C Copyright(C) 1999-2020 National Technology & Engineering Solutions
C of Sandia, LLC (NTESS).  Under the terms of Contract DE-NA0003525 with
C NTESS, the U.S. Government retains certain rights in this software.
C
C See packages/seacas/LICENSE for details

C=======================================================================
      LOGICAL FUNCTION MPVIEW(LEFT,RIGHT,BOTTOM,TOP)
      COMMON /MAP/MODEL(4,4),VIEW(4,4),PROJ(4,4),CPNEAR,CPFAR,VWPORT(4),
     *       MVP(4,4),VP(4,4),CPLINE(2,2,10),CPPLAN(2,3,10),PEYE(3),
     *       PLOOK(3),ETWIST,NCPLIN,NCPLAN,TMAT1(4,4),TMAT2(4,4),
     *       TMAT3(4,4),TVEC1(4),TVEC2(4),TVEC3(4),TVEC4(4),TARR1(32),
     *       TARR2(32),TARR3(32),TARR4(32),TARR5(32),TARR6(32),
     *       TARR7(32),TARR8(32)
      REAL MODEL,MVP
      REAL DEVCAP(23)
      REAL DEFOUT(7)
      COMMON /STATUS/DEVCAP,DEFOUT
      REAL DEVP(5)
      COMMON /DEVICE/DEVP
      REAL COLP(3)
      REAL PALETT(3,16)
      COMMON /COLOR/COLP,PALETT
      REAL TEXTP(40)
      COMMON /TEXT/TEXTP
      REAL VECTP(5)
      REAL XCUR
      REAL YCUR
      COMMON /VECTRC/VECTP,XCUR,YCUR
      INTEGER IDEX(200,2)
      INTEGER NVECT(200,2)
      REAL XSIZE(200,2)
      REAL YSIZE(200,2)
      REAL X0(2300,2)
      REAL Y0(2300,2)
      REAL X1(2300,2)
      REAL Y1(2300,2)
      COMMON /FONT/IDEX,NVECT,XSIZE,YSIZE,X0,Y0,X1,Y1
      REAL GRAPHP(100)
      COMMON /GRAPH/GRAPHP
      COMMON /MAPPAR/MAPP(11)
      REAL MAPP
      COMMON /STORAG/MEMORY(1000)
      REAL LEFT
      CHARACTER*6 SUBNAM
      PARAMETER (SUBNAM='MPVIEW')

      MPVIEW = .FALSE.
      IF (LEFT.GE.RIGHT) THEN
         CALL PLTFLU
         CALL SIORPT(SUBNAM,
     *  'You cannot specify the left viewport edge >= to the right edge'
     *               ,2)
         RETURN

      END IF

      IF (TOP.LE.BOTTOM) THEN
         CALL PLTFLU
         CALL SIORPT(SUBNAM,
     *  'You cannot specify the top viewport edge <= to the bottom edge'
     *               ,2)
         RETURN

      END IF

      IF (TOP.LT.0 .OR. TOP.GT.DEVP(5)) THEN
         CALL PLTFLU
         CALL SIORPT(SUBNAM,'Top viewport specification out of range',2)
         RETURN

      END IF

      IF (BOTTOM.LT.0 .OR. BOTTOM.GT.DEVP(5)) THEN
         CALL PLTFLU
         CALL SIORPT(SUBNAM,'Bottom viewport specification out of range'
     *               ,2)
         RETURN

      END IF

      IF (LEFT.LT.0 .OR. LEFT.GT.DEVP(4)) THEN
         CALL PLTFLU
         CALL SIORPT(SUBNAM,'Left viewport specification out of range',
     *               2)
         RETURN

      END IF

      IF (RIGHT.LT.0 .OR. RIGHT.GT.DEVP(4)) THEN
         CALL PLTFLU
         CALL SIORPT(SUBNAM,'Right viewport specification out of range',
     *               2)
         RETURN

      END IF

      MPVIEW = .TRUE.
      VWPORT(1) = LEFT
      VWPORT(2) = RIGHT
      VWPORT(3) = BOTTOM
      VWPORT(4) = TOP
      RETURN

      END