-- TJaMGraphicsImpl.mesa
-- Last changed by Bill Paxton, March 12, 1982 8:19 am
-- Last changed by Maureen Stone April 11, 1983 3:35 pm
-- Last changed by McGregor, September 13, 1982 1:44 pm
-- Last changed by Doug Wyatt, September 16, 1982 12:14 am

DIRECTORY
  Graphics,
  GraphicsOps,
  GL USING [ Start, End, Draw],
  GraphicsBasic USING [Vec],
  CGVector USING [Sub, Cross],
  Rope USING [FromRefText],
  Spline USING [Ref, Knot, Enter],
  ViewerOps USING[PaintViewer],
  ViewerClasses USING [Viewer],
  JaMBasic USING [Object],
  JaMInternal USING [Frame],
  JaMOps USING [defaultFrame, PopInteger, PushInteger, PushReal, PopReal, PopString,
    PushBoolean, PopBoolean, RegisterExplicit, StringText],
  TJaMGraphics,
  TJaMGraphicsContexts,
  TJaMGraphicsInfo;

TJaMGraphicsImpl: MONITOR
IMPORTS JaMOps, TJaMGraphics, TJaMGraphicsInfo,
  Graphics, GraphicsOps, CGVector, Rope, Spline, ViewerOps, GL, TJaMGraphicsContexts 
EXPORTS TJaMGraphics, TJaMGraphicsInfo = {
OPEN J: JaMOps, G: Graphics, E: GraphicsOps,
  Vector: CGVector, TJaMGraphics, TJaMGraphicsInfo, TDC: TJaMGraphicsContexts;

Vec: TYPE = GraphicsBasic.Vec;
GProc: TYPE = TDC.GProc;

PopString: PROC [info: Info] = {
  J.StringText[J.PopString[info.frame.opstk],LOOPHOLE[info.text, LONG STRING]];
  };

Paint: PUBLIC ENTRY SAFE PROCEDURE [self: ViewerClasses.Viewer, context: G.Context,
  whatChanged: REF ANY, clear: BOOL] = TRUSTED {
  ENABLE UNWIND => NULL;
  info: Info _ NARROW[self.data];
  IF whatChanged=NIL THEN { -- reestablish context and erase
    G.SetCP[context, 0, 0];
    info.vinitdc _ G.CopyContext[context];
    info.vdc _G.CopyContext[info.vinitdc];
    IF ~clear THEN { -- cannot simply call JErase because of monitor deadlock
      mark: G.Mark _ G.Save[info.vdc];
      G.SetColor[info.vdc, G.white];
      G.DrawBox[info.vdc,G.GetBounds[info.vdc]];
      G.Restore[info.vdc,mark] };
    IF info.drawGL THEN {
        gl: TDC.DCList _ NIL;
        FOR l: TDC.DCList _ info.dcList, l.next UNTIL l=NIL DO
            IF l.name=$GList THEN gl _ l;
            ENDLOOP;
        info.gl _ GL.End[gl.dc];
        IF info.gl#NIL THEN GL.Draw[info.vdc,info.gl];
        gl.dc _ GL.Start[info.gl];
        };
    RETURN };
  info.proc[info];
  };

Painter: PUBLIC PROCEDURE[proc: PROC [Graphics.Context], frame: Frame _ NIL] = {
  info: Info;
  CallBack: PROC [info: Info] = { proc[info.vdc] };
  IF frame=NIL THEN frame _ J.defaultFrame;
  info _ GetInfo[frame];
  TDC.ForAllDCs[info.dcList,proc];
  IF info.venabled THEN {
      info.proc _ CallBack;
      ViewerOps.PaintViewer[viewer: info.viewer, hint: client, whatChanged: info, clearClient: FALSE];
      };
  };

PushDC: PROCEDURE [frame: Frame] = {
  pushdc: GProc = {[] _ G.Save[dc]};
  Painter[pushdc,frame];
  };

PopDC: PROCEDURE [frame: Frame] = {
    popdc: GProc = {[] _ G.Restore[dc]};
      Painter[popdc, frame];
  };

GetVec: PROCEDURE [frame: Frame] RETURNS[Vec] = {
  y: REAL _ J.PopReal[frame.opstk]; x: REAL _ J.PopReal[frame.opstk]; RETURN[[x,y]] };

GetPoint: PROCEDURE [frame: Frame] RETURNS[x,y: REAL] = {
  y _ J.PopReal[frame.opstk]; x _ J.PopReal[frame.opstk]; RETURN[x,y] };

PutPoint: PROCEDURE[frame: Frame, x,y: REAL] = {
    J.PushReal[frame.opstk,x]; J.PushReal[frame.opstk,y] };

Rect: TYPE = RECORD[xmin,ymin,xmax,ymax: REAL];

GetRect: PROCEDURE [frame: Frame] RETURNS[r: Rect] = {
  [r.xmax,r.ymax] _ GetPoint[frame];
  [r.xmin,r.ymin] _ GetPoint[frame];
  RETURN[r];
  };

PutRect: PROCEDURE[frame: Frame, r: Rect] = {
  PutPoint[frame,r.xmin,r.ymin];
  PutPoint[frame,r.xmax,r.ymax];
  };

JSetVw: PROCEDURE [frame: Frame] = {
  rt: Rect _ GetRect[frame];
  rf: Rect _ GetRect[frame];
  -- *** fix this
  -- SetView[dc,@rf,@rt];
  };

JClipArea: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  paint: GProc ={G.ClipArea[self: dc, path: info.path]};
  Painter[paint,frame];
  };

JClipEOArea: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  paint: GProc ={G.ClipArea[self: dc, path: info.path, parityFill: TRUE]};
  Painter[paint,frame];
  };

JClipXArea: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  paint: GProc ={G.ClipArea[self: dc, path: info.path, exclude: TRUE]};
  Painter[paint,frame];
  };

JClipBox: PROCEDURE [frame: Frame] = {
  paint: GProc ={G.ClipBox[dc, box]};
  box: G.Box _ GetBox[frame]; 
  Painter[paint,frame];
  };

JClipXBox: PROCEDURE [frame: Frame] = {
  paint: GProc ={G.ClipBox[dc,box,TRUE]};
  box: G.Box _ GetBox[frame]; 
  Painter[paint,frame];
  };

JTranslate: PROCEDURE [frame: Frame] = {
    paint: GProc ={G.Translate[dc,tx,ty]};
    tx,ty: REAL;
    [tx,ty]_GetPoint[frame];
    Painter[paint,frame];
    };

JScale: PROCEDURE [frame: Frame] = {
    paint: GProc ={ G.Scale[dc,sx,sy]};
    sx,sy: REAL;
    [sx,sy]_GetPoint[frame];
    Painter[paint,frame];
    };

JRotate: PROCEDURE [frame: Frame] = {
    paint: GProc ={G.Rotate[dc,a]};
    a: REAL _ J.PopReal[frame.opstk];
    Painter[paint,frame];
  };

JSixPoint: PROCEDURE [frame: Frame] = {
    paint: GProc ={
        G.Translate[dc,t1.x,t1.y];
        G.Concat[dc,m11,m12,m21,m22];
        G.Translate[dc,-f1.x,-f1.y];
        };
    f1,f2,f3,t1,t2,t3,df1,df2,dt1,dt2: Vec;
    adet: REAL;
    m11,m12,m21,m22: REAL;
    t3_GetVec[frame];
    t2_GetVec[frame];
    t1_GetVec[frame];
    f3_GetVec[frame];
    f2_GetVec[frame];
    f1_GetVec[frame];
    dt1_Vector.Sub[t2,t1];
    df1_Vector.Sub[f2,f1];
    dt2_Vector.Sub[t3,t1];
    df2_Vector.Sub[f3,f1];
    adet_1.0/Vector.Cross[df1,df2]; 
    m11_(dt1.x*df2.y-dt2.x*df1.y)*adet;
    m12_(dt1.y*df2.y-dt2.y*df1.y)*adet; 
    m21_(df1.x*dt2.x-df2.x*dt1.x)*adet;
    m22_(df1.x*dt2.y-df2.x*dt1.y)*adet;
    Painter[paint,frame];
    };

JConcat: PROCEDURE [frame: Frame] = {
  paint: GProc ={G.Concat[dc,m11,m12,m21,m22]};
  m11,m12,m21,m22: REAL;
  m22 _ J.PopReal[frame.opstk];
  m21 _ J.PopReal[frame.opstk];
  m12 _ J.PopReal[frame.opstk];
  m11 _ J.PopReal[frame.opstk];
  Painter[paint,frame];
  };

--note multiple display context behavior
JGetPos: PROCEDURE [frame: Frame] = {
  paint: GProc ={[x,y]_G.GetCP[dc]};
  x,y: REAL; 
  Painter[paint,frame];
  PutPoint[frame,x,y];
  };

JSetPos: PROCEDURE [frame: Frame] = {
  paint: GProc ={G.SetCP[dc,x,y]};
  x,y: REAL; [x,y] _ GetPoint[frame]; 
  Painter[paint,frame];
  };

JRelSetPos: PROCEDURE [frame: Frame] = {
  paint: GProc ={ G.SetCP[dc,x,y,TRUE]};
  x,y: REAL; [x,y]_GetPoint[frame];
  Painter[paint,frame];
  };

JDrawTo: PROCEDURE [frame: Frame] = {
  paint: GProc ={G.DrawTo[dc,x,y]};
  x,y: REAL;
  [x,y]_GetPoint[frame]; 
  Painter[paint,frame];
  };

JRelDrawTo: PROCEDURE [frame: Frame] = {
  paint: GProc ={G.DrawTo[dc,x,y,TRUE]};
  x,y: REAL;
  [x,y]_GetPoint[frame]; 
  Painter[paint,frame];
  };


JDrawBox: PROCEDURE [frame: Frame] = {
  paint: GProc ={G.DrawBox[dc,box]};
  box: G.Box _ GetBox[frame];
  Painter[paint,frame];
  };

JCover: PROCEDURE [frame: Frame] = {
  paint: GProc ={G.DrawBox[dc,G.GetBounds[dc]]};
  Painter[paint,frame];
  };

JSetInvert: PROCEDURE [frame: Frame] = {
  paint: GProc ={[] _ G.SetPaintMode[dc, invert]};
  Painter[paint,frame];
  };

JSetFat: PROCEDURE [frame: Frame] = {
  paint: GProc ={[] _ G.SetFat[dc,b]};
  b: BOOLEAN _ J.PopBoolean[frame.opstk]; 
  Painter[paint,frame];
  };

JSetOpaque: PROCEDURE [frame: Frame] = {
  paint: GProc ={[] _ G.SetPaintMode[dc,IF b THEN opaque ELSE transparent]};
  b: BOOLEAN _ J.PopBoolean[frame.opstk];
  Painter[paint,frame];
  };

JGetTouch: PROCEDURE [frame: Frame] = {
  mx,my: REAL;
  [mx,my] _ RealViewerMouse[frame,TRUE];
  PutPoint[frame,mx,my];
  };

JGetMouse: PROCEDURE [frame: Frame] = {
  mx,my: REAL;
  [mx,my] _ RealViewerMouse[frame,FALSE];
  PutPoint[frame,mx,my];
  };

JSetFont: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  PopString[info];
  info.font _ G.MakeFont[Rope.FromRefText[info.text]];
  };

JGetYMode: PROCEDURE [frame: Frame] = {
  paint: GProc ={mode _ E.GetYMode[dc]};
  mode: E.YMode;
  Painter[paint,frame];
  J.PushInteger[frame.opstk, IF mode=topDown THEN 1 ELSE 0];
  };

JSetYMode: PROCEDURE [frame: Frame] = {
  mode: LONG INTEGER _ J.PopInteger[frame.opstk];
  paint: GProc ={E.SetYMode[dc,IF mode>0 THEN topDown ELSE bottomUp]};
  Painter[paint,frame];
  };

JDrawChar: PROCEDURE [frame: Frame] = {
  paint: GProc ={E.DrawText[self: dc, text: info.text, font: info.font]};
  info: Info _ GetInfo[frame];
  PopString[info];
  IF info.text.length>0 THEN info.text.length _ 1;
  Painter[paint,frame];
  };

JDrawText: PROCEDURE [frame: Frame] = {
  paint: GProc ={E.DrawText[self: dc, text: info.text, font: info.font]};
  info: Info _ GetInfo[frame];
  PopString[info];
  Painter[paint,frame];
  };

JCharBox: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  PopString[info];
  IF info.text.length>0 THEN info.text.length _ 1;
  PushTextBox[frame,info.text];
  };

JTextBox: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  PopString[info];
  PushTextBox[frame,info.text];
  };

JCharWidth: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  PopString[info];
  IF info.text.length>0 THEN info.text.length _ 1;
  PushTextWidth[frame,info.text];
  };

JTextWidth: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  PopString[info];
  PushTextWidth[frame,info.text];
  };

PushTextBox: PROCEDURE[frame: Frame, text: REF READONLY TEXT] = {
  info: Info _ GetInfo[frame];
  xmin,xmax,ymin,ymax: REAL;
  [xmin: xmin, ymin: ymin, xmax: xmax, ymax: ymax] _ E.TextBox[info.font,info.text];
  J.PushReal[frame.opstk,xmin];
  J.PushReal[frame.opstk,ymin];
  J.PushReal[frame.opstk,xmax];
  J.PushReal[frame.opstk,ymax];
  };

PushTextWidth: PROCEDURE[frame: Frame, text: REF READONLY TEXT] = {
  info: Info _ GetInfo[frame];
  xw,yw: REAL;
  [xw: xw, yw: yw] _ E.TextWidth[info.font,info.text];
  J.PushReal[frame.opstk,xw];
  J.PushReal[frame.opstk,yw];
  };

JFontBox: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  xmin,xmax,ymin,ymax: REAL;
  [xmin: xmin, ymin: ymin, xmax: xmax, ymax: ymax] _ G.FontBox[info.font];
  J.PushReal[frame.opstk,xmin];
  J.PushReal[frame.opstk,ymin];
  J.PushReal[frame.opstk,xmax];
  J.PushReal[frame.opstk,ymax];
  };

PutBox: PROC[frame: Frame, b: G.Box] = {
  PutPoint[frame,b.xmin,b.ymin];
  PutPoint[frame,b.xmax,b.ymax];
  };

GetBox: PROC [frame: Frame] RETURNS[G.Box] = {
  b: G.Box;
  [b.xmax,b.ymax] _ GetPoint[frame];
  [b.xmin,b.ymin] _ GetPoint[frame];
  RETURN[b];
  };

JStartBoxing: PROCEDURE [frame: Frame] = {
--  info: Info _ GetInfo[frame];
--  E.BeginBox[dc];
  };

JStopBoxing: PROCEDURE [frame: Frame] = {
--  info: Info _ GetInfo[frame];
--  b: G.Box _ E.EndBox[dc];
--  PutBox[frame,b];
  };

JPushBox: PROCEDURE [frame: Frame] = {
--  b: G.Box _ GetBox[frame];
--  G.PushClipBox[dc,b];
-- **** temporarily removed ****
  };

JPopBox: PROCEDURE [frame: Frame] = {
--  G.PopClipBox[dc];
-- **** temporarily removed ****
  };

JVisible: PROCEDURE [frame: Frame] = {
  b: BOOLEAN;
  paint: GProc = {b _ G.Visible[dc]};
  Painter[paint,frame];
  J.PushBoolean[frame.opstk,b];
  };

JFlushPath: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  G.FlushPath[info.path];
  };

JMoveTo: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  x,y: REAL; [x,y]_GetPoint[frame];
  G.MoveTo[info.path,x,y];
  };

JMoveToNext: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  x,y: REAL; [x,y]_GetPoint[frame];
  G.MoveTo[info.path,x,y,FALSE];
  };

JLineTo: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  x,y: REAL; [x,y]_GetPoint[frame];
  G.LineTo[info.path,x,y];
  };

JCurveTo: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  x1,y1,x2,y2,x3,y3: REAL;
  [x3,y3]_GetPoint[frame];
  [x2,y2]_GetPoint[frame];
  [x1,y1]_GetPoint[frame];
  G.CurveTo[info.path,x1,y1,x2,y2,x3,y3];
  };

JRectangle: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  x0,y0,x1,y1: REAL;
  [x1,y1]_GetPoint[frame];
  [x0,y0]_GetPoint[frame];
  G.Rectangle[info.path,x0,y0,x1,y1];
  };

JDrawArea: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  paint: GProc = {G.DrawArea[dc, info.path]};
  Painter[paint,frame];
  };

JDrawEOArea: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  paint: GProc = {G.DrawArea[dc,info.path,TRUE]};
  Painter[paint,frame];
  };

JDrawStroke: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  paint: GProc = {G.DrawStroke[dc,info.path,width,FALSE,ends]};
  i: INTEGER _ J.PopInteger[frame.opstk];
  width: REAL _ J.PopReal[frame.opstk];
  ends: G.StrokeEnds _ (IF i=1 THEN square ELSE IF i=2 THEN round ELSE butt);
  Painter[paint,frame];
  };

JDrawStrokeClosed: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  paint: GProc = {G.DrawStroke[dc,info.path,width,TRUE]};
  width: REAL _ J.PopReal[frame.opstk];
  Painter[paint,frame];
  };

JKnot: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  y: REAL _ J.PopReal[frame.opstk];
  x: REAL _ J.PopReal[frame.opstk];
  Spline.Knot[info.spline,x,y];
  };

JSpline: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  Spline.Enter[info.spline,info.path,FALSE];
  };

JCSpline: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  Spline.Enter[info.spline,info.path,TRUE];
  };

bmw: CARDINAL = 250;
bmh: CARDINAL = 200;

GetBitmapSize: PUBLIC PROC RETURNS [w, h: CARDINAL] = {RETURN[bmw,bmh]};

JBitmap: PROCEDURE [frame: Frame] = {
  info: Info _ GetInfo[frame];
  paint: GProc = {E.DrawBitmap[dc,info.bitmap,bmw,bmh,0,0,0,bmh]};
  Painter[paint,frame];
  };

JSetTarget: PROC [frame: Frame] = {
  info: Info _ GetInfo[frame];
  b: BOOLEAN _ J.PopBoolean[frame.opstk];
  paint: GProc = {E.SetTargetBitmap[dc,IF b THEN info.bitmap ELSE NIL]};
  Painter[paint,frame];
  };

JScreenCoords: PROCEDURE [frame: Frame] = {
  y: REAL _ J.PopReal[frame.opstk];
  x: REAL _ J.PopReal[frame.opstk];
  paint: GProc = {[x, y] _ Graphics.UserToWorld[dc, x, y]}; -- get screen coordinates
  Painter[paint,frame];
  J.PushReal[frame.opstk,x];
  J.PushReal[frame.opstk,y];
  };

JUserCoords: PROCEDURE [frame: Frame] = {
  y: REAL _ J.PopReal[frame.opstk];
  x: REAL _ J.PopReal[frame.opstk];
  paint: GProc = {[x, y] _ Graphics.WorldToUser[dc, x, y]}; -- get user coordinates
  Painter[paint,frame];
  J.PushReal[frame.opstk,x];
  J.PushReal[frame.opstk,y];
  };

-- Initialization starts here

Init: PROC = {
  frame: Frame _ J.defaultFrame;

  J.RegisterExplicit[frame,".pushdc"L,PushDC];
  J.RegisterExplicit[frame,".popdc"L,PopDC];
 -- J.RegisterExplicit[frame,".setview"L,JSetVw];
  J.RegisterExplicit[frame,".translate"L,JTranslate];
  J.RegisterExplicit[frame,".scale"L,JScale];
  J.RegisterExplicit[frame,".rotate"L,JRotate];
  J.RegisterExplicit[frame,".sixpoint"L,JSixPoint];
  J.RegisterExplicit[frame,".concat"L,JConcat];
  J.RegisterExplicit[frame,".getpos"L,JGetPos];
  J.RegisterExplicit[frame,".setpos"L,JSetPos];
  J.RegisterExplicit[frame,".rsetpos"L,JRelSetPos];
  J.RegisterExplicit[frame,".drawto"L,JDrawTo];
  J.RegisterExplicit[frame,".rdrawto"L,JRelDrawTo];
  J.RegisterExplicit[frame,".drawbox"L,JDrawBox];
  J.RegisterExplicit[frame,".cover"L,JCover];
  J.RegisterExplicit[frame,".setinvert"L,JSetInvert];
  J.RegisterExplicit[frame,".setfat"L,JSetFat];
  J.RegisterExplicit[frame,".setopaque"L,JSetOpaque];
  J.RegisterExplicit[frame,".touch"L,JGetTouch];
  J.RegisterExplicit[frame,".mouse"L,JGetMouse];
  J.RegisterExplicit[frame,".setfont"L,JSetFont];
  J.RegisterExplicit[frame,".drawchar"L,JDrawChar];
  J.RegisterExplicit[frame,".drawtext"L,JDrawText];
  J.RegisterExplicit[frame,".charbox"L,JCharBox];
  J.RegisterExplicit[frame,".textbox"L,JTextBox];
  J.RegisterExplicit[frame,".charwidth"L,JCharWidth];
  J.RegisterExplicit[frame,".textwidth"L,JTextWidth];
  J.RegisterExplicit[frame,".fontbox"L,JFontBox];
--  J.RegisterExplicit[frame,".initboxer"L,JStartBoxing];
--  J.RegisterExplicit[frame,".stopboxer"L,JStopBoxing];
--  J.RegisterExplicit[frame,".pushbox"L,JPushBox];
--  J.RegisterExplicit[frame,".popbox"L,JPopBox];
  J.RegisterExplicit[frame,".visible"L,JVisible];
  J.RegisterExplicit[frame,".cliparea"L,JClipArea];
  J.RegisterExplicit[frame,".clipbox"L,JClipBox];
  J.RegisterExplicit[frame,".flushpath"L,JFlushPath];
  J.RegisterExplicit[frame,".moveto"L,JMoveTo];
  J.RegisterExplicit[frame,".movetonext"L,JMoveToNext];
  J.RegisterExplicit[frame,".lineto"L,JLineTo];
  J.RegisterExplicit[frame,".curveto"L,JCurveTo];
  J.RegisterExplicit[frame,".rect"L,JRectangle];
  J.RegisterExplicit[frame,".drawarea"L,JDrawArea];
  J.RegisterExplicit[frame,".draweoarea"L,JDrawEOArea];
  J.RegisterExplicit[frame,".drawstroke"L,JDrawStroke];
  J.RegisterExplicit[frame,".drawstrokeclosed"L,JDrawStrokeClosed];
  J.RegisterExplicit[frame,".knot"L,JKnot];
  J.RegisterExplicit[frame,".spline"L,JSpline];
  J.RegisterExplicit[frame,".cspline"L,JCSpline];
  J.RegisterExplicit[frame,".bitmap"L,JBitmap];
  J.RegisterExplicit[frame,".clipeoarea"L,JClipEOArea];
  J.RegisterExplicit[frame,".clipxarea"L,JClipXArea];
  J.RegisterExplicit[frame,".clipxbox"L,JClipXBox];
  J.RegisterExplicit[frame,".getymode"L,JGetYMode];
  J.RegisterExplicit[frame,".setymode"L,JSetYMode];
  J.RegisterExplicit[frame,".settarget"L,JSetTarget];
  J.RegisterExplicit[frame,".screencoords"L,JScreenCoords];
  J.RegisterExplicit[frame,".usercoords"L,JUserCoords];
  };

Init;

}.