Do not flash too much on throttled zoom

[llpp.git] / main.ml

type under =
    | Unone
    | Ulinkuri of string
    | Ulinkgoto of (int * int)
    | Utext of facename
and facename = string;;

let dolog fmt = Printf.kprintf prerr_endline fmt;;
let now = Unix.gettimeofday;;

exception Quit;;

type params = (angle * proportional * trimparams
                * texcount * sliceheight * memsize
                * colorspace * wmclasshack * fontpath)
and pageno         = int
and width          = int
and height         = int
and leftx          = int
and opaque         = string
and recttype       = int
and pixmapsize     = int
and angle          = int
and proportional   = bool
and trimmargins    = bool
and interpagespace = int
and texcount       = int
and sliceheight    = int
and gen            = int
and top            = float
and fontpath       = string
and memsize        = int
and aalevel        = int
and wmclasshack    = bool
and irect          = (int * int * int * int)
and trimparams     = (trimmargins * irect)
and colorspace     = | Rgb | Bgr | Gray
;;

type platform = | Punknown | Plinux | Pwindows | Posx | Psun
                | Pfreebsd | Pdragonflybsd | Popenbsd | Pmingw | Pcygwin;;

external init : Unix.file_descr -> params -> unit = "ml_init";;
external seltext : string -> (int * int * int * int) -> unit = "ml_seltext";;
external copysel : string ->  unit = "ml_copysel";;
external getpdimrect : int -> float array = "ml_getpdimrect";;
external whatsunder : string -> int -> int -> under = "ml_whatsunder";;
external zoomforh : int -> int -> int -> float = "ml_zoom_for_height";;
external drawstr : int -> int -> int -> string -> float = "ml_draw_string";;
external measurestr : int -> string -> float = "ml_measure_string";;
external getmaxw : unit -> float = "ml_getmaxw";;
external postprocess : opaque -> bool -> int -> int -> unit = "ml_postprocess";;
external pagebbox : opaque -> (int * int * int * int) = "ml_getpagebox";;
external platform : unit -> platform = "ml_platform";;
external setaalevel : int -> unit = "ml_setaalevel";;

let platform_to_string = function
  | Punknown      -> "unknown"
  | Plinux        -> "Linux"
  | Pwindows      -> "Windows"
  | Posx          -> "OSX"
  | Psun          -> "Sun"
  | Pfreebsd      -> "FreeBSD"
  | Pdragonflybsd -> "DragonflyBSD"
  | Popenbsd      -> "OpenBSD"
  | Pcygwin       -> "Cygwin"
  | Pmingw        -> "MingW"
;;

let platform = platform ();;

let is_windows =
  match platform with
  | Pwindows | Pmingw -> true
  | _ -> false
;;

type x = int
and y = int
and tilex = int
and tiley = int
and tileparams = (x * y * width * height * tilex * tiley)
;;

external drawtile : tileparams -> string -> unit = "ml_drawtile";;

type mpos = int * int
and mstate =
    | Msel of (mpos * mpos)
    | Mpan of mpos
    | Mscrolly | Mscrollx
    | Mzoom of (int * int)
    | Mzoomrect of (mpos * mpos)
    | Mnone
;;

type textentry = string * string * onhist option * onkey * ondone
and onkey = string -> int -> te
and ondone = string -> unit
and histcancel = unit -> unit
and onhist = ((histcmd -> string) * histcancel)
and histcmd = HCnext | HCprev | HCfirst | HClast
and te =
    | TEstop
    | TEdone of string
    | TEcont of string
    | TEswitch of textentry
;;

type 'a circbuf =
    { store : 'a array
    ; mutable rc : int
    ; mutable wc : int
    ; mutable len : int
    }
;;

let bound v minv maxv =
  max minv (min maxv v);
;;

let cbnew n v =
  { store = Array.create n v
  ; rc = 0
  ; wc = 0
  ; len = 0
  }
;;

let drawstring size x y s =
  Gl.enable `blend;
  Gl.enable `texture_2d;
  ignore (drawstr size x y s);
  Gl.disable `blend;
  Gl.disable `texture_2d;
;;

let drawstring1 size x y s =
  drawstr size x y s;
;;

let drawstring2 size x y fmt =
  Printf.kprintf (drawstring size (x+1) (y+size+1)) fmt
;;

let cbcap b = Array.length b.store;;

let cbput b v =
  let cap = cbcap b in
  b.store.(b.wc) <- v;
  b.wc <- (b.wc + 1) mod cap;
  b.rc <- b.wc;
  b.len <- min (b.len + 1) cap;
;;

let cbempty b = b.len = 0;;

let cbgetg b circular dir =
  if cbempty b
  then b.store.(0)
  else
    let rc = b.rc + dir in
    let rc =
      if circular
      then (
        if rc = -1
        then b.len-1
        else (
          if rc = b.len
          then 0
          else rc
        )
      )
      else max 0 (min rc (b.len-1))
    in
    b.rc <- rc;
    b.store.(rc);
;;

let cbget b = cbgetg b false;;
let cbgetc b = cbgetg b true;;

type page =
    { pageno    : int
    ; pagedimno : int
    ; pagew     : int
    ; pageh     : int
    ; pagex     : int
    ; pagey     : int
    ; pagevw    : int
    ; pagevh    : int
    ; pagedispx : int
    ; pagedispy : int
    }
;;

let debugl l =
  dolog "l %d dim=%d {" l.pageno l.pagedimno;
  dolog "  WxH     %dx%d" l.pagew l.pageh;
  dolog "  vWxH    %dx%d" l.pagevw l.pagevh;
  dolog "  pagex,y %d,%d" l.pagex l.pagey;
  dolog "  dispx,y %d,%d" l.pagedispx l.pagedispy;
  dolog "}";
;;

let debugrect (x0, y0, x1, y1, x2, y2, x3, y3) =
  dolog "rect {";
  dolog "  x0,y0=(% f, % f)" x0 y0;
  dolog "  x1,y1=(% f, % f)" x1 y1;
  dolog "  x2,y2=(% f, % f)" x2 y2;
  dolog "  x3,y3=(% f, % f)" x3 y3;
  dolog "}";
;;

type conf =
    { mutable scrollbw       : int
    ; mutable scrollh        : int
    ; mutable icase          : bool
    ; mutable preload        : bool
    ; mutable pagebias       : int
    ; mutable verbose        : bool
    ; mutable debug          : bool
    ; mutable scrollstep     : int
    ; mutable maxhfit        : bool
    ; mutable crophack       : bool
    ; mutable autoscrollstep : int
    ; mutable maxwait        : float option
    ; mutable hlinks         : bool
    ; mutable underinfo      : bool
    ; mutable interpagespace : interpagespace
    ; mutable zoom           : float
    ; mutable presentation   : bool
    ; mutable angle          : angle
    ; mutable winw           : int
    ; mutable winh           : int
    ; mutable savebmarks     : bool
    ; mutable proportional   : proportional
    ; mutable trimmargins    : trimmargins
    ; mutable trimfuzz       : irect
    ; mutable memlimit       : memsize
    ; mutable texcount       : texcount
    ; mutable sliceheight    : sliceheight
    ; mutable thumbw         : width
    ; mutable jumpback       : bool
    ; mutable bgcolor        : float * float * float
    ; mutable bedefault      : bool
    ; mutable scrollbarinpm  : bool
    ; mutable tilew          : int
    ; mutable tileh          : int
    ; mutable mumemlimit     : memsize
    ; mutable checkers       : bool
    ; mutable aalevel        : int
    ; mutable urilauncher    : string
    ; mutable colorspace     : colorspace
    ; mutable invert         : bool
    ; mutable colorscale     : float
    }
;;

type anchor = pageno * top;;

type outline = string * int * anchor;;

type rect = float * float * float * float * float * float * float * float;;

type tile = opaque * pixmapsize * elapsed
and elapsed = float;;
type pagemapkey = pageno * gen;;
type tilemapkey = pageno * gen * colorspace * angle * width * height * col * row
and row = int
and col = int;;

let emptyanchor = (0, 0.0);;

type infochange = | Memused | Docinfo | Pdim;;

class type uioh = object
  method display : unit
  method key : int -> uioh
  method special : Glut.special_key_t -> uioh
  method button :
    Glut.button_t -> Glut.mouse_button_state_t -> int -> int -> uioh
  method motion : int -> int -> uioh
  method pmotion : int -> int -> uioh
  method infochanged : infochange -> unit
end;;

type mode =
    | Birdseye of (conf * leftx * pageno * pageno * anchor)
    | Textentry of (textentry * onleave)
    | View
and onleave = leavetextentrystatus -> unit
and leavetextentrystatus = | Cancel | Confirm
and helpitem = string * int * action
and action =
    | Noaction
    | Action of (uioh -> uioh)
;;

let isbirdseye = function Birdseye _ -> true | _ -> false;;
let istextentry = function Textentry _ -> true | _ -> false;;

type currently =
    | Idle
    | Loading of (page * gen)
    | Tiling of (
        page * opaque * colorspace * angle * gen * col * row * width * height
      )
    | Outlining of outline list
;;

let nouioh : uioh = object (self)
  method display = ()
  method key _ = self
  method special _ = self
  method button _ _ _ _ = self
  method motion _ _ = self
  method pmotion _ _ = self
  method infochanged _ = ()
end;;

type state =
    { mutable csock         : Unix.file_descr
    ; mutable ssock         : Unix.file_descr
    ; mutable w             : int
    ; mutable x             : int
    ; mutable y             : int
    ; mutable scrollw       : int
    ; mutable hscrollh      : int
    ; mutable anchor        : anchor
    ; mutable maxy          : int
    ; mutable layout        : page list
    ; pagemap               : (pagemapkey, opaque) Hashtbl.t
    ; tilemap               : (tilemapkey, tile) Hashtbl.t
    ; tilelru               : (tilemapkey * opaque * pixmapsize) Queue.t
    ; mutable pdims         : (pageno * width * height * leftx) list
    ; mutable pagecount     : int
    ; mutable currently     : currently
    ; mutable mstate        : mstate
    ; mutable searchpattern : string
    ; mutable rects         : (pageno * recttype * rect) list
    ; mutable rects1        : (pageno * recttype * rect) list
    ; mutable text          : string
    ; mutable fullscreen    : (width * height) option
    ; mutable mode          : mode
    ; mutable uioh          : uioh
    ; mutable outlines      : outline array
    ; mutable bookmarks     : outline list
    ; mutable path          : string
    ; mutable password      : string
    ; mutable invalidated   : int
    ; mutable memused       : memsize
    ; mutable gen           : gen
    ; mutable throttle      : (page list * int * float) option
    ; mutable autoscroll    : int option
    ; mutable help          : helpitem array
    ; mutable docinfo       : (int * string) list
    ; mutable deadline      : float
    ; mutable texid         : GlTex.texture_id option
    ; hists                 : hists
    ; mutable prevzoom      : float
    ; mutable progress      : float
    }
and hists =
    { pat : string circbuf
    ; pag : string circbuf
    ; nav : anchor circbuf
    }
;;

let defconf =
  { scrollbw       = 7
  ; scrollh        = 12
  ; icase          = true
  ; preload        = true
  ; pagebias       = 0
  ; verbose        = false
  ; debug          = false
  ; scrollstep     = 24
  ; maxhfit        = true
  ; crophack       = false
  ; autoscrollstep = 2
  ; maxwait        = None
  ; hlinks         = false
  ; underinfo      = false
  ; interpagespace = 2
  ; zoom           = 1.0
  ; presentation   = false
  ; angle          = 0
  ; winw           = 900
  ; winh           = 900
  ; savebmarks     = true
  ; proportional   = true
  ; trimmargins    = false
  ; trimfuzz       = (0,0,0,0)
  ; memlimit       = 32 lsl 20
  ; texcount       = 256
  ; sliceheight    = 24
  ; thumbw         = 76
  ; jumpback       = true
  ; bgcolor        = (0.5, 0.5, 0.5)
  ; bedefault      = false
  ; scrollbarinpm  = true
  ; tilew          = 2048
  ; tileh          = 2048
  ; mumemlimit     = 128 lsl 20
  ; checkers       = true
  ; aalevel        = 8
  ; urilauncher    =
      (match platform with
      | Plinux | Pfreebsd | Pdragonflybsd | Popenbsd | Psun -> "xdg-open \"%s\""
      | Posx -> "open \"%s\""
      | Pwindows | Pcygwin | Pmingw -> "iexplore \"%s\""
      | _ -> "")
  ; colorspace = Rgb
  ; invert = false
  ; colorscale = 1.0
  }
;;

let conf = { defconf with angle = defconf.angle };;

type fontstate =
    { mutable fontsize : int
    ; mutable wwidth : float
    ; mutable maxrows : int
    }
;;

let fstate =
  { fontsize = 14
  ; wwidth = nan
  ; maxrows = -1
  }
;;

let setfontsize n =
  fstate.fontsize <- n;
  fstate.wwidth <- measurestr fstate.fontsize "w";
  fstate.maxrows <- (conf.winh - fstate.fontsize - 1) / (fstate.fontsize + 1);
;;

let gotouri uri =
  if String.length conf.urilauncher = 0
  then print_endline uri
  else
    let re = Str.regexp "%s" in
    let command = Str.global_replace re uri conf.urilauncher in
    let optic =
      try Some (Unix.open_process_in command)
      with exn ->
        Printf.eprintf
          "failed to execute `%s': %s\n" command (Printexc.to_string exn);
        flush stderr;
        None
    in
    match optic with
    | Some ic -> close_in ic
    | None -> ()
;;

let makehelp () =
  let strings = ("llpp version " ^ Help.version) :: "" :: Help.keys in
  Array.of_list (
    let r = Str.regexp "\\(http://[^ ]+\\)" in
    List.map (fun s ->
      if (try Str.search_forward r s 0 with Not_found -> -1) >= 0
      then
        let uri = Str.matched_string s in
        (s, 0, Action (fun u -> gotouri uri; u))
      else s, 0, Noaction) strings
  );
;;

let state =
  { csock         = Unix.stdin
  ; ssock         = Unix.stdin
  ; x             = 0
  ; y             = 0
  ; w             = 0
  ; scrollw       = 0
  ; hscrollh      = 0
  ; anchor        = emptyanchor
  ; layout        = []
  ; maxy          = max_int
  ; tilelru       = Queue.create ()
  ; pagemap       = Hashtbl.create 10
  ; tilemap       = Hashtbl.create 10
  ; pdims         = []
  ; pagecount     = 0
  ; currently     = Idle
  ; mstate        = Mnone
  ; rects         = []
  ; rects1        = []
  ; text          = ""
  ; mode          = View
  ; fullscreen    = None
  ; searchpattern = ""
  ; outlines      = [||]
  ; bookmarks     = []
  ; path          = ""
  ; password      = ""
  ; invalidated   = 0
  ; hists         =
      { nav       = cbnew 10 (0, 0.0)
      ; pat       = cbnew 1 ""
      ; pag       = cbnew 1 ""
      }
  ; memused       = 0
  ; gen           = 0
  ; throttle      = None
  ; autoscroll    = None
  ; help          = makehelp ()
  ; docinfo       = []
  ; deadline      = nan
  ; texid         = None
  ; prevzoom      = 1.0
  ; progress      = -1.0
  ; uioh          = nouioh
  }
;;

let vlog fmt =
  if conf.verbose
  then
    Printf.kprintf prerr_endline fmt
  else
    Printf.kprintf ignore fmt
;;

module G =
struct
  let postRedisplay who =
    if conf.verbose
    then prerr_endline ("redisplay for " ^ who);
    Glut.postRedisplay ();
  ;;
end;;

let addchar s c =
  let b = Buffer.create (String.length s + 1) in
  Buffer.add_string b s;
  Buffer.add_char b c;
  Buffer.contents b;
;;

let colorspace_of_string s =
  match String.lowercase s with
  | "rgb" -> Rgb
  | "bgr" -> Bgr
  | "gray" -> Gray
  | _ -> failwith "invalid colorspace"
;;

let int_of_colorspace = function
  | Rgb -> 0
  | Bgr -> 1
  | Gray -> 2
;;

let colorspace_of_int = function
  | 0 -> Rgb
  | 1 -> Bgr
  | 2 -> Gray
  | n -> failwith ("invalid colorspace index " ^ string_of_int n)
;;

let colorspace_to_string = function
  | Rgb -> "rgb"
  | Bgr -> "bgr"
  | Gray -> "gray"
;;

let intentry_with_suffix text key =
  let c = Char.unsafe_chr key in
  match Char.lowercase c with
  | '0' .. '9' ->
      let text = addchar text c in
      TEcont text

  | 'k' | 'm' | 'g' ->
      let text = addchar text c in
      TEcont text

  | _ ->
      state.text <- Printf.sprintf "invalid char (%d, `%c')" key c;
      TEcont text
;;

let writecmd fd s =
  let len = String.length s in
  let n = 4 + len in
  let b = Buffer.create n in
  Buffer.add_char b (Char.chr ((len lsr 24) land 0xff));
  Buffer.add_char b (Char.chr ((len lsr 16) land 0xff));
  Buffer.add_char b (Char.chr ((len lsr  8) land 0xff));
  Buffer.add_char b (Char.chr ((len lsr  0) land 0xff));
  Buffer.add_string b s;
  let s' = Buffer.contents b in
  let n' = Unix.write fd s' 0 n in
  if n' != n then failwith "write failed";
;;

let readcmd fd =
  let s = "xxxx" in
  let n = Unix.read fd s 0 4 in
  if n != 4 then failwith "incomplete read(len)";
  let len = 0
    lor (Char.code s.[0] lsl 24)
    lor (Char.code s.[1] lsl 16)
    lor (Char.code s.[2] lsl  8)
    lor (Char.code s.[3] lsl  0)
  in
  let s = String.create len in
  let n = Unix.read fd s 0 len in
  if n != len then failwith "incomplete read(data)";
  s
;;

let makecmd s l =
  let b = Buffer.create 10 in
  Buffer.add_string b s;
  let rec combine = function
    | [] -> b
    | x :: xs ->
        Buffer.add_char b ' ';
        let s =
          match x with
          | `b b -> if b then "1" else "0"
          | `s s -> s
          | `i i -> string_of_int i
          | `f f -> string_of_float f
          | `I f -> string_of_int (truncate f)
        in
        Buffer.add_string b s;
        combine xs;
  in
  combine l;
;;

let wcmd s l =
  let cmd = Buffer.contents (makecmd s l) in
  writecmd state.csock cmd;
;;

let calcips h =
  if conf.presentation
  then
    let d = conf.winh - h in
    max 0 ((d + 1) / 2)
  else
    conf.interpagespace
;;

let calcheight () =
  let rec f pn ph pi fh l =
    match l with
    | (n, _, h, _) :: rest ->
        let ips = calcips h in
        let fh =
          if conf.presentation
          then fh+ips
          else (
            if isbirdseye state.mode && pn = 0
            then fh + ips
            else fh
          )
        in
        let fh = fh + ((n - pn) * (ph + pi)) in
        f n h ips fh rest;

    | [] ->
        let inc =
          if conf.presentation || (isbirdseye state.mode && pn = 0)
          then 0
          else -pi
        in
        let fh = fh + ((state.pagecount - pn) * (ph + pi)) + inc in
        max 0 fh
  in
  let fh = f 0 0 0 0 state.pdims in
  fh;
;;

let getpageyh pageno =
  let rec f pn ph pi y l =
    match l with
    | (n, _, h, _) :: rest ->
        let ips = calcips h in
        if n >= pageno
        then
          let h = if n = pageno then h else ph in
          if conf.presentation && n = pageno
          then
            y + (pageno - pn) * (ph + pi) + pi, h
          else
            y + (pageno - pn) * (ph + pi), h
        else
          let y = y + (if conf.presentation then pi else 0) in
          let y = y + (n - pn) * (ph + pi) in
          f n h ips y rest

    | [] ->
        y + (pageno - pn) * (ph + pi), ph
  in
  f 0 0 0 0 state.pdims
;;

let getpagedim pageno =
  let rec f ppdim l =
    match l with
    | (n, _, _, _) as pdim :: rest ->
        if n >= pageno
        then (if n = pageno then pdim else ppdim)
        else f pdim rest

    | [] -> ppdim
  in
  f (-1, -1, -1, -1) state.pdims
;;

let getpageh pageno =
  let _, _, h, _ = getpagedim pageno in
  h
;;

let getpagew pageno =
  let _, w, _, _ = getpagedim pageno in
  w
;;

let getpagey pageno = fst (getpageyh pageno);;

let layout y sh =
  let sh = sh - state.hscrollh in
  let rec f ~pageno ~pdimno ~prev ~py ~dy ~pdims ~accu =
    let ((w, h, ips, xoff) as curr), rest, pdimno, yinc =
      match pdims with
      | (pageno', w, h, xoff) :: rest when pageno' = pageno ->
          let ips = calcips h in
          let yinc =
            if conf.presentation || (isbirdseye state.mode && pageno = 0)
            then ips
            else 0
          in
          (w, h, ips, xoff), rest, pdimno + 1, yinc
      | _ ->
          prev, pdims, pdimno, 0
    in
    let dy = dy + yinc in
    let py = py + yinc in
    if pageno = state.pagecount || dy >= sh
    then
      accu
    else
      let vy = y + dy in
      if py + h <= vy - yinc
      then
        let py = py + h + ips in
        let dy = max 0 (py - y) in
        f ~pageno:(pageno+1)
          ~pdimno
          ~prev:curr
          ~py
          ~dy
          ~pdims:rest
          ~accu
      else
        let pagey = vy - py in
        let pagevh = h - pagey in
        let pagevh = min (sh - dy) pagevh in
        let off = if yinc > 0 then py - vy else 0 in
        let py = py + h + ips in
        let pagex, dx =
          let xoff = xoff +
            if state.w < conf.winw - state.scrollw
            then (conf.winw - state.scrollw - state.w) / 2
            else 0
          in
          let dispx = xoff + state.x in
          if dispx < 0
          then (-dispx, 0)
          else (0, dispx)
        in
        let pagevw =
          let lw = w - pagex in
          min lw (conf.winw - state.scrollw)
        in
        let e =
          { pageno = pageno
          ; pagedimno = pdimno
          ; pagew = w
          ; pageh = h
          ; pagex = pagex
          ; pagey = pagey + off
          ; pagevw = pagevw
          ; pagevh = pagevh - off
          ; pagedispx = dx
          ; pagedispy = dy + off
          }
        in
        let accu = e :: accu in
        f ~pageno:(pageno+1)
          ~pdimno
          ~prev:curr
          ~py
          ~dy:(dy+pagevh+ips)
          ~pdims:rest
          ~accu
  in
  if state.invalidated = 0
  then (
    let accu =
      f
        ~pageno:0
        ~pdimno:~-1
        ~prev:(0,0,0,0)
        ~py:0
        ~dy:0
        ~pdims:state.pdims
        ~accu:[]
    in
    List.rev accu
  )
  else
    []
;;

let clamp incr =
  let y = state.y + incr in
  let y = max 0 y in
  let y = min y (state.maxy - (if conf.maxhfit then conf.winh else 0)) in
  y;
;;

let getopaque pageno =
  try Some (Hashtbl.find state.pagemap (pageno, state.gen))
  with Not_found -> None
;;

let putopaque pageno opaque =
  Hashtbl.replace state.pagemap (pageno, state.gen) opaque
;;

let itertiles l f =
  let tilex = l.pagex mod conf.tilew in
  let tiley = l.pagey mod conf.tileh in

  let col = l.pagex / conf.tilew in
  let row = l.pagey / conf.tileh in

  let vw =
    let a = l.pagew - l.pagex in
    let b = conf.winw - state.scrollw in
    min a b
  and vh = l.pagevh in

  let rec rowloop row y0 dispy h =
    if h = 0
    then ()
    else (
      let dh = conf.tileh - y0 in
      let dh = min h dh in
      let rec colloop col x0 dispx w =
        if w = 0
        then ()
        else (
          let dw = conf.tilew - x0 in
          let dw = min w dw in

          f col row dispx dispy x0 y0 dw dh;
          colloop (col+1) 0 (dispx+dw) (w-dw)
        )
      in
      colloop col tilex l.pagedispx vw;
      rowloop (row+1) 0 (dispy+dh) (h-dh)
    )
  in
  if vw > 0 && vh > 0
  then rowloop row tiley l.pagedispy vh;
;;

let gettileopaque l col row =
  let key =
    l.pageno, state.gen, conf.colorspace, conf.angle, l.pagew, l.pageh, col, row
  in
  try Some (Hashtbl.find state.tilemap key)
  with Not_found -> None
;;

let puttileopaque l col row gen colorspace angle opaque size elapsed =
  let key = l.pageno, gen, colorspace, angle, l.pagew, l.pageh, col, row in
  Hashtbl.add state.tilemap key (opaque, size, elapsed)
;;

let drawtiles l color =
  GlDraw.color color;
  let f col row x y tilex tiley w h =
    match gettileopaque l col row with
    | Some (opaque, _, t) ->
        let params = x, y, w, h, tilex, tiley in
        if conf.invert
        then (
          Gl.enable `blend;
          GlFunc.blend_func `zero `one_minus_src_color;
        );
        drawtile params opaque;
        if conf.invert
        then Gl.disable `blend;
        if conf.debug
        then (
          let s = Printf.sprintf
            "%d[%d,%d] %f sec"
            l.pageno col row t
          in
          let ww = fstate.wwidth in
          GlMisc.push_attrib [`current];
          GlDraw.color (0.0, 0.0, 0.0);
          GlDraw.rect
            (float (x-2), float (y-2))
            (float (x+2) +. ww, float (y + fstate.fontsize + 2));
          GlDraw.color (1.0, 1.0, 1.0);
          drawstring fstate.fontsize x (y + fstate.fontsize - 1) s;
          GlMisc.pop_attrib ();
        );

    | _ ->
        let w =
          let lw = conf.winw - state.scrollw - x in
          min lw w
        and h =
          let lh = conf.winh - y in
          min lh h
        in
        Gl.enable `texture_2d;
        begin match state.texid with
        | Some id ->
            GlTex.bind_texture `texture_2d id;
            let x0 = float x
            and y0 = float y
            and x1 = float (x+w)
            and y1 = float (y+h) in

            let tw = float w /. 64.0
            and th = float h /. 64.0 in
            let tx0 = float tilex /. 64.0
            and ty0 = float tiley /. 64.0 in
            let tx1 = tx0 +. tw
            and ty1 = ty0 +. th in
            GlDraw.begins `quads;
            GlTex.coord2 (tx0, ty0); GlDraw.vertex2 (x0, y0);
            GlTex.coord2 (tx0, ty1); GlDraw.vertex2 (x0, y1);
            GlTex.coord2 (tx1, ty1); GlDraw.vertex2 (x1, y1);
            GlTex.coord2 (tx1, ty0); GlDraw.vertex2 (x1, y0);
            GlDraw.ends ();

            Gl.disable `texture_2d;
        | None ->
            GlDraw.color (1.0, 1.0, 1.0);
            GlDraw.rect
              (float x, float y)
              (float (x+w), float (y+h));
        end;
        if w > 128 && h > fstate.fontsize + 10
        then (
          GlDraw.color (0.0, 0.0, 0.0);
          let c, r =
            if conf.verbose
            then (col*conf.tilew, row*conf.tileh)
            else col, row
          in
          drawstring2 fstate.fontsize x y "Loading %d [%d,%d]" l.pageno c r;
        );
        GlDraw.color color;
  in
  itertiles l f
;;

let pagevisible layout n = List.exists (fun l -> l.pageno = n) layout;;

let tilevisible1 l x y =
  let ax0 = l.pagex
  and ax1 = l.pagex + l.pagevw
  and ay0 = l.pagey
  and ay1 = l.pagey + l.pagevh in

  let bx0 = x
  and by0 = y in
  let bx1 = min (bx0 + conf.tilew) l.pagew
  and by1 = min (by0 + conf.tileh) l.pageh in

  let rx0 = max ax0 bx0
  and ry0 = max ay0 by0
  and rx1 = min ax1 bx1
  and ry1 = min ay1 by1 in

  let nonemptyintersection = rx1 > rx0 && ry1 > ry0 in
  nonemptyintersection
;;

let tilevisible layout n x y =
  let rec findpageinlayout = function
    | l :: _ when l.pageno = n -> tilevisible1 l x y
    | _ :: rest -> findpageinlayout rest
    | [] -> false
  in
  findpageinlayout layout
;;

let tileready l x y =
  tilevisible1 l x y &&
    gettileopaque l (x/conf.tilew) (y/conf.tileh) != None
;;

let tilepage n p layout =
  let rec loop = function
    | l :: rest ->
        if l.pageno = n
        then
          let f col row _ _ _ _ _ _ =
            if state.currently = Idle
            then
              match gettileopaque l col row with
              | Some _ -> ()
              | None ->
                  let x = col*conf.tilew
                  and y = row*conf.tileh in
                  let w =
                    let w = l.pagew - x in
                    min w conf.tilew
                  in
                  let h =
                    let h = l.pageh - y in
                    min h conf.tileh
                  in
                  wcmd "tile"
                    [`s p
                    ;`i x
                    ;`i y
                    ;`i w
                    ;`i h
                    ];
                  state.currently <-
                    Tiling (
                      l, p, conf.colorspace, conf.angle, state.gen, col, row,
                      conf.tilew, conf.tileh
                    );
          in
          itertiles l f;
        else
          loop rest

    | [] -> ()
  in
  if state.invalidated = 0 then loop layout;
;;

let preloadlayout visiblepages =
  let presentation = conf.presentation in
  let interpagespace = conf.interpagespace in
  let maxy = state.maxy in
  conf.presentation <- false;
  conf.interpagespace <- 0;
  state.maxy <- calcheight ();
  let y =
    match visiblepages with
    | [] -> 0
    | l :: _ -> getpagey l.pageno + l.pagey
  in
  let y = if y < conf.winh then 0 else y - conf.winh in
  let h = state.y - y + conf.winh*3 in
  let pages = layout y h in
  conf.presentation <- presentation;
  conf.interpagespace <- interpagespace;
  state.maxy <- maxy;
  pages
;;

let load pages =
  let rec loop pages =
    if state.currently != Idle
    then ()
    else
      match pages with
      | l :: rest ->
          begin match getopaque l.pageno with
          | None ->
              wcmd "page" [`i l.pageno; `i l.pagedimno];
              state.currently <- Loading (l, state.gen);
          | Some opaque ->
              tilepage l.pageno opaque pages;
              loop rest
          end;
      | _ -> ()
  in
  if state.invalidated = 0 then loop pages
;;

let preload pages =
  load pages;
  if conf.preload && state.currently = Idle
  then load (preloadlayout pages);
;;

let layoutready layout =
  let rec fold all ls =
    all && match ls with
    | l :: rest ->
        let seen = ref false in
        let allvisible = ref true in
        let foo col row _ _ _ _ _ _ =
          seen := true;
          allvisible := !allvisible &&
            begin match gettileopaque l col row with
            | Some _ -> true
            | None -> false
            end
        in
        itertiles l foo;
        fold (!seen && !allvisible) rest
    | [] -> true
  in
  let alltilesvisible = fold true layout in
  alltilesvisible;
;;

let gotoy y =
  let y = bound y 0 state.maxy in
  let y, layout, proceed =
    match conf.maxwait with
    | Some time ->
        begin match state.throttle with
        | None ->
            let layout = layout y conf.winh in
            let ready = layoutready layout in
            if not ready
            then (
              load layout;
              state.throttle <- Some (layout, y, now ());
            )
            else G.postRedisplay "gotoy showall (None)";
            y, layout, ready
        | Some (_, _, started) ->
            let dt = now () -. started in
            if dt > time
            then (
              state.throttle <- None;
              let layout = layout y conf.winh in
              load layout;
              G.postRedisplay "maxwait";
              y, layout, true
            )
            else -1, [], false
        end

    | None ->
        let layout = layout y conf.winh in
        if true || layoutready layout
        then G.postRedisplay "gotoy ready";
        y, layout, true
  in
  if proceed
  then (
    state.y <- y;
    state.layout <- layout;
    begin match state.mode with
    | Birdseye (conf, leftx, pageno, hooverpageno, anchor) ->
        if not (pagevisible layout pageno)
        then (
          match state.layout with
          | [] -> ()
          | l :: _ ->
              state.mode <- Birdseye (
                conf, leftx, l.pageno, hooverpageno, anchor
              )
        );
    | _ -> ()
    end;
    preload layout;
  );
;;

let conttiling pageno opaque =
  tilepage pageno opaque
    (if conf.preload then preloadlayout state.layout else state.layout)
;;

let gotoy_and_clear_text y =
  gotoy y;
  if not conf.verbose then state.text <- "";
;;

let getanchor () =
  match state.layout with
  | []     -> emptyanchor
  | l :: _ -> (l.pageno, float l.pagey /. float l.pageh)
;;

let getanchory (n, top) =
  let y, h = getpageyh n in
  y + (truncate (top *. float h));
;;

let gotoanchor anchor =
  gotoy (getanchory anchor);
;;

let addnav () =
  cbput state.hists.nav (getanchor ());
;;

let getnav dir =
  let anchor = cbgetc state.hists.nav dir in
  getanchory anchor;
;;

let gotopage n top =
  let y, h = getpageyh n in
  gotoy_and_clear_text (y + (truncate (top *. float h)));
;;

let gotopage1 n top =
  let y = getpagey n in
  gotoy_and_clear_text (y + top);
;;

let invalidate () =
  state.layout <- [];
  state.pdims <- [];
  state.rects <- [];
  state.rects1 <- [];
  state.invalidated <- state.invalidated + 1;
;;

let writeopen path password  =
  writecmd state.csock ("open " ^ path ^ "\000" ^ password ^ "\000");
;;

let opendoc path password =
  invalidate ();
  state.path <- path;
  state.password <- password;
  state.gen <- state.gen + 1;
  state.docinfo <- [];

  setaalevel conf.aalevel;
  writeopen path password;
  Glut.setWindowTitle ("llpp " ^ Filename.basename path);
  wcmd "geometry" [`i state.w; `i conf.winh];
;;

let scalecolor c =
  let c = c *. conf.colorscale in
  (c, c, c);
;;

let scalecolor2 (r, g, b) =
  (r *. conf.colorscale, g *. conf.colorscale, b *. conf.colorscale);
;;

let represent () =
  state.maxy <- calcheight ();
  state.hscrollh <-
    if state.w <= conf.winw - state.scrollw
    then 0
    else state.scrollw
  ;
  match state.mode with
  | Birdseye (_, _, pageno, _, _) ->
      let y, h = getpageyh pageno in
      let top = (conf.winh - h) / 2 in
      gotoy (max 0 (y - top))
  | _ -> gotoanchor state.anchor
;;

let reshape =
  let firsttime = ref true in
  fun ~w ~h ->
    GlDraw.viewport 0 0 w h;
    if state.invalidated = 0 && not !firsttime
    then state.anchor <- getanchor ();

    firsttime := false;
    conf.winw <- w;
    let w = truncate (float w *. conf.zoom) - state.scrollw in
    let w = max w 2 in
    state.w <- w;
    conf.winh <- h;
    setfontsize fstate.fontsize;
    GlMat.mode `modelview;
    GlMat.load_identity ();

    GlMat.mode `projection;
    GlMat.load_identity ();
    GlMat.rotate ~x:1.0 ~angle:180.0 ();
    GlMat.translate ~x:~-.1.0 ~y:~-.1.0 ();
    GlMat.scale3 (2.0 /. float conf.winw, 2.0 /. float conf.winh, 1.0);

    invalidate ();
    wcmd "geometry" [`i w; `i h];
;;

let enttext () =
  let len = String.length state.text in
  let drawstring s =
    let hscrollh =
      match state.mode with
      | View -> state.hscrollh
      | _ -> 0
    in
    let rect x w =
      GlDraw.rect
        (x, float (conf.winh - (fstate.fontsize + 4) - hscrollh))
        (x+.w, float (conf.winh - hscrollh))
    in

    let w = float (conf.winw - state.scrollw - 1) in
    if state.progress >= 0.0 && state.progress < 1.0
    then (
      GlDraw.color (0.3, 0.3, 0.3);
      let w1 = w *. state.progress in
      rect 0.0 w1;
      GlDraw.color (0.0, 0.0, 0.0);
      rect w1 (w-.w1)
    )
    else (
      GlDraw.color (0.0, 0.0, 0.0);
      rect 0.0 w;
    );

    GlDraw.color (1.0, 1.0, 1.0);
    drawstring fstate.fontsize
      (if len > 0 then 8 else 2) (conf.winh - hscrollh - 5) s;
  in
  match state.mode with
  | Textentry ((prefix, text, _, _, _), _) ->
      let s =
        if len > 0
        then
          Printf.sprintf "%s%s_ [%s]" prefix text state.text
        else
          Printf.sprintf "%s%s_"  prefix text
      in
      drawstring s

  | _ ->
      if len > 0 then drawstring state.text
;;

let showtext c s =
  state.text <- Printf.sprintf "%c%s" c s;
  G.postRedisplay "showtext";
;;

let gctiles () =
  let len = Queue.length state.tilelru in
  let rec loop qpos =
    if state.memused <= conf.memlimit
    then ()
    else (
      if qpos < len
      then
        let (k, p, s) as lruitem = Queue.pop state.tilelru in
        let n, gen, colorspace, angle, pagew, pageh, col, row = k in
        if
          gen = state.gen
          && colorspace = conf.colorspace
          && angle = conf.angle
          && pagew = getpagew n
          && pageh = getpageh n
          && (
            let layout =
              if conf.preload
              then preloadlayout state.layout
              else state.layout
            in
            let x = col*conf.tilew
            and y = row*conf.tileh in
            tilevisible layout n x y
          )
        then Queue.push lruitem state.tilelru
        else (
          wcmd "freetile" [`s p];
          state.memused <- state.memused - s;
          state.uioh#infochanged Memused;
          Hashtbl.remove state.tilemap k;
        );
        loop (qpos+1)
    )
  in
  loop 0
;;

let flushtiles () =
  Queue.iter (fun (k, p, s) ->
    wcmd "freetile" [`s p];
    state.memused <- state.memused - s;
    state.uioh#infochanged Memused;
    Hashtbl.remove state.tilemap k;
  ) state.tilelru;
  Queue.clear state.tilelru;
  load state.layout;
;;

let logcurrently = function
  | Idle -> dolog "Idle"
  | Loading (l, gen) ->
      dolog "Loading %d gen=%d curgen=%d" l.pageno gen state.gen
  | Tiling (l, pageopaque, colorspace, angle, gen, col, row, tilew, tileh) ->
      dolog
        "Tiling %d[%d,%d] page=%s cs=%s angle"
        l.pageno col row pageopaque
        (colorspace_to_string colorspace)
      ;
      dolog "gen=(%d,%d) (%d,%d) tile=(%d,%d) (%d,%d)"
        angle gen conf.angle state.gen
        tilew tileh
        conf.tilew conf.tileh
      ;
  | Outlining _ ->
      dolog "outlining"
;;

let act cmds =
  (* dolog "%S" cmds; *)
  let op, args =
    let spacepos =
      try String.index cmds ' '
      with Not_found -> -1
    in
    if spacepos = -1
    then cmds, ""
    else
      let l = String.length cmds in
      let op = String.sub cmds 0 spacepos in
      op, begin
        if l - spacepos < 2 then ""
        else String.sub cmds (spacepos+1) (l-spacepos-1)
      end
  in
  match op with
  | "clear" ->
      state.uioh#infochanged Pdim;
      state.pdims <- [];

  | "clearrects" ->
      state.rects <- state.rects1;
      G.postRedisplay "clearrects";

  | "continue" ->
      let n =
        try Scanf.sscanf args "%u" (fun n -> n)
        with exn ->
          dolog "error processing 'continue' %S: %s"
            cmds (Printexc.to_string exn);
          exit 1;
      in
      state.pagecount <- n;
      state.invalidated <- state.invalidated - 1;
      begin match state.currently with
      | Outlining l ->
          state.currently <- Idle;
          state.outlines <- Array.of_list (List.rev l)
      | _ -> ()
      end;
      if state.invalidated = 0
      then represent ();
      if conf.maxwait = None
      then G.postRedisplay "continue";

  | "title" ->
      Glut.setWindowTitle args

  | "msg" ->
      showtext ' ' args

  | "vmsg" ->
      if conf.verbose
      then showtext ' ' args

  | "progress" ->
      let progress, text =
        try
          Scanf.sscanf args "%f %n"
            (fun f pos ->
              f, String.sub args pos (String.length args - pos))
        with exn ->
          dolog "error processing 'progress' %S: %s"
            cmds (Printexc.to_string exn);
          exit 1;
      in
      state.text <- text;
      state.progress <- progress;
      G.postRedisplay "progress"

  | "firstmatch" ->
      let pageno, c, x0, y0, x1, y1, x2, y2, x3, y3 =
        try
          Scanf.sscanf args "%u %d %f %f %f %f %f %f %f %f"
            (fun p c x0 y0 x1 y1 x2 y2 x3 y3 ->
              (p, c, x0, y0, x1, y1, x2, y2, x3, y3))
        with exn ->
          dolog "error processing 'firstmatch' %S: %s"
            cmds (Printexc.to_string exn);
          exit 1;
      in
      let y = (getpagey pageno) + truncate y0 in
      addnav ();
      gotoy y;
      state.rects1 <- [pageno, c, (x0, y0, x1, y1, x2, y2, x3, y3)]

  | "match" ->
      let pageno, c, x0, y0, x1, y1, x2, y2, x3, y3 =
        try
          Scanf.sscanf args "%u %d %f %f %f %f %f %f %f %f"
            (fun p c x0 y0 x1 y1 x2 y2 x3 y3 ->
              (p, c, x0, y0, x1, y1, x2, y2, x3, y3))
        with exn ->
          dolog "error processing 'match' %S: %s"
            cmds (Printexc.to_string exn);
          exit 1;
      in
      state.rects1 <-
        (pageno, c, (x0, y0, x1, y1, x2, y2, x3, y3)) :: state.rects1

  | "page" ->
      let pageopaque, t =
        try
          Scanf.sscanf args "%s %f" (fun p t -> p, t)
        with exn ->
          dolog "error processing 'page' %S: %s"
            cmds (Printexc.to_string exn);
          exit 1;
      in
      begin match state.currently with
      | Loading (l, gen) ->
          vlog "page %d took %f sec" l.pageno t;
          Hashtbl.replace state.pagemap (l.pageno, gen) pageopaque;
          begin match state.throttle with
          | None ->
              let preloadedpages =
                if conf.preload
                then preloadlayout state.layout
                else state.layout
              in
              let evict () =
                let module IntSet =
                  Set.Make (struct type t = int let compare = (-) end) in
                let set =
                  List.fold_left (fun s l -> IntSet.add l.pageno s)
                    IntSet.empty preloadedpages
                in
                let evictedpages =
                  Hashtbl.fold (fun ((pageno, _) as key) opaque accu ->
                    if not (IntSet.mem pageno set)
                    then (
                      wcmd "freepage" [`s opaque];
                      key :: accu
                    )
                    else accu
                  ) state.pagemap []
                in
                List.iter (Hashtbl.remove state.pagemap) evictedpages;
              in
              evict ();
              state.currently <- Idle;
              if gen = state.gen
              then (
                tilepage l.pageno pageopaque state.layout;
                load state.layout;
                load preloadedpages;
                if pagevisible state.layout l.pageno
                  && layoutready state.layout
                then G.postRedisplay "page";
              )

          | Some (layout, _, _) ->
              state.currently <- Idle;
              tilepage l.pageno pageopaque layout;
              load state.layout
          end;

      | _ ->
          dolog "Inconsistent loading state";
          logcurrently state.currently;
          raise Quit;
      end

  | "tile" ->
      let (x, y, opaque, size, t) =
        try
          Scanf.sscanf args "%u %u %s %u %f"
            (fun x y p size t -> (x, y, p, size, t))
        with exn ->
          dolog "error processing 'tile' %S: %s"
            cmds (Printexc.to_string exn);
          exit 1;
      in
      begin match state.currently with
      | Tiling (l, pageopaque, cs, angle, gen, col, row, tilew, tileh) ->
          vlog "tile %d [%d,%d] took %f sec" l.pageno col row t;

          if tilew != conf.tilew || tileh != conf.tileh
          then (
            wcmd "freetile" [`s opaque];
            state.currently <- Idle;
            load state.layout;
          )
          else  (
            puttileopaque l col row gen cs angle opaque size t;
            state.memused <- state.memused + size;
            state.uioh#infochanged Memused;
            gctiles ();
            Queue.push ((l.pageno, gen, cs, angle, l.pagew, l.pageh, col, row),
                       opaque, size) state.tilelru;

            state.currently <- Idle;
            if   gen = state.gen
              && conf.colorspace = cs
              && conf.angle = angle
              && tilevisible state.layout l.pageno x y
            then conttiling l.pageno pageopaque;

            begin match state.throttle with
            | None ->
                preload state.layout;
                if   gen = state.gen
                  && conf.colorspace = cs
                  && conf.angle = angle
                  && tilevisible state.layout l.pageno x y
                then G.postRedisplay "tile nothrottle";

            | Some (layout, y, _) ->
                let ready = layoutready layout in
                if ready
                then (
                  state.y <- y;
                  state.layout <- layout;
                  state.throttle <- None;
                  G.postRedisplay "throttle";
                )
                else load layout;
            end;
          );

      | _ ->
          dolog "Inconsistent tiling state";
          logcurrently state.currently;
          raise Quit;
      end

  | "pdim" ->
      let pdim =
        try
          Scanf.sscanf args "%u %u %u %u" (fun n w h x -> n, w, h, x)
        with exn ->
          dolog "error processing 'pdim' %S: %s"
            cmds (Printexc.to_string exn);
          exit 1;
      in
      state.uioh#infochanged Pdim;
      state.pdims <- pdim :: state.pdims

  | "o" ->
      let (l, n, t, h, pos) =
        try
          Scanf.sscanf args "%u %u %d %u %n"
            (fun l n t h pos -> l, n, t, h, pos)
        with exn ->
          dolog "error processing 'o' %S: %s"
            cmds (Printexc.to_string exn);
          exit 1;
      in
      let s = String.sub args pos (String.length args - pos) in
      let outline = (s, l, (n, float t /. float h)) in
      begin match state.currently with
        | Outlining outlines ->
            state.currently <- Outlining (outline :: outlines)
        | Idle ->
            state.currently <- Outlining [outline]
        | currently ->
            dolog "invalid outlining state";
            logcurrently currently
      end

  | "info" ->
      state.docinfo <- (1, args) :: state.docinfo

  | "infoend" ->
      state.uioh#infochanged Docinfo;
      state.docinfo <- List.rev state.docinfo

  | _ ->
      dolog "unknown cmd `%S'" cmds
;;

let idle () =
  if state.deadline == nan then state.deadline <- now ();
  let rec loop delay =
    let timeout =
      if delay > 0.0
      then max 0.0 (state.deadline -. now ())
      else 0.0
    in
    let r, _, _ = Unix.select [state.csock] [] [] timeout in
    begin match r with
    | [] ->
        begin match state.autoscroll with
        | Some step when step != 0 ->
            let y = state.y + step in
            let y =
              if y < 0
              then state.maxy
              else if y >= state.maxy then 0 else y
            in
            gotoy y;
            if state.mode = View
            then state.text <- "";
            state.deadline <- state.deadline +. 0.005;

        | _ ->
            state.deadline <- state.deadline +. delay;
        end;

    | _ ->
        let cmd = readcmd state.csock in
        act cmd;
        loop 0.0
    end;
  in loop 0.007
;;

let onhist cb =
  let rc = cb.rc in
  let action = function
  | HCprev   -> cbget cb ~-1
  | HCnext   -> cbget cb 1
  | HCfirst  -> cbget cb ~-(cb.rc)
  | HClast   -> cbget cb (cb.len - 1 - cb.rc)
  and cancel () = cb.rc <- rc
  in (action, cancel)
;;

let search pattern forward =
  if String.length pattern > 0
  then
    let pn, py =
      match state.layout with
      | [] -> 0, 0
      | l :: _ ->
          l.pageno, (l.pagey + if forward then 0 else 0*l.pagevh)
    in
    let cmd =
      let b = makecmd "search"
        [`b conf.icase; `i pn; `i py; `i (if forward then 1 else 0)]
      in
      Buffer.add_char b ',';
      Buffer.add_string b pattern;
      Buffer.add_char b '\000';
      Buffer.contents b;
    in
    writecmd state.csock cmd;
;;

let intentry text key =
  let c = Char.unsafe_chr key in
  match c with
  | '0' .. '9' ->
      let text = addchar text c in
      TEcont text

  | _ ->
      state.text <- Printf.sprintf "invalid char (%d, `%c')" key c;
      TEcont text
;;

let textentry text key =
  let c = Char.unsafe_chr key in
  match c with
  | _ when key >= 32 && key < 127 ->
      let text = addchar text c in
      TEcont text

  | _ ->
      dolog "unhandled key %d char `%c'" key (Char.unsafe_chr key);
      TEcont text
;;

let reqlayout angle proportional =
  match state.throttle with
  | None ->
      if state.invalidated = 0 then state.anchor <- getanchor ();
      conf.angle <- angle mod 360;
      conf.proportional <- proportional;
      invalidate ();
      wcmd "reqlayout" [`i conf.angle; `b proportional];
  | _ -> ()
;;

let settrim trimmargins trimfuzz =
  if state.invalidated = 0 then state.anchor <- getanchor ();
  conf.trimmargins <- trimmargins;
  conf.trimfuzz <- trimfuzz;
  let x0, y0, x1, y1 = trimfuzz in
  invalidate ();
  wcmd "settrim" [
    `b conf.trimmargins;
    `i x0;
    `i y0;
    `i x1;
    `i y1;
  ];
  Hashtbl.iter (fun _ opaque ->
    wcmd "freepage" [`s opaque];
  ) state.pagemap;
  Hashtbl.clear state.pagemap;
;;

let setzoom zoom =
  match state.throttle with
  | None ->
      let zoom = max 0.01 zoom in
      if zoom <> conf.zoom
      then (
        state.prevzoom <- conf.zoom;
        let relx =
          if zoom <= 1.0
          then (state.x <- 0; 0.0)
          else float state.x /. float state.w
        in
        conf.zoom <- zoom;
        reshape conf.winw conf.winh;
        if zoom > 1.0
        then (
          let x = relx *. float state.w in
          state.x <- truncate x;
        );
        state.text <- Printf.sprintf "zoom is now %-5.1f" (zoom *. 100.0);
      )

  | Some (layout, y, started) ->
      let time =
        match conf.maxwait with
        | None -> 0.0
        | Some t -> t
      in
      let dt = now () -. started in
      if dt > time
      then (
        state.y <- y;
        load layout;
      )
;;

let enterbirdseye () =
  let zoom = float conf.thumbw /. float conf.winw in
  let birdseyepageno =
    let cy = conf.winh / 2 in
    let fold = function
      | [] -> 0
      | l :: rest ->
          let rec fold best = function
            | [] -> best.pageno
            | l :: rest ->
                let d = cy - (l.pagedispy + l.pagevh/2)
                and dbest = cy - (best.pagedispy + best.pagevh/2) in
                if abs d < abs dbest
                then fold l rest
                else best.pageno
          in fold l rest
    in
    fold state.layout
  in
  state.mode <- Birdseye (
    { conf with zoom = conf.zoom }, state.x, birdseyepageno, -1, getanchor ()
  );
  conf.zoom <- zoom;
  conf.presentation <- false;
  conf.interpagespace <- 10;
  conf.hlinks <- false;
  state.x <- 0;
  state.mstate <- Mnone;
  conf.maxwait <- None;
  Glut.setCursor Glut.CURSOR_INHERIT;
  if conf.verbose
  then
    state.text <- Printf.sprintf "birds eye mode on (zoom %3.1f%%)"
      (100.0*.zoom)
  else
    state.text <- ""
  ;
  reshape conf.winw conf.winh;
;;

let leavebirdseye (c, leftx, pageno, _, anchor) goback =
  state.mode <- View;
  conf.zoom <- c.zoom;
  conf.presentation <- c.presentation;
  conf.interpagespace <- c.interpagespace;
  conf.maxwait <- c.maxwait;
  conf.hlinks <- c.hlinks;
  state.x <- leftx;
  if conf.verbose
  then
    state.text <- Printf.sprintf "birds eye mode off (zoom %3.1f%%)"
      (100.0*.conf.zoom)
  ;
  reshape conf.winw conf.winh;
  state.anchor <- if goback then anchor else (pageno, 0.0);
;;

let togglebirdseye () =
  match state.mode with
  | Birdseye vals -> leavebirdseye vals true
  | View -> enterbirdseye ()
  | _ -> ()
;;

let upbirdseye (conf, leftx, pageno, hooverpageno, anchor) =
  let pageno = max 0 (pageno - 1) in
  let rec loop = function
    | [] -> gotopage1 pageno 0
    | l :: _ when l.pageno = pageno ->
        if l.pagedispy >= 0 && l.pagey = 0
        then G.postRedisplay "upbirdseye"
        else gotopage1 pageno 0
    | _ :: rest -> loop rest
  in
  loop state.layout;
  state.mode <- Birdseye (conf, leftx, pageno, hooverpageno, anchor)
;;

let downbirdseye (conf, leftx, pageno, hooverpageno, anchor) =
  let pageno = min (state.pagecount - 1) (pageno + 1) in
  state.mode <- Birdseye (conf, leftx, pageno, hooverpageno, anchor);
  let rec loop = function
    | [] ->
        let y, h = getpageyh pageno in
        let dy = (y - state.y) - (conf.winh - h - conf.interpagespace) in
        gotoy (clamp dy)
    | l :: _ when l.pageno = pageno ->
        if l.pagevh != l.pageh
        then gotoy (clamp (l.pageh - l.pagevh + conf.interpagespace))
        else G.postRedisplay "downbirdseye"
    | _ :: rest -> loop rest
  in
  loop state.layout
;;

let optentry mode _ key =
  let btos b = if b then "on" else "off" in
  let c = Char.unsafe_chr key in
  match c with
  | 's' ->
      let ondone s =
        try conf.scrollstep <- int_of_string s with exc ->
          state.text <- Printf.sprintf "bad integer `%s': %s"
            s (Printexc.to_string exc)
      in
      TEswitch ("scroll step: ", "", None, intentry, ondone)

  | 'A' ->
      let ondone s =
        try
          conf.autoscrollstep <- int_of_string s;
          if state.autoscroll <> None
          then state.autoscroll <- Some conf.autoscrollstep
        with exc ->
          state.text <- Printf.sprintf "bad integer `%s': %s"
            s (Printexc.to_string exc)
      in
      TEswitch ("auto scroll step: ", "", None, intentry, ondone)

  | 'Z' ->
      let ondone s =
        try
          let zoom = float (int_of_string s) /. 100.0 in
          setzoom zoom
        with exc ->
          state.text <- Printf.sprintf "bad integer `%s': %s"
            s (Printexc.to_string exc)
      in
      TEswitch ("zoom: ", "", None, intentry, ondone)

  | 't' ->
      let ondone s =
        try
          conf.thumbw <- bound (int_of_string s) 2 4096;
          state.text <-
            Printf.sprintf "thumbnail width is set to %d" conf.thumbw;
          begin match mode with
          | Birdseye beye ->
              leavebirdseye beye false;
              enterbirdseye ();
          | _ -> ();
          end
        with exc ->
          state.text <- Printf.sprintf "bad integer `%s': %s"
            s (Printexc.to_string exc)
      in
      TEswitch ("thumbnail width: ", "", None, intentry, ondone)

  | 'R' ->
      let ondone s =
        match try
            Some (int_of_string s)
          with exc ->
            state.text <- Printf.sprintf "bad integer `%s': %s"
              s (Printexc.to_string exc);
            None
        with
        | Some angle -> reqlayout angle conf.proportional
        | None -> ()
      in
      TEswitch ("rotation: ", "", None, intentry, ondone)

  | 'i' ->
      conf.icase <- not conf.icase;
      TEdone ("case insensitive search " ^ (btos conf.icase))

  | 'p' ->
      conf.preload <- not conf.preload;
      gotoy state.y;
      TEdone ("preload " ^ (btos conf.preload))

  | 'v' ->
      conf.verbose <- not conf.verbose;
      TEdone ("verbose " ^ (btos conf.verbose))

  | 'd' ->
      conf.debug <- not conf.debug;
      TEdone ("debug " ^ (btos conf.debug))

  | 'h' ->
      conf.maxhfit <- not conf.maxhfit;
      state.maxy <-
        state.maxy + (if conf.maxhfit then -conf.winh else conf.winh);
      TEdone ("maxhfit " ^ (btos conf.maxhfit))

  | 'c' ->
      conf.crophack <- not conf.crophack;
      TEdone ("crophack " ^ btos conf.crophack)

  | 'a' ->
      let s =
        match conf.maxwait with
        | None ->
            conf.maxwait <- Some infinity;
            "always wait for page to complete"
        | Some _ ->
            conf.maxwait <- None;
            "show placeholder if page is not ready"
      in
      TEdone s

  | 'f' ->
      conf.underinfo <- not conf.underinfo;
      TEdone ("underinfo " ^ btos conf.underinfo)

  | 'P' ->
      conf.savebmarks <- not conf.savebmarks;
      TEdone ("persistent bookmarks " ^ btos conf.savebmarks)

  | 'S' ->
      let ondone s =
        try
          let pageno, py =
            match state.layout with
            | [] -> 0, 0
            | l :: _ ->
                l.pageno, l.pagey
          in
          conf.interpagespace <- int_of_string s;
          state.maxy <- calcheight ();
          let y = getpagey pageno in
          gotoy (y + py)
        with exc ->
          state.text <- Printf.sprintf "bad integer `%s': %s"
            s (Printexc.to_string exc)
      in
      TEswitch ("vertical margin: ", "", None, intentry, ondone)

  | 'l' ->
      reqlayout conf.angle (not conf.proportional);
      TEdone ("proportional display " ^ btos conf.proportional)

  | 'T' ->
      settrim (not conf.trimmargins) conf.trimfuzz;
      TEdone ("trim margins " ^ btos conf.trimmargins)

  | 'I' ->
      conf.invert <- not conf.invert;
      TEdone ("invert colors " ^ btos conf.invert)

  | _ ->
      state.text <- Printf.sprintf "bad option %d `%c'" key c;
      TEstop
;;

class type lvsource = object
  method getitemcount : int
  method getitem : int -> (string * int)
  method hasaction : int -> bool
  method exit :
    uioh:uioh ->
    cancel:bool ->
    active:int ->
    first:int ->
    pan:int ->
    qsearch:string ->
    uioh option
  method getactive : int
  method getfirst : int
  method getqsearch : string
  method setqsearch : string -> unit
  method getpan : int
end;;

class virtual lvsourcebase = object
  val mutable m_active = 0
  val mutable m_first = 0
  val mutable m_qsearch = ""
  val mutable m_pan = 0
  method getactive = m_active
  method getfirst = m_first
  method getqsearch = m_qsearch
  method getpan = m_pan
  method setqsearch s = m_qsearch <- s
end;;

let textentryspecial key = function
  | ((c, _, (Some (action, _) as onhist), onkey, ondone), mode) ->
      let s =
        match key with
        | Glut.KEY_UP    -> action HCprev
        | Glut.KEY_DOWN  -> action HCnext
        | Glut.KEY_HOME  -> action HCfirst
        | Glut.KEY_END   -> action HClast
          | _ -> state.text
      in
      state.mode <- Textentry ((c, s, onhist, onkey, ondone), mode);
      G.postRedisplay "special textentry";
  | _ -> ()
;;

let textentrykeyboard key ((c, text, opthist, onkey, ondone), onleave) =
  let enttext te =
    state.mode <- Textentry (te, onleave);
    state.text <- "";
    enttext ();
    G.postRedisplay "textentrykeyboard enttext";
  in
  match Char.unsafe_chr key with
  | '\008' ->                           (* backspace *)
      let len = String.length text in
      if len = 0
      then (
        onleave Cancel;
        G.postRedisplay "textentrykeyboard after cancel";
      )
      else (
        let s = String.sub text 0 (len - 1) in
        enttext (c, s, opthist, onkey, ondone)
      )

  | '\r' | '\n' ->
      ondone text;
      onleave Confirm;
      G.postRedisplay "textentrykeyboard after confirm"

  | '\007'                              (* ctrl-g *)
  | '\027' ->                           (* escape *)
      if String.length text = 0
      then (
        begin match opthist with
        | None -> ()
        | Some (_, onhistcancel) -> onhistcancel ()
        end;
        onleave Cancel;
        state.text <- "";
        G.postRedisplay "textentrykeyboard after cancel2"
      )
      else (
        enttext (c, "", opthist, onkey, ondone)
      )

  | '\127' -> ()                        (* delete *)

  | _ ->
      begin match onkey text key with
      | TEdone text ->
          ondone text;
          onleave Confirm;
          G.postRedisplay "textentrykeyboard after confirm2";

      | TEcont text ->
          enttext (c, text, opthist, onkey, ondone);

      | TEstop ->
          onleave Cancel;
          state.text <- "";
          G.postRedisplay "textentrykeyboard after cancel3"

      | TEswitch te ->
          state.mode <- Textentry (te, onleave);
          G.postRedisplay "textentrykeyboard switch";
      end;
;;

let firstof first active =
  if first > active || abs (first - active) > fstate.maxrows - 1
  then max 0 (active - (fstate.maxrows/2))
  else first
;;

let calcfirst first active =
  if active > first
  then
    let rows = active - first in
    if rows > fstate.maxrows then active - fstate.maxrows else first
  else active
;;

let coe s = (s :> uioh);;

class listview ~(source:lvsource) ~trusted =
object (self)
  val m_pan = source#getpan
  val m_first = source#getfirst
  val m_active = source#getactive
  val m_qsearch = source#getqsearch
  val m_prev_uioh = state.uioh

  method private elemunder y =
    let n = y / (fstate.fontsize+1) in
    if m_first + n < source#getitemcount
    then (
      if source#hasaction (m_first + n)
      then Some (m_first + n)
      else None
    )
    else None

  method display =
    Gl.enable `blend;
    GlFunc.blend_func `src_alpha `one_minus_src_alpha;
    GlDraw.color (0., 0., 0.) ~alpha:0.85;
    GlDraw.rect (0., 0.) (float conf.winw, float conf.winh);
    GlDraw.color (1., 1., 1.);
    Gl.enable `texture_2d;
    let fs = fstate.fontsize in
    let nfs = fs + 1 in
    let ww = fstate.wwidth in
    let tabw = 30.0*.ww in
    let rec loop row =
      if (row - m_first) * nfs > conf.winh
      then ()
      else (
        if row >= 0 && row < source#getitemcount
        then (
          let (s, level) = source#getitem row in
          let y = (row - m_first) * nfs in
          let x = 5.0 +. float (level + m_pan) *. ww in
          if row = m_active
          then (
            Gl.disable `texture_2d;
            GlDraw.polygon_mode `both `line;
            GlDraw.color (1., 1., 1.) ~alpha:0.9;
            GlDraw.rect (1., float (y + 1))
              (float (conf.winw - 1), float (y + fs + 3));
            GlDraw.polygon_mode `both `fill;
            GlDraw.color (1., 1., 1.);
            Gl.enable `texture_2d;
          );

          let drawtabularstring s =
            let drawstr x s = drawstring1 fs (truncate x) (y+nfs) s in
            if trusted
            then
              let tabpos = try String.index s '\t' with Not_found -> -1 in
              if tabpos > 0
              then
                let len = String.length s - tabpos - 1 in
                let s1 = String.sub s 0 tabpos
                and s2 = String.sub s (tabpos + 1) len in
                let nx = drawstr x s1 in
                let sw = nx -. x in
                let x = x +. (max tabw sw) in
                drawstr x s2
              else
                drawstr x s
            else
              drawstr x s
          in
          let _ = drawtabularstring s in
          loop (row+1)
        )
      )
    in
    loop 0;
    Gl.disable `blend;
    Gl.disable `texture_2d;

  method updownlevel incr =
    let len = source#getitemcount  in
    let _, curlevel = source#getitem m_active in
    let rec flow i =
      if i = len then i-1 else if i = -1 then 0 else
          let _, l = source#getitem i in
          if l != curlevel then i else flow (i+incr)
    in
    let active = flow m_active in
    let first = calcfirst m_first active in
    G.postRedisplay "special outline updownlevel";
    {< m_active = active; m_first = first >}

  method private key1 key =
    let set active first qsearch =
      coe {< m_active = active; m_first = first; m_qsearch = qsearch >}
    in
    let search active pattern incr =
      let dosearch re =
        let rec loop n =
          if n >= 0 && n < source#getitemcount
          then (
            let s, _ = source#getitem n in
            if
              (try ignore (Str.search_forward re s 0); true
                with Not_found -> false)
            then Some n
            else loop (n + incr)
          )
          else None
        in
        loop active
      in
      try
        let re = Str.regexp_case_fold pattern in
        dosearch re
      with Failure s ->
        state.text <- s;
        None
    in
    match key with
    | 18 | 19 ->                          (* ctrl-r/ctlr-s *)
        let incr = if key = 18 then -1 else 1 in
        let active, first =
          match search (m_active + incr) m_qsearch incr with
          | None ->
              state.text <- m_qsearch ^ " [not found]";
              m_active, m_first
          | Some active ->
              state.text <- m_qsearch;
              active, firstof m_first active
        in
        G.postRedisplay "listview ctrl-r/s";
        set active first m_qsearch;

    | 8 ->                                (* backspace *)
        let len = String.length m_qsearch in
        if len = 0
        then coe self
        else (
          if len = 1
          then (
            state.text <- "";
            G.postRedisplay "listview empty qsearch";
            set m_active m_first "";
          )
          else
            let qsearch = String.sub m_qsearch 0 (len - 1) in
            let active, first =
              match search m_active qsearch ~-1 with
              | None ->
                  state.text <- qsearch ^ " [not found]";
                  m_active, m_first
              | Some active ->
                  state.text <- qsearch;
                  active, firstof m_first active
            in
            G.postRedisplay "listview backspace qsearch";
            set active first qsearch
        );

    | _ when key >= 32 && key < 127 ->
        let pattern = addchar m_qsearch (Char.chr key) in
        let active, first =
          match search m_active pattern 1 with
          | None ->
              state.text <- pattern ^ " [not found]";
              m_active, m_first
          | Some active ->
              state.text <- pattern;
              active, firstof m_first active
        in
        G.postRedisplay "listview qsearch add";
        set active first pattern;

    | 27 ->                               (* escape *)
        state.text <- "";
        if String.length m_qsearch = 0
        then (
          G.postRedisplay "list view escape";
          begin
            match
              source#exit (coe self) true m_active m_first m_pan m_qsearch
            with
            | None -> m_prev_uioh
            | Some uioh -> uioh
          end
        )
        else (
          G.postRedisplay "list view kill qsearch";
          source#setqsearch "";
          coe {< m_qsearch = "" >}
        )

    | 13 ->                               (* enter *)
        state.text <- "";
        let self = {< m_qsearch = "" >} in
        source#setqsearch "";
        let opt =
          G.postRedisplay "listview enter";
          if m_active >= 0 && m_active < source#getitemcount
          then (
            source#exit (coe self) false m_active m_first m_pan "";
          )
          else (
            source#exit (coe self) true m_active m_first m_pan "";
          );
        in
        begin match opt with
        | None -> m_prev_uioh
        | Some uioh -> uioh
        end

    | 127 ->                            (* delete *)
        coe self

    | _ -> dolog "unknown key %d" key; coe self

  method private special1 key =
    let itemcount = source#getitemcount in
    let find start incr =
      let rec find i =
        if i = -1 || i = itemcount
        then -1
        else (
          if source#hasaction i
          then i
          else find (i + incr)
        )
      in
      find start
    in
    let set active first =
      let first = bound first 0 (itemcount - fstate.maxrows) in
      state.text <- "";
      coe {< m_active = active; m_first = first >}
    in
    let navigate incr =
      let isvisible first n = n >= first && n - first <= fstate.maxrows in
      let active, first =
        let incr1 = if incr > 0 then 1 else -1 in
        if isvisible m_first m_active
        then
          let next =
            let next = m_active + incr in
            let next =
              if next < 0 || next >= itemcount
              then -1
              else find next incr1
            in
            if next = -1 || abs (m_active - next) > fstate.maxrows
            then -1
            else next
          in
          if next = -1
          then
            let first = m_first + incr in
            let first = bound first 0 (itemcount - 1) in
            let next =
              let next = m_active + incr in
              let next = bound next 0 (itemcount - 1) in
              find next ~-incr1
            in
            let active = if next = -1 then m_active else next in
            active, first
          else
            let first = min next m_first in
            next, first
        else
          let first = m_first + incr in
          let first = bound first 0 (itemcount - 1) in
          let active =
            let next = m_active + incr in
            let next = bound next 0 (itemcount - 1) in
            let next = find next incr1 in
            if next = -1 || abs (m_active - first) > fstate.maxrows
            then m_active
            else next
          in
          active, first
      in
      G.postRedisplay "listview navigate";
      set active first;
    in
    begin match key with
    | Glut.KEY_UP        -> navigate ~-1
    | Glut.KEY_DOWN      -> navigate   1
    | Glut.KEY_PAGE_UP   -> navigate ~-(fstate.maxrows)
    | Glut.KEY_PAGE_DOWN -> navigate   fstate.maxrows

    | Glut.KEY_RIGHT ->
        state.text <- "";
        G.postRedisplay "listview right";
        coe {< m_pan = m_pan - 1 >}

    | Glut.KEY_LEFT ->
        state.text <- "";
        G.postRedisplay "listview left";
        coe {< m_pan = m_pan + 1 >}

    | Glut.KEY_HOME ->
        let active = find 0 1 in
        G.postRedisplay "listview home";
        set active 0;

    | Glut.KEY_END ->
        let first = max 0 (itemcount - fstate.maxrows) in
        let active = find (itemcount - 1) ~-1 in
        G.postRedisplay "listview end";
        set active first;

    | _ -> coe self
    end;

  method key key =
    match state.mode with
    | Textentry te -> textentrykeyboard key te; coe self
    | _ -> self#key1 key

  method special key =
    match state.mode with
    | Textentry te -> textentryspecial key te; coe self
    | _ -> self#special1 key

  method button button bstate _ y =
    let opt =
      match button with
      | Glut.LEFT_BUTTON when bstate = Glut.UP ->
          begin match self#elemunder y with
          | Some n ->
              G.postRedisplay "listview click";
              source#exit
                (coe {< m_active = n >}) false n m_first m_pan m_qsearch
          | _ ->
              Some (coe self)
          end
      | Glut.OTHER_BUTTON n when (n == 3 || n == 4) && bstate = Glut.UP ->
          let len = source#getitemcount in
          let first =
            if m_first + fstate.maxrows >= len
            then
              m_first
            else
              let first = m_first + (if n == 3 then -1 else 1) in
              bound first 0 (len - 1)
          in
          G.postRedisplay "listview wheel";
          Some (coe {< m_first = first >})
      | _ ->
          Some (coe self)
    in
    match opt with
    | None -> m_prev_uioh
    | Some uioh -> uioh

  method motion _ _ = coe self

  method pmotion _ y =
    let n =
      match self#elemunder y with
      | None -> Glut.setCursor Glut.CURSOR_INHERIT; m_active
      | Some n -> Glut.setCursor Glut.CURSOR_INFO; n
    in
    let o =
      if n != m_active
      then (G.postRedisplay "listview pmotion"; {< m_active = n >})
      else self
    in
    coe o

  method infochanged _ = ()
end;;

class outlinelistview ~source =
object (self)
  inherit listview ~source:(source :> lvsource) ~trusted:false as super

  method key key =
    match key with
    | 14 ->                             (* ctrl-n *)
        source#narrow m_qsearch;
        G.postRedisplay "outline ctrl-n";
        coe {< m_first = 0; m_active = 0 >}

    | 21 ->                             (* ctrl-u *)
        source#denarrow;
        G.postRedisplay "outline ctrl-u";
        coe {< m_first = 0; m_active = 0 >}

    | 12 ->                             (* ctrl-l *)
        let first = m_active - (fstate.maxrows / 2) in
        G.postRedisplay "outline ctrl-l";
        coe {< m_first = first >}

    | 127 ->                            (* delete *)
        source#remove m_active;
        G.postRedisplay "outline delete";
        let active = max 0 (m_active-1) in
        coe {< m_first = firstof m_first active;
               m_active = active >}

    | key -> super#key key

  method special key =
    let calcfirst first active =
      if active > first
      then
        let rows = active - first in
        if rows > fstate.maxrows then active - fstate.maxrows else first
      else active
    in
    let navigate incr =
      let active = m_active + incr in
      let active = bound active 0 (source#getitemcount - 1) in
      let first = calcfirst m_first active in
      G.postRedisplay "special outline navigate";
      coe {< m_active = active; m_first = first >}
    in
    match key with
    | Glut.KEY_UP        -> navigate ~-1
    | Glut.KEY_DOWN      -> navigate   1
    | Glut.KEY_PAGE_UP   -> navigate ~-(fstate.maxrows)
    | Glut.KEY_PAGE_DOWN -> navigate   fstate.maxrows

    | Glut.KEY_RIGHT ->
        let o =
          if Glut.getModifiers () land Glut.active_ctrl != 0
          then (
            G.postRedisplay "special outline right";
            {< m_pan = m_pan + 1 >}
          )
          else self#updownlevel 1
        in
        coe o

    | Glut.KEY_LEFT ->
        let o =
          if Glut.getModifiers () land Glut.active_ctrl != 0
          then (
            G.postRedisplay "special outline left";
            {< m_pan = m_pan - 1 >}
          )
          else self#updownlevel ~-1
        in
        coe o

    | Glut.KEY_HOME ->
        G.postRedisplay "special outline home";
        coe {< m_first = 0; m_active = 0 >}

    | Glut.KEY_END ->
        let active = source#getitemcount - 1 in
        let first = max 0 (active - fstate.maxrows) in
        G.postRedisplay "special outline end";
        coe {< m_active = active; m_first = first >}

    | _ -> super#special key
end

let outlinesource usebookmarks =
  let empty = [||] in
  (object
    inherit lvsourcebase
    val mutable m_items = empty
    val mutable m_orig_items = empty
    val mutable m_prev_items = empty
    val mutable m_narrow_pattern = ""
    val mutable m_hadremovals = false

    method getitemcount =
      Array.length m_items + (if m_hadremovals then 1 else 0)

    method getitem n =
      if n == Array.length m_items && m_hadremovals
      then
        ("[Confirm removal]", 0)
      else
        let s, n, _ = m_items.(n) in
        (s, n)

    method exit ~uioh ~cancel ~active ~first ~pan ~qsearch =
      ignore (uioh, first, pan, qsearch);
      let confrimremoval = m_hadremovals && active = Array.length m_items in
      let items =
        if String.length m_narrow_pattern = 0
        then m_orig_items
        else m_items
      in
      if not cancel
      then (
        if not confrimremoval
        then(
          let _, _, anchor = m_items.(active) in
          gotoanchor anchor;
          m_items <- items;
        )
        else (
          state.bookmarks <- Array.to_list m_items;
          m_orig_items <- m_items;
        )
      )
      else m_items <- items;
      None

    method hasaction _ = true

    method greetmsg =
      if Array.length m_items != Array.length m_orig_items
      then "Narrowed to " ^ m_narrow_pattern ^ " (ctrl-u to restore)"
      else ""

    method narrow pattern =
      let reopt = try Some (Str.regexp_case_fold pattern) with _ -> None in
      match reopt with
      | None -> ()
      | Some re ->
          let rec loop accu n =
            if n = -1
            then (
              m_narrow_pattern <- pattern;
              m_items <- Array.of_list accu
            )
            else
              let (s, _, _) as o = m_items.(n) in
              let accu =
                if (try ignore (Str.search_forward re s 0); true
                  with Not_found -> false)
                then o :: accu
                else accu
              in
              loop accu (n-1)
          in
          loop [] (Array.length m_items - 1)

    method denarrow =
      m_orig_items <- (
        if usebookmarks
        then Array.of_list state.bookmarks
        else state.outlines
      );
      m_items <- m_orig_items

    method remove m =
      if usebookmarks
      then
        if m >= 0 && m < Array.length m_items
        then (
          m_hadremovals <- true;
          m_items <- Array.init (Array.length m_items - 1) (fun n ->
            let n = if n >= m then n+1 else n in
            m_items.(n)
          )
        )

    method reset pageno items =
      m_hadremovals <- false;
      if m_orig_items == empty || m_prev_items != items
      then (
        m_orig_items <- items;
        if String.length m_narrow_pattern = 0
        then m_items <- items;
      );
      m_prev_items <- items;
      let active =
        let rec loop n best bestd =
          if n = Array.length m_items
          then best
          else
            let (_, _, (outlinepageno, _)) = m_items.(n) in
            let d = abs (outlinepageno - pageno) in
            if d < bestd
            then loop (n+1) n d
            else loop (n+1) best bestd
        in
        loop 0 ~-1 max_int
      in
      m_active <- active;
      m_first <- firstof m_first active
  end)
;;

let enterselector usebookmarks =
  let source = outlinesource usebookmarks in
  fun errmsg ->
    let outlines =
      if usebookmarks
      then Array.of_list state.bookmarks
      else state.outlines
    in
    if Array.length outlines = 0
    then (
      showtext ' ' errmsg;
    )
    else (
      state.text <- source#greetmsg;
      Glut.setCursor Glut.CURSOR_INHERIT;
      let pageno =
        match state.layout with
        | [] -> -1
        | {pageno=pageno} :: _ -> pageno
      in
      source#reset pageno outlines;
      state.uioh <- coe (new outlinelistview ~source);
      G.postRedisplay "enter selector";
    )
;;

let enteroutlinemode =
  let f = enterselector false in
  fun ()-> f "Document has no outline";
;;

let enterbookmarkmode =
  let f = enterselector true in
  fun () -> f "Document has no bookmarks (yet)";
;;

let color_of_string s =
  Scanf.sscanf s "%d/%d/%d" (fun r g b ->
    (float r /. 256.0, float g /. 256.0, float b /. 256.0)
  )
;;

let color_to_string (r, g, b) =
  let r = truncate (r *. 256.0)
  and g = truncate (g *. 256.0)
  and b = truncate (b *. 256.0) in
  Printf.sprintf "%d/%d/%d" r g b
;;

let irect_of_string s =
  Scanf.sscanf s "%d/%d/%d/%d" (fun x0 y0 x1 y1  -> (x0,y0,x1,y1))
;;

let irect_to_string (x0,y0,x1,y1) =
  Printf.sprintf "%d/%d/%d/%d" x0 y0 x1 y1
;;

let makecheckers () =
  (* Appropriated from lablGL-1.04/LablGlut/examples/lablGL/checker.ml which had
     following to say:
     converted by Issac Trotts.  July 25, 2002 *)
  let image_height = 64
  and image_width = 64 in

  let make_image () =
    let image =
      GlPix.create `ubyte ~format:`rgb ~width:image_width ~height:image_height
    in
    for i = 0 to image_width - 1 do
      for j = 0 to image_height - 1 do
        Raw.sets (GlPix.to_raw image) ~pos:(3*(i*image_height+j))
          (if (i land 8 ) lxor (j land 8) = 0
          then [|255;255;255|] else [|200;200;200|])
      done
    done;
    image
  in
  let image = make_image () in
  let id = GlTex.gen_texture () in
  GlTex.bind_texture `texture_2d id;
  GlPix.store (`unpack_alignment 1);
  GlTex.image2d image;
  List.iter (GlTex.parameter ~target:`texture_2d)
    [ `wrap_s `repeat;
      `wrap_t `repeat;
      `mag_filter `nearest;
      `min_filter `nearest ];
  id;
;;

let setcheckers enabled =
  match state.texid with
  | None ->
      if enabled then state.texid <- Some (makecheckers ())

  | Some texid ->
      if not enabled
      then (
        GlTex.delete_texture texid;
        state.texid <- None;
      );
;;

let int_of_string_with_suffix s =
  let l = String.length s in
  let s1, shift =
    if l > 1
    then
      let suffix = Char.lowercase s.[l-1] in
      match suffix with
      | 'k' -> String.sub s 0 (l-1), 10
      | 'm' -> String.sub s 0 (l-1), 20
      | 'g' -> String.sub s 0 (l-1), 30
      | _ -> s, 0
    else s, 0
  in
  let n = int_of_string s1 in
  let m = n lsl shift in
  if m < 0 || m < n
  then raise (Failure "value too large")
  else m
;;

let string_with_suffix_of_int n =
  if n = 0
  then "0"
  else
    let n, s =
      if n = 0
      then 0, ""
      else (
        if n land ((1 lsl 20) - 1) = 0
        then n lsr 20, "M"
        else (
          if n land ((1 lsl 10) - 1) = 0
          then n lsr 10, "K"
          else n, ""
        )
      )
    in
    let rec loop s n =
      let h = n mod 1000 in
      let n = n / 1000 in
      if n = 0
      then string_of_int h ^ s
      else (
        let s = Printf.sprintf "_%03d%s" h s in
        loop s n
      )
    in
    loop "" n ^ s;
;;

let describe_location () =
  let f (fn, _) l =
    if fn = -1 then l.pageno, l.pageno else fn, l.pageno
  in
  let fn, ln = List.fold_left f (-1, -1) state.layout in
  let maxy = state.maxy - (if conf.maxhfit then conf.winh else 0) in
  let percent =
    if maxy <= 0
    then 100.
    else (100. *. (float state.y /. float maxy))
  in
  if fn = ln
  then
    Printf.sprintf "page %d of %d [%.2f%%]"
      (fn+1) state.pagecount percent
  else
    Printf.sprintf
      "pages %d-%d of %d [%.2f%%]"
      (fn+1) (ln+1) state.pagecount percent
;;

let enterinfomode =
  let btos b = if b then "\xe2\x88\x9a" else "" in
  let showextended = ref false in
  let leave mode = function
    | Confirm -> state.mode <- mode
    | Cancel -> state.mode <- mode in
  let src =
    (object
      val mutable m_first_time = true
      val mutable m_l = []
      val mutable m_a = [||]
      val mutable m_prev_uioh = nouioh
      val mutable m_prev_mode = View

      inherit lvsourcebase

      method reset prev_mode prev_uioh =
        m_a <- Array.of_list (List.rev m_l);
        m_l <- [];
        m_prev_mode <- prev_mode;
        m_prev_uioh <- prev_uioh;
        if m_first_time
        then (
          let rec loop n =
            if n >= Array.length m_a
            then ()
            else
              match m_a.(n) with
              | _, _, _, Action _ -> m_active <- n
              | _ -> loop (n+1)
          in
          loop 0;
          m_first_time <- false;
        )

      method int name get set =
        m_l <-
          (name, `int get, 1, Action (
            fun u ->
              let ondone s =
                try set (int_of_string s)
                with exn ->
                  state.text <- Printf.sprintf "bad integer `%s': %s"
                    s (Printexc.to_string exn)
              in
              state.text <- "";
              let te = name ^ ": ", "", None, intentry, ondone in
              state.mode <- Textentry (te, leave m_prev_mode);
              u
          )) :: m_l

      method int_with_suffix name get set =
        m_l <-
          (name, `intws get, 1, Action (
            fun u ->
              let ondone s =
                try set (int_of_string_with_suffix s)
                with exn ->
                  state.text <- Printf.sprintf "bad integer `%s': %s"
                    s (Printexc.to_string exn)
              in
              state.text <- "";
              let te =
                name ^ ": ", "", None, intentry_with_suffix, ondone
              in
              state.mode <- Textentry (te, leave m_prev_mode);
              u
          )) :: m_l

      method bool ?(offset=1) ?(btos=btos) name get set =
        m_l <-
          (name, `bool (btos, get), offset, Action (
            fun u ->
              let v = get () in
              set (not v);
              u
          )) :: m_l

      method color name get set =
        m_l <-
          (name, `color get, 1, Action (
            fun u ->
              let invalid = (nan, nan, nan) in
              let ondone s =
                let c =
                  try color_of_string s
                  with exn ->
                    state.text <- Printf.sprintf "bad color `%s': %s"
                      s (Printexc.to_string exn);
                    invalid
                in
                if c <> invalid
                then set c;
              in
              let te = name ^ ": ", "", None, textentry, ondone in
              state.text <- color_to_string (get ());
              state.mode <- Textentry (te, leave m_prev_mode);
              u
          )) :: m_l

      method string name get set =
        m_l <-
          (name, `string get, 1, Action (
            fun u ->
              let ondone s = set s in
              let te = name ^ ": ", "", None, textentry, ondone in
              state.mode <- Textentry (te, leave m_prev_mode);
              u
          )) :: m_l

      method colorspace name get set =
        m_l <-
          (name, `string get, 1, Action (
            fun _ ->
              let source =
                let vals = [| "rgb"; "bgr"; "gray" |] in
                (object
                  inherit lvsourcebase

                  initializer
                    m_active <- int_of_colorspace conf.colorspace;
                    m_first <- 0;

                  method getitemcount = Array.length vals
                  method getitem n = (vals.(n), 0)
                  method exit ~uioh ~cancel ~active ~first ~pan ~qsearch =
                    ignore (uioh, first, pan, qsearch);
                    if not cancel then set active;
                    None
                  method hasaction _ = true
                end)
              in
              state.text <- "";
              coe (new listview ~source ~trusted:true)
          )) :: m_l

      method caption s offset =
        m_l <- (s, `empty, offset, Noaction) :: m_l

      method caption2 s f offset =
        m_l <- (s, `string f, offset, Noaction) :: m_l

      method getitemcount = Array.length m_a

      method getitem n =
        let tostr = function
          | `int f -> string_of_int (f ())
          | `intws f -> string_with_suffix_of_int (f ())
          | `string f -> f ()
          | `color f -> color_to_string (f ())
          | `bool (btos, f) -> btos (f ())
          | `empty -> ""
        in
        let name, t, offset, _ = m_a.(n) in
        ((let s = tostr t in
          if String.length s > 0
          then Printf.sprintf "%s\t%s" name s
          else name),
        offset)

      method exit ~uioh ~cancel ~active ~first ~pan ~qsearch =
        let uiohopt =
          if not cancel
          then (
            m_qsearch <- qsearch;
            let uioh =
              match m_a.(active) with
              | _, _, _, Action f -> f uioh
              | _ -> uioh
            in
            Some uioh
          )
          else None
        in
        m_active <- active;
        m_first <- first;
        m_pan <- pan;
        uiohopt

      method hasaction n =
        match m_a.(n) with
        | _, _, _, Action _ -> true
        | _ -> false
    end)
  in
  let rec fillsrc prevmode prevuioh =
    let sep () = src#caption "" 0 in
    let colorp name get set =
      src#string name
        (fun () -> color_to_string (get ()))
        (fun v ->
          try
            let c = color_of_string v in
            set c
          with exn ->
            state.text <- Printf.sprintf "bad color `%s': %s"
              v (Printexc.to_string exn);
        )
    in
    let oldmode = state.mode in
    let birdseye = isbirdseye state.mode in

    src#caption (if birdseye then "Setup (Bird's eye)" else "Setup") 0;

    src#bool "presentation mode"
      (fun () -> conf.presentation)
      (fun v ->
        conf.presentation <- v;
        state.anchor <- getanchor ();
        represent ());

    src#bool "ignore case in searches"
      (fun () -> conf.icase)
      (fun v -> conf.icase <- v);

    src#bool "preload"
      (fun () -> conf.preload)
      (fun v -> conf.preload <- v);

    src#bool "highlight links"
      (fun () -> conf.hlinks)
      (fun v -> conf.hlinks <- v);

    src#bool "under info"
      (fun () -> conf.underinfo)
      (fun v -> conf.underinfo <- v);

    src#bool "persistent bookmarks"
      (fun () -> conf.savebmarks)
      (fun v -> conf.savebmarks <- v);

    src#bool "proportional display"
      (fun () -> conf.proportional)
      (fun v -> reqlayout conf.angle v);

    src#bool "trim margins"
      (fun () -> conf.trimmargins)
      (fun v -> settrim v conf.trimfuzz; fillsrc prevmode prevuioh);

    src#bool "persistent location"
      (fun () -> conf.jumpback)
      (fun v -> conf.jumpback <- v);

    sep ();
    src#int "vertical margin"
      (fun () -> conf.interpagespace)
      (fun n ->
        conf.interpagespace <- n;
        let pageno, py =
          match state.layout with
          | [] -> 0, 0
          | l :: _ ->
              l.pageno, l.pagey
        in
        state.maxy <- calcheight ();
        let y = getpagey pageno in
        gotoy (y + py)
      );

    src#int "page bias"
      (fun () -> conf.pagebias)
      (fun v -> conf.pagebias <- v);

    src#int "scroll step"
      (fun () -> conf.scrollstep)
      (fun n -> conf.scrollstep <- n);

    src#int "auto scroll step"
      (fun () ->
        match state.autoscroll with
        | Some step -> step
        | _ -> conf.autoscrollstep)
      (fun n ->
        if state.autoscroll <> None
        then state.autoscroll <- Some n;
        conf.autoscrollstep <- n);

    src#int "zoom"
      (fun () -> truncate (conf.zoom *. 100.))
      (fun v -> setzoom ((float v) /. 100.));

    src#int "rotation"
      (fun () -> conf.angle)
      (fun v -> reqlayout v conf.proportional);

    src#int "scroll bar width"
      (fun () -> state.scrollw)
      (fun v ->
        state.scrollw <- v;
        conf.scrollbw <- v;
        reshape conf.winw conf.winh;
      );

    src#int "scroll handle height"
      (fun () -> conf.scrollh)
      (fun v -> conf.scrollh <- v;);

    src#int "thumbnail width"
      (fun () -> conf.thumbw)
      (fun v ->
        conf.thumbw <- min 4096 v;
        match oldmode with
        | Birdseye beye ->
            leavebirdseye beye false;
            enterbirdseye ()
        | _ -> ()
      );

    sep ();
    src#caption "Presentation mode" 0;
    src#bool "scrollbar visible"
      (fun () -> conf.scrollbarinpm)
      (fun v ->
        if v != conf.scrollbarinpm
        then (
          conf.scrollbarinpm <- v;
          if conf.presentation
          then (
            state.scrollw <- if v then conf.scrollbw else 0;
            reshape conf.winw conf.winh;
          )
        );
      );

    sep ();
    src#caption "Pixmap cache" 0;
    src#int_with_suffix "size (advisory)"
      (fun () -> conf.memlimit)
      (fun v -> conf.memlimit <- v);

    src#caption2 "used"
      (fun () -> Printf.sprintf "%s bytes, %d tiles"
        (string_with_suffix_of_int state.memused)
        (Hashtbl.length state.tilemap)) 1;

    sep ();
    src#caption "Layout" 0;
    src#caption2 "Dimension"
      (fun () ->
        Printf.sprintf "%dx%d (virtual %dx%d)"
          conf.winw conf.winh
          state.w state.maxy)
      1;
    if conf.debug
    then
      src#caption2 "Position" (fun () ->
        Printf.sprintf "%dx%d" state.x state.y
      ) 1
    else
      src#caption2 "Visible" (fun () -> describe_location ()) 1
    ;

    sep ();
    src#bool ~offset:0 ~btos:(fun v -> if v then "(on)" else "(off)")
      "Save these parameters as global defaults at exit"
      (fun () -> conf.bedefault)
      (fun v -> conf.bedefault <- v)
    ;

    sep ();
    let btos b = if b then "\xc2\xab" else "\xc2\xbb" in
    src#bool ~offset:0 ~btos "Extended parameters"
      (fun () -> !showextended)
      (fun v -> showextended := v; fillsrc prevmode prevuioh);
    if !showextended
    then (
      src#bool "checkers"
        (fun () -> conf.checkers)
        (fun v -> conf.checkers <- v; setcheckers v);
      src#bool "verbose"
        (fun () -> conf.verbose)
        (fun v -> conf.verbose <- v);
      src#bool "invert colors"
        (fun () -> conf.invert)
        (fun v -> conf.invert <- v);
      src#bool "max fit"
        (fun () -> conf.maxhfit)
        (fun v -> conf.maxhfit <- v);
      src#string "uri launcher"
        (fun () -> conf.urilauncher)
        (fun v -> conf.urilauncher <- v);
      src#string "tile size"
        (fun () -> Printf.sprintf "%dx%d" conf.tilew conf.tileh)
        (fun v ->
          try
            let w, h = Scanf.sscanf v "%dx%d" (fun w h -> w, h) in
            conf.tileh <- max 64 w;
            conf.tilew <- max 64 h;
            flushtiles ();
          with exn ->
            state.text <- Printf.sprintf "bad tile size `%s': %s"
              v (Printexc.to_string exn));
      src#int "anti-aliasing level"
        (fun () -> conf.aalevel)
        (fun v ->
          conf.aalevel <- bound v 0 8;
          state.anchor <- getanchor ();
          opendoc state.path state.password;
        );
      src#int "ui font size"
        (fun () -> fstate.fontsize)
        (fun v -> setfontsize (bound v 5 100));
      colorp "background color"
        (fun () -> conf.bgcolor)
        (fun v -> conf.bgcolor <- v);
      src#bool "crop hack"
        (fun () -> conf.crophack)
        (fun v -> conf.crophack <- v);
      src#string "trim fuzz"
        (fun () -> irect_to_string conf.trimfuzz)
        (fun v ->
          try
            conf.trimfuzz <- irect_of_string v;
            if conf.trimmargins
            then settrim true conf.trimfuzz;
          with exn ->
            state.text <- Printf.sprintf "bad irect `%s': %s"
              v (Printexc.to_string exn)
        );
      src#string "throttle"
        (fun () ->
          match conf.maxwait with
          | None -> "show place holder if page is not ready"
          | Some time ->
              if time = infinity
              then "wait for page to fully render"
              else
                "wait " ^ string_of_float time
                ^ " seconds before showing placeholder"
        )
        (fun v ->
          try
            let f = float_of_string v in
            if f <= 0.0
            then conf.maxwait <- None
            else conf.maxwait <- Some f
          with exn ->
            state.text <- Printf.sprintf "bad time `%s': %s"
              v (Printexc.to_string exn)
        );
      src#colorspace "color space"
        (fun () -> colorspace_to_string conf.colorspace)
        (fun v ->
          conf.colorspace <- colorspace_of_int v;
          wcmd "cs" [`i v];
          load state.layout;
        )
    );

    sep ();
    src#caption "Document" 0;
    List.iter (fun (_, s) -> src#caption s 1) state.docinfo;
    if conf.trimmargins
    then (
      sep ();
      src#caption "Trimmed margins" 0;
      src#caption2 "Dimensions"
        (fun () -> string_of_int (List.length state.pdims)) 1;
    );

    src#reset prevmode prevuioh;
  in
  fun () ->
    state.text <- "";
    let prevmode = state.mode
    and prevuioh = state.uioh in
    fillsrc prevmode prevuioh;
    let source = (src :> lvsource) in
    state.uioh <- coe (object (self)
      inherit listview ~source ~trusted:true as super
      val mutable m_prevmemused = 0
      method infochanged = function
        | Memused ->
            if m_prevmemused != state.memused
            then (
              m_prevmemused <- state.memused;
              G.postRedisplay "memusedchanged";
            )
        | Pdim -> G.postRedisplay "pdimchanged"
        | Docinfo -> fillsrc prevmode prevuioh

      method special key =
        if Glut.getModifiers () land Glut.active_ctrl = 0
        then
          match key with
          | Glut.KEY_LEFT  -> coe (self#updownlevel ~-1)
          | Glut.KEY_RIGHT -> coe (self#updownlevel 1)
          | _ -> super#special key
        else super#special key
    end);
    G.postRedisplay "info";
;;

let enterhelpmode =
  let source =
    (object
      inherit lvsourcebase
      method getitemcount = Array.length state.help
      method getitem n =
        let s, n, _ = state.help.(n) in
        (s, n)

      method exit ~uioh ~cancel ~active ~first ~pan ~qsearch =
        let optuioh =
          if not cancel
          then (
            m_qsearch <- qsearch;
            match state.help.(active) with
            | _, _, Action f -> Some (f uioh)
            | _ -> Some (uioh)
          )
          else None
        in
        m_active <- active;
        m_first <- first;
        m_pan <- pan;
        optuioh

      method hasaction n =
        match state.help.(n) with
        | _, _, Action _ -> true
        | _ -> false

      initializer
        m_active <- -1
    end)
  in fun () ->
    state.uioh <- coe (new listview ~source ~trusted:true);
    G.postRedisplay "help";
;;

let quickbookmark ?title () =
  match state.layout with
  | [] -> ()
  | l :: _ ->
      let title =
        match title with
        | None ->
            let sec = Unix.gettimeofday () in
            let tm = Unix.localtime sec in
            Printf.sprintf "Quick (page %d) (bookmarked at %d/%d/%d %d:%d)"
              (l.pageno+1)
              tm.Unix.tm_mday
              tm.Unix.tm_mon
              (tm.Unix.tm_year + 1900)
              tm.Unix.tm_hour
              tm.Unix.tm_min
        | Some title -> title
      in
      state.bookmarks <-
        (title, 0, (l.pageno, float l.pagey /. float l.pageh))
      :: state.bookmarks
;;

let doreshape w h =
  state.fullscreen <- None;
  Glut.reshapeWindow w h;
;;

let viewkeyboard key =
  let enttext te =
    let mode = state.mode in
    state.mode <- Textentry (te, fun _ -> state.mode <- mode);
    state.text <- "";
    enttext ();
    G.postRedisplay "view:enttext"
  in
  let c = Char.chr key in
  match c with
  | '\027' | 'q' ->                     (* escape *)
      begin match state.mstate with
      | Mzoomrect _ ->
          state.mstate <- Mnone;
          Glut.setCursor Glut.CURSOR_INHERIT;
          G.postRedisplay "kill zoom rect";
      | _ ->
          raise Quit
      end;

  | '\008' ->                           (* backspace *)
      let y = getnav ~-1 in
      gotoy_and_clear_text y

  | 'o' ->
      enteroutlinemode ()

  | 'u' ->
      state.rects <- [];
      state.text <- "";
      G.postRedisplay "dehighlight";

  | '/' | '?' ->
      let ondone isforw s =
        cbput state.hists.pat s;
        state.searchpattern <- s;
        search s isforw
      in
      let s = String.create 1 in
      s.[0] <- c;
      enttext (s, "", Some (onhist state.hists.pat),
              textentry, ondone (c ='/'))

  | '+' when Glut.getModifiers () land Glut.active_ctrl != 0 ->
      let incr = if conf.zoom +. 0.01 > 0.1 then 0.1 else 0.01 in
      setzoom (conf.zoom +. incr)

  | '+' ->
      let ondone s =
        let n =
          try int_of_string s with exc ->
            state.text <- Printf.sprintf "bad integer `%s': %s"
              s (Printexc.to_string exc);
            max_int
        in
        if n != max_int
        then (
          conf.pagebias <- n;
          state.text <- "page bias is now " ^ string_of_int n;
        )
      in
      enttext ("page bias: ", "", None, intentry, ondone)

  | '-' when Glut.getModifiers () land Glut.active_ctrl != 0 ->
      let decr = if conf.zoom -. 0.1 < 0.1 then 0.01 else 0.1 in
      setzoom (max 0.01 (conf.zoom -. decr))

  | '-' ->
      let ondone msg = state.text <- msg in
      enttext (
        "option [acfhilpstvAPRSZTI]: ", "", None,
        optentry state.mode, ondone
      )

  | '0' when (Glut.getModifiers () land Glut.active_ctrl != 0) ->
      setzoom 1.0

  | '1' when (Glut.getModifiers () land Glut.active_ctrl != 0) ->
      let zoom = zoomforh conf.winw conf.winh state.scrollw in
      if zoom < 1.0
      then setzoom zoom

  | '9' when (Glut.getModifiers () land Glut.active_ctrl != 0) ->
      togglebirdseye ()

  | '0' .. '9' ->
      let ondone s =
        let n =
          try int_of_string s with exc ->
            state.text <- Printf.sprintf "bad integer `%s': %s"
              s (Printexc.to_string exc);
            -1
        in
        if n >= 0
        then (
          addnav ();
          cbput state.hists.pag (string_of_int n);
          gotoy_and_clear_text (getpagey (n + conf.pagebias - 1))
        )
      in
      let pageentry text key =
        match Char.unsafe_chr key with
        | 'g' -> TEdone text
        | _ -> intentry text key
      in
      let text = "x" in text.[0] <- c;
      enttext (":", text, Some (onhist state.hists.pag), pageentry, ondone)

  | 'b' ->
      state.scrollw <- if state.scrollw > 0 then 0 else conf.scrollbw;
      reshape conf.winw conf.winh;

  | 'l' ->
      conf.hlinks <- not conf.hlinks;
      state.text <- "highlightlinks " ^ if conf.hlinks then "on" else "off";
      G.postRedisplay "toggle highlightlinks";

  | 'a' ->
      begin match state.autoscroll with
      | Some step ->
          conf.autoscrollstep <- step;
          state.autoscroll <- None
      | None ->
          if conf.autoscrollstep = 0
          then state.autoscroll <- Some 1
          else state.autoscroll <- Some conf.autoscrollstep
      end

  | 'P' ->
      conf.presentation <- not conf.presentation;
      if conf.presentation
      then (
        if not conf.scrollbarinpm
        then state.scrollw <- 0;
      )
      else
        state.scrollw <- conf.scrollbw;

      showtext ' ' ("presentation mode " ^
                       if conf.presentation then "on" else "off");
      state.anchor <- getanchor ();
      represent ()

  | 'f' ->
      begin match state.fullscreen with
      | None ->
          state.fullscreen <- Some (conf.winw, conf.winh);
          Glut.fullScreen ()
      | Some (w, h) ->
          state.fullscreen <- None;
          doreshape w h
      end

  | 'g' ->
      gotoy_and_clear_text 0

  | 'G' ->
      gotopage1 (state.pagecount - 1) 0

  | 'n' ->
      search state.searchpattern true

  | 'p' | 'N' ->
      search state.searchpattern false

  | 't' ->
      begin match state.layout with
      | [] -> ()
      | l :: _ ->
          gotoy_and_clear_text (getpagey l.pageno)
      end

  | ' ' ->
      begin match List.rev state.layout with
      | [] -> ()
      | l :: _ ->
          let pageno = min (l.pageno+1) (state.pagecount-1) in
          gotoy_and_clear_text (getpagey pageno)
      end

  | '\127' ->                           (* del *)
      begin match state.layout with
      | [] -> ()
      | l :: _ ->
          let pageno = max 0 (l.pageno-1) in
          gotoy_and_clear_text (getpagey pageno)
      end

  | '=' ->
      showtext ' ' (describe_location ());

  | 'w' ->
      begin match state.layout with
      | [] -> ()
      | l :: _ ->
          doreshape (l.pagew + state.scrollw) l.pageh;
          G.postRedisplay "w"
      end

  | '\'' ->
      enterbookmarkmode ()

  | 'h' ->
      enterhelpmode ()

  | 'i' ->
      enterinfomode ()

  | 'm' ->
      let ondone s =
        match state.layout with
        | l :: _ ->
            state.bookmarks <-
              (s, 0, (l.pageno, float l.pagey /. float l.pageh))
            :: state.bookmarks
        | _ -> ()
      in
      enttext ("bookmark: ", "", None, textentry, ondone)

  | '~' ->
      quickbookmark ();
      showtext ' ' "Quick bookmark added";

  | 'z' ->
      begin match state.layout with
      | l :: _ ->
          let rect = getpdimrect l.pagedimno in
          let w, h =
            if conf.crophack
            then
              (truncate (1.8 *. (rect.(1) -. rect.(0))),
              truncate (1.2 *. (rect.(3) -. rect.(0))))
            else
              (truncate (rect.(1) -. rect.(0)),
              truncate (rect.(3) -. rect.(0)))
          in
          let w = truncate ((float w)*.conf.zoom)
          and h = truncate ((float h)*.conf.zoom) in
          if w != 0 && h != 0
          then (
            state.anchor <- getanchor ();
            doreshape (w + state.scrollw) (h + conf.interpagespace)
          );
          G.postRedisplay "z";

      | [] -> ()
      end

  | '\000' ->                           (* ctrl-2 *)
      let maxw = getmaxw () in
      if maxw > 0.0
      then setzoom (maxw /. float conf.winw)

  | '<' | '>' ->
      reqlayout (conf.angle + (if c = '>' then 30 else -30)) conf.proportional

  | '[' | ']' ->
      conf.colorscale <-
        bound (conf.colorscale +. (if c = ']' then 0.1 else -0.1)) 0.0 1.0
      ;
      G.postRedisplay "brightness";

  | 'k' ->
      begin match state.mode with
      | Birdseye beye -> upbirdseye beye
      | _ -> gotoy (clamp (-conf.scrollstep))
      end

  | 'j' ->
      begin match state.mode with
      | Birdseye beye -> downbirdseye beye
      | _ -> gotoy (clamp conf.scrollstep)
      end

  | 'r' ->
      state.anchor <- getanchor ();
      opendoc state.path state.password

  | 'v' when conf.debug ->
      state.rects <- [];
      List.iter (fun l ->
        match getopaque l.pageno with
        | None -> ()
        | Some opaque ->
            let x0, y0, x1, y1 = pagebbox opaque in
            let a,b = float x0, float y0 in
            let c,d = float x1, float y0 in
            let e,f = float x1, float y1 in
            let h,j = float x0, float y1 in
            let rect = (a,b,c,d,e,f,h,j) in
            debugrect rect;
            state.rects <- (l.pageno, l.pageno mod 3, rect) :: state.rects;
      ) state.layout;
      G.postRedisplay "v";

  | _ ->
      vlog "huh? %d %c" key (Char.chr key);
;;

let birdseyekeyboard key ((_, _, pageno, _, _) as beye) =
  match key with
  | 27 ->                               (* escape *)
      leavebirdseye beye true

  | 12 ->                               (* ctrl-l *)
      let y, h = getpageyh pageno in
      let top = (conf.winh - h) / 2 in
      gotoy (max 0 (y - top))

  | 13 ->                               (* enter *)
      leavebirdseye beye false

  | _ ->
      viewkeyboard key
;;

let keyboard ~key ~x ~y =
  ignore x;
  ignore y;
  if key = 7 && not (istextentry state.mode) (* ctrl-g *)
  then wcmd "interrupt" []
  else state.uioh <- state.uioh#key key
;;

let birdseyespecial key ((conf, leftx, _, hooverpageno, anchor) as beye) =
  match key with
  | Glut.KEY_UP -> upbirdseye beye
  | Glut.KEY_DOWN -> downbirdseye beye

  | Glut.KEY_PAGE_UP ->
      begin match state.layout with
      | l :: _ ->
          if l.pagey != 0
          then (
            state.mode <- Birdseye (
              conf, leftx, l.pageno, hooverpageno, anchor
            );
            gotopage1 l.pageno 0;
          )
          else (
            let layout = layout (state.y-conf.winh) conf.winh in
            match layout with
            | [] -> gotoy (clamp (-conf.winh))
            | l :: _ ->
                state.mode <- Birdseye (
                  conf, leftx, l.pageno, hooverpageno, anchor
                );
                gotopage1 l.pageno 0
          );

      | [] -> gotoy (clamp (-conf.winh))
      end;

  | Glut.KEY_PAGE_DOWN ->
      begin match List.rev state.layout with
      | l :: _ ->
          let layout = layout (state.y + conf.winh) conf.winh in
          begin match layout with
          | [] ->
              let incr = l.pageh - l.pagevh in
              if incr = 0
              then (
                state.mode <-
                  Birdseye (
                    conf, leftx, state.pagecount - 1, hooverpageno, anchor
                  );
                G.postRedisplay "birdseye pagedown";
              )
              else gotoy (clamp (incr + conf.interpagespace*2));

          | l :: _ ->
              state.mode <-
                Birdseye (conf, leftx, l.pageno, hooverpageno, anchor);
              gotopage1 l.pageno 0;
          end

      | [] -> gotoy (clamp conf.winh)
      end;

  | Glut.KEY_HOME ->
      state.mode <- Birdseye (conf, leftx, 0, hooverpageno, anchor);
      gotopage1 0 0

  | Glut.KEY_END ->
      let pageno = state.pagecount - 1 in
      state.mode <- Birdseye (conf, leftx, pageno, hooverpageno, anchor);
      if not (pagevisible state.layout pageno)
      then
        let h =
          match List.rev state.pdims with
          | [] -> conf.winh
          | (_, _, h, _) :: _ -> h
        in
        gotoy (max 0 (getpagey pageno - (conf.winh - h - conf.interpagespace)))
      else G.postRedisplay "birdseye end";
  | _ -> ()
;;

let setautoscrollspeed step goingdown =
  let incr = max 1 ((abs step) / 2) in
  let incr = if goingdown then incr else -incr in
  let astep = step + incr  in
  state.autoscroll <- Some astep;
;;

let special ~key ~x ~y =
  ignore x;
  ignore y;
  state.uioh <- state.uioh#special key
;;

let drawpage l =
  let color =
    match state.mode with
    | Textentry _ -> scalecolor 0.4
    | View -> scalecolor 1.0
    | Birdseye (_, _, pageno, hooverpageno, _) ->
        if l.pageno = hooverpageno
        then scalecolor 0.9
        else (
          if l.pageno = pageno
          then scalecolor 1.0
          else scalecolor 0.8
        )
  in
  drawtiles l color;
  begin match getopaque l.pageno with
  | Some opaque ->
      if tileready l l.pagex l.pagey
      then
        let x = l.pagedispx - l.pagex
        and y = l.pagedispy - l.pagey in
        postprocess opaque conf.hlinks x y;

  | _ -> ()
  end;
;;

let scrollph y =
  let maxy = state.maxy - (if conf.maxhfit then conf.winh else 0) in
  let sh = (float (maxy + conf.winh) /. float conf.winh) in
  let sh = float conf.winh /. sh in
  let sh = max sh (float conf.scrollh) in

  let percent =
    if y = state.maxy
    then 1.0
    else float y /. float maxy
  in
  let position = (float conf.winh -. sh) *. percent in

  let position =
    if position +. sh > float conf.winh
    then float conf.winh -. sh
    else position
  in
  position, sh;
;;

let scrollpw x =
  let winw = conf.winw - state.scrollw - 1 in
  let fwinw = float winw in
  let sw =
    let sw = fwinw /. float state.w  in
    let sw = fwinw *. sw in
    max sw (float conf.scrollh)
  in
  let position, sw =
    let f = state.w+winw in
    let r = float (winw-x) /. float f in
    let p = fwinw *. r in
    p-.sw/.2., sw
  in
  let sw =
    if position +. sw > fwinw
    then fwinw -. position
    else sw
  in
  position, sw;
;;

let scrollindicator () =
  GlDraw.color (0.64 , 0.64, 0.64);
  GlDraw.rect
    (float (conf.winw - state.scrollw), 0.)
    (float conf.winw, float conf.winh)
  ;
  GlDraw.rect
    (0., float (conf.winh - state.hscrollh))
    (float (conf.winw - state.scrollw - 1), float conf.winh)
  ;
  GlDraw.color (0.0, 0.0, 0.0);

  let position, sh = scrollph state.y in
  GlDraw.rect
    (float (conf.winw - state.scrollw), position)
    (float conf.winw, position +. sh)
  ;
  let position, sw = scrollpw state.x in
  GlDraw.rect
    (position, float (conf.winh - state.hscrollh))
    (position +. sw, float conf.winh)
  ;
;;

let pagetranslatepoint l x y =
  let dy = y - l.pagedispy in
  let y = dy + l.pagey in
  let dx = x - l.pagedispx in
  let x = dx + l.pagex in
  (x, y);
;;

let showsel () =
  match state.mstate with
  | Mnone | Mscrolly | Mscrollx | Mpan _ | Mzoom _ | Mzoomrect _ ->
      ()

  | Msel ((x0, y0), (x1, y1)) ->
      let rec loop = function
        | l :: ls ->
            if (y0 >= l.pagedispy && y0 <= (l.pagedispy + l.pagevh))
              || ((y1 >= l.pagedispy && y1 <= (l.pagedispy + l.pagevh)))
            then
              match getopaque l.pageno with
              | Some opaque ->
                  let dx, dy = pagetranslatepoint l 0 0 in
                  let x0 = x0 + dx
                  and y0 = y0 + dy
                  and x1 = x1 + dx
                  and y1 = y1 + dy in
                  GlMat.mode `modelview;
                  GlMat.push ();
                  GlMat.translate ~x:(float ~-dx) ~y:(float ~-dy) ();
                  seltext opaque (x0, y0, x1, y1);
                  GlMat.pop ();
              | _ -> ()
            else loop ls
        | [] -> ()
      in
      loop state.layout
;;

let showrects () =
  Gl.enable `blend;
  GlDraw.color (0.0, 0.0, 1.0) ~alpha:0.5;
  GlDraw.polygon_mode `both `fill;
  GlFunc.blend_func `src_alpha `one_minus_src_alpha;
  List.iter
    (fun (pageno, c, (x0, y0, x1, y1, x2, y2, x3, y3)) ->
      List.iter (fun l ->
        if l.pageno = pageno
        then (
          let dx = float (l.pagedispx - l.pagex) in
          let dy = float (l.pagedispy - l.pagey) in
          GlDraw.color (0.0, 0.0, 1.0 /. float c) ~alpha:0.5;
          GlDraw.begins `quads;
          (
            GlDraw.vertex2 (x0+.dx, y0+.dy);
            GlDraw.vertex2 (x1+.dx, y1+.dy);
            GlDraw.vertex2 (x2+.dx, y2+.dy);
            GlDraw.vertex2 (x3+.dx, y3+.dy);
          );
          GlDraw.ends ();
        )
      ) state.layout
    ) state.rects
  ;
  Gl.disable `blend;
;;

let display () =
  GlClear.color (scalecolor2 conf.bgcolor);
  GlClear.clear [`color];
  List.iter drawpage state.layout;
  showrects ();
  showsel ();
  scrollindicator ();
  state.uioh#display;
  begin match state.mstate with
  | Mzoomrect ((x0, y0), (x1, y1)) ->
      Gl.enable `blend;
      GlDraw.color (0.3, 0.3, 0.3) ~alpha:0.5;
      GlDraw.polygon_mode `both `fill;
      GlFunc.blend_func `src_alpha `one_minus_src_alpha;
      GlDraw.rect (float x0, float y0)
        (float x1, float y1);
      Gl.disable `blend;
  | _ -> ()
  end;
  enttext ();
  Glut.swapBuffers ();
;;

let getunder x y =
  let rec f = function
    | l :: rest ->
        begin match getopaque l.pageno with
        | Some opaque ->
            let x0 = l.pagedispx in
            let x1 = x0 + l.pagevw in
            let y0 = l.pagedispy in
            let y1 = y0 + l.pagevh in
            if y >= y0 && y <= y1 && x >= x0 && x <= x1
            then
              let px, py = pagetranslatepoint l x y in
              match whatsunder opaque px py with
              | Unone -> f rest
              | under -> under
            else f rest
        | _ ->
            f rest
        end
    | [] -> Unone
  in
  f state.layout
;;

let zoomrect x y x1 y1 =
  let x0 = min x x1
  and x1 = max x x1
  and y0 = min y y1 in
  gotoy (state.y + y0);
  state.anchor <- getanchor ();
  let zoom = (float conf.winw *. conf.zoom) /. float (x1 - x0) in
  let margin =
    if state.w < conf.winw - state.scrollw
    then (conf.winw - state.scrollw - state.w) / 2
    else 0
  in
  state.x <- (state.x + margin) - x0;
  setzoom zoom;
  Glut.setCursor Glut.CURSOR_INHERIT;
  state.mstate <- Mnone;
;;

let scrollx x =
  let winw = conf.winw - state.scrollw - 1 in
  let s = float x /. float winw in
  let destx = truncate (float (state.w + winw) *. s) in
  state.x <- winw - destx;
  gotoy_and_clear_text state.y;
  state.mstate <- Mscrollx;
;;

let scrolly y =
  let s = float y /. float conf.winh in
  let desty = truncate (float (state.maxy - conf.winh) *. s) in
  gotoy_and_clear_text desty;
  state.mstate <- Mscrolly;
;;

let viewmouse button bstate x y =
  match button with
  | Glut.OTHER_BUTTON n when (n == 3 || n == 4) && bstate = Glut.UP ->
      if Glut.getModifiers () land Glut.active_ctrl != 0
      then (
        match state.mstate with
        | Mzoom (oldn, i) ->
            if oldn = n
            then (
              if i = 2
              then
                let incr =
                  match n with
                  | 4 ->
                      if conf.zoom +. 0.01 > 0.1 then 0.1 else 0.01
                  | _ ->
                      if conf.zoom -. 0.1 < 0.1 then -0.01 else -0.1
                in
                let zoom = conf.zoom -. incr in
                setzoom zoom;
                state.mstate <- Mzoom (n, 0);
              else
                state.mstate <- Mzoom (n, i+1);
            )
            else state.mstate <- Mzoom (n, 0)

        | _ -> state.mstate <- Mzoom (n, 0)
      )
      else (
        match state.autoscroll with
        | Some step -> setautoscrollspeed step (n=4)
        | None ->
            let incr =
              if n = 3
              then -conf.scrollstep
              else conf.scrollstep
            in
            let incr = incr * 2 in
            let y = clamp incr in
            gotoy_and_clear_text y
      )

  | Glut.LEFT_BUTTON when Glut.getModifiers () land Glut.active_ctrl != 0 ->
      if bstate = Glut.DOWN
      then (
        Glut.setCursor Glut.CURSOR_CROSSHAIR;
        state.mstate <- Mpan (x, y)
      )
      else
        state.mstate <- Mnone

  | Glut.RIGHT_BUTTON ->
      if bstate = Glut.DOWN
      then (
        Glut.setCursor Glut.CURSOR_CYCLE;
        let p = (x, y) in
        state.mstate <- Mzoomrect (p, p)
      )
      else (
        match state.mstate with
        | Mzoomrect ((x0, y0), _) -> zoomrect x0 y0 x y
        | _ ->
            Glut.setCursor Glut.CURSOR_INHERIT;
            state.mstate <- Mnone
      )

  | Glut.LEFT_BUTTON when x > conf.winw - state.scrollw ->
      if bstate = Glut.DOWN
      then
        let position, sh = scrollph state.y in
        if y > truncate position && y < truncate (position +. sh)
        then state.mstate <- Mscrolly
        else scrolly y
      else
        state.mstate <- Mnone

  | Glut.LEFT_BUTTON when y > conf.winh - state.hscrollh ->
      if bstate = Glut.DOWN
      then
        let position, sw = scrollpw state.x in
        if x > truncate position && x < truncate (position +. sw)
        then state.mstate <- Mscrollx
        else scrollx x
      else
        state.mstate <- Mnone

  | Glut.LEFT_BUTTON ->
      let dest = if bstate = Glut.DOWN then getunder x y else Unone in
      begin match dest with
      | Ulinkgoto (pageno, top) ->
          if pageno >= 0
          then (
            addnav ();
            gotopage1 pageno top;
          )

      | Ulinkuri s ->
          gotouri s

      | Unone when bstate = Glut.DOWN ->
          Glut.setCursor Glut.CURSOR_CROSSHAIR;
          state.mstate <- Mpan (x, y);

      | Unone | Utext _ ->
          if bstate = Glut.DOWN
          then (
            if conf.angle mod 360 = 0
            then (
              state.mstate <- Msel ((x, y), (x, y));
              G.postRedisplay "mouse select";
            )
          )
          else (
            match state.mstate with
            | Mnone  -> ()

            | Mzoom _ | Mscrollx | Mscrolly ->
                state.mstate <- Mnone

            | Mzoomrect ((x0, y0), _) ->
                zoomrect x0 y0 x y

            | Mpan _ ->
                Glut.setCursor Glut.CURSOR_INHERIT;
                state.mstate <- Mnone

            | Msel ((_, y0), (_, y1)) ->
                let f l =
                  if (y0 >= l.pagedispy && y0 <= (l.pagedispy + l.pagevh))
                    || ((y1 >= l.pagedispy && y1 <= (l.pagedispy + l.pagevh)))
                  then
                    match getopaque l.pageno with
                    | Some opaque ->
                        copysel opaque
                    | _ -> ()
                in
                List.iter f state.layout;
                copysel "";             (* ugly *)
                Glut.setCursor Glut.CURSOR_INHERIT;
                state.mstate <- Mnone;
          )
      end

  | _ -> ()
;;

let birdseyemouse button bstate x y
    (conf, leftx, _, hooverpageno, anchor) =
  match button with
  | Glut.LEFT_BUTTON when bstate = Glut.UP ->
      let margin = (conf.winw - (state.w + state.scrollw)) / 2 in
      let rec loop = function
        | [] -> ()
        | l :: rest ->
            if y > l.pagedispy && y < l.pagedispy + l.pagevh
              && x > margin && x < margin + l.pagew
            then (
              leavebirdseye (conf, leftx, l.pageno, hooverpageno, anchor) false;
            )
            else loop rest
      in
      loop state.layout
  | Glut.OTHER_BUTTON _ -> viewmouse button bstate x y
  | _ -> ()
;;

let mouse bstate button x y =
  state.uioh <- state.uioh#button button bstate x y;
;;

let mouse ~button ~state ~x ~y = mouse state button x y;;

let motion ~x ~y =
  state.uioh <- state.uioh#motion x y
;;

let pmotion ~x ~y =
  state.uioh <- state.uioh#pmotion x y;
;;

let uioh = object
  method display = ()

  method key key =
    begin match state.mode with
    | Textentry textentry -> textentrykeyboard key textentry
    | Birdseye birdseye -> birdseyekeyboard key birdseye
    | View -> viewkeyboard key
    end;
    state.uioh

  method special key =
    begin match state.mode with
    | View | (Birdseye _) when key = Glut.KEY_F9 ->
        togglebirdseye ()

    | Birdseye vals ->
        birdseyespecial key vals

    | View when key = Glut.KEY_F1 ->
        enterhelpmode ()

    | View ->
        begin match state.autoscroll with
        | Some step when key = Glut.KEY_DOWN || key = Glut.KEY_UP ->
            setautoscrollspeed step (key = Glut.KEY_DOWN)

        | _ ->
            let y =
              match key with
              | Glut.KEY_F3        -> search state.searchpattern true; state.y
              | Glut.KEY_UP        ->
                  if Glut.getModifiers () land Glut.active_ctrl != 0
                  then
                    if Glut.getModifiers () land Glut.active_shift != 0
                    then (setzoom state.prevzoom; state.y)
                    else clamp (-conf.winh/2)
                  else clamp (-conf.scrollstep)
              | Glut.KEY_DOWN      ->
                  if Glut.getModifiers () land Glut.active_ctrl != 0
                  then
                    if Glut.getModifiers () land Glut.active_shift != 0
                    then (setzoom state.prevzoom; state.y)
                    else clamp (conf.winh/2)
                  else clamp (conf.scrollstep)
              | Glut.KEY_PAGE_UP   ->
                  if Glut.getModifiers () land Glut.active_ctrl != 0
                  then
                    match state.layout with
                    | [] -> state.y
                    | l :: _ -> state.y - l.pagey
                  else
                    clamp (-conf.winh)
              | Glut.KEY_PAGE_DOWN ->
                  if Glut.getModifiers () land Glut.active_ctrl != 0
                  then
                    match List.rev state.layout with
                    | [] -> state.y
                    | l :: _ -> getpagey l.pageno
                  else
                    clamp conf.winh
              | Glut.KEY_HOME ->
                  addnav ();
                  0
              | Glut.KEY_END ->
                  addnav ();
                  state.maxy - (if conf.maxhfit then conf.winh else 0)

              | (Glut.KEY_RIGHT | Glut.KEY_LEFT) when
                    Glut.getModifiers () land Glut.active_alt != 0 ->
                  getnav (if key = Glut.KEY_LEFT then 1 else -1)

              | Glut.KEY_RIGHT when conf.zoom > 1.0 ->
                  let dx =
                    if Glut.getModifiers () land Glut.active_ctrl != 0
                    then (conf.winw / 2)
                    else 10
                  in
                  state.x <- state.x - dx;
                  state.y
              | Glut.KEY_LEFT when conf.zoom > 1.0 ->
                  let dx =
                    if Glut.getModifiers () land Glut.active_ctrl != 0
                    then (conf.winw / 2)
                    else 10
                  in
                  state.x <- state.x + dx;
                  state.y

              | _ -> state.y
            in
            gotoy_and_clear_text y
        end

    | Textentry te -> textentryspecial key te
    end;
    state.uioh

  method button button bstate x y =
    begin match state.mode with
    | View -> viewmouse button bstate x y
    | Birdseye beye -> birdseyemouse button bstate x y beye
    | Textentry _ -> ()
    end;
    state.uioh

  method motion x y =
    begin  match state.mode with
    | Textentry _ -> ()
    | View | Birdseye _ ->
        match state.mstate with
        | Mzoom _ | Mnone -> ()

        | Mpan (x0, y0) ->
            let dx = x - x0
            and dy = y0 - y in
            state.mstate <- Mpan (x, y);
            if conf.zoom > 1.0 then state.x <- state.x + dx;
            let y = clamp dy in
            gotoy_and_clear_text y

        | Msel (a, _) ->
            state.mstate <- Msel (a, (x, y));
            G.postRedisplay "motion select";

        | Mscrolly ->
            let y = min conf.winh (max 0 y) in
            scrolly y

        | Mscrollx ->
            let x = min conf.winw (max 0 x) in
            scrollx x

        | Mzoomrect (p0, _) ->
            state.mstate <- Mzoomrect (p0, (x, y));
            G.postRedisplay "motion zoomrect";
    end;
    state.uioh

  method pmotion x y =
    begin match state.mode with
    | Birdseye (conf, leftx, pageno, hooverpageno, anchor) ->
        let margin = (conf.winw - (state.w + state.scrollw)) / 2 in
        let rec loop = function
          | [] ->
              if hooverpageno != -1
              then (
                state.mode <- Birdseye (conf, leftx, pageno, -1, anchor);
                G.postRedisplay "pmotion birdseye no hoover";
              )
          | l :: rest ->
              if y > l.pagedispy && y < l.pagedispy + l.pagevh
                && x > margin && x < margin + l.pagew
              then (
                state.mode <- Birdseye (conf, leftx, pageno, l.pageno, anchor);
                G.postRedisplay "pmotion birdseye hoover";
              )
              else loop rest
        in
        loop state.layout

    | Textentry _ -> ()

    | View ->
        match state.mstate with
        | Mnone ->
            begin match getunder x y with
            | Unone -> Glut.setCursor Glut.CURSOR_INHERIT
            | Ulinkuri uri ->
                if conf.underinfo then showtext 'u' ("ri: " ^ uri);
                Glut.setCursor Glut.CURSOR_INFO
            | Ulinkgoto (page, _) ->
                if conf.underinfo
                then showtext 'p' ("age: " ^ string_of_int (page+1));
                Glut.setCursor Glut.CURSOR_INFO
            | Utext s ->
                if conf.underinfo then showtext 'f' ("ont: " ^ s);
                Glut.setCursor Glut.CURSOR_TEXT
            end

        | Mpan _ | Msel _ | Mzoom _ | Mscrolly | Mscrollx | Mzoomrect _ ->
            ()
    end;
    state.uioh

  method infochanged _ = ()
end;;

module Config =
struct
  open Parser

  let fontpath = ref "";;
  let wmclasshack = ref false;;

  let unent s =
    let l = String.length s in
    let b = Buffer.create l in
    unent b s 0 l;
    Buffer.contents b;
  ;;

  let home =
    try
      match platform with
      | Pwindows | Pmingw -> Sys.getenv "HOMEPATH"
      | _ -> Sys.getenv "HOME"
    with exn ->
      prerr_endline
        ("Can not determine home directory location: " ^
            Printexc.to_string exn);
      ""
  ;;

  let config_of c attrs =
    let apply c k v =
      try
        match k with
        | "scroll-bar-width" -> { c with scrollbw = max 0 (int_of_string v) }
        | "scroll-handle-height" -> { c with scrollh = max 0 (int_of_string v) }
        | "case-insensitive-search" -> { c with icase = bool_of_string v }
        | "preload" -> { c with preload = bool_of_string v }
        | "page-bias" -> { c with pagebias = int_of_string v }
        | "scroll-step" -> { c with scrollstep = max 1 (int_of_string v) }
        | "auto-scroll-step" ->
            { c with autoscrollstep = max 0 (int_of_string v) }
        | "max-height-fit" -> { c with maxhfit = bool_of_string v }
        | "crop-hack" -> { c with crophack = bool_of_string v }
        | "throttle" ->
            let mw =
              match String.lowercase v with
              | "true" -> Some infinity
              | "false" -> None
              | f -> Some (float_of_string f)
            in
            { c with maxwait = mw}
        | "highlight-links" -> { c with hlinks = bool_of_string v }
        | "under-cursor-info" -> { c with underinfo = bool_of_string v }
        | "vertical-margin" ->
            { c with interpagespace = max 0 (int_of_string v) }
        | "zoom" ->
            let zoom = float_of_string v /. 100. in
            let zoom = max zoom 0.0 in
            { c with zoom = zoom }
        | "presentation" -> { c with presentation = bool_of_string v }
        | "rotation-angle" -> { c with angle = int_of_string v }
        | "width" -> { c with winw = max 20 (int_of_string v) }
        | "height" -> { c with winh = max 20 (int_of_string v) }
        | "persistent-bookmarks" -> { c with savebmarks = bool_of_string v }
        | "proportional-display" -> { c with proportional = bool_of_string v }
        | "pixmap-cache-size" ->
            { c with memlimit = max 2 (int_of_string_with_suffix v) }
        | "tex-count" -> { c with texcount = max 1 (int_of_string v) }
        | "slice-height" -> { c with sliceheight = max 2 (int_of_string v) }
        | "thumbnail-width" -> { c with thumbw = max 2 (int_of_string v) }
        | "persistent-location" -> { c with jumpback = bool_of_string v }
        | "background-color" -> { c with bgcolor = color_of_string v }
        | "scrollbar-in-presentation" ->
            { c with scrollbarinpm = bool_of_string v }
        | "tile-width" -> { c with tilew = max 2 (int_of_string v) }
        | "tile-height" -> { c with tileh = max 2 (int_of_string v) }
        | "memlimit" ->
            { c with mumemlimit = max 1024 (int_of_string_with_suffix v) }
        | "checkers" -> { c with checkers = bool_of_string v }
        | "aalevel" -> { c with aalevel = max 0 (int_of_string v) }
        | "trim-margins" -> { c with trimmargins = bool_of_string v }
        | "trim-fuzz" -> { c with trimfuzz = irect_of_string v }
        | "wmclass-hack" -> wmclasshack := bool_of_string v; c
        | "uri-launcher" -> { c with urilauncher = unent v }
        | "color-space" -> { c with colorspace = colorspace_of_string v }
        | "invert-colors" -> { c with invert  = bool_of_string v }
        | "brightness" -> { c with colorscale = float_of_string v }
        | _ -> c
      with exn ->
        prerr_endline ("Error processing attribute (`" ^
                          k ^ "'=`" ^ v ^ "'): " ^ Printexc.to_string exn);
        c
    in
    let rec fold c = function
      | [] -> c
      | (k, v) :: rest ->
          let c = apply c k v in
          fold c rest
    in
    fold c attrs;
  ;;

  let fromstring f pos n v d =
    try f v
    with exn ->
      dolog "Error processing attribute (%S=%S) at %d\n%s"
        n v pos (Printexc.to_string exn)
      ;
      d
  ;;

  let bookmark_of attrs =
    let rec fold title page rely = function
      | ("title", v) :: rest -> fold v page rely rest
      | ("page", v) :: rest -> fold title v rely rest
      | ("rely", v) :: rest -> fold title page v rest
      | _ :: rest -> fold title page rely rest
      | [] -> title, page, rely
    in
    fold "invalid" "0" "0" attrs
  ;;

  let doc_of attrs =
    let rec fold path page rely pan = function
      | ("path", v) :: rest -> fold v page rely pan rest
      | ("page", v) :: rest -> fold path v rely pan rest
      | ("rely", v) :: rest -> fold path page v pan rest
      | ("pan", v) :: rest -> fold path page rely v rest
      | _ :: rest -> fold path page rely pan rest
      | [] -> path, page, rely, pan
    in
    fold "" "0" "0" "0" attrs
  ;;

  let setconf dst src =
    dst.scrollbw       <- src.scrollbw;
    dst.scrollh        <- src.scrollh;
    dst.icase          <- src.icase;
    dst.preload        <- src.preload;
    dst.pagebias       <- src.pagebias;
    dst.verbose        <- src.verbose;
    dst.scrollstep     <- src.scrollstep;
    dst.maxhfit        <- src.maxhfit;
    dst.crophack       <- src.crophack;
    dst.autoscrollstep <- src.autoscrollstep;
    dst.maxwait        <- src.maxwait;
    dst.hlinks         <- src.hlinks;
    dst.underinfo      <- src.underinfo;
    dst.interpagespace <- src.interpagespace;
    dst.zoom           <- src.zoom;
    dst.presentation   <- src.presentation;
    dst.angle          <- src.angle;
    dst.winw           <- src.winw;
    dst.winh           <- src.winh;
    dst.savebmarks     <- src.savebmarks;
    dst.memlimit       <- src.memlimit;
    dst.proportional   <- src.proportional;
    dst.texcount       <- src.texcount;
    dst.sliceheight    <- src.sliceheight;
    dst.thumbw         <- src.thumbw;
    dst.jumpback       <- src.jumpback;
    dst.bgcolor        <- src.bgcolor;
    dst.scrollbarinpm  <- src.scrollbarinpm;
    dst.tilew          <- src.tilew;
    dst.tileh          <- src.tileh;
    dst.mumemlimit     <- src.mumemlimit;
    dst.checkers       <- src.checkers;
    dst.aalevel        <- src.aalevel;
    dst.trimmargins    <- src.trimmargins;
    dst.trimfuzz       <- src.trimfuzz;
    dst.urilauncher    <- src.urilauncher;
    dst.colorspace     <- src.colorspace;
    dst.invert         <- src.invert;
    dst.colorscale     <- src.colorscale;
  ;;

  let get s =
    let h = Hashtbl.create 10 in
    let dc = { defconf with angle = defconf.angle } in
    let rec toplevel v t spos _ =
      match t with
      | Vdata | Vcdata | Vend -> v
      | Vopen ("llppconfig", _, closed) ->
          if closed
          then v
          else { v with f = llppconfig }
      | Vopen _ ->
          error "unexpected subelement at top level" s spos
      | Vclose _ -> error "unexpected close at top level" s spos

    and llppconfig v t spos _ =
      match t with
      | Vdata | Vcdata -> v
      | Vend -> error "unexpected end of input in llppconfig" s spos
      | Vopen ("defaults", attrs, closed) ->
          let c = config_of dc attrs in
          setconf dc c;
          if closed
          then v
          else { v with f = skip "defaults" (fun () -> v) }

      | Vopen ("ui-font", attrs, closed) ->
          let rec getsize size = function
            | [] -> size
            | ("size", v) :: rest ->
                let size =
                  fromstring int_of_string spos "size" v fstate.fontsize in
                getsize size rest
            | l -> getsize size l
          in
          fstate.fontsize <- getsize fstate.fontsize attrs;
          if closed
          then v
          else { v with f = uifont (Buffer.create 10) }

      | Vopen ("doc", attrs, closed) ->
          let pathent, spage, srely, span = doc_of attrs in
          let path = unent pathent
          and pageno = fromstring int_of_string spos "page" spage 0
          and rely = fromstring float_of_string spos "rely" srely 0.0
          and pan = fromstring int_of_string spos "pan" span 0 in
          let c = config_of dc attrs in
          let anchor = (pageno, rely) in
          if closed
          then (Hashtbl.add h path (c, [], pan, anchor); v)
          else { v with f = doc path pan anchor c [] }

      | Vopen _ ->
          error "unexpected subelement in llppconfig" s spos

      | Vclose "llppconfig" ->  { v with f = toplevel }
      | Vclose _ -> error "unexpected close in llppconfig" s spos

    and uifont b v t spos epos =
      match t with
      | Vdata | Vcdata ->
          Buffer.add_substring b s spos (epos - spos);
          v
      | Vopen (_, _, _) ->
          error "unexpected subelement in ui-font" s spos
      | Vclose "ui-font" ->
          if String.length !fontpath = 0
          then fontpath := Buffer.contents b;
          { v with f = llppconfig }
      | Vclose _ -> error "unexpected close in ui-font" s spos
      | Vend -> error "unexpected end of input in ui-font" s spos

    and doc path pan anchor c bookmarks v t spos _ =
      match t with
      | Vdata | Vcdata -> v
      | Vend -> error "unexpected end of input in doc" s spos
      | Vopen ("bookmarks", _, closed) ->
          if closed
          then v
          else { v with f = pbookmarks path pan anchor c bookmarks }

      | Vopen (_, _, _) ->
          error "unexpected subelement in doc" s spos

      | Vclose "doc" ->
          Hashtbl.add h path (c, List.rev bookmarks, pan, anchor);
          { v with f = llppconfig }

      | Vclose _ -> error "unexpected close in doc" s spos

    and pbookmarks path pan anchor c bookmarks v t spos _ =
      match t with
      | Vdata | Vcdata -> v
      | Vend -> error "unexpected end of input in bookmarks" s spos
      | Vopen ("item", attrs, closed) ->
          let titleent, spage, srely = bookmark_of attrs in
          let page = fromstring int_of_string spos "page" spage 0
          and rely = fromstring float_of_string spos "rely" srely 0.0 in
          let bookmarks = (unent titleent, 0, (page, rely)) :: bookmarks in
          if closed
          then { v with f = pbookmarks path pan anchor c bookmarks }
          else
            let f () = v in
            { v with f = skip "item" f }

      | Vopen _ ->
          error "unexpected subelement in bookmarks" s spos

      | Vclose "bookmarks" ->
          { v with f = doc path pan anchor c bookmarks }

      | Vclose _ -> error "unexpected close in bookmarks" s spos

    and skip tag f v t spos _ =
      match t with
      | Vdata | Vcdata -> v
      | Vend ->
          error ("unexpected end of input in skipped " ^ tag) s spos
      | Vopen (tag', _, closed) ->
          if closed
          then v
          else
            let f' () = { v with f = skip tag f } in
            { v with f = skip tag' f' }
      | Vclose ctag ->
          if tag = ctag
          then f ()
          else error ("unexpected close in skipped " ^ tag) s spos
    in

    parse { f = toplevel; accu = () } s;
    h, dc;
  ;;

  let do_load f ic =
    try
      let len = in_channel_length ic in
      let s = String.create len in
      really_input ic s 0 len;
      f s;
    with
    | Parse_error (msg, s, pos) ->
        let subs = subs s pos in
        let s = Printf.sprintf "%s: at %d [..%s..]" msg pos subs in
        failwith ("parse error: " ^ s)

    | exn ->
        failwith ("config load error: " ^ Printexc.to_string exn)
  ;;

  let defconfpath =
    let dir =
      try
        let dir = Filename.concat home ".config" in
        if Sys.is_directory dir then dir else home
      with _ -> home
    in
    Filename.concat dir "llpp.conf"
  ;;

  let confpath = ref defconfpath;;

  let load1 f =
    if Sys.file_exists !confpath
    then
      match
        (try Some (open_in_bin !confpath)
          with exn ->
            prerr_endline
              ("Error opening configuation file `" ^ !confpath ^ "': " ^
                  Printexc.to_string exn);
            None
        )
      with
      | Some ic ->
          begin try
              f (do_load get ic)
            with exn ->
              prerr_endline
                ("Error loading configuation from `" ^ !confpath ^ "': " ^
                    Printexc.to_string exn);
          end;
          close_in ic;

      | None -> ()
    else
      f (Hashtbl.create 0, defconf)
  ;;

  let load () =
    let f (h, dc) =
      let pc, pb, px, pa =
        try
          Hashtbl.find h (Filename.basename state.path)
        with Not_found -> dc, [], 0, (0, 0.0)
      in
      setconf defconf dc;
      setconf conf pc;
      state.bookmarks <- pb;
      state.x <- px;
      state.scrollw <- conf.scrollbw;
      if conf.jumpback
      then state.anchor <- pa;
      cbput state.hists.nav pa;
    in
    load1 f
  ;;

  let add_attrs bb always dc c =
    let ob s a b =
      if always || a != b
      then Printf.bprintf bb "\n    %s='%b'" s a
    and oi s a b =
      if always || a != b
      then Printf.bprintf bb "\n    %s='%d'" s a
    and oI s a b =
      if always || a != b
      then Printf.bprintf bb "\n    %s='%s'" s (string_with_suffix_of_int a)
    and oz s a b =
      if always || a <> b
      then Printf.bprintf bb "\n    %s='%d'" s (truncate (a*.100.))
    and oF s a b =
      if always || a <> b
      then Printf.bprintf bb "\n    %s='%f'" s a
    and oc s a b =
      if always || a <> b
      then
        Printf.bprintf bb "\n    %s='%s'" s (color_to_string a)
    and oC s a b =
      if always || a <> b
      then
        Printf.bprintf bb "\n    %s='%s'" s (colorspace_to_string a)
    and oR s a b =
      if always || a <> b
      then
        Printf.bprintf bb "\n    %s='%s'" s (irect_to_string a)
    and os s a b =
      if always || a <> b
      then
        Printf.bprintf bb "\n    %s='%s'" s (enent a 0 (String.length a))
    and oW s a b =
      if always || a <> b
      then
        let v =
          match a with
          | None -> "false"
          | Some f ->
              if f = infinity
              then "true"
              else string_of_float f
        in
        Printf.bprintf bb "\n    %s='%s'" s v
    in
    let w, h =
      if always
      then dc.winw, dc.winh
      else
        match state.fullscreen with
        | Some wh -> wh
        | None -> c.winw, c.winh
    in
    let zoom, presentation, interpagespace, maxwait =
      if always
      then dc.zoom, dc.presentation, dc.interpagespace, dc.maxwait
      else
        match state.mode with
        | Birdseye (bc, _, _, _, _) ->
            bc.zoom, bc.presentation, bc.interpagespace, bc.maxwait
        | _ -> c.zoom, c.presentation, c.interpagespace, c.maxwait
    in
    oi "width" w dc.winw;
    oi "height" h dc.winh;
    oi "scroll-bar-width" c.scrollbw dc.scrollbw;
    oi "scroll-handle-height" c.scrollh dc.scrollh;
    ob "case-insensitive-search" c.icase dc.icase;
    ob "preload" c.preload dc.preload;
    oi "page-bias" c.pagebias dc.pagebias;
    oi "scroll-step" c.scrollstep dc.scrollstep;
    oi "auto-scroll-step" c.autoscrollstep dc.autoscrollstep;
    ob "max-height-fit" c.maxhfit dc.maxhfit;
    ob "crop-hack" c.crophack dc.crophack;
    oW "throttle" maxwait dc.maxwait;
    ob "highlight-links" c.hlinks dc.hlinks;
    ob "under-cursor-info" c.underinfo dc.underinfo;
    oi "vertical-margin" interpagespace dc.interpagespace;
    oz "zoom" zoom dc.zoom;
    ob "presentation" presentation dc.presentation;
    oi "rotation-angle" c.angle dc.angle;
    ob "persistent-bookmarks" c.savebmarks dc.savebmarks;
    ob "proportional-display" c.proportional dc.proportional;
    oI "pixmap-cache-size" c.memlimit dc.memlimit;
    oi "tex-count" c.texcount dc.texcount;
    oi "slice-height" c.sliceheight dc.sliceheight;
    oi "thumbnail-width" c.thumbw dc.thumbw;
    ob "persistent-location" c.jumpback dc.jumpback;
    oc "background-color" c.bgcolor dc.bgcolor;
    ob "scrollbar-in-presentation" c.scrollbarinpm dc.scrollbarinpm;
    oi "tile-width" c.tilew dc.tilew;
    oi "tile-height" c.tileh dc.tileh;
    oI "mupdf-memlimit" c.mumemlimit dc.mumemlimit;
    ob "checkers" c.checkers dc.checkers;
    oi "aalevel" c.aalevel dc.aalevel;
    ob "trim-margins" c.trimmargins dc.trimmargins;
    oR "trim-fuzz" c.trimfuzz dc.trimfuzz;
    os "uri-launcher" c.urilauncher dc.urilauncher;
    oC "color-space" c.colorspace dc.colorspace;
    ob "invert-colors" c.invert dc.invert;
    oF "brightness" c.colorscale dc.colorscale;
    if always
    then ob "wmclass-hack" !wmclasshack false;
  ;;

  let save () =
    let uifontsize = fstate.fontsize in
    let bb = Buffer.create 32768 in
    let f (h, dc) =
      let dc = if conf.bedefault then conf else dc in
      Buffer.add_string  bb "<llppconfig>\n";

      if String.length !fontpath > 0
      then
        Printf.bprintf bb "<ui-font size='%d'><![CDATA[%s]]></ui-font>\n"
          uifontsize
          !fontpath
      else (
        if uifontsize <> 14
        then
          Printf.bprintf bb "<ui-font size='%d'/>\n" uifontsize
      );

      Buffer.add_string bb "<defaults ";
      add_attrs bb true dc dc;
      Buffer.add_string bb "/>\n";

      let adddoc path pan anchor c bookmarks =
        if bookmarks == [] && c = dc && anchor = emptyanchor
        then ()
        else (
          Printf.bprintf bb "<doc path='%s'"
            (enent path 0 (String.length path));

          if anchor <> emptyanchor
          then (
            let n, y = anchor in
            Printf.bprintf bb " page='%d'" n;
            if y > 1e-6
            then
              Printf.bprintf bb " rely='%f'" y
            ;
          );

          if pan != 0
          then Printf.bprintf bb " pan='%d'" pan;

          add_attrs bb false dc c;

          begin match bookmarks with
          | [] -> Buffer.add_string bb "/>\n"
          | _ ->
              Buffer.add_string bb ">\n<bookmarks>\n";
              List.iter (fun (title, _level, (page, rely)) ->
                Printf.bprintf bb
                  "<item title='%s' page='%d'"
                  (enent title 0 (String.length title))
                  page
                ;
                if rely > 1e-6
                then
                  Printf.bprintf bb " rely='%f'" rely
                ;
                Buffer.add_string bb "/>\n";
              ) bookmarks;
              Buffer.add_string bb "</bookmarks>\n</doc>\n";
          end;
        )
      in

      let pan =
        match state.mode with
        | Birdseye (_, pan, _, _, _) -> pan
        | _ -> state.x
      in
      let basename = Filename.basename state.path in
      adddoc basename pan (getanchor ())
        { conf with
          autoscrollstep =
            match state.autoscroll with
            | Some step -> step
            | None -> conf.autoscrollstep }
        (if conf.savebmarks then state.bookmarks else []);

      Hashtbl.iter (fun path (c, bookmarks, x, y) ->
        if basename <> path
        then adddoc path x y c bookmarks
      ) h;
      Buffer.add_string bb "</llppconfig>";
    in
    load1 f;
    if Buffer.length bb > 0
    then
      try
        let tmp = !confpath ^ ".tmp" in
        let oc = open_out_bin tmp in
        Buffer.output_buffer oc bb;
        close_out oc;
        Unix.rename tmp !confpath;
      with exn ->
        prerr_endline
          ("error while saving configuration: " ^ Printexc.to_string exn)
  ;;
end;;

let () =
  Arg.parse
    (Arg.align
        [("-p", Arg.String (fun s -> state.password <- s) ,
         "<password> Set password");

         ("-f", Arg.String (fun s -> Config.fontpath := s),
         "<path> Set path to the user interface font");

         ("-c", Arg.String (fun s -> Config.confpath := s),
         "<path> Set path to the configuration file");

         ("-v", Arg.Unit (fun () ->
           Printf.printf
             "%s\nconfiguration path: %s\n"
             Help.version
             Config.defconfpath
           ;
           exit 0), " Print version and exit");
        ]
    )
    (fun s -> state.path <- s)
    ("Usage: " ^ Sys.argv.(0) ^ " [options] some.pdf\nOptions:")
  ;
  if String.length state.path = 0
  then (prerr_endline "file name missing"; exit 1);

  Config.load ();

  let _ = Glut.init Sys.argv in
  let () = Glut.initDisplayMode ~depth:false ~double_buffer:true () in
  let () = Glut.initWindowSize conf.winw conf.winh in
  let _ = Glut.createWindow ("llpp " ^ Filename.basename state.path) in

  if not (Glut.extensionSupported "GL_ARB_texture_rectangle"
           || Glut.extensionSupported "GL_EXT_texture_rectangle")
  then (prerr_endline "OpenGL does not suppport rectangular textures"; exit 1);

  let csock, ssock =
    if not is_windows
    then
      Unix.socketpair Unix.PF_UNIX Unix.SOCK_STREAM 0
    else
      let addr = Unix.ADDR_INET (Unix.inet_addr_loopback, 1337) in
      let sock = Unix.socket Unix.PF_INET Unix.SOCK_STREAM 0 in
      Unix.setsockopt sock Unix.SO_REUSEADDR true;
      Unix.bind sock addr;
      Unix.listen sock 1;
      let csock = Unix.socket Unix.PF_INET Unix.SOCK_STREAM 0 in
      Unix.connect csock addr;
      let ssock, _ = Unix.accept sock in
      Unix.close sock;
      let opts sock =
        Unix.setsockopt sock Unix.TCP_NODELAY true;
        Unix.setsockopt_optint sock Unix.SO_LINGER None;
      in
      opts ssock;
      opts csock;
      ssock, csock
  in

  let () = Glut.displayFunc display in
  let () = Glut.reshapeFunc reshape in
  let () = Glut.keyboardFunc keyboard in
  let () = Glut.specialFunc special in
  let () = Glut.idleFunc (Some idle) in
  let () = Glut.mouseFunc mouse in
  let () = Glut.motionFunc motion in
  let () = Glut.passiveMotionFunc pmotion in

  setcheckers conf.checkers;
  init ssock (
    conf.angle, conf.proportional, (conf.trimmargins, conf.trimfuzz),
    conf.texcount, conf.sliceheight, conf.mumemlimit, conf.colorspace,
    !Config.wmclasshack, !Config.fontpath
  );
  state.csock <- csock;
  state.ssock <- ssock;
  state.text <- "Opening " ^ state.path;
  setaalevel conf.aalevel;
  writeopen state.path state.password;
  state.uioh <- uioh;
  setfontsize fstate.fontsize;

  while true do
    try
      Glut.mainLoop ();
    with
    | Glut.BadEnum "key in special_of_int" ->
        showtext '!' " LablGlut bug: special key not recognized";

    | Quit ->
        wcmd "quit" [];
        Config.save ();
        exit 0
  done;
;;