$alias fdopen='fdopen'(%val, %ref)      include 'phigs.f1.h'			! get the HP-PHIGS aliases      program Bicycle				! program "Bicycle.f"      include 'phigs.f2.h'			! get the HP-PHIGS constants      integer*4	WorkstnID			! workstation identifier      parameter	(WorkstnID=1)			! value chosen by the user      integer*4	ConnID				! connection identifier      integer*4	WorkstnType			! workstation type      parameter	(WorkstnType=POIDDX)		! out/in, direct, dbl bfr, X      integer*4	Bike, Wheel, Frame		! \ structure IDs      parameter	(Bike=1, Wheel=2, Frame=3)	! / (defined by user)      real	WheelAngle			! current rotation of wheels      real	Xpos				! current position of bike      real	pi, dTheta, dX			! required constants      integer*4	Spokes				! \ specifies number of spokes      parameter	(Spokes=30)			! / and number of sides on rim      parameter	(pi=3.14159265358979323846)	! circumference/diameter      parameter	(dTheta=2*pi/Spokes)		! angle between spokes      parameter	(dX=-.003)			! speed of moving bike      real	FAreaX(26), FAreaY(26)		! points for fill area (frame)      real	PolylineX(100), PolylineY(100)	! points for circles (wheels)      real	SpokeX(2), SpokeY(2)		! points for spokes      data	FAreaX /-0.95, -0.87, -0.60, 			! fork     +		  -0.05, 1.00, 0.55, 0.50, 0.85, 0.08, 0.60,	! r. triangle     +		  0.70, 0.73, 0.70, 0.37, 0.34, 0.51,		! seat     +		  -0.01, -0.56, -0.52, 0.40, 0.44, -0.51,	! fr. triangle     +		  -0.45, -0.10, -0.10, -0.50/			! handlebars      data	FAreaY /-1.03, -1.05, -0.33,			! fork     +		  -1.05, -1.05, 0.00, -0.10, -0.95, -0.95, 0.10,! r. triangle     +		  0.10, 0.15, 0.20, 0.20, 0.15, 0.13,		! seat     +		  -0.92, -0.20, -0.10, -0.10, 0.00, 0.00,	! fr. triangle     +		  0.15, 0.15, 0.20, 0.20/			! handlebars      !--- transformation matrix variables -----------------------------++++++      real	Translation(3,3), Scaling(3,3)	! transformation matrices      real	Matrix(3,3)			! temporary matrix      real	TransXf, TransXr, TransY, Scale	! front/rear transl., scaling      parameter	(TransXf=-0.9, TransXr=0.9, TransY=-1.0, Scale=0.5)      integer*4	Error				! error-return variable      integer*4	I				! loop control variable      real	Theta				! temporary variable      integer*4	fdopen				! to get file descriptor      real	rad, d				! \ for converting degrees      rad(d)=	(d*pi/180.0)			! / to radians      call popph(fdopen(fnum(7), 'w'//char(0)), 0)	! open phigs      call pue004('/dev/screen/phigs_window', ConnID)	! get connection ID      call popwk(WorkstnID, ConnID, WorkstnType)	! open workstation      call psdus(WorkstnID, PWAITD, PNIVE)	! set display update state      call ppost(WorkstnID, Bike, 1.)		! mark structure for display      !=== define all CSS structures ===================================++++++      !--- define the "Frame" structure --------------------------------++++++      call popst(Frame)				! open structure      call pfa(26, FAreaX, FAreaY)		! fill area primitive      call pbltm(0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, Error, Matrix)      call pslmt(Matrix, PCREPL)		! set local transformation      call pexst(Wheel)				! execute structure      call pslmt(Matrix, PCREPL)		! set local transformation      call pexst(Wheel)				! execute structure      call pclst				! close structure      !--- define the "Wheel" structure --------------------------------++++++      call popst(Wheel)				! open structure      do I=1, Spokes+1				! define the wheel rim	  Theta=(I-1)*dTheta			! calculate required angle	  PolylineX(I)=cos(Theta)		! x=r*cos(Theta) where r=1	  PolylineY(I)=sin(Theta)		! y=r*sin(Theta) where r=1      end do      call ppl(Spokes+1, PolylineX, PolylineY)	! 2D polyline      do I=0, Spokes				! define the spokes	  Theta=(I-1)*dTheta			! calculate required angle	  SpokeX(1)=0.0				! \  start defining each	  SpokeY(1)=0.0				!  \ spoke from the center,	  SpokeX(2)=cos(Theta)			!  / and then proceed	  SpokeY(2)=sin(Theta)			! /  rimward.	  call ppl(2, SpokeX, SpokeY)		! 2D polyline      end do      call pclst				! close structure      !--- define the "Bike" structure ---------------------------------++++++      call popst(Bike)				! open structure      call pschh(0.04)				! set character height      call ptx(0.1, 0.8, 'Joe''s Olde Bike Shoppe')	! 2D text      call psc(0.25, 0.25, Error, Scaling)		! scale      call ptr(0.6, 0.6, Error, Translation)		! translate      call pcom(Translation, Scaling, Error, Matrix)	! concatenate matrices      call pslmt(Matrix, PCREPL)		! set local transform      call pexst(Frame)				! execute structure      call pclst				! close the structure      !=== display the stucture ========================================++++++      call ppost(WorkstnID, Bike, 1.0)		! post structure      call psedm(PREPLC)			! set edit mode to replace      Xpos=1.4					! starting location for bike      WheelAngle=0.0				! starting rotation for wheels      do while (Xpos .gt. -.36)			! loop for structure editing	  !--- first, open "Bike" structure and move the frame ---------++++++	  call popst(Bike)			! open structure	  call psep(3)				! bike xform is element #3	  call ptr(Xpos, 0.6, Error, Translation)! build translation matrix	  call pcom(Translation, Scaling, Error, Matrix)! concatenate matrices	  call pslmt(Matrix, PCREPL)		! set local transform	  call pclst()				! close structure	  Xpos=Xpos+dX				! increment X value	  !--- next, open the "Frame" structure and rotate the wheels --++++++	  call popst(Frame)			! open structure	  call pbltm(0.0, 0.0, TransXr, 	! build matrix     +	    TransY, rad(WheelAngle), Scale, Scale, Error, Matrix)	  call psep(2)				! front wheel xform is ele. #2	  call pslmt(Matrix, PCREPL)		! set local transform	  call psep(4)				! back wheel xform is ele. #4	  call pbltm(0.0, 0.0, TransXf,		! build matrix     +	    TransY, rad(WheelAngle+5.), Scale, Scale, Error, Matrix)	  call pslmt(Matrix, PCREPL)		! set local transform	  WheelAngle=WheelAngle-dX*3000/(2*pi)	! increment wheel angle	  call pclst()				! close structure	  call puwk(WorkstnID, PPERFO)		! update workstation      end do					! end of movement loop      call pclwk(WorkstnID)			! close workstation      call pclph				! close phigs      stop					! stop processing      end					! end of program