-// value of GL_MAX_TEXTURE_<various>_SIZE
-int gl_max_texture_size = 0;
-int gl_max_3d_texture_size = 0;
-int gl_max_cube_map_texture_size = 0;
-int gl_max_rectangle_texture_size = 0;
-// GL_ARB_multitexture
-int gl_textureunits = 1;
-// GL_ARB_texture_env_combine or GL_EXT_texture_env_combine
-int gl_combine_extension = false;
-// GL_EXT_compiled_vertex_array
-int gl_supportslockarrays = false;
-// 3D textures available
-int gl_texture3d = false;
-// GL_ARB_texture_cubemap
-int gl_texturecubemap = false;
-// GL_ARB_texture_rectangle
-int gl_texturerectangle = false;
-// GL_ARB_texture_non_power_of_two
-int gl_support_arb_texture_non_power_of_two = false;
-// GL_ARB_texture_env_dot3
-int gl_dot3arb = false;
-// GL_ARB_depth_texture
-int gl_depthtexture = false;
-// GL_ARB_shadow
-int gl_support_arb_shadow = false;
-// GL_SGIS_texture_edge_clamp
-int gl_support_clamptoedge = false;
-// GL_EXT_texture_filter_anisotropic
-int gl_support_anisotropy = false;
-int gl_max_anisotropy = 1;
-// OpenGL2.0 core glStencilOpSeparate, or GL_ATI_separate_stencil
-int gl_support_separatestencil = false;
-// GL_EXT_stencil_two_side
-int gl_support_stenciltwoside = false;
-// GL_EXT_blend_minmax
-int gl_support_ext_blend_minmax = false;
-// GL_EXT_blend_subtract
-int gl_support_ext_blend_subtract = false;
-// GL_ARB_shader_objects
-int gl_support_shader_objects = false;
-// GL_ARB_shading_language_100
-int gl_support_shading_language_100 = false;
-// GL_ARB_vertex_shader
-int gl_support_vertex_shader = false;
-// GL_ARB_fragment_shader
-int gl_support_fragment_shader = false;
-//GL_ARB_vertex_buffer_object
-int gl_support_arb_vertex_buffer_object = false;
-//GL_EXT_framebuffer_object
-int gl_support_ext_framebuffer_object = false;
-//GL_ARB_texture_compression
-int gl_support_texture_compression = false;
-//GL_ARB_occlusion_query
-int gl_support_arb_occlusion_query = false;
-//GL_AMD_texture_texture4
-int gl_support_amd_texture_texture4 = false;
-//GL_ARB_texture_gather
-int gl_support_arb_texture_gather = false;
-