GL.
There is some duplication with ra_format and gl_format handling. In the
end, only the ra variants will be needed (plus the gl_format table of
course). For now, this is simpler, because for some reason lots of hwdec
code still requires the GL variants, and would have to be updated to
use the ra ones.
Currently, the video.c code accesses private ra_gl fields. In the end,
it should not do that of course, and it would not include ra_gl.h.
Probably adds bugs, but you can keep them.
Instead of setting up a weird swizzle (which is linked to how the
internal renderer code works, rather than the generic format code), add
per-component mapping to gl_imgfmt_desc.
The renderer still computes the weird swizzle, but at least it's
confined to itself. Also, it appears the hwdec backends don't need this
anymore.
It's really nice that the messy init_format() goes away too.
All supported pixel formats have a specific "mapping" of CPU data to
textures. This function determines the number and the formats of these
textures. Moving it to a helper will be useful for some hardware decode
interop backends, since they all need similar things.
GL_LUMINANCE_ALPHA is the only reason why per-plane swizzles exist.
Remove per-plane swizzles (again), and regrettably handle them as
special cases (again). Carry along the logical texture format (called
gl_format in some parts of the code, including the new one).
We also don't need a use_integer flag, since the new gl_format member
implies whether it's an integer texture. (Yes, the there are separate
logical GL formats for integer textures. This aspect of the OpenGL API
is hysteric at best.)
This should change nothing about actual rendering logic and GL API
usage.
Some of these checks became pointless after dropping ES 2.0 support for
extended filtering.
GL_EXT_texture_rg is part of core in ES 3.0, and we already check for
this version, so testing for the extension is redundant.
GL_OES_texture_half_float_linear is also always available, at least as
far as our needs go.
The functionality we need from GL_EXT_color_buffer_half_float is always
available in ES 3.2, and we explicitly check for ES 3.2, so reject this
extension if the ES version is new enough.
This merges all knowledge about texture format into a central table.
Most of the work done here is actually identifying which formats exactly
are supported by OpenGL(ES) under which circumstances, and keeping this
information in the format table in a somewhat declarative way. (Although
only to the extend needed by mpv.) In particular, ES and float formats
are a horrible mess.
Again this is a big refactor that might cause regression on "obscure"
configurations.
