Backport 1210067fbeb21bdce34ec710e66749de981a1617.

ecore_evas/wayland_egl: Only render if last frame has been presented.

This avoids blocking in eglSwapBuffers and has the side effect of
avoiding doing unnecessary work - painting where a frame won't be
presented.

We do this by using the event that the wayland compositor will send us
to tell us that the frame has been presented. Due to the fact that
evas_render_updates() could do no work and not cause a eglSwapBuffers we
must always have a frame callback listener setup.

Original patch by: Rob Bradford <rob@linux.intel.com>

(I just adjusted the patch to the single efl tree)

diff --git a/src/lib/ecore_evas/ecore_evas_wayland_egl.c b/src/lib/ecore_evas/ecore_evas_wayland_egl.c
index 25aa6e0..01224ac 100644 (file)
--- a/src/lib/ecore_evas/ecore_evas_wayland_egl.c
+++ b/src/lib/ecore_evas/ecore_evas_wayland_egl.c
@@ -176,7 +176,7 @@ static Ecore_Evas_Engine_Func _ecore_wl_engine_func =
    NULL,
    NULL,
    NULL,
-   _ecore_evas_wl_render, 
+   _ecore_evas_wl_render,
    _ecore_evas_wl_screen_geometry_get,
    _ecore_evas_wl_screen_dpi_get,
    NULL, // wm_rot_preferred_rotation_set
@@ -830,6 +830,30 @@ _ecore_evas_wl_transparent_set(Ecore_Evas *ee, int transparent)
      }
 }
 
+static void
+_ecore_evas_wl_frame_complete(void *data, struct wl_callback *callback, uint32_t time __UNUSED__);
+
+static const struct wl_callback_listener frame_listener = {
+   _ecore_evas_wl_frame_complete,
+};
+
+static void
+_ecore_evas_wl_frame_complete(void *data, struct wl_callback *callback, uint32_t time __UNUSED__)
+{
+   Ecore_Evas *ee = data;
+   Ecore_Wl_Window *win = ee->engine.wl.win;
+
+   win->frame_callback = NULL;
+   win->frame_pending = EINA_FALSE;
+   wl_callback_destroy(callback);
+
+   win->frame_callback =
+      wl_surface_frame(win->surface);
+
+   wl_callback_add_listener(win->frame_callback,
+                            &frame_listener, ee);
+}
+
 static int 
 _ecore_evas_wl_render(Ecore_Evas *ee)
 {
@@ -842,6 +866,7 @@ _ecore_evas_wl_render(Ecore_Evas *ee)
      {
         Eina_List *ll = NULL, *updates = NULL;
         Ecore_Evas *ee2 = NULL;
+        Ecore_Wl_Window *win = NULL;
 
         if (ee->func.fn_pre_render) ee->func.fn_pre_render(ee);
 
@@ -853,25 +878,40 @@ _ecore_evas_wl_render(Ecore_Evas *ee)
              if (ee2->func.fn_post_render) ee2->func.fn_post_render(ee2);
           }
 
-        if ((updates = evas_render_updates(ee->evas))) 
+        win = ee->engine.wl.win;
+
+        if (!win->frame_pending)
           {
-             Eina_List *l = NULL;
-             Eina_Rectangle *r;
+             if (!win->frame_callback)
+               {
+                  win->frame_callback = wl_surface_frame(win->surface);
+                  wl_callback_add_listener(win->frame_callback,
+                                           &frame_listener, ee);
+               }
+
+             if ((updates = evas_render_updates(ee->evas)))
+               {
+                  Eina_List *l = NULL;
+                  Eina_Rectangle *r;
+
+                  LOGFN(__FILE__, __LINE__, __FUNCTION__);
 
-             LOGFN(__FILE__, __LINE__, __FUNCTION__);
+                  EINA_LIST_FOREACH(updates, l, r)
+                     ecore_wl_window_damage(win,
+                                            r->x, r->y, r->w, r->h);
 
-             EINA_LIST_FOREACH(updates, l, r) 
-               ecore_wl_window_damage(ee->engine.wl.win, 
-                                      r->x, r->y, r->w, r->h);
+                  ecore_wl_flush();
 
-             ecore_wl_flush();
+                  evas_render_updates_free(updates);
+                  _ecore_evas_idle_timeout_update(ee);
+                  rend = 1;
+
+                  win->frame_pending = EINA_TRUE;
+               }
 
-             evas_render_updates_free(updates);
-             _ecore_evas_idle_timeout_update(ee);
-             rend = 1;
+             if (ee->func.fn_post_render) ee->func.fn_post_render(ee);
           }
 
-        if (ee->func.fn_post_render) ee->func.fn_post_render(ee);
      }
    return rend;
 }