Add initial prototype.

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

@@ -0,0 +1,47 @@
+with
+     openGL.surface_Profile,
+     openGL.Display;
+
+--  private
+--  with
+--       Glx;
+
+limited
+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;   surface_Profile : in openGL.surface_Profile.item'Class;
+                                           Display         : in openGL.Display.Item;
+                                           Window_Id       : in Natural);
+
+
+   --  Operations
+   --
+   procedure swap_Buffers (Self : in Item);
+
+
+
+private
+
+   type Item is tagged
+      record
+--           glx_Surface :        glx.GLXDrawable;
+         Context     : access openGL.Context.item'Class;
+         Display     :        openGL.Display.item;
+      end record;
+
+end openGL.Surface;