OSX: run native event loop in a separate thread

This commit is a followup on the previous one and uses a solution I like more
since it totally decouples the Cocoa code from mpv's core and tries to emulate
a generic Cocoa application's lifecycle as much as possible without fighting
the framework.

mpv's main is executed in a pthread while the main thread runs the native cocoa
event loop.

All of the thread safety is mainly accomplished with additional logic in
cocoa_common as to not increase complexity on the crossplatform parts of the
code.

1 files changed, 7 insertions, 0 deletions

diff --git a/video/out/gl_common.h b/video/out/gl_common.h
index 18d1cf8879..1956b73616 100644
--- a/video/out/gl_common.h
+++ b/video/out/gl_common.h
@@ -131,6 +131,13 @@ typedef struct MPGLContext {
     void (*border)(struct vo *vo);
     void (*update_xinerama_info)(struct vo *vo);
 
+    // An optional function to register a resize callback in the backend that
+    // can be called on separate thread to handle resize events immediately
+    // (without waiting for vo_check_events, which will come later for the
+    // proper resize)
+    void (*register_resize_callback)(struct vo *vo,
+                                     void (*cb)(struct vo *vo, int w, int h));
+
     // For free use by the backend.
     void *priv;
 } MPGLContext;