with
     gel.Applet.gui_World,
     gel.Window.setup,
     gel.Camera,
     gel.Forge,
     gel.Sprite,
     physics.Model,

     openGL.Model.any,
     openGL.Light,

     ada.Calendar,
     ada.Text_IO,
     ada.Exceptions;

pragma Unreferenced (gel.Window.setup);


procedure launch_opengl_Model
--
-- Shows a human head model imported from a wavefront '.obj' file
--   and a human body model imported from a collada   '.dae' file.
--
--
is
   use ada.Calendar,
       ada.Text_IO,
       ada.Exceptions;


   the_Applet : constant gel.Applet.gui_World.view := gel.Forge.new_gui_Applet ("openGL Model", 500, 500);


   the_human_graphics_Model : constant openGL.Model.any.view
     := openGL.Model.any.new_Model (Model            => openGL.to_Asset ("./assets/opengl/model/human.obj"),
                                    Texture          => openGL.null_Asset,
                                    Texture_is_lucid => False);

   the_human_physics_Model : constant physics.Model.view
     := physics.Model.Forge.new_physics_Model (shape_Info => (Kind         => physics.Model.Cube,
                                                              half_Extents => (4.0, 1.0, 2.0)),
                                               Mass       => 1.0);
   the_Human : constant gel.Sprite.view
     := gel.Sprite.forge.new_Sprite (Name           => "Clarence",
                                     World          => the_Applet.gui_World.all'Access,
                                     at_Site        => gel.Math.Origin_3D,
                                     graphics_Model => the_human_graphics_Model,
                                     physics_Model  => the_human_physics_Model);



   the_cobra_graphics_Model : aliased constant openGL.Model.any.view
     := openGL.Model.any.new_Model (Model            => openGL.to_Asset ("./assets/oolite_cobra3.obj"),
                                    Texture          => openGL.to_Asset ("./assets/oolite_cobra3_diffuse.png"),
                                    Texture_is_lucid => False);

   the_cobra_physics_Model : constant physics.Model.view
     := physics.Model.Forge.new_physics_Model (shape_Info => (Kind         => physics.Model.Cube,
                                                              half_Extents => (4.0, 1.0, 2.0)),
                                               Mass       => 0.0);
   the_Cobra : constant gel.Sprite.view
     := gel.Sprite.forge.new_Sprite (Name           => "Cobra",
                                     World          => the_Applet.gui_World.all'Access,
                                     at_Site        => gel.Math.Origin_3D,
                                     graphics_Model => the_cobra_graphics_Model,
                                     physics_Model  => the_cobra_physics_Model);




   the_Ground : constant gel.Sprite.view := gel.Forge.new_box_Sprite (the_Applet.gui_World,
                                                                      Mass => 0.0,
                                                                      Size => (50.0, 1.0, 50.0));
   next_render_Time : ada.calendar.Time;

begin
   the_Applet.gui_World.Gravity_is ((0.0, -9.8, 0.0));

   the_Applet.gui_World.add (the_Ground);                  -- Add ground.

   the_Applet.gui_World.add (the_Human);                   -- Add human.
   the_Human.Site_is ((0.0, 5.0, 0.0));                    --

   --  the_Applet.gui_World.add (the_Cobra);               -- Add cobra.
   --  the_Cobra.Site_is ((0.0,  5.0,  0.0));              --

   the_Applet.gui_Camera.Site_is ((0.0, 1.5, 2.6));        -- Position the camera.
   --  the_Applet.gui_Camera.Site_is ((0.0, 100.0, 0.0));    -- Position the camera.
   the_Applet.enable_simple_Dolly (in_World => 1);         -- Enable user camera control via keyboards.
   the_Applet.Dolly.Speed_is (0.1);                        -- Slow down the rate at which the dolly moves.
   --  the_Applet.Dolly.Speed_is (0.5);                    -- Slow down the rate at which the dolly moves.

   -- Set the lights position.
   --
   declare
      Light : openGL.Light.item := the_Applet.Renderer.new_Light;
   begin
      Light.Site_is ((0.0, 1000.0, 1000.0));
      the_Applet.Renderer.set (Light);
   end;


   next_render_Time := ada.Calendar.clock;

   while the_Applet.is_open
   loop
      the_Applet.freshen;                              -- Evolve the world, handle any new events and update the display.

      next_render_Time := next_render_Time + 1.0/60.0;
      delay until next_render_Time;
   end loop;


   the_Applet.destroy;

exception
   when E : others =>
      put_Line (Exception_Information (E));
end launch_opengl_Model;