)abbrev domain VIEW3D ThreeDimensionalViewport
++ Author: Jim Wen
++ Date Created: 28 April 1989
++ Basic Operations:
++ Related Constructors:
++ Also See:
++ AMS Classifications:
++ Keywords:
++ References:
++ Description: ThreeDimensionalViewport creates viewports to display graphs
VIEW    ==> _$ViewportServer$Lisp
sendI   ==> sockSendInt$Lisp
sendSF  ==> sockSendFloat$Lisp
sendSTR ==> sockSendString$Lisp
getI    ==> sockGetInt$Lisp
getSF   ==> sockGetFloat$Lisp

typeVIEW3D   ==> 1$I
typeVIEWTube ==> 4

makeVIEW3D ==> (-1)$SingleInteger

ThreeDimensionalViewport() : Exports == Implementation where
  I   ==> Integer
  PI  ==> PositiveInteger
  NNI ==> NonNegativeInteger
  XY  ==> Record( X : I, Y : I )
  XYP ==> Record( X : PI, Y : PI )
  XYNN ==> Record( X : NNI, Y : NNI )
  SF  ==> DoubleFloat
  F   ==> Float
  L   ==> List
  Pt ==> ColoredThreeDimensionalPoint
  SEG ==> Segment
  S   ==> String
  E   ==> OutputForm
  PLOT3D ==> Plot3D
  TUBE   ==> TubePlot
  V   ==> Record( theta : SF, phi : SF, scale : SF, scaleX : SF, scaleY : SF, scaleZ : SF, deltaX : SF, deltaY : SF )
  H   ==> Record( hueOffset : I, hueNumber : I)
  FLAG   ==> Record( showCP : I, style : I, axesOn : I, diagonalsOn : I, outlineRenderOn : I, showRegionField : I )
  FR  ==> Record( fn : Fn2, fc : FnU, xmin : SF, xmax : SF, ymin : SF, ymax : SF, xnum : I, ynum : I )
  FParamR ==> Record( theTube : TUBE )
  LR  ==> Record( lightX : SF, lightY : SF, lightZ : SF, lightTheta : SF, lightPhi : SF , translucence : SF)
  UFR ==> Union(FR,FParamR,"undefined")
  PR  ==> Record( perspectiveField : I, eyeDistance : SF, hitherPlane : SF)
  VR  ==> Record( clipXMin : SF, clipXMax : SF, clipYMin : SF, clipYMax : SF, clipZMin : SF, clipZMax : SF, clipRegionField : I, clipSurfaceField : I)
  C   ==> Color()
  B   ==> Boolean
  POINT ==> Point(SF)
  SUBSPACE ==> SubSpace(3, SF)
  SPACE3 ==> ThreeSpace(SF)
  DROP ==> DrawOption
  COORDSYS ==> CoordinateSystems(SF)

    -- the below macros correspond to the ones in include/actions.h
  ROTATE       ==> 0$I  -- rotate      in actions.h
  ZOOM         ==> 1$I  -- zoom        in actions.h
  TRANSLATE    ==> 2    -- translate   in actions.h
  rendered     ==> 3    -- render      in actions.h
  hideControl  ==> 4
  closeAll     ==> 5
  axesOnOff    ==> 6
  opaque       ==> 7    -- opaqueMesh  in action.h
  contour      ==> 24
  RESET        ==> 8
  wireMesh     ==> 9    -- transparent in actions.h
  region3D     ==> 12
  smooth       ==> 22
  diagOnOff    ==> 26
  outlineOnOff ==> 13
  zoomx        ==> 14
  zoomy        ==> 15
  zoomz        ==> 16
  perspectiveOnOff ==> 27
  clipRegionOnOff ==> 66
  clipSurfaceOnOff ==> 67

  SPADBUTTONPRESS ==> 100
  COLORDEF        ==> 101
  MOVE            ==> 102
  RESIZE          ==> 103
  TITLE           ==> 104
  lightDef        ==> 108
  translucenceDef ==> 109
  writeView       ==> 110
  eyeDistanceData ==> 111
  modifyPOINT     ==> 114
--  printViewport   ==> 115
  hitherPlaneData ==> 116
  queryVIEWPOINT  ==> 117
  changeVIEWPOINT ==> 118

  noControl ==> 0$I

  yes       ==> 1$I
  no        ==> 0$I

  EYED      ==> 500::SF  -- see draw.h, should be the same(?) as clipOffset
  HITHER    ==> (-250)::SF   -- see process.h in view3D/ (not yet passed to viewman)

  openTube  ==> 1$I
  closedTube ==> 0$I

  fun2Var3D  ==> "   Three Dimensional Viewport: Function of Two Variables"
  para1Var3D ==> "   Three Dimensional Viewport: Parametric Curve of One Variable"
  undef3D    ==> "   Three Dimensional Viewport: No function defined for this viewport yet"

  Exports ==> SetCategory with
    viewThetaDefault      : ()                                       -> F
      ++ viewThetaDefault() returns the current default longitudinal
      ++ view angle in radians.
    viewThetaDefault      : F                                        -> F
      ++ viewThetaDefault(t) sets the current default longitudinal
      ++ view angle in radians to the value t and returns t.
    viewPhiDefault        : ()                                       -> F
      ++ viewPhiDefault() returns the current default latitudinal
      ++ view angle in radians.
    viewPhiDefault        : F                                        -> F
      ++ viewPhiDefault(p) sets the current default latitudinal
      ++ view angle in radians to the value p and returns p.
    viewZoomDefault       : ()                                       -> F
      ++ viewZoomDefault() returns the current default graph scaling
      ++ value.
    viewZoomDefault       : F                                        -> F
      ++ viewZoomDefault(s) sets the current default graph scaling
      ++ value to s and returns s.
    viewDeltaXDefault     : ()                                       -> F
      ++ viewDeltaXDefault() returns the current default horizontal
      ++ offset from the center of the viewport window.
    viewDeltaXDefault     : F                                        -> F
      ++ viewDeltaXDefault(dx) sets the current default horizontal
      ++ offset from the center of the viewport window to be \spad{dx}
      ++ and returns \spad{dx}.
    viewDeltaYDefault     : ()                                       -> F
      ++ viewDeltaYDefault() returns the current default vertical
      ++ offset from the center of the viewport window.
    viewDeltaYDefault     : F                                        -> F
      ++ viewDeltaYDefault(dy) sets the current default vertical
      ++ offset from the center of the viewport window to be \spad{dy}
      ++ and returns \spad{dy}.
    viewport3D            : ()                                       -> %
      ++ viewport3D() returns an undefined three-dimensional viewport
      ++ of the domain \spadtype{ThreeDimensionalViewport} whose
      ++ contents are empty.
    makeViewport3D        : %                                        -> %
      ++ makeViewport3D(v) takes the given three-dimensional viewport,
      ++ v, of the domain \spadtype{ThreeDimensionalViewport} and
      ++ displays a viewport window on the screen which contains
      ++ the contents of v.
    makeViewport3D        : (SPACE3, S)                               -> %
      ++ makeViewport3D(sp, s) takes the given space, \spad{sp} which is
      ++ of the domain \spadtype{ThreeSpace} and displays a viewport
      ++ window on the screen which contains the contents of \spad{sp},
      ++ and whose title is given by s.
    makeViewport3D        : (SPACE3, L DROP)                          -> %
      ++ makeViewport3D(sp, lopt) takes the given space, \spad{sp} which is
      ++ of the domain \spadtype{ThreeSpace} and displays a viewport
      ++ window on the screen which contains the contents of \spad{sp},
      ++ and whose draw options are indicated by the list \spad{lopt}, which
      ++ is a list of options from the domain \spad{DrawOption}.
    subspace              : %                                        -> SPACE3
      ++ subspace(v) returns the contents of the viewport v, which is
      ++ of the domain \spadtype{ThreeDimensionalViewport}, as a subspace
      ++ of the domain \spad{ThreeSpace}.
    subspace              : (%, SPACE3)                               -> %
      ++ subspace(v, sp) places the contents of the viewport v, which is
      ++ of the domain \spadtype{ThreeDimensionalViewport}, in the subspace
      ++ \spad{sp}, which is of the domain \spad{ThreeSpace}.
    modifyPointData       : (%, NNI, POINT)                            -> Void
      ++ modifyPointData(v, ind, pt) takes the viewport, v, which is of the
      ++ domain \spadtype{ThreeDimensionalViewport}, and places the data
      ++ point, \spad{pt} into the list of points database of v at the index
      ++ location given by \spad{ind}.
    options               : %                                        -> L DROP
      ++ options(v) takes the viewport, v, which is of the domain
      ++ \spadtype{ThreeDimensionalViewport} and returns a list of all
      ++ the draw options from the domain \spad{DrawOption} which are
      ++ being used by v.
    options               : (%, L DROP)                               -> %
      ++ options(v, lopt) takes the viewport, v, which is of the domain
      ++ \spadtype{ThreeDimensionalViewport} and sets the draw options
      ++ being used by v to those indicated in the list, \spad{lopt},
      ++ which is a list of options from the domain \spad{DrawOption}.
    move                  : (%, NNI, NNI)                              -> Void
      ++ move(v, x, y) displays the three-dimensional viewport, v, which
      ++ is of domain \spadtype{ThreeDimensionalViewport}, with the upper
      ++ left-hand corner of the viewport window at the screen
      ++ coordinate position x, y.
    resize                : (%, PI, PI)                                -> Void
      ++ resize(v, w, h) displays the three-dimensional viewport, v, which
      ++ is of domain \spadtype{ThreeDimensionalViewport}, with a width
      ++ of w and a height of h, keeping the upper left-hand corner
      ++ position unchanged.
    title                 : (%, S)                                    -> Void
      ++ title(v, s) changes the title which is shown in the three-dimensional
      ++ viewport window, v of domain \spadtype{ThreeDimensionalViewport}.
    dimensions            : (%, NNI, NNI, PI, PI)                        -> Void
      ++ dimensions(v, x, y, width, height) sets the position of the
      ++ upper left-hand corner of the three-dimensional viewport, v,
      ++ which is of domain \spadtype{ThreeDimensionalViewport}, to
      ++ the window coordinate x, y, and sets the dimensions of the
      ++ window to that of \spad{width}, \spad{height}.  The new
      ++ dimensions are not displayed until the function
      ++ \spadfun{makeViewport3D} is executed again for v.
    viewpoint             : (%, F, F, F, F, F)                            -> Void
      ++ viewpoint(v, th, phi, s, dx, dy) sets the longitudinal view angle
      ++ to \spad{th} radians, the latitudinal view angle to \spad{phi}
      ++ radians, the scale factor to \spad{s}, the horizontal viewport
      ++ offset to \spad{dx}, and the vertical viewport offset to \spad{dy}
      ++ for the viewport v, which is of the domain
      ++ \spadtype{ThreeDimensionalViewport}.  The new viewpoint position
      ++ is not displayed until the function \spadfun{makeViewport3D} is
      ++ executed again for v.
    viewpoint             : (%)                                     -> V
      ++ viewpoint(v) returns the current viewpoint setting of the given
      ++ viewport, v.  This function is useful in the situation where the
      ++ user has created a viewport, proceeded to interact with it via
      ++ the control panel and desires to save the values of the viewpoint
      ++ as the default settings for another viewport to be created using
      ++ the system.
    viewpoint             : (%, V)                                    -> Void
      ++ viewpoint(v, viewpt) sets the viewpoint for the viewport.  The
      ++ viewport record consists of the latitudal and longitudal angles,
      ++ the zoom factor, the X, Y, and Z scales, and the X and Y displacements.
    viewpoint             : (%, I, I, F, F, F)                            -> Void
      ++ viewpoint(v, th, phi, s, dx, dy) sets the longitudinal view angle
      ++ to \spad{th} degrees, the latitudinal view angle to \spad{phi}
      ++ degrees, the scale factor to \spad{s}, the horizontal viewport
      ++ offset to \spad{dx}, and the vertical viewport offset to \spad{dy}
      ++ for the viewport v, which is of the domain
      ++ \spadtype{ThreeDimensionalViewport}.  The new viewpoint position
      ++ is not displayed until the function \spadfun{makeViewport3D} is
      ++ executed again for v.
    viewpoint             : (%, F, F)                                  -> Void
      ++ viewpoint(v, th, phi) sets the longitudinal view angle to \spad{th}
      ++ radians and the latitudinal view angle to \spad{phi} radians
      ++ for the viewport v, which is of the domain
      ++ \spadtype{ThreeDimensionalViewport}.  The new viewpoint position
      ++ is not displayed until the function \spadfun{makeViewport3D} is
      ++ executed again for v.
    viewpoint             : (%, F, F, F)                                -> Void
      ++ viewpoint(v, rotx, roty, rotz) sets the rotation about the x-axis
      ++ to be \spad{rotx} radians, sets the rotation about the y-axis
      ++ to be \spad{roty} radians, and sets the rotation about the z-axis
      ++ to be \spad{rotz} radians, for the viewport v, which is of the
      ++ domain \spadtype{ThreeDimensionalViewport} and displays v with
      ++ the new view position.
    controlPanel          : (%, S)                                    -> Void
      ++ controlPanel(v, s) displays the control panel of the given
      ++ three-dimensional viewport, v, which is of domain
      ++ \spadtype{ThreeDimensionalViewport}, if s is "on", or hides
      ++ the control panel if s is "off".
    axes                  : (%, S)                                    -> Void
      ++ axes(v, s) displays the axes of the given three-dimensional
      ++ viewport, v, which is of domain \spadtype{ThreeDimensionalViewport},
      ++ if s is "on", or does not display the axes if s is "off".
    diagonals             : (%, S)                                    -> Void
      ++ diagonals(v, s) displays the diagonals of the polygon outline
      ++ showing a triangularized surface instead of a quadrilateral
      ++ surface outline, for the given three-dimensional viewport v
      ++ which is of domain \spadtype{ThreeDimensionalViewport}, if s is
      ++ "on", or does not display the diagonals if s is "off".
    outlineRender         : (%, S)                                    -> Void
      ++ outlineRender(v, s) displays the polygon outline showing either
      ++ triangularized surface or a quadrilateral surface outline depending
      ++ on the whether the \spadfun{diagonals} function has been set, for
      ++ the given three-dimensional viewport v which is of domain
      ++ \spadtype{ThreeDimensionalViewport}, if s is "on", or does not
      ++ display the polygon outline if s is "off".
    drawStyle             : (%, S)                                    -> Void
      ++ drawStyle(v, s) displays the surface for the given three-dimensional
      ++ viewport v which is of domain \spadtype{ThreeDimensionalViewport}
      ++ in the style of drawing indicated by s.  If s is not a valid
      ++ drawing style the style is wireframe by default.  Possible
      ++ styles are \spad{"shade"}, \spad{"solid"} or \spad{"opaque"},
      ++ \spad{"smooth"}, and \spad{"wireMesh"}.
    rotate                : (%, F, F)                                  -> Void
      ++ rotate(v, th, phi) rotates the graph to the longitudinal view angle
      ++ \spad{th} radians and the latitudinal view angle \spad{phi} radians
      ++ for the viewport v, which is of the domain
      ++ \spadtype{ThreeDimensionalViewport}.
    rotate                : (%, I, I)                                  -> Void
      ++ rotate(v, th, phi) rotates the graph to the longitudinal view angle
      ++ \spad{th} degrees and the latitudinal view angle \spad{phi} degrees
      ++ for the viewport v, which is of the domain
      ++ \spadtype{ThreeDimensionalViewport}.  The new rotation position
      ++ is not displayed until the function \spadfun{makeViewport3D} is
      ++ executed again for v.
    zoom                  : (%, F)                                    -> Void
      ++ zoom(v, s) sets the graph scaling factor to s, for the viewport v,
      ++ which is of the domain \spadtype{ThreeDimensionalViewport}.
    zoom                  : (%, F, F, F)                                -> Void
      ++ zoom(v, sx, sy, sz) sets the graph scaling factors for the x-coordinate
      ++ axis to \spad{sx}, the y-coordinate axis to \spad{sy} and the
      ++ z-coordinate axis to \spad{sz} for the viewport v, which is of
      ++ the domain \spadtype{ThreeDimensionalViewport}.
    translate             : (%, F, F)                                  -> Void
      ++ translate(v, dx, dy) sets the horizontal viewport offset to \spad{dx}
      ++ and the vertical viewport offset to \spad{dy}, for the viewport v,
      ++ which is of the domain \spadtype{ThreeDimensionalViewport}.
    perspective           : (%, S)                                    -> Void
      ++ perspective(v,s) displays the graph in perspective if s is "on",
      ++ or does not display perspective if s is "off" for the given
      ++ three-dimensional viewport, v, which is of domain
      ++ \spadtype{ThreeDimensionalViewport}.
    eyeDistance           : (%, F)                                    -> Void
      ++ eyeDistance(v, d) sets the distance of the observer from the center
      ++ of the graph to d, for the viewport v, which is of the domain
      ++ \spadtype{ThreeDimensionalViewport}.
    hitherPlane           : (%, F)                                    -> Void
      ++ hitherPlane(v, h) sets the hither clipping plane of the graph to h,
      ++ for the viewport v, which is of the domain
      ++ \spadtype{ThreeDimensionalViewport}.
    showRegion            : (%, S)                                    -> Void
      ++ showRegion(v, s) displays the bounding box of the given
      ++ three-dimensional viewport, v, which is of domain
      ++ \spadtype{ThreeDimensionalViewport}, if s is "on", or does not
      ++ display the box if s is "off".
    showClipRegion        : (%, S)                                    -> Void
      ++ showClipRegion(v, s) displays the clipping region of the given
      ++ three-dimensional viewport, v, which is of domain
      ++ \spadtype{ThreeDimensionalViewport}, if s is "on", or does not
      ++ display the region if s is "off".
    clipSurface           : (%, S)                                    -> Void
      ++ clipSurface(v, s) displays the graph with the specified
      ++ clipping region removed if s is "on", or displays the graph
      ++ without clipping implemented if s is "off", for the given
      ++ three-dimensional viewport, v, which is of domain
      ++ \spadtype{ThreeDimensionalViewport}.
    lighting              : (%, F, F, F)                                -> Void
      ++ lighting(v, x, y, z) sets the position of the light source to
      ++ the coordinates x, y, and z and displays the graph for the given
      ++ three-dimensional viewport, v, which is of domain
      ++ \spadtype{ThreeDimensionalViewport}.
    intensity             : (%, F)                                    -> Void
      ++ intensity(v, i) sets the intensity of the light source to i, for
      ++ the given three-dimensional viewport, v, which is of domain
      ++ \spadtype{ThreeDimensionalViewport}.
    reset                 :  %                                       -> Void
      ++ reset(v) sets the current state of the graph characteristics
      ++ of the given three-dimensional viewport, v, which is of domain
      ++ \spadtype{ThreeDimensionalViewport}, back to their initial settings.
    colorDef              : (%, C, C)                                  -> Void
      ++ colorDef(v, c1, c2) sets the range of colors along the colormap so
      ++ that the lower end of the colormap is defined by \spad{c1} and the
      ++ top end of the colormap is defined by \spad{c2}, for the given
      ++ three-dimensional viewport, v, which is of domain
      ++ \spadtype{ThreeDimensionalViewport}.
    write                 : (%, S)                                    -> S
      ++ write(v, s) takes the given three-dimensional viewport, v, which
      ++ is of domain \spadtype{ThreeDimensionalViewport}, and creates
      ++ a directory indicated by s, which contains the graph data
      ++ file for v.
    write                 : (%, S, S)                                  -> S
      ++ write(v, s, f) takes the given three-dimensional viewport, v, which
      ++ is of domain \spadtype{ThreeDimensionalViewport}, and creates
      ++ a directory indicated by s, which contains the graph data
      ++ file for v and an optional file type f.
    write                 : (%, S, L S)                                -> S
      ++ write(v, s, lf) takes the given three-dimensional viewport, v, which
      ++ is of domain \spadtype{ThreeDimensionalViewport}, and creates
      ++ a directory indicated by s, which contains the graph data
      ++ file for v and the optional file types indicated by the list lf.
    close                 :  %                                       -> Void
      ++ close(v) closes the viewport window of the given
      ++ three-dimensional viewport, v, which is of domain
      ++ \spadtype{ThreeDimensionalViewport}, and terminates the
      ++ corresponding process ID.
    key                   :  %                                       -> I
      ++ key(v) returns the process ID number of the given three-dimensional
      ++ viewport, v, which is of domain \spadtype{ThreeDimensionalViewport}.
--    print                 :  %                                       -> Void

  Implementation ==> add
    import from Color()
    import from ViewDefaultsPackage()
    import from Plot3D()
    import from TubePlot()
    import from POINT
    import from PointPackage(SF)
    import from SubSpaceComponentProperty()
    import from SPACE3
    import from MeshCreationRoutinesForThreeDimensions()
    import from DrawOptionFunctions0
    import from COORDSYS
    import from Set(PositiveInteger)

    Rep := Record (key : I, fun : I, _
                   title : S, moveTo : XYNN, size : XYP, viewpoint : V, colors : H, flags : FLAG, _
                   lighting : LR, perspective : PR, volume : VR, _
                   space3D : SPACE3, _
                   optionsField : L DROP)

    import from FLAG
    import from LR
    import from V
    import from PR
    import from VR

    degrees := pi()$F / 180.0
    degreesSF := pi()$SF / 180
    defaultTheta  : SF := convert(pi()$F/4.0)@SF
    defaultPhi    : SF := convert(-pi()$F/4.0)@SF
    defaultZoom   : SF := convert(1.2)@SF
    defaultDeltaX : SF := 0
    defaultDeltaY : SF := 0


--%Local Functions
    checkViewport (viewport : %) : B ==
        -- checks to see if this viewport still exists
        -- by sending the key to the viewport manager and
        -- waiting for its reply after it checks it against
        -- the viewports in its list. a -1 means it doesn't
        -- exist.  As side effect selects the viewport for
        -- current operation.
      sendI(VIEW, viewport.key)
      i : Integer := getI(VIEW)
      (i < 0$I) =>
        viewport.key := 0$I
        error "This viewport has already been closed!"
      true

    doOptions(v : Rep) : Void ==
      v.title := title(v.optionsField,"FriCAS3D")
      st:S := style(v.optionsField, "render")
      if (st = "shade" or st = "render") then
        v.flags.style := rendered
      else if (st = "solid" or st = "opaque") then
        v.flags.style := opaque
      else if (st = "contour") then
        v.flags.style := contour
      else if (st = "smooth") then
        v.flags.style := smooth
      else if (st = "wireMesh") then
        v.flags.style := wireMesh
      else
        v.flags.style := rendered
      v.viewpoint := viewpoint(v.optionsField,
        [defaultTheta, defaultPhi, defaultZoom, _
          1$SF, 1$SF, 1$SF, defaultDeltaX, defaultDeltaY])
        -- etc - 3D specific stuff...

--%Exported Functions : Default Settings
    viewport3D() ==
      [0,typeVIEW3D,"FriCAS3D",[viewPosDefault().1,viewPosDefault().2], _
       [viewSizeDefault().1, viewSizeDefault().2], _
        [defaultTheta, defaultPhi, defaultZoom, _
          1$SF, 1$SF, 1$SF, defaultDeltaX, defaultDeltaY], _
        [0, 27], [noControl, rendered, yes, no, yes, no], _
        [0$SF, 0$SF, 1$SF, 0$SF, 0$SF, 1$SF], _
        [yes, EYED, HITHER], [0$SF, 1$SF, 0$SF, 1$SF, 0$SF, 1$SF, no, yes], _
                create3Space()$SPACE3, [] ]

    subspace viewport ==
      viewport.space3D

    subspace(viewport, space) ==
      viewport.space3D := space
      viewport

    options viewport ==
      viewport.optionsField

    options(viewport, opts) ==
      viewport.optionsField := opts
      viewport

    makeViewport3D0 : % -> %

    makeViewport3D viewport == makeViewport3D0 copy(viewport::Rep)

    makeViewport3D(space : SPACE3, Title : S) : % ==
      v := viewport3D()
      v.space3D := space
      v.optionsField := [title(Title)]
      makeViewport3D0 v

    makeViewport3D(space : SPACE3, opts : L DROP) : % ==
      v := viewport3D()
      v.space3D := space
      v.optionsField := opts
      makeViewport3D0 v

    makeViewport3D0 viewport ==
      doOptions viewport --local function to extract and assign optional arguments for 3D viewports
      say("   Transmitting data...")$DisplayPackage
      transform := coord(viewport.optionsField, cartesian$COORDSYS)$DrawOptionFunctions0
      check(viewport.space3D)
      lpts := lp(viewport.space3D)
      lllipts  := lllip(viewport.space3D)
      llprops := llprop(viewport.space3D)
      lprops  := lprop(viewport.space3D)
        -- check for dimensionality of points
        -- if they are all 4D points, then everything is okay
        -- if they are all 3D points, then pad an extra constant
        -- coordinate for color
        -- if they have varying dimensionalities, give an error
      s := empty()$Set(PI)
      for pt in lpts repeat
        insert!(dimension pt, s)
      #s > 1 => error "All points should have the same dimension"
      (n := first parts s) < 3 => error "Dimension of points should be greater than 2"
      sendI(VIEW, viewport.fun)
      sendI(VIEW, makeVIEW3D)
      sendSTR(VIEW, viewport.title)
      sendSF(VIEW, viewport.viewpoint.deltaX)
      sendSF(VIEW, viewport.viewpoint.deltaY)
      sendSF(VIEW, viewport.viewpoint.scale)
      sendSF(VIEW, viewport.viewpoint.scaleX)
      sendSF(VIEW, viewport.viewpoint.scaleY)
      sendSF(VIEW, viewport.viewpoint.scaleZ)
      sendSF(VIEW, viewport.viewpoint.theta)
      sendSF(VIEW, viewport.viewpoint.phi)
      sendI(VIEW, viewport.moveTo.X)
      sendI(VIEW, viewport.moveTo.Y)
      sendI(VIEW, viewport.size.X)
      sendI(VIEW, viewport.size.Y)
      sendI(VIEW, viewport.flags.showCP)
      sendI(VIEW, viewport.flags.style)
      sendI(VIEW, viewport.flags.axesOn)
      sendI(VIEW, viewport.flags.diagonalsOn)
      sendI(VIEW, viewport.flags.outlineRenderOn)
      sendI(VIEW, viewport.flags.showRegionField)  -- add to make3D.c
      sendI(VIEW, viewport.volume.clipRegionField)  -- add to make3D.c
      sendI(VIEW, viewport.volume.clipSurfaceField)  -- add to make3D.c
      sendI(VIEW, viewport.colors.hueOffset)
      sendI(VIEW, viewport.colors.hueNumber)
      sendSF(VIEW, viewport.lighting.lightX)
      sendSF(VIEW, viewport.lighting.lightY)
      sendSF(VIEW, viewport.lighting.lightZ)
      sendSF(VIEW, viewport.lighting.translucence)
      sendI(VIEW, viewport.perspective.perspectiveField)
      sendSF(VIEW, viewport.perspective.eyeDistance)
        -- new, crazy points domain stuff
          -- first, send the point data list
      sendI(VIEW, #lpts)
      for pt in lpts repeat
        aPoint := transform pt
        sendSF(VIEW, xCoord aPoint)
        sendSF(VIEW, yCoord aPoint)
        sendSF(VIEW, zCoord aPoint)
        n = 3 => sendSF(VIEW, zCoord aPoint)
        sendSF(VIEW, color aPoint)  -- change to c
          -- now, send the 3d subspace structure
      sendI(VIEW, #lllipts)
      for allipts in lllipts for oneprop in lprops for onelprops in llprops repeat
           -- the following is false for f(x, y) and user-defined for [x(t), y(t), z(t)]
           -- this is temporary - until the generalized points stuff gets put in
        sendI(VIEW, (closed? oneprop => yes; no))
        sendI(VIEW, (solid? oneprop => yes; no))
        sendI(VIEW, #allipts)
        for alipts in allipts for tinyprop in onelprops repeat
           -- the following is false for f(x, y) and true for [x(t), y(t), z(t)]
           -- this is temporary -- until the generalized points stuff gets put in
          sendI(VIEW, (closed? tinyprop => yes;no))
          sendI(VIEW, (solid? tinyprop => yes;no))
          sendI(VIEW, #alipts)
          for oneIndexedPoint in alipts repeat
            sendI(VIEW, oneIndexedPoint)
      viewport.key := getI(VIEW)
      viewport
         -- the key (now set to 0) should be what the viewport returns

    viewThetaDefault    == convert(defaultTheta)@F
    viewThetaDefault  t ==
      defaultTheta := convert(t)@SF
      t
    viewPhiDefault      == convert(defaultPhi)@F
    viewPhiDefault    t ==
      defaultPhi := convert(t)@SF
      t
    viewZoomDefault     == convert(defaultZoom)@F
    viewZoomDefault   t ==
      defaultZoom := convert(t)@SF
      t
    viewDeltaXDefault   == convert(defaultDeltaX)@F
    viewDeltaXDefault t ==
      defaultDeltaX := convert(t)@SF
      t
    viewDeltaYDefault   == convert(defaultDeltaY)@F
    viewDeltaYDefault t ==
      defaultDeltaY := convert(t)@SF
      t

--Exported Functions: Available features for 3D viewports
    lighting(viewport, Xlight, Ylight, Zlight) ==
      viewport.lighting.lightX := convert(Xlight)@SF
      viewport.lighting.lightY := convert(Ylight)@SF
      viewport.lighting.lightZ := convert(Zlight)@SF
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, lightDef)
        checkViewport viewport =>
          sendSF(VIEW, viewport.lighting.lightX)
          sendSF(VIEW, viewport.lighting.lightY)
          sendSF(VIEW, viewport.lighting.lightZ)
          getI(VIEW)          -- acknowledge

    axes (viewport, onOff) ==
      if onOff = "on" then viewport.flags.axesOn := yes
      else viewport.flags.axesOn := no
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, axesOnOff)
        checkViewport viewport =>
          sendI(VIEW, viewport.flags.axesOn)
          getI(VIEW)          -- acknowledge

    diagonals (viewport, onOff) ==
      if onOff = "on" then viewport.flags.diagonalsOn := yes
      else viewport.flags.diagonalsOn := no
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, diagOnOff)
        checkViewport viewport =>
          sendI(VIEW, viewport.flags.diagonalsOn)
          getI(VIEW)          -- acknowledge

    outlineRender (viewport, onOff) ==
      if onOff = "on" then viewport.flags.outlineRenderOn := yes
      else viewport.flags.outlineRenderOn := no
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, outlineOnOff)
        checkViewport viewport =>
          sendI(VIEW, viewport.flags.outlineRenderOn)
          getI(VIEW)          -- acknowledge

    controlPanel (viewport, onOff) ==
      if onOff = "on" then viewport.flags.showCP := yes
      else viewport.flags.showCP := no
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, hideControl)
        checkViewport viewport =>
          sendI(VIEW, viewport.flags.showCP)
          getI(VIEW)          -- acknowledge

    drawStyle (viewport, how) ==
      if (how = "shade") then                    -- render
        viewport.flags.style := rendered
      else if (how = "solid") then               -- opaque
        viewport.flags.style := opaque
      else if (how = "contour") then             -- contour
        viewport.flags.style := contour
      else if (how = "smooth") then              -- smooth
        viewport.flags.style := smooth
      else viewport.flags.style := wireMesh
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, viewport.flags.style)
        checkViewport viewport =>
          getI(VIEW)          -- acknowledge

    reset viewport ==
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, SPADBUTTONPRESS)
        checkViewport viewport =>
          sendI(VIEW, RESET)
          getI(VIEW)          -- acknowledge
      void()

    close viewport ==
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, closeAll)
        checkViewport viewport =>
          getI(VIEW)          -- acknowledge
          viewport.key := 0$I
      void()

    viewpoint (viewport : %) : V ==
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, queryVIEWPOINT)
        checkViewport viewport =>
          deltaX_sf : SF := getSF(VIEW)
          deltaY_sf : SF := getSF(VIEW)
          scale_sf  : SF := getSF(VIEW)
          scaleX_sf : SF := getSF(VIEW)
          scaleY_sf : SF := getSF(VIEW)
          scaleZ_sf : SF := getSF(VIEW)
          theta_sf  : SF := getSF(VIEW)
          phi_sf    : SF := getSF(VIEW)
          getI(VIEW)          -- acknowledge
          viewport.viewpoint :=
            [ theta_sf, phi_sf, scale_sf, scaleX_sf, scaleY_sf, scaleZ_sf,
              deltaX_sf, deltaY_sf ]
        viewport.viewpoint
      viewport.viewpoint

    viewpoint (viewport : %, viewpt : V) : Void ==
      viewport.viewpoint := viewpt
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, changeVIEWPOINT)
        checkViewport viewport =>
          sendSF(VIEW, viewport.viewpoint.deltaX)
          sendSF(VIEW, viewport.viewpoint.deltaY)
          sendSF(VIEW, viewport.viewpoint.scale)
          sendSF(VIEW, viewport.viewpoint.scaleX)
          sendSF(VIEW, viewport.viewpoint.scaleY)
          sendSF(VIEW, viewport.viewpoint.scaleZ)
          sendSF(VIEW, viewport.viewpoint.theta)
          sendSF(VIEW, viewport.viewpoint.phi)
          getI(VIEW)          -- acknowledge


    viewpoint (viewport : %, Theta : F, Phi : F, Scale : F, DeltaX : F, DeltaY : F) : Void ==
      viewport.viewpoint :=
        [convert(Theta)@SF, convert(Phi)@SF, convert(Scale)@SF, 1$SF, 1$SF, 1$SF, convert(DeltaX)@SF, convert(DeltaY)@SF]

    viewpoint (viewport : %, Theta : I, Phi : I, Scale : F, DeltaX : F, DeltaY : F) : Void ==
      viewport.viewpoint := [convert(Theta)@SF * degreesSF, convert(Phi)@SF * degreesSF,
        convert(Scale)@SF, 1$SF, 1$SF, 1$SF, convert(DeltaX)@SF, convert(DeltaY)@SF]

    viewpoint (viewport : %, Theta : F, Phi : F) : Void ==
      viewport.viewpoint.theta := convert(Theta)@SF
      viewport.viewpoint.phi   := convert(Phi)@SF

    viewpoint (viewport : %, X : F, Y : F, Z : F) : Void ==
      Theta : F
      Phi : F
      if (X = 0$F) and (Y = 0$F) then
        Theta := 0$F
        if (Z>=0$F) then
          Phi := 0$F
        else
          Phi := pi()
      else
        Theta := asin(Y/(R := sqrt(X*X+Y*Y)))
        if (Z = 0$F) then
          Phi := pi()/(2::F)
        else
          Phi := atan(Z/R)
      rotate(viewport, Theta, Phi)

    title (viewport, Title) ==
      viewport.title := Title
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, TITLE)
        checkViewport viewport =>
          sendSTR(VIEW, Title)
          getI(VIEW)          -- acknowledge

    colorDef (viewport, HueOffset, HueNumber) ==
      viewport.colors := [h := (hue HueOffset), (hue HueNumber) - h]
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, COLORDEF)
        checkViewport viewport =>
          sendI(VIEW, hue HueOffset)
          sendI(VIEW, hue HueNumber)
          getI(VIEW)          -- acknowledge

    dimensions (viewport, ViewX, ViewY, ViewWidth, ViewHeight) ==
      viewport.moveTo := [ViewX, ViewY]
      viewport.size   := [ViewWidth, ViewHeight]

    move(viewport, xLoc, yLoc) ==
      viewport.moveTo := [xLoc, yLoc]
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, MOVE)
        checkViewport viewport =>
          sendI(VIEW, xLoc)
          sendI(VIEW, yLoc)
          getI(VIEW)          -- acknowledge

    resize(viewport, xSize, ySize) ==
      viewport.size := [xSize, ySize]
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, RESIZE)
        checkViewport viewport =>
          sendI(VIEW, xSize)
          sendI(VIEW, ySize)
          getI(VIEW)          -- acknowledge

    coerce viewport ==
      (key(viewport) = 0$I) =>
        hconcat
          [message("Closed or Undefined ThreeDimensionalViewport: "),
           (viewport.title)::E]
      hconcat [message("ThreeDimensionalViewport: "), (viewport.title)::E]

    key viewport == viewport.key

    rotate(viewport : %, Theta : I, Phi : I) ==
      rotate(viewport, Theta::F * degrees, Phi::F * degrees)

    rotate(viewport : %, Theta : F, Phi : F) ==
      viewport.viewpoint.theta := convert(Theta)@SF
      viewport.viewpoint.phi   := convert(Phi)@SF
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, ROTATE)
        checkViewport viewport =>
          sendSF(VIEW, viewport.viewpoint.theta)
          sendSF(VIEW, viewport.viewpoint.phi)
          getI(VIEW)          -- acknowledge

    zoom(viewport : %, Scale : F) ==
      viewport.viewpoint.scale := convert(Scale)@SF
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, ZOOM)
        checkViewport viewport =>
          sendSF(VIEW, viewport.viewpoint.scale)
          getI(VIEW)          -- acknowledge

    zoom(viewport : %, ScaleX : F, ScaleY : F, ScaleZ : F) ==
      viewport.viewpoint.scaleX := convert(ScaleX)@SF
      viewport.viewpoint.scaleY := convert(ScaleY)@SF
      viewport.viewpoint.scaleZ := convert(ScaleZ)@SF
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, zoomx)
        checkViewport viewport =>
          sendSF(VIEW, viewport.viewpoint.scaleX)
          sendSF(VIEW, viewport.viewpoint.scaleY)
          sendSF(VIEW, viewport.viewpoint.scaleZ)
          getI(VIEW)          -- acknowledge

    translate(viewport, DeltaX, DeltaY) ==
      viewport.viewpoint.deltaX := convert(DeltaX)@SF
      viewport.viewpoint.deltaY := convert(DeltaY)@SF
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, TRANSLATE)
        checkViewport viewport =>
          sendSF(VIEW, viewport.viewpoint.deltaX)
          sendSF(VIEW, viewport.viewpoint.deltaY)
          getI(VIEW)          -- acknowledge

    intensity(viewport, Amount) ==
      if (Amount < 0$F) or (Amount > 1$F) then
        error "The intensity must be a value between 0 and 1, inclusively."
      viewport.lighting.translucence := convert(Amount)@SF
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, translucenceDef)
        checkViewport viewport =>
          sendSF(VIEW, viewport.lighting.translucence)
          getI(VIEW)          -- acknowledge

    write(viewport : %, Filename : S, aThingToWrite : S) ==
      write(viewport, Filename, [aThingToWrite])

    write(viewport, Filename) ==
      write(viewport, Filename, viewWriteDefault())

    write(viewport : %, Filename : S, thingsToWrite : L S) ==
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, writeView)
        checkViewport viewport =>
          sendSTR(VIEW, Filename)
          m := minIndex(avail := viewWriteAvailable())
          for aTypeOfFile in thingsToWrite repeat
            if (writeTypeInt:= position(upperCase aTypeOfFile, avail)-m) < 0 then
              say(["  > ", aTypeOfFile,
                " is not a valid file type for writing a 3D viewport"
                       ])$DisplayPackage
            else
              sendI(VIEW, writeTypeInt + 1$I)
          sendI(VIEW, 0$I)     -- no more types of things to write
          getI(VIEW)          -- acknowledge
          Filename
        error "write: problem with viewport"
      error "write: problem contacting viewman"

    perspective (viewport, onOff) ==
      if onOff = "on" then viewport.perspective.perspectiveField := yes
      else viewport.perspective.perspectiveField := no
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, perspectiveOnOff)
        checkViewport viewport =>
          sendI(VIEW, viewport.perspective.perspectiveField)
          getI(VIEW)          -- acknowledge

    showRegion (viewport, onOff) ==
      if onOff = "on" then viewport.flags.showRegionField := yes
      else viewport.flags.showRegionField := no
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, region3D)
        checkViewport viewport =>
          sendI(VIEW, viewport.flags.showRegionField)
          getI(VIEW)          -- acknowledge

    showClipRegion (viewport, onOff) ==
      if onOff = "on" then viewport.volume.clipRegionField := yes
      else viewport.volume.clipRegionField := no
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, clipRegionOnOff)
        checkViewport viewport =>
          sendI(VIEW, viewport.volume.clipRegionField)
          getI(VIEW)          -- acknowledge

    clipSurface (viewport, onOff) ==
      if onOff = "on" then viewport.volume.clipSurfaceField := yes
      else viewport.volume.clipSurfaceField := no
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, clipSurfaceOnOff)
        checkViewport viewport =>
          sendI(VIEW, viewport.volume.clipSurfaceField)
          getI(VIEW)          -- acknowledge

    eyeDistance(viewport : %, EyeDistance : F) ==
      viewport.perspective.eyeDistance := convert(EyeDistance)@SF
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, eyeDistanceData)
        checkViewport viewport =>
          sendSF(VIEW, viewport.perspective.eyeDistance)
          getI(VIEW)          -- acknowledge

    hitherPlane(viewport : %, HitherPlane : F) ==
      viewport.perspective.hitherPlane := convert(HitherPlane)@SF
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, hitherPlaneData)
        checkViewport viewport =>
          sendSF(VIEW, viewport.perspective.hitherPlane)
          getI(VIEW)          -- acknowledge

    modifyPointData(viewport, anIndex, aPoint) ==
      (n := dimension aPoint) < 3 => error "The point should have dimension of at least 3"
      viewport.space3D := modifyPointData(viewport.space3D, anIndex, aPoint)
      (key(viewport) ~= 0$I) =>
        sendI(VIEW, typeVIEW3D)
        sendI(VIEW, modifyPOINT)
        checkViewport viewport =>
          sendI(VIEW, anIndex)
          sendSF(VIEW, xCoord aPoint)
          sendSF(VIEW, yCoord aPoint)
          sendSF(VIEW, zCoord aPoint)
          if (n = 3) then sendSF(VIEW, convert(0.5)@SF)
          else sendSF(VIEW, color aPoint)
          getI(VIEW)          -- acknowledge

--    print viewport ==
--      (key(viewport) ~= 0$I) =>
--        sendI(VIEW, typeVIEW3D)
--        sendI(VIEW, printViewport)
--        checkViewport viewport =>
--          getI(VIEW)          -- acknowledge

--Copyright (c) 1991-2002, The Numerical ALgorithms Group Ltd.
--All rights reserved.
--
--Redistribution and use in source and binary forms, with or without
--modification, are permitted provided that the following conditions are
--met:
--
--    - Redistributions of source code must retain the above copyright
--      notice, this list of conditions and the following disclaimer.
--
--    - Redistributions in binary form must reproduce the above copyright
--      notice, this list of conditions and the following disclaimer in
--      the documentation and/or other materials provided with the
--      distribution.
--
--    - Neither the name of The Numerical ALgorithms Group Ltd. nor the
--      names of its contributors may be used to endorse or promote products
--      derived from this software without specific prior written permission.
--
--THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
--IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
--TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
--PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
--OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
--EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
--PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
--PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
--LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
--NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
--SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

-- this is a new graphics package and does not depend on any of the
-- current plotting stuff
-- so it is best to run it in a minimum system (like spadsys)
