Add initial prototype.

3-mid/opengl/source/opengl-tasks.ads

@@ -0,0 +1,22 @@
+with
+     ada.Task_Identification;
+
+package openGL.Tasks
+--
+--  Allow checking that a GL operation is called only in the GL renderer engine task.
+--
+is
+
+   Renderer_Task : ada.Task_Identification.Task_Id := ada.Task_Identification.null_Task_Id;
+   --
+   -- The current renderer task.
+
+
+   procedure check;
+   function  check return Boolean;
+   --
+   -- Check if the calling task is the renderer task.
+   -- Otherwise, gives an assertion error.
+
+
+end openGL.Tasks;