sig
  type enabled_cap =
      GL_ALPHA_TEST
    | GL_AUTO_NORMAL
    | GL_BLEND
    | GL_CLIP_PLANE0
    | GL_CLIP_PLANE1
    | GL_CLIP_PLANE2
    | GL_CLIP_PLANE3
    | GL_CLIP_PLANE4
    | GL_CLIP_PLANE5
    | GL_COLOR_ARRAY
    | GL_COLOR_LOGIC_OP
    | GL_COLOR_MATERIAL
    | GL_COLOR_SUM
    | GL_COLOR_TABLE
    | GL_CONVOLUTION_1D
    | GL_CONVOLUTION_2D
    | GL_CULL_FACE
    | GL_DEPTH_TEST
    | GL_DITHER
    | GL_EDGE_FLAG_ARRAY
    | GL_FOG
    | GL_FOG_COORD_ARRAY
    | GL_HISTOGRAM
    | GL_INDEX_ARRAY
    | GL_INDEX_LOGIC_OP
    | GL_LIGHT0
    | GL_LIGHT1
    | GL_LIGHT2
    | GL_LIGHT3
    | GL_LIGHT4
    | GL_LIGHT5
    | GL_LIGHT6
    | GL_LIGHT7
    | GL_LIGHTING
    | GL_LINE_SMOOTH
    | GL_LINE_STIPPLE
    | GL_MAP1_COLOR_4
    | GL_MAP1_INDEX
    | GL_MAP1_NORMAL
    | GL_MAP1_TEXTURE_COORD_1
    | GL_MAP1_TEXTURE_COORD_2
    | GL_MAP1_TEXTURE_COORD_3
    | GL_MAP1_TEXTURE_COORD_4
    | GL_MAP2_COLOR_4
    | GL_MAP2_INDEX
    | GL_MAP2_NORMAL
    | GL_MAP2_TEXTURE_COORD_1
    | GL_MAP2_TEXTURE_COORD_2
    | GL_MAP2_TEXTURE_COORD_3
    | GL_MAP2_TEXTURE_COORD_4
    | GL_MAP2_VERTEX_3
    | GL_MAP2_VERTEX_4
    | GL_MINMAX
    | GL_MULTISAMPLE
    | GL_NORMAL_ARRAY
    | GL_NORMALIZE
    | GL_POINT_SMOOTH
    | GL_POINT_SPRITE
    | GL_POLYGON_SMOOTH
    | GL_POLYGON_OFFSET_FILL
    | GL_POLYGON_OFFSET_LINE
    | GL_POLYGON_OFFSET_POINT
    | GL_POLYGON_STIPPLE
    | GL_POST_COLOR_MATRIX_COLOR_TABLE
    | GL_POST_CONVOLUTION_COLOR_TABLE
    | GL_RESCALE_NORMAL
    | GL_SAMPLE_ALPHA_TO_COVERAGE
    | GL_SAMPLE_ALPHA_TO_ONE
    | GL_SAMPLE_COVERAGE
    | GL_SCISSOR_TEST
    | GL_SECONDARY_COLOR_ARRAY
    | GL_SEPARABLE_2D
    | GL_STENCIL_TEST
    | GL_TEXTURE_1D
    | GL_TEXTURE_2D
    | GL_TEXTURE_3D
    | GL_TEXTURE_COORD_ARRAY
    | GL_TEXTURE_CUBE_MAP
    | GL_TEXTURE_GEN_Q
    | GL_TEXTURE_GEN_R
    | GL_TEXTURE_GEN_S
    | GL_TEXTURE_GEN_T
    | GL_VERTEX_ARRAY
    | GL_VERTEX_PROGRAM_POINT_SIZE
    | GL_VERTEX_PROGRAM_TWO_SIDE
end