exception GLerror of string
type rgb = float * float * float
type rgba = float * float * float * float
type point2 = float * float
type point3 = float * float * float
type point4 = float * float * float * float
type vect3 = float * float * float
type clampf = float
type short = int
type kind =
    [ `bitmap | `byte | `float | `int | `short | `ubyte | `uint | `ushort ]
type real_kind =
    [ `byte | `float | `int | `short | `ubyte | `uint | `ushort ]
type format =
    [ `alpha
    | `blue
    | `color_index
    | `depth_component
    | `green
    | `luminance
    | `luminance_alpha
    | `red
    | `rgb
    | `rgba
    | `stencil_index ]
val format_size : [< format ] -> int
type target =
    [ `color_4
    | `index
    | `normal
    | `texture_coord_1
    | `texture_coord_2
    | `texture_coord_3
    | `texture_coord_4
    | `trim_2
    | `trim_3
    | `vertex_3
    | `vertex_4 ]
val target_size : [< target ] -> int
type cmp_func =
    [ `always
    | `equal
    | `gequal
    | `greater
    | `lequal
    | `less
    | `never
    | `notequal ]
type face = [ `back | `both | `front ]
val flush : unit -> unit
val finish : unit -> unit
type cap =
    [ `alpha_test
    | `auto_normal
    | `blend
    | `clip_plane0
    | `clip_plane1
    | `clip_plane2
    | `clip_plane3
    | `clip_plane4
    | `clip_plane5
    | `color_logic_op
    | `color_material
    | `cull_face
    | `depth_test
    | `dither
    | `fog
    | `index_logic_op
    | `light0
    | `light1
    | `light2
    | `light3
    | `light4
    | `light5
    | `light6
    | `light7
    | `lighting
    | `line_smooth
    | `line_stipple
    | `map1_color_4
    | `map1_index
    | `map1_normal
    | `map1_texture_coord_1
    | `map1_texture_coord_2
    | `map1_texture_coord_3
    | `map1_texture_coord_4
    | `map1_vertex_3
    | `map1_vertex_4
    | `map2_color_4
    | `map2_index
    | `map2_normal
    | `map2_texture_coord_1
    | `map2_texture_coord_2
    | `map2_texture_coord_3
    | `map2_texture_coord_4
    | `map2_vertex_3
    | `map2_vertex_4
    | `normalize
    | `point_smooth
    | `polygon_smooth
    | `polygon_stipple
    | `scissor_test
    | `stencil_test
    | `texture_1d
    | `texture_2d
    | `texture_gen_q
    | `texture_gen_r
    | `texture_gen_s
    | `texture_gen_t ]
val enable : cap -> unit
val disable : cap -> unit
val is_enabled : cap -> bool
type error =
    [ `invalid_enum
    | `invalid_operation
    | `invalid_value
    | `no_error
    | `out_of_memory
    | `stack_overflow
    | `stack_underflow
    | `table_too_large ]
val get_error : unit -> error
val raise_error : string -> unit