--  SPDX-License-Identifier: Apache-2.0
--
--  Copyright (c) 2012 Felix Krause <contact@flyx.org>
--
--  Licensed under the Apache License, Version 2.0 (the "License");
--  you may not use this file except in compliance with the License.
--  You may obtain a copy of the License at
--
--      http://www.apache.org/licenses/LICENSE-2.0
--
--  Unless required by applicable law or agreed to in writing, software
--  distributed under the License is distributed on an "AS IS" BASIS,
--  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
--  See the License for the specific language governing permissions and
--  limitations under the License.

with Ada.Finalization;

with GL.Types.Debug;

package GL.Objects is
   pragma Preelaborate;

   use GL.Types;

   type GL_Object is abstract new Ada.Finalization.Controlled with private;

   overriding procedure Initialize (Object : in out GL_Object);
   --  Create the object in OpenGL memory.

   overriding procedure Adjust (Object : in out GL_Object);
   --  Increase reference count.

   overriding procedure Finalize (Object : in out GL_Object);
   --  Decrease reference count. Deletes the GL object when it reaches zero.

   procedure Initialize_Id (Object : in out GL_Object) is abstract;
   --  Create an OpenGL ID for this object. This has to be done before
   --  the object is used in any way. After calling this procedure,
   --  Initialized will be true.

   procedure Delete_Id (Object : in out GL_Object) is abstract;
   --  Delete the ID of an object. After calling this procedure,
   --  Initialized will be false.

   function Raw_Id (Object : GL_Object) return UInt
     with Inline;
   --  This getter is provided for low-level access. Its primary use is to
   --  interact with other C interfaces (e.g. OpenCL)

   function Identifier (Object : GL_Object)
     return Types.Debug.Identifier is abstract;
   --  Return the namespace identifier of the object. Used to annotate
   --  the object in GL.Debug.

   overriding
   function "=" (Left, Right : GL_Object) return Boolean;

private

   type GL_Object_Reference is record
      GL_Id           : UInt;
      Reference_Count : Natural;
   end record;

   type GL_Object_Reference_Access is access all GL_Object_Reference;

   type GL_Object is abstract new Ada.Finalization.Controlled with record
      Reference : GL_Object_Reference_Access;
   end record;

   use type UInt;

end GL.Objects;