Texture.surface_to

let surface_to_texture ?texture surface =        

        (*try*)

                Init.init_sdl_once () ;

                let surface_fmt_to_pix surface = 

                        let bits = Sdlvideo.surface_bpp surface in

                        if bits = 24 then `rgb else

                        if bits = 32 then `rgba else

                        raise (Invalid_surface_format ((Printf.sprintf "I don't know how to handle an image depth of %d bits.  Please convert to 24bit RGB or 32bit RGBA format." bits),bits))

                in

        

                let surface_info = Sdlvideo.surface_info surface in

                let pix_fmt = surface_fmt_to_pix surface in

                let texture_id = match texture with

                  None -> print_endline "gentex" ; GlTex.gen_texture () 

                | Some texture_id -> print_endline "usetex" ; texture_id

                in

                let pix = GlPix.of_raw (surface_to_raw surface) 

                                       ~format:(surface_fmt_to_pix surface)

                                                           ~width:surface_info.Sdlvideo.w

                                                           ~height:surface_info.Sdlvideo.h

                in

                GlTex.bind_texture `texture_2d texture_id ;

                GlTex.image2d pix ;

                GlTex.parameter `texture_2d (`mag_filter `linear) ;

                GlTex.parameter `texture_2d (`min_filter `linear) ;

                texture_id