-+-+-+-+-+-+-+-+ START OF PART 280 -+-+-+-+-+-+-+-+
X  ptk_rotateline3(&origin, &vpn, windptr->twistangle, PPOSTCONCATENATE,
X                  twistmat, &err);
X  vup = ptk_transform3(twistmat, &vup);
X  ptk_pevalvieworientationmatrix3(&vrp, &vpn, &vup, &err,`20
X                                  vrep.orientation_matrix);
X  windptr->lastvpn = vpn;
X  vrep.clip_limit = windptr->viewlims;
X  vrep.clip_xy = PCLIP;
X  vrep.clip_back = vrep.clip_front = PCLIP;
X  vmap.window = ptk_limit(-windptr->viewvolume.x / 2.0,`20
X                          windptr->viewvolume.x / 2.0,`20
X                          -windptr->viewvolume.y / 2.0,`20
X                          windptr->viewvolume.y / 2.0);
X  vmap.viewport = windptr->viewbox;
X  vmap.proj = windptr->cameraproj;
X  vmap.prp = ptk_point3(0.0, 0.0, windptr->viewvolume.z);
X  vmap.front_plane = windptr->viewvolume.z / 2.0;
X  vmap.view_plane = 0.0;
X  vmap.back_plane = -windptr->viewvolume.z / 2.0;
X
X  pevalviewmappingmatrix3(&vmap, &err, vrep.mapping_matrix);
X  psetviewrep3(windptr->wsid, windptr->windowviewind, &vrep);
X`7D  /* updatecamera */
X
X/*--------------------------------------------------------------------------
V*/
X
Xstatic void updatewindowview()
X`7B
X  if (windptr->cameraswitch == PTKECAMERAON)
X    updatecamera();
X  else
X    updateview();
X`7D  /* updatewindowview */
X
X/*--------------------------------------------------------------------------
V*/
X
Xstatic void initialiseterminal()
X`7B
X  Pfloat oneline;
X
X  /* view mapping */
X  windptr->proj = PPARALLEL;
X  windptr->prp = ptk_point3(windptr->windowsize.x / 2.0,
X                            windptr->windowsize.y / 2.0, 1.0);
X  windptr->window = ptk_limit(0.0, windptr->windowsize.x, 0.0,`20
X                             windptr->windowsize.y);
X  windptr->viewport = windptr->cliplimit = windptr->viewlims;
X  windptr->backplane = windptr->viewplane = 0.0;
X  windptr->frontplane = 1.0;
X  /* view orientation */
X  oneline = -windptr->windowsize.y/(Pfloat)windptr->term.lines;
X  windptr->vrp = ptk_point3(0.0, -windptr->windowsize.y +`20
X                   (oneline * (Pfloat)(windptr->term.visline - 1)), 0.0);
X  windptr->vpn = ptk_point3(0.0, 0.0, 1.0);
X  windptr->vup = ptk_point3(0.0, 1.0, 0.0);
X  /* set view rep */
X  updateview();
X`7D  /* initialiseterminal */
X`20
X/*--------------------------------------------------------------------------
V*/
X/*------------------------ Camera functions --------------------------------
V*/
X/*--------------------------------------------------------------------------
V*/
X
X/*function:external*/
Xextern void ptk_rotatecameraposition(C(Pint) windid, C(Pfloat) angle)
XPreANSI(Pint windid)`20
XPreANSI(Pfloat angle)
X/*
X** \parambegin
X** \param`7BPint`7D`7Bwindid`7D`7Bwindow identifier`7D`7BIN`7D
X** \param`7BPfloat`7D`7Bangle`7D`7Brotation angle in degrees`7D`7BIN`7D
X** \paramend`20
X** \blurb`7BThis function rotates the camera position in a circle centred
X** at the point of interest and about the axis defined by the function
X** `7B\tt ptk\_setpositionaxis`7D. The amount of rotation is `7B\tt angle`7D
X** degrees and the function is useful for rotating around an object.`7D
X*/
X`7B
X  Pmatrix3 spinmat, mat;
X  Ppoint3 origin;
X  Ppoint3 shiftprp;
X  Pint err;
X
X  setwindow(windid);
X  if (windptr != NULL)
X  `7B
X    /* shift by -(vrp), rotate about arbitrary axis, shift by (vrp) */
X    shiftprp = ptk_scalev3(&windptr->ptinterest, -1.0);`20
X    ptk_shift3(&shiftprp, PREPLACE, spinmat);
X    origin = ptk_point3(0.0, 0.0, 0.0);
X    ptk_rotateline3(&origin, &windptr->positionaxis,`20
X                    angle, PPOSTCONCATENATE, spinmat, &err);
X    ptk_shift3(&windptr->ptinterest, PPOSTCONCATENATE, spinmat);
X    windptr->position = ptk_transform3(spinmat, &windptr->position);
X    /* transform fixed x and y axes */
X    ptk_rotateline3(&origin, &windptr->positionaxis, angle,`20
X                    PREPLACE, mat, &err);
X    windptr->xaxis = ptk_transform3(mat, &windptr->xaxis);
X    windptr->yaxis = ptk_transform3(mat, &windptr->yaxis);
X    updatecamera();
X  `7D
X`7D  /* ptk_rotatecameraposition */
X
X/*--------------------------------------------------------------------------
V*/
X
X/*function:external*/
Xextern void ptk_setpositionaxis(C(Pint) windid, C(Ppoint3 *) axis)
XPreANSI(Pint windid)
XPreANSI(Ppoint3 *axis)
X/*
X** \parambegin
X** \param`7BPint`7D`7Bwindid`7D`7Bwindow identifier`7D`7BIN`7D
X** \param`7BPpoint3 *`7D`7Baxis`7D`7Baxis of rotation`7D`7BIN`7D
X** \paramend`20
X** \blurb`7BThis function sets the axis of rotation for rotating`20
X** the camera position using the function `7B\tt ptk\_rotatecameraposition`7
VD.`7D
X*/
X`7B
X  setwindow(windid);
X  if (windptr != NULL)
X    windptr->positionaxis = *axis;
X`7D  /* ptk_setpositionaxis */
X
X/*--------------------------------------------------------------------------
V*/
X
X/*function:external*/
Xextern void ptk_setptinterestaxis(C(Pint) windid, C(Ppoint3 *) axis)
XPreANSI(Pint windid)
XPreANSI(Ppoint3 *axis)
X/*
X** \parambegin
X** \param`7BPint`7D`7Bwindid`7D`7Bwindow identifier`7D`7BIN`7D
X** \param`7BPpoint3 *`7D`7Baxis`7D`7Baxis of rotation`7D`7BIN`7D
X** \paramend`20
X** \blurb`7BThis function sets the axis of rotation for rotating`20
X** the camera point of interest using the function
X** `7B\tt ptk\_rotatecameraptinterest`7D.`7D
X*/
X`7B
X  setwindow(windid);
X  if (windptr != NULL)
X    windptr->ptinterestaxis = *axis;
X`7D  /* ptk_setptinterestaxis */
X
X/*--------------------------------------------------------------------------
V*/
X
X/*function:external*/
Xextern void ptk_scaleviewwindow(C(Pint) windid, C(Pfloat) scalefactor)
XPreANSI(Pint windid)`20
XPreANSI(Pfloat scalefactor)
X/*
X** \parambegin
X** \param`7BPint`7D`7Bwindid`7D`7Bwindow identifier`7D`7BIN`7D
X** \param`7BPfloat`7D`7Bscalefactor`7D`7Bscale factor`7D`7BIN`7D
X** \paramend`20
X** \blurb`7BThis function scales the view window uniformly
X** by `7B\tt scalefactor`7D. A scalefactor in the range `5B0, 1`5D will
X** scale down the view window and create a zoom-in effect.
X** A scalefactor greater than 1.0 will give a zoom-out effect.`7D
X*/
X`7B
X  setwindow(windid);
X  if (windptr != NULL)
X  `7B
X    if (scalefactor != 0.0)
X    `7B
X      windptr->viewvolume.x *= scalefactor;
X      windptr->viewvolume.y *= scalefactor;
X      updatecamera();
X    `7D
X  `7D
X`7D  /* ptk_scaleviewwindow */
X
X/*--------------------------------------------------------------------------
V*/
X
X/*function:external*/
Xextern void ptk_rotatecameraptinterest(C(Pint) windid, C(Pfloat) angle)
XPreANSI(Pint windid)`20
XPreANSI(Pfloat angle)
X/*
X** \parambegin
X** \param`7BPint`7D`7Bwindid`7D`7Bwindow identifier`7D`7BIN`7D
X** \param`7BPfloat`7D`7Bangle`7D`7Brotation angle in degrees`7D`7BIN`7D
X** \paramend`20
X** \blurb`7BThis function rotates the camera point of interest in a circle`2
V0
X** centred at the camera position and about the axis defined by the function
X** `7B\tt ptk\_setptinterestaxis`7D. The amount of rotation is `7B\tt angle`
V7D
X** degrees and the function is useful for panning around a scene.`7D
X*/
X`7B
X  Pmatrix3 spinmat, mat;
X  Ppoint3 origin;
X  Ppoint3 shiftprp;
X  Pint err;
X
X  setwindow(windid);
X  if (windptr != NULL)
X  `7B
X    /* shift by -(prp), rotate about arbitrary axis, shift by (prp) */
X    shiftprp = ptk_scalev3(&windptr->position, -1.0);
X    ptk_shift3(&shiftprp, PREPLACE, spinmat);
X    origin = ptk_point3(0.0, 0.0, 0.0);
X    ptk_rotateline3(&origin, &windptr->ptinterestaxis,`20
X                    angle, PPOSTCONCATENATE, spinmat, &err);
X    ptk_shift3(&windptr->position, PPOSTCONCATENATE, spinmat);
X    windptr->ptinterest = ptk_transform3(spinmat, &windptr->ptinterest);
X    /* transform fixed x and y axes */
X    ptk_rotateline3(&origin, &windptr->ptinterestaxis, angle,`20
X                    PREPLACE, mat, &err);
X    windptr->xaxis = ptk_transform3(mat, &windptr->xaxis);
X    windptr->yaxis = ptk_transform3(mat, &windptr->yaxis);
X    updatecamera();
X  `7D
X`7D  /* ptk_rotatecameraptinterest */
X
X/*--------------------------------------------------------------------------
V*/
X
X/*function:external*/
Xextern void ptk_rotatecameraupvector(C(Pint) windid, C(Pfloat) angle)
XPreANSI(Pint windid)`20
XPreANSI(Pfloat angle)
X/*
X** \parambegin
X** \param`7BPint`7D`7Bwindid`7D`7Bwindow identifier`7D`7BIN`7D
X** \param`7BPfloat`7D`7Bangle`7D`7Brotation angle in degrees`7D`7BIN`7D
X** \paramend`20
X** \blurb`7BThis function rotates the camera up vector`20
X** about the axis joining the camera position to the point of interest by
X** `7B\tt angle`7D degrees.`7D
X*/
X`7B
X  Pmatrix3 mat;
X  Pint err;
X  Ppoint3 zaxis;
X
X  setwindow(windid);
X  if (windptr != NULL)
X  `7B
X    /* rotate about z axis */
X    windptr->twistangle += angle;
X    zaxis = ptk_crossv3(&windptr->xaxis, &windptr->yaxis);
X    ptk_rotateline3(&origin, &zaxis, angle, PREPLACE, mat, &err);
X    windptr->xaxis = ptk_transform3(mat, &windptr->xaxis);
X    windptr->yaxis = ptk_transform3(mat, &windptr->yaxis);
X    updatecamera();
X  `7D
X`7D  /* ptk_rotatecameraupvector */
X
X/*--------------------------------------------------------------------------
V*/
X
X/*function:external*/
Xextern void ptk_rotatepositionyaxis(C(Pint) windid, C(Pfloat) angle)
XPreANSI(Pint windid)`20
XPreANSI(Pfloat angle)
X/*
X** \parambegin
X** \param`7BPint`7D`7Bwindid`7D`7Bwindow identifier`7D`7BIN`7D
X** \param`7BPfloat`7D`7Bangle`7D`7Brotation angle in degrees`7D`7BIN`7D
X** \paramend`20
X** \blurb`7BThis function rotates the camera position in a circle centred
X** at the point of interest and about the y axis of a right-handed
X** coordinate system whose z axis is defined by the camera position and
X** point of interest.`7D
X*/
X`7B
X  Pmatrix3 mat;
X  Pint err;
X
X  setwindow(windid);
X  if (windptr != NULL)
X  `7B
X    ptk_setpositionaxis(windid, &windptr->yaxis);
X    ptk_rotatecameraposition(windid, -angle);
X    /* rotate x axis about current y axis */
X    updatecamera();
X  `7D
X`7D  /* ptk_rotatepositionyaxis */
X
X/*--------------------------------------------------------------------------
V*/
X
X/*function:external*/
Xextern void ptk_rotatepositionxaxis(C(Pint) windid, C(Pfloat) angle)
XPreANSI(Pint windid)`20
XPreANSI(Pfloat angle)
X/*
X** \parambegin
X** \param`7BPint`7D`7Bwindid`7D`7Bwindow identifier`7D`7BIN`7D
X** \param`7BPfloat`7D`7Bangle`7D`7Brotation angle in degrees`7D`7BIN`7D
X** \paramend`20
X** \blurb`7BThis function rotates the camera position in a circle centred
X** at the point of interest and about the x axis of a right-handed
X** coordinate system whose z axis is defined by the camera position and
X** point of interest.`7D
X*/
X`7B
X  Pmatrix3 mat;
X  Pint err;
X
X  setwindow(windid);
X  if (windptr != NULL)
X  `7B
X    ptk_setpositionaxis(windid, &windptr->xaxis);
X    ptk_rotatecameraposition(windid, -angle);
X  `7D
X`7D  /* ptk_rotatepositionxaxis */
X
X/*--------------------------------------------------------------------------
V*/
X
X/*function:external*/
Xextern void ptk_rotateptinterestyaxis(C(Pint) windid, C(Pfloat) angle)
XPreANSI(Pint windid)`20
XPreANSI(Pfloat angle)
X/*
X** \parambegin
X** \param`7BPint`7D`7Bwindid`7D`7Bwindow identifier`7D`7BIN`7D
X** \param`7BPfloat`7D`7Bangle`7D`7Brotation angle in degrees`7D`7BIN`7D
X** \paramend`20
X** \blurb`7BThis function rotates the camera point of interest
X** in a circle centred
X** at the camera position and about the y axis of a right-handed
X** coordinate system whose z axis is defined by the camera position and
X** point of interest.`7D
X*/
X`7B
X  Pmatrix3 mat;
X  Pint err;
X
X  setwindow(windid);
X  if (windptr != NULL)
X  `7B
X    ptk_setptinterestaxis(windid, &windptr->yaxis);
X    ptk_rotatecameraptinterest(windid, -angle);
X  `7D
X`7D  /* ptk_rotateptinterestyaxis */
X
X/*--------------------------------------------------------------------------
V*/
X
X/*function:external*/
Xextern void ptk_rotateptinterestxaxis(C(Pint) windid, C(Pfloat) angle)
XPreANSI(Pint windid)`20
XPreANSI(Pfloat angle)
X/*
X** \parambegin
X** \param`7BPint`7D`7Bwindid`7D`7Bwindow identifier`7D`7BIN`7D
X** \param`7BPfloat`7D`7Bangle`7D`7Brotation angle in degrees`7D`7BIN`7D
X** \paramend`20
X** \blurb`7BThis function rotates the camera point of interest
X** in a circle centred
X** at the camera position and about the x axis of a right-handed
X** coordinate system whose z axis is defined by the camera position and
X** point of interest.`7D
X*/
X`7B
X  Pmatrix3 mat;
X  Pint err;
X
X  setwindow(windid);
X  if (windptr != NULL)
X  `7B
X    ptk_setptinterestaxis(windid, &windptr->xaxis);
X    ptk_rotatecameraptinterest(windid, -angle);
X  `7D
X`7D  /* ptk_rotateptinterestxaxis */
X
X/*--------------------------------------------------------------------------
V*/
X
X/*function:external*/
Xextern void ptk_setcameraposition(C(Pint) windid, C(Ppoint3 *) position)
XPreANSI(Pint windid)
XPreANSI(Ppoint3 *position)
X/*
X** \parambegin
X** \param`7BPint`7D`7Bwindid`7D`7Bwindow identifier`7D`7BIN`7D
X** \param`7BPpoint3 *`7D`7Bposition`7D`7Bcamera position`7D`7BIN`7D
X** \paramend`20
X** \blurb`7BThis function sets the camera position to `7B\tt position`7D
X** which is given in World Coordinates.`7D
X*/
X`7B
X  setwindow(windid);
X  if (windptr != NULL)
X  `7B
X    windptr->position = *position;
X    updatecamera();
X  `7D
X`7D  /* ptk_setcameraposition */
X
X/*--------------------------------------------------------------------------
V*/
X
X/*function:external*/
Xextern void ptk_setcameraptinterest(C(Pint) windid, C(Ppoint3 *) ptinterest)
XPreANSI(Pint windid)
XPreANSI(Ppoint3 *ptinterest)
X/*
X** \parambegin
X** \param`7BPint`7D`7Bwindid`7D`7Bwindow identifier`7D`7BIN`7D
X** \param`7BPpoint3 *`7D`7Bptinterest`7D`7Bpoint of interest`7D`7BIN`7D
X** \paramend`20
X** \blurb`7BThis function sets the camera point of interest to
X** `7B\tt ptinterest`7D which is given in World Corrdinates.`7D
X*/
X`7B
X  setwindow(windid);
X  if (windptr != NULL)
X  `7B
X    windptr->ptinterest = *ptinterest;
X    updatecamera();
X  `7D
X`7D  /* ptk_setcameraptinterest */
X
X/*--------------------------------------------------------------------------
V*/
X
X/*function:external*/
Xextern void ptk_setcameraprojtype(C(Pint) windid, C(Pprojtype) proj)
XPreANSI(Pint windid)
+-+-+-+-+-+-+-+-  END  OF PART 280 +-+-+-+-+-+-+-+-