Efl.Canvas.Vg: When VG container has transparency, ector buffer created synchronously

Summary:
If the container has transparency, it internally alpha blends with ector buffer.
So ector buffer must be created synchronously.

Test Plan: N/A

Reviewers: Hermet, smohanty

Reviewed By: Hermet

Subscribers: #reviewers, #committers, cedric, herb, kimcinoo

Tags: #efl

Differential Revision: https://phab.enlightenment.org/D12140

src/lib/evas/canvas/efl_canvas_vg_container.c

@@ -192,6 +192,14 @@ _efl_canvas_vg_container_render_pre(Evas_Object_Protected_Data *vg_pd,
                              ptransform, ctransform, p_opacity, c_a, comp, comp_method);
      }
 
+   //If the container has transparency, it internally alpha blends with ector buffer.
+   //So ector buffer must be created synchronously.
+   if (c_a < 255 && vg_pd && vg_pd->object)
+     {
+        Efl_Canvas_Vg_Object_Data *od = efl_data_scope_get(vg_pd->object, EFL_CANVAS_VG_OBJECT_CLASS);
+        od->sync_render = EINA_TRUE;
+     }
+
    EINA_LIST_FOREACH(pd->children, l, child)
      {
         //Don't need to update composite nodes.

src/lib/evas/canvas/efl_canvas_vg_object.c

@@ -389,6 +389,8 @@ _efl_canvas_vg_object_efl_object_constructor(Eo *eo_obj, Efl_Canvas_Vg_Object_Da
    pd->obj = obj;
    pd->root = efl_add_ref(EFL_CANVAS_VG_CONTAINER_CLASS, NULL);
 
+   pd->sync_render = EINA_FALSE;
+
    eina_array_step_set(&pd->cleanup, sizeof(pd->cleanup), 8);
 
    return eo_obj;
@@ -537,6 +539,8 @@ _render_to_buffer(Evas_Object_Protected_Data *obj, Efl_Canvas_Vg_Object_Data *pd
    //ector begin - end for drawing composite images.
    _evas_vg_render_pre(obj, root, engine, buffer, context, ector, NULL, 255, NULL, 0);
 
+   if (pd->sync_render) do_async = EINA_FALSE;
+
    //Actual content drawing
    if (!ENFN->ector_begin(engine, buffer, context, ector, x, y, do_async))
      {

src/lib/evas/canvas/evas_vg_private.h

@@ -55,6 +55,7 @@ struct _Efl_Canvas_Vg_Object_Data
    void                      *ckeys[2];  //cache keys for first, last frames if animation
 
    Eina_Bool                  changed : 1;
+   Eina_Bool                  sync_render : 1;
 };
 
 struct _Efl_Canvas_Vg_Node_Data