present_sync: only save as many entries as the swapchain depth

Saving more than the swapchain depth is just wasteful. We can just save
a copy of the vo_opts here and check the value whenever we're updating
values.

video/out/drm_common.c

@@ -1030,7 +1030,7 @@ bool vo_drm_init(struct vo *vo)
 
     drm->ev.version = DRM_EVENT_CONTEXT_VERSION;
     drm->ev.page_flip_handler = &drm_pflip_cb;
-    drm->present = mp_present_initialize(drm, VO_MAX_SWAPCHAIN_DEPTH);
+    drm->present = mp_present_initialize(drm, drm->vo->opts, VO_MAX_SWAPCHAIN_DEPTH);
 
     return true;
 

video/out/present_sync.c

@@ -57,13 +57,14 @@ void present_sync_get_info(struct mp_present *present, struct vo_vsync_info *inf
     LL_APPEND(list_node, present, cur);
 }
 
-struct mp_present *mp_present_initialize(void *talloc_ctx, int entries)
+struct mp_present *mp_present_initialize(void *talloc_ctx, struct mp_vo_opts *opts, int entries)
 {
     struct mp_present *present = talloc_zero(talloc_ctx, struct mp_present);
     for (int i = 0; i < entries; i++) {
         struct mp_present_entry *entry = talloc_zero(present, struct mp_present_entry);
         LL_APPEND(list_node, present, entry);
     }
+    present->opts = opts;
     return present;
 }
 
@@ -120,8 +121,9 @@ void present_sync_update_values(struct mp_present *present, int64_t ust,
                                 int64_t msc)
 {
     struct mp_present_entry *cur = present->head;
-    while (cur) {
-        if (!cur->ust)
+    int index = 0;
+    while (cur && ++index) {
+        if (!cur->ust || index == present->opts->swapchain_depth)
             break;
         cur = cur->list_node.next;
     }

video/out/present_sync.h

@@ -39,9 +39,10 @@ struct mp_present_entry {
 
 struct mp_present {
     struct mp_present_entry *head, *tail;
+    struct mp_vo_opts *opts;
 };
 
-struct mp_present *mp_present_initialize(void *talloc_ctx, int entries);
+struct mp_present *mp_present_initialize(void *talloc_ctx, struct mp_vo_opts *opts, int entries);
 
 // Used during the get_vsync call to deliver the presentation statistics to the VO.
 void present_sync_get_info(struct mp_present *present, struct vo_vsync_info *info);

video/out/wayland_common.c

@@ -2283,7 +2283,7 @@ bool vo_wayland_init(struct vo *vo)
         wl->fback_pool->len = VO_MAX_SWAPCHAIN_DEPTH;
         wl->fback_pool->fback = talloc_zero_array(wl->fback_pool, struct wp_presentation_feedback *,
                                                   wl->fback_pool->len);
-        wl->present = mp_present_initialize(wl, VO_MAX_SWAPCHAIN_DEPTH);
+        wl->present = mp_present_initialize(wl, wl->vo_opts, VO_MAX_SWAPCHAIN_DEPTH);
     } else {
         MP_VERBOSE(wl, "Compositor doesn't support the %s protocol!\n",
                    wp_presentation_interface.name);

video/out/x11_common.c

@@ -626,7 +626,7 @@ bool vo_x11_init(struct vo *vo)
 
     x11_error_output = x11->log;
     XSetErrorHandler(x11_errorhandler);
-    x11->present = mp_present_initialize(x11, VO_MAX_SWAPCHAIN_DEPTH);
+    x11->present = mp_present_initialize(x11, x11->opts, VO_MAX_SWAPCHAIN_DEPTH);
 
     dispName = XDisplayName(NULL);