package GL.Skins is

type Veneer is abstract tagged null record;

type Skin is abstract tagged
      record
         null;
      end record;

type Skin_opaque_unlit_mono_color is new Skin with
      record
         Color  : RGB_Color;
      end record;

type Veneer_opaque_lit_mono_color (Max_Normals  : GL.Geometry.vertex_Id) is new Veneer with
      record
         Normals  : GL.Geometry.GL_Normals_Vertex_Id (1 .. Max_Normals);
      end record;

type Skin_opaque_lit_mono_color is new Skin with
      record
         Material  : GL.Materials.Material_type := Materials.neutral_material;
      end record;

type Veneer_transparent_unlit_textured (Num_Coordinates  : GL.Geometry.vertex_Id) is new Veneer with
      record
         Texture_Coordinates  : GL.Textures.Coordinate_2D_array (1 .. Num_Coordinates);
      end record;

type Skin_transparent_unlit_textured is new Skin with
      record
         Texture               : GL.Textures.Object;
         Coordinate_Generator  : GL.Textures.p_coordinate_Generator;
      end record;

type Veneer_unlit_textured_vbo is new Veneer with
      record
         -- texture_Coordinates  : GL.Buffer.vertex_buffer_Object;
         texture_Coordinates  : GL.Buffer.texture_coords.General_Object;
      end record;

type Skin_unlit_textured_vbo is new Skin with
      record
         Texture  : GL.Textures.Object;
      end record;

type p_Veneer is access all Veneer'Class;

type p_Skin is access all Skin'Class;

type Skin_Array is array (Positive range <>) of p_Skin;

type p_Veneer_transparent_unlit_textured is access all Veneer_transparent_unlit_textured'Class;

type p_Skin_transparent_unlit_textured is access all Skin_transparent_unlit_textured;

type p_Veneer_unlit_textured_vbo is access all Veneer_unlit_textured_vbo'Class;

type p_Skin_unlit_textured_vbo is access all Skin_unlit_textured_vbo;

null_Skins : constant Skin_Array (1 .. 0) := (others => null);

green_Skin     : p_Skin := new GL.Skins.Skin_opaque_unlit_mono_color'(Color => (Red   => 1.0,
                                                                                   Green => 1.0,
                                                                                   Blue  => 1.0));

lit_green_Skin : p_Skin := new GL.Skins.Skin_opaque_lit_mono_color;

procedure Destroy 
(
Self
: in out Veneer);

procedure Free    
(
Self
: in out p_Veneer);

procedure Enable 
(
Self
: in out Veneer)   is abstract;

procedure Destroy 
(
Self
: in out Skin);

procedure Free    
(
Self
: in out p_Skin);

function  New_Veneer 
(
Self
: Skin;
for_Geometry
: GL.Geometry.Geometry_t'Class) return p_Veneer is abstract;

procedure Enable         
(
Self
: in out Skin)                  is abstract;

function  is_Transparent 
(
Self
:        Skin) return Boolean   is abstract;

overriding function  New_Veneer     
(
Self
:        Skin_opaque_unlit_mono_color;
for_Geometry
: GL.Geometry.Geometry_t'Class) return p_Veneer;

overriding procedure Enable         
(
Self
: in out Skin_opaque_unlit_mono_color);

overriding function  is_Transparent 
(
Self
:        Skin_opaque_unlit_mono_color) return Boolean;

overriding procedure Enable 
(
Self
: in out Veneer_opaque_lit_mono_color);

overriding function  new_Veneer 
(
Self
:        Skin_opaque_lit_mono_color;
for_Geometry
: GL.Geometry.Geometry_t'Class) return p_Veneer;

overriding procedure Enable     
(
Self
: in out Skin_opaque_lit_mono_color);

overriding function  is_Transparent 
(
Self
: Skin_opaque_lit_mono_color) return Boolean;

overriding procedure Enable 
(
Self
: in out Veneer_transparent_unlit_textured);

overriding procedure Destroy 
(
Self
: in out Skin_transparent_unlit_textured);

overriding function  New_Veneer     
(
Self
:        Skin_transparent_unlit_textured;
for_Geometry
:  GL.Geometry.Geometry_t'Class) return p_Veneer;

overriding procedure Enable         
(
Self
: in out Skin_transparent_unlit_textured);

overriding function  is_Transparent 
(
Self
:        Skin_transparent_unlit_textured) return Boolean;

overriding procedure Enable 
(
Self
: in out Veneer_unlit_textured_vbo);

overriding procedure Destroy 
(
Self
: in out Skin_unlit_textured_vbo);

overriding function  new_Veneer 
(
Self
:        Skin_unlit_textured_vbo;
for_Geometry
: GL.Geometry.Geometry_t'Class) return p_Veneer;

overriding procedure Enable     
(
Self
: in out Skin_unlit_textured_vbo);

overriding function  is_Transparent 
(
Self
: Skin_unlit_textured_vbo) return Boolean;