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, 130 insertions, 0 deletions

diff --git a/video/out/gpu/hwdec.h b/video/out/gpu/hwdec.h
new file mode 100644
index 0000000000..20bbaae9eb
--- /dev/null
+++ b/video/out/gpu/hwdec.h
@@ -0,0 +1,130 @@
+#ifndef MPGL_HWDEC_H_
+#define MPGL_HWDEC_H_
+
+#include "video/mp_image.h"
+#include "ra.h"
+#include "video/hwdec.h"
+
+struct ra_hwdec {
+    const struct ra_hwdec_driver *driver;
+    struct mp_log *log;
+    struct mpv_global *global;
+    struct ra *ra;
+    struct mp_hwdec_devices *devs;
+    // GLSL extensions required to sample textures from this.
+    const char **glsl_extensions;
+    // For free use by hwdec driver
+    void *priv;
+    // For working around the vdpau vs. vaapi mess.
+    bool probing;
+    // Used in overlay mode only.
+    float overlay_colorkey[4];
+};
+
+struct ra_hwdec_mapper {
+    const struct ra_hwdec_mapper_driver *driver;
+    struct mp_log *log;
+    struct ra *ra;
+    void *priv;
+    struct ra_hwdec *owner;
+    // Input frame parameters. (Set before init(), immutable.)
+    struct mp_image_params src_params;
+    // Output frame parameters (represents the format the textures return). Must
+    // be set by init(), immutable afterwards,
+    struct mp_image_params dst_params;
+
+    // The currently mapped source image (or the image about to be mapped in
+    // ->map()). NULL if unmapped. The mapper can also clear this reference if
+    // the mapped textures contain a full copy.
+    struct mp_image *src;
+
+    // The mapped textures and metadata about them. These fields change if a
+    // new frame is mapped (or unmapped), but otherwise remain constant.
+    // The common code won't mess with these, so you can e.g. set them in the
+    // .init() callback.
+    struct ra_tex *tex[4];
+    bool vdpau_fields;
+};
+
+// This can be used to map frames of a specific hw format as GL textures.
+struct ra_hwdec_mapper_driver {
+    // Used to create ra_hwdec_mapper.priv.
+    size_t priv_size;
+
+    // Init the mapper implementation. At this point, the field src_params,
+    // fns, devs, priv are initialized.
+    int (*init)(struct ra_hwdec_mapper *mapper);
+    // Destroy the mapper. unmap is called before this.
+    void (*uninit)(struct ra_hwdec_mapper *mapper);
+
+    // Map mapper->src as texture, and set mapper->frame to textures using it.
+    // It is expected that that the textures remain valid until the next unmap
+    // or uninit call.
+    // The function is allowed to unref mapper->src if it's not needed (i.e.
+    // this function creates a copy).
+    // The underlying format can change, so you might need to do some form
+    // of change detection. You also must reject unsupported formats with an
+    // error.
+    // On error, returns negative value on error and remains unmapped.
+    int (*map)(struct ra_hwdec_mapper *mapper);
+    // Unmap the frame. Does nothing if already unmapped. Optional.
+    void (*unmap)(struct ra_hwdec_mapper *mapper);
+};
+
+struct ra_hwdec_driver {
+    // Name of the interop backend. This is used for informational purposes only.
+    const char *name;
+    // Used to create ra_hwdec.priv.
+    size_t priv_size;
+    // Used to explicitly request a specific API.
+    enum hwdec_type api;
+    // One of the hardware surface IMGFMT_ that must be passed to map_image later.
+    // Terminated with a 0 entry. (Extend the array size as needed.)
+    const int imgfmts[3];
+    // Dosn't load this unless requested by name.
+    bool testing_only;
+
+    // Create the hwdec device. It must add it to hw->devs, if applicable.
+    int (*init)(struct ra_hwdec *hw);
+    void (*uninit)(struct ra_hwdec *hw);
+
+    // This will be used to create a ra_hwdec_mapper from ra_hwdec.
+    const struct ra_hwdec_mapper_driver *mapper;
+
+    // The following function provides an alternative API. Each ra_hwdec_driver
+    // must have either provide a mapper or overlay_frame (not both or none), and
+    // if overlay_frame is set, it operates in overlay mode. In this mode,
+    // OSD etc. is rendered via OpenGL, but the video is rendered as a separate
+    // layer below it.
+    // Non-overlay mode is strictly preferred, so try not to use overlay mode.
+    // Set the given frame as overlay, replacing the previous one. This can also
+    // just change the position of the overlay.
+    // hw_image==src==dst==NULL is passed to clear the overlay.
+    int (*overlay_frame)(struct ra_hwdec *hw, struct mp_image *hw_image,
+                         struct mp_rect *src, struct mp_rect *dst, bool newframe);
+};
+
+struct ra_hwdec *ra_hwdec_load_api(struct mp_log *log, struct ra *ra,
+                                   struct mpv_global *g,
+                                   struct mp_hwdec_devices *devs,
+                                   enum hwdec_type api);
+
+struct ra_hwdec *ra_hwdec_load(struct mp_log *log, struct ra *ra,
+                               struct mpv_global *g,
+                               struct mp_hwdec_devices *devs,
+                               const char *name);
+
+int ra_hwdec_validate_opt(struct mp_log *log, const m_option_t *opt,
+                          struct bstr name, struct bstr param);
+
+void ra_hwdec_uninit(struct ra_hwdec *hwdec);
+
+bool ra_hwdec_test_format(struct ra_hwdec *hwdec, int imgfmt);
+
+struct ra_hwdec_mapper *ra_hwdec_mapper_create(struct ra_hwdec *hwdec,
+                                               struct mp_image_params *params);
+void ra_hwdec_mapper_free(struct ra_hwdec_mapper **mapper);
+void ra_hwdec_mapper_unmap(struct ra_hwdec_mapper *mapper);
+int ra_hwdec_mapper_map(struct ra_hwdec_mapper *mapper, struct mp_image *img);
+
+#endif