Add initial Lua scripting support

This is preliminary. There are still tons of issues, and any aspect
of scripting may change in the future. I decided to merge this
(preliminary) work now because it makes it easier to develop it, not
because it's done. lua.rst is clear enough about it (plus some
sarcasm).

This requires linking to Lua. Lua has no official pkg-config file, but
there are distribution specific .pc files, all with different names.
Adding a non-pkg-config based configure test was considered, but we'd
rather not.

One major complication is that libquvi links against Lua too, and if
the Lua version is different from mpv's, you will get a crash as soon
as libquvi uses Lua. (libquvi by design always runs when a file is
opened.) I would consider this the problem of distros and whoever
builds mpv, but to make things easier for users, we add a terrible
runtime test to the configure script, which probes whether libquvi
will crash. This is disabled when cross-compiling, but in that case
we hope the user knows what he is doing.

1 files changed, 10 insertions, 0 deletions

diff --git a/sub/sub.h b/sub/sub.h
index 3cb140565c..35527f266b 100644
--- a/sub/sub.h
+++ b/sub/sub.h
@@ -90,6 +90,8 @@ enum mp_osdtype {
     OSDTYPE_PROGBAR,
     OSDTYPE_OSD,
 
+    OSDTYPE_EXTERNAL,
+
     MAX_OSD_PARTS
 };
 
@@ -137,6 +139,9 @@ struct osd_state {
     float progbar_value;   // range 0.0-1.0
     float *progbar_stops;  // used for chapter indicators (0.0-1.0 each)
     int progbar_num_stops;
+    // OSDTYPE_EXTERNAL
+    char *external;
+    int external_res_x, external_res_y;
     // OSDTYPE_SUB
     struct dec_sub *dec_sub;
 
@@ -219,10 +224,15 @@ void osd_draw_on_image_p(struct osd_state *osd, struct mp_osd_res res,
                          double video_pts, int draw_flags,
                          struct mp_image_pool *pool, struct mp_image *dest);
 
+void osd_object_get_scale_factor(struct osd_state *osd, struct osd_object *obj,
+                                 double *sw, double *sh);
+
 // defined in osd_libass.c and osd_dummy.c
 
 void osd_object_get_bitmaps(struct osd_state *osd, struct osd_object *obj,
                             struct sub_bitmaps *out_imgs);
+void osd_object_get_resolution(struct osd_state *osd, struct osd_object *obj,
+                               int *out_w, int *out_h);
 void osd_get_function_sym(char *buffer, size_t buffer_size, int osd_function);
 void osd_init_backend(struct osd_state *osd);
 void osd_destroy_backend(struct osd_state *osd);