Add initial prototype.

3-mid/opengl/source/platform/glx/opengl-surface.ads

@@ -0,0 +1,41 @@
+with
+     openGL.surface_Profile;
+
+private
+with
+     Glx;
+
+limited private
+with
+     openGL.Context;
+
+package openGL.Surface
+--
+--  Models an openGL surface.
+--
+is
+   type Item  is tagged private;
+   type Items is array (Positive range <>) of aliased Item;
+
+   type View  is access all Item'Class;
+   type Views is array (Positive range <>) of View;
+
+
+   procedure define (Self : in out Item;   Profile   : in surface_Profile.item'Class;
+                                           Window_Id : in Natural);
+
+   --  Operations
+   --
+   procedure swap_Buffers (Self : in Item);
+
+
+
+private
+
+   type Item is tagged
+      record
+         glx_Surface :        glx.Drawable;
+         Context     : access openGL.Context.item'Class;
+      end record;
+
+end openGL.Surface;