vo_opengl: refactor into vo_gpu

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.

1 files changed, 8 insertions, 3 deletions

diff --git a/options/options.c b/options/options.c
index 7dc3b0b160..18b6bb8dd8 100644
--- a/options/options.c
+++ b/options/options.c
@@ -57,8 +57,8 @@
 #include "video/out/drm_common.h"
 #endif
 
-#if HAVE_GL
-#include "video/out/opengl/hwdec.h"
+#if HAVE_GPU
+#include "video/out/gpu/hwdec.h"
 #endif
 
 static void print_version(struct mp_log *log)
@@ -90,6 +90,7 @@ extern const struct m_obj_list af_obj_list;
 extern const struct m_obj_list vo_obj_list;
 extern const struct m_obj_list ao_obj_list;
 
+extern const struct m_sub_options opengl_conf;
 extern const struct m_sub_options angle_conf;
 extern const struct m_sub_options cocoa_conf;
 
@@ -687,10 +688,14 @@ const m_option_t mp_opts[] = {
     OPT_SUBSTRUCT("", vo, vo_sub_opts, 0),
     OPT_SUBSTRUCT("", demux_opts, demux_conf, 0),
 
-#if HAVE_GL
+#if HAVE_GPU
     OPT_SUBSTRUCT("", gl_video_opts, gl_video_conf, 0),
 #endif
 
+#if HAVE_GL
+    OPT_SUBSTRUCT("", opengl_opts, opengl_conf, 0),
+#endif
+
 #if HAVE_EGL_ANGLE_WIN32
     OPT_SUBSTRUCT("", angle_opts, angle_conf, 0),
 #endif