(* $Id: glFunc.ml,v 1.7 2000-04-12 07:40:23 garrigue Exp $ *) open Gl external accum : op:[`accum|`load|`add|`mult|`return] -> float -> unit    = "ml_glAccum"external alpha_func : cmp_func -> ref:clampf -> unit = "ml_glAlphaFunc" type sfactor = [    `zero  | `one  | `dst_color  | `one_minus_dst_color  | `src_alpha  | `one_minus_src_alpha  | `dst_alpha  | `one_minus_dst_alpha  | `src_alpha_saturate]type dfactor = [    `zero  | `one  | `src_color  | `one_minus_src_color  | `src_alpha  | `one_minus_src_alpha  | `dst_alpha  | `one_minus_dst_alpha]external blend_func : src:sfactor -> dst:dfactor -> unit = "ml_glBlendFunc" external color_mask : bool -> bool -> bool -> bool -> unit    = "ml_glColorMask"let color_mask ?(red=false) ?(green=false) ?(blue=false) ?(alpha=false) ()=  color_mask red green blue alpha external depth_func : cmp_func -> unit = "ml_glDepthFunc"external depth_mask : bool -> unit = "ml_glDepthMask"external depth_range : near:float -> far:float -> unit = "ml_glDepthRange" type draw_buffer =    [`none|`front_left|`front_right|`back_left|`back_right    |`front|`back|`left|`right|`front_and_back|`aux of int]external draw_buffer : draw_buffer -> unit = "ml_glDrawBuffer" external index_mask : int -> unit = "ml_glIndexMask" type logic_op =    [`clear|`set|`copy|`copy_inverted|`noop|`invert|`And|`nand|`Or|`nor    |`xor|`equiv|`and_reverse|`and_inverted|`or_reverse|`or_inverted]external logic_op : logic_op -> unit = "ml_glLogicOp" type read_buffer =    [`front_left|`front_right|`back_left|`back_right|`front|`back    |`left|`right|`aux of int]external read_buffer : read_buffer -> unit = "ml_glReadBuffer" external stencil_func : cmp_func -> ref:int -> mask:int -> unit    = "ml_glStencilFunc"external stencil_mask : int -> unit = "ml_glStencilMask"type stencil_op = [`keep|`zero|`replace|`incr|`decr|`invert]external stencil_op :    fail:stencil_op -> zfail:stencil_op -> zpass:stencil_op -> unit    = "ml_glStencilOp"let stencil_op ?(fail=`keep) ?(zfail=`keep) ?(zpass=`keep) () =  stencil_op ~fail ~zfail ~zpass