!!  Copyright (C) Stichting Deltares, 2005-2014.
!!
!!  This file is part of iMOD.
!!
!!  This program is free software: you can redistribute it and/or modify
!!  it under the terms of the GNU General Public License as published by
!!  the Free Software Foundation, either version 3 of the License, or
!!  (at your option) any later version.
!!
!!  This program is distributed in the hope that it will be useful,
!!  but WITHOUT ANY WARRANTY; without even the implied warranty of
!!  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
!!  GNU General Public License for more details.
!!
!!  You should have received a copy of the GNU General Public License
!!  along with this program.  If not, see <http://www.gnu.org/licenses/>.
!!
!!  Contact: imod.support@deltares.nl
!!  Stichting Deltares
!!  P.O. Box 177
!!  2600 MH Delft, The Netherlands.
!!
MODULE MOD_3D_DISPLAY

USE IMODVAR, ONLY : IDIAGERROR
USE MODPLOT, ONLY : MP
USE MOD_UTL, ONLY : UTL_MESSAGEHANDLE3D,UTL_MESSAGEHANDLE,RTOS,UTL_WSELECTFILE
USE MOD_IDF, ONLY : IDFDEALLOCATE
USE MOD_3D_PAR
USE MOD_3D_UTL, ONLY : IMOD3D_SETCOLOR,IMOD3D_RETURNCOLOR,IMOD3D_GETCOLOR
USE MOD_IPF_PAR, ONLY : ASSF

CONTAINS

 !###======================================================================
 SUBROUTINE IMOD3D_DISPLAY(IMODE)
 !###======================================================================
 IMPLICIT NONE
 INTEGER,INTENT(IN) :: IMODE
 REAL(KIND=GLFLOAT) :: XR,XG,XB
 INTEGER :: I,IR,IG,IB,J
 REAL(KIND=GLDOUBLE) :: Z
 INTEGER(GLINT) :: IVIEWPORT(4)
 TYPE (SPHERE3D) :: SLOOKFROM
 LOGICAL(GLBOOLEAN) :: LRED,LGREEN,LBLUE,LALPHA
 
 CALL IMOD3D_ERROR('IMOD3D_DISPLAY_ENTRY')

 IF(IMODE.EQ.1)THEN
  CALL GLENABLE(GL_DITHER)
  !## antialiasing points
  CALL GLENABLE(GL_POINT_SMOOTH)
  !## antialiasing lines
  CALL GLENABLE(GL_LINE_SMOOTH)
  !## enable blending -  aliasing werkt (nog) niet voor polygonen... komt door ontbreken alpha factor!
  CALL GLENABLE(GL_BLEND)
  !## fastest mode
  CALL GLHINT(GL_POINT_SMOOTH_HINT,GL_FASTEST)
  !## fastest mode
  CALL GLHINT(GL_LINE_SMOOTH_HINT,GL_FASTEST)
 !## select mode --- force plotting idf/iff/gen/axes with color zero!
 ELSEIF(IMODE.EQ.2)THEN
  CALL GLDISABLE(GL_POINT_SMOOTH)
  CALL GLDISABLE(GL_LINE_SMOOTH)
  CALL GLDISABLE(GL_POLYGON_SMOOTH)
  CALL GLDISABLE(GL_BLEND)
  CALL GLDISABLE(GL_DITHER)
 ENDIF

 !## set light at position "pos" --- stationary
 CALL GLMATRIXMODE(GL_MODELVIEW)
 CALL GLPOPMATRIX()   !## pops off the top matrix second-from-the top becomes the top
 CALL GLPUSHMATRIX()  !## pushes all matrices in the current stack down one level, topmost is copied
 CALL GLLIGHTFV(GL_LIGHT0,GL_POSITION,POS)

 DO J=1,IANAGLYPHS+1
  
  !## set right image if anaglyphs are active
  IF(J.EQ.2)CALL IMOD3D_ANAGLYPHS()
  
  !## set modelview matrix
  CALL IMOD3D_RESET_VIEW()

  !## set background
  CALL WRGBSPLIT(BGCOLOR,IR,IG,IB)
  XR=REAL(IR)/255.0_GLFLOAT; XG=REAL(IG)/255.0_GLFLOAT; XB=REAL(IB)/255.0_GLFLOAT
  CALL GLCLEARCOLOR(XR,XG,XB,0.0_GLFLOAT)

  CALL GLCOLORMASK(.TRUE._GLBOOLEAN,.TRUE._GLBOOLEAN,.TRUE._GLBOOLEAN,.TRUE._GLBOOLEAN)
  CALL GLCLEAR(IOR(GL_COLOR_BUFFER_BIT,GL_DEPTH_BUFFER_BIT))   !## clear color and depth buffer each time a drawing is drawn

  IF(IANAGLYPHS.EQ.1)THEN
   IF(J.EQ.1)THEN
    LRED=  .FALSE._GLBOOLEAN  !## do not write red buffer
    LGREEN= .TRUE._GLBOOLEAN  !## do write green buffer
   ELSE
    LRED=  .TRUE._GLBOOLEAN   !## do write red buffer
    LGREEN= .FALSE._GLBOOLEAN !## do not write green buffer
   ENDIF
  ELSE
   LRED=   .TRUE._GLBOOLEAN   !## do write red buffer
   LGREEN= .TRUE._GLBOOLEAN   !## do write green buffer 
  ENDIF
  LBLUE =.TRUE._GLBOOLEAN
  LALPHA=.TRUE._GLBOOLEAN
  
  CALL GLCOLORMASK(LRED,LGREEN,LBLUE,LALPHA)
 
  DO I=1,NCLPLIST
   IF(CLPPLOT(I)%ISEL.EQ.1)THEN
    CALL GLENABLE(CLPPLANES(I))
    CALL GLPUSHMATRIX()
    CALL GLTRANSLATED(CLPPLOT(I)%X,CLPPLOT(I)%Y,CLPPLOT(I)%Z)
    CALL GLCLIPPLANE(CLPPLANES(I),CLPPLOT(I)%EQN)
    CALL GLPOPMATRIX()
   ELSE
    CALL GLDISABLE(CLPPLANES(I))
   ENDIF
  END DO

  !## draw idf's - last cause antialiasing and blending not for polygons
  IF(NIDFLIST.GT.0)CALL IMOD3D_DISPLAY_IDF(IMODE)
  !## draw ipf-drills/points
  IF(NIPFLIST.GT.0)CALL IMOD3D_DISPLAY_IPF(IMODE)
  !## draw iff's
  IF(NIFFLIST.GT.0)CALL IMOD3D_DISPLAY_IFF()
  !## draw sol's
  IF(NSOLLIST.GT.0)CALL IMOD3D_DISPLAY_SOL()
  !## draw gen's
  IF(NGENLIST.GT.0)CALL IMOD3D_DISPLAY_GEN()

  DO I=1,NCLPLIST; CALL GLDISABLE(CLPPLANES(I)); END DO

  !## draw axes,roundbox
  IF(IMODE.EQ.1.AND.IBNDBOX.EQ.1)THEN
   CALL GLBLENDFUNC(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA)  !## (1) source (2) destination
  !## draw filled background in gl_cull_face mode
   CALL IMOD3D_SETCOLOR(BCOLOR)
   CALL GLLINEWIDTH(1.0_GLFLOAT)
   !## draw box
   IF(AXESINDEX(1).GT.0)CALL GLCALLLIST(AXESINDEX(1))
   !## draw axes
   IF(AXESINDEX(2).GT.0)CALL GLCALLLIST(AXESINDEX(2))
  ENDIF
 
  !## draw axes text,roundbox
  IF(IMODE.EQ.1.AND.IAXES.EQ.1)THEN
   CALL GLBLENDFUNC(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA)  !## (1) source (2) destination
   !## draw labels
   CALL IMOD3D_SETCOLOR(ACOLOR)
   IF(AXESINDEX(3).GT.0)CALL GLCALLLIST(AXESINDEX(3))
  ENDIF
 
  !## plot and update indentifier-position
  IF(IINDPOS.EQ.1)THEN
   CALL IMOD3D_PLOT_INDPOS()
  ENDIF
  
  !## draw bmp
  CALL IMOD3D_DISPLAY_BMP()
 
 ENDDO
 
 !## draw axes,roundbox
 IF(IORIENT.EQ.1)THEN

  CALL GLMATRIXMODE(GL_MODELVIEW)
  CALL GLPOPMATRIX()   !## pops off the top matrix second-from-the top becomes the top
  CALL GLPUSHMATRIX()  !## pushes all matrices in the current stack down one level, topmost is copied

  !## lookat is the coordinate 0,0,0
  !## lookfrom is the coordinate 10,-20,5
  !## scale factors 1,1,1

  SLOOKFROM=CART2SPHERE(LOOKFROM-LOOKAT)
  Z        =INIT_SHIFTZ-SLOOKFROM%RHO

  !## displacement in the left-corner
  CALL GLTRANSLATED(-2.0_GLDOUBLE,-2.0_GLDOUBLE,-2.0_GLDOUBLE)
  !## no moving and/or zooming
  CALL GLTRANSLATED(0.0_GLDOUBLE,0.0_GLDOUBLE,Z)  !%z affected by zoom
  CALL GLROTATED(ANGLE%X, 0.0_GLDOUBLE, 0.0_GLDOUBLE, 1.0_GLDOUBLE)
  CALL GLROTATED(ANGLE%Y, COS(PI*ANGLE%X/180.0_GLDOUBLE), &
                 -SIN(PI*ANGLE%X/180.0_GLDOUBLE), 0.0_GLDOUBLE)
  CALL GLTRANSLATED(-LOOKAT%X, -LOOKAT%Y, -LOOKAT%Z)

  CALL IMOD3D_SETCOLOR(OCOLOR)
  CALL GLLINEWIDTH(1.0_GLFLOAT)
  CALL GLCALLLIST(ORIENTINDEX)

 ENDIF

 CALL IMOD3D_DISPLAY_LEGEND()

 !## show buffer only in imode.eq.1, other mode will be used for selecting in false-colour mode
 IF(IMODE.EQ.1)CALL WGLSWAPBUFFERS()

 CALL GLMATRIXMODE(GL_PROJECTION)
 CALL GLLOADIDENTITY()
 
 IF(IORTHO.EQ.0)THEN
  CALL GLUPERSPECTIVE(FOVY,RAT,ZNEAR,ZFAR)    !## angle(fovy), aspect (ratio:w/h), near () and far()
 ELSE
  CALL GLORTHO(ZLEFT,ZRIGHT,ZBOTTOM,ZTOP,ZNEAR,ZFAR)
 ENDIF
 
 CALL IMOD3D_ERROR('IMOD3D_DISPLAY')

 END SUBROUTINE IMOD3D_DISPLAY
 
 !###======================================================================
 SUBROUTINE IMOD3D_PLOT_INDPOS()
 !###======================================================================
 IMPLICIT NONE
 REAL(KIND=GLFLOAT) :: X1,X2,Y1,Y2,Z1,Z2

 X1=-XYZAXES(1)
 X2= XYZAXES(1)
 Y1=-XYZAXES(2)
 Y2= XYZAXES(2)
 Z1= BOT%Z
 Z2= TOP%Z
 
 !## plot lookat-point, midpos
 CALL GLPOINTSIZE(5.0_GLFLOAT)
 CALL GLBEGIN(GL_POINTS)
 CALL IMOD3D_SETCOLOR(WRGB(0,255,0))
 IF(INDPOS%X.EQ.0.0_GLFLOAT.AND.INDPOS%Y.EQ.0.0_GLFLOAT.AND.INDPOS%Z.EQ.0.0_GLFLOAT)THEN
  INDPOS%X=LOOKAT%X; INDPOS%Y=LOOKAT%Y; INDPOS%Z=LOOKAT%Z
 ENDIF
 CALL IMOD3D_SETTINGSPUT_INDPOS()
 CALL GLVERTEX3F(INDPOS%X,INDPOS%Y,INDPOS%Z)
 CALL GLEND()
 
 CALL IMOD3D_SETCOLOR(WRGB(0,200,0))
 CALL GLLINEWIDTH(1.0_GLFLOAT)
 CALL GLBEGIN(GL_LINE_STRIP)
  CALL GLVERTEX3F(INDPOS%X,      Y2,      Z1)
  CALL GLVERTEX3F(INDPOS%X,INDPOS%Y,      Z1)
  CALL GLVERTEX3F(INDPOS%X,INDPOS%Y,INDPOS%Z)
  CALL GLVERTEX3F(INDPOS%X,      Y2,INDPOS%Z)
  CALL GLVERTEX3F(INDPOS%X,      Y2,      Z1)
 CALL GLEND()
 CALL GLBEGIN(GL_LINE_STRIP)
  CALL GLVERTEX3F(INDPOS%X,INDPOS%Y,      Z1)
  CALL GLVERTEX3F(X2      ,INDPOS%Y,      Z1)
  CALL GLVERTEX3F(X2      ,INDPOS%Y,INDPOS%Z)
  CALL GLVERTEX3F(INDPOS%X,INDPOS%Y,INDPOS%Z)
  CALL GLVERTEX3F(INDPOS%X,INDPOS%Y,      Z1)
 CALL GLEND()
  
 END SUBROUTINE IMOD3D_PLOT_INDPOS

 !###======================================================================
 SUBROUTINE IMOD3D_SETTINGSPUT_INDPOS()
 !###======================================================================
 IMPLICIT NONE
 REAL :: X,DX
 
 DX=TOP%X-BOT%X
 X=BOT%X+DX*(INDPOS%X+XYZAXES(1))/(XYZAXES(1)*2.0_GLFLOAT)
 CALL WDIALOGPUTREAL(IDF_REAL7,X,'(F8.1)')
 DX=TOP%Y-BOT%Y
 X=BOT%Y+DX*(INDPOS%Y+XYZAXES(2))/(XYZAXES(2)*2.0_GLFLOAT)
 CALL WDIALOGPUTREAL(IDF_REAL8,X,'(F8.1)')
 X=INDPOS%Z; CALL WDIALOGPUTREAL(IDF_REAL9,X,'(F8.1)')
 
 END SUBROUTINE IMOD3D_SETTINGSPUT_INDPOS
  
 !###======================================================================
 SUBROUTINE IMOD3D_LIGHT()
 !###======================================================================
 IMPLICIT NONE
 INTEGER :: I

 CALL WDIALOGSELECT(ID_D3DSETTINGS_TAB5)

 CALL WDIALOGGETTRACKBAR(IDF_TRACKBAR2,I); F_L1_AMBIENT=REAL(I)/100.0
 CALL WDIALOGGETTRACKBAR(IDF_TRACKBAR3,I); F_L1_DIFFUSE=REAL(I)/100.0
 CALL WDIALOGGETTRACKBAR(IDF_TRACKBAR4,I); F_L1_SPECULAR=REAL(I)/100.0
 
 L1_AMBIENT= (/F_L1_AMBIENT,F_L1_AMBIENT,F_L1_AMBIENT,1.0_GLFLOAT/)
 L1_DIFFUSE= (/F_L1_DIFFUSE,F_L1_DIFFUSE,F_L1_DIFFUSE,1.0_GLFLOAT/)
 L1_SPECULAR=(/F_L1_SPECULAR,F_L1_SPECULAR,F_L1_SPECULAR,1.0_GLFLOAT/)

!The ambient component is the light from that source that's been scattered so much by the environment
!that its direction is impossible to determine - it seems to come from all directions. Backlighting in a room
!has a large ambient component, since most of the light that reaches your eye has bounced off many
!surfaces first. A spotlight outdoors has a tiny ambient component; most of the light travels in the same
!direction, and since you're outdoors, very little of the light reaches your eye after bouncing off other
!objects. When ambient light strikes a surface, it's scattered equally in all directions.

!--- flattens image ----
 CALL GLLIGHTFV(GL_LIGHT0, GL_AMBIENT, L1_AMBIENT) 
!Diffuse light comes from one direction, so it's brighter if it comes squarely down on a surface than if it
!barely glances off the surface. Once it hits a surface, however, it's scattered equally in all directions, so it
!appears equally bright, no matter where the eye is located. Any light coming from a particular position or
!direction probably has a diffuse component.
 CALL GLLIGHTFV(GL_LIGHT0, GL_DIFFUSE,L1_DIFFUSE)
!Finally, specular light comes from a particular direction, and it tends to bounce off the surface in a
!preferred direction. A well-collimated laser beam bouncing off a high-quality mirror produces almost 100
!percent specular reflection. Shiny metal or plastic has a high specular component, and chalk or carpet has
!almost none. You can think of specularity as shininess.
 CALL GLLIGHTFV(GL_LIGHT0, GL_SPECULAR,L1_SPECULAR)

 END SUBROUTINE IMOD3D_LIGHT

 !###======================================================================
 SUBROUTINE IMOD3D_RESET_TO_INIT()
 !###======================================================================
 !## This resets the view to the initial configuration
 IMPLICIT NONE
 TYPE (SPHERE3D) :: SLOOKFROM

 !## lookat is the coordinate 0,0,0
 !## lookfrom is the coordinate 10,-20,5
 !## scale factors 1,1,1

 SLOOKFROM    = CART2SPHERE(LOOKFROM-LOOKAT)
 ANGLE%X      =-180.0_GLDOUBLE*SLOOKFROM%THETA/PI - 90.0_GLDOUBLE
 ANGLE%Y      =-180.0_GLDOUBLE*SLOOKFROM%PHI/PI
 SHIFT%X      = INIT_SHIFTX
 SHIFT%Y      = INIT_SHIFTY
 SHIFT%Z      = INIT_SHIFTZ-SLOOKFROM%RHO
 XSCALE_FACTOR= INIT_XSCALE_FACTOR
 YSCALE_FACTOR= INIT_YSCALE_FACTOR
 ZSCALE_FACTOR= INIT_ZSCALE_FACTOR

 CALL IMOD3D_ERROR('IMOD3D_RESET_TO_INIT')

 END SUBROUTINE IMOD3D_RESET_TO_INIT

 !###======================================================================
 SUBROUTINE IMOD3D_DISPLAY_IPF(IMODE)
 !###======================================================================
 IMPLICIT NONE
 INTEGER,INTENT(IN) :: IMODE
 INTEGER :: IASSF,IIPF
 REAL(KIND=GLFLOAT) :: LT !## linethickness
   
 !## associated file drawn
 DO IASSF=1,NIPFLIST
  !## active based upon selection
  IF(IPFDLIST(5,IASSF).EQ.0)CYCLE
  !## part of selected ipf
  IIPF=IPFDLIST(1,IASSF); IF(IIPF.EQ.0)CYCLE
  !## selected in menu-field
  IF(IPFPLOT(IIPF)%ISEL.NE.1.OR.IPFLISTINDEX(IASSF,IMODE).EQ.0)CYCLE
   
  IF(IMODE.EQ.1)then
   !## line width
   IF(ISELECTED.EQ.IASSF)THEN
    IF(IPFPLOT(IIPF)%IFANCY.EQ.0)THEN
     CALL GLLINEWIDTH(10.0_GLFLOAT)
     CALL GLPOINTSIZE(10.0_GLFLOAT)
    ELSEIF(IPFPLOT(IIPF)%IFANCY.EQ.1)THEN
     CALL GLPOLYGONMODE(GL_FRONT,GL_LINE); CALL GLPOLYGONMODE(GL_BACK, GL_LINE)
     CALL GLLINEWIDTH(1.0_GLFLOAT)
    ENDIF
   ELSE
    !## mark whenever drill has been selected/activated to be interpolated
    LT=2.0_GLFLOAT
    CALL GLLINEWIDTH(LT)
    CALL GLPOINTSIZE(4.0_GLFLOAT)
   ENDIF
  
   IF(IPFPLOT(IIPF)%IFANCY.EQ.1)THEN
    IF(IPFPLOT(IIPF)%ISHADE.EQ.1.AND.IMODE.EQ.1)THEN
     CALL GLSHADEMODEL(GL_FLAT); CALL GLENABLE(GL_LIGHTING); CALL GLDISABLE(GL_BLEND)
    ENDIF
   ENDIF

  ENDIF

  CALL GLCALLLIST(IPFLISTINDEX(IASSF,IMODE))

  IF(IMODE.EQ.1)THEN
   IF(IPFPLOT(IIPF)%IFANCY.EQ.1)THEN
    IF(IPFPLOT(IIPF)%ISHADE.EQ.1.AND.IMODE.EQ.1)THEN
     CALL GLDISABLE(GL_LIGHTING); CALL GLENABLE(GL_BLEND)
    ENDIF
   ENDIF
   CALL GLPOLYGONMODE(GL_BACK, GL_FILL); CALL GLPOLYGONMODE(GL_FRONT,GL_FILL)
  ENDIF

 END DO

 !## draw ipf labels
 IF(IMODE.EQ.1.AND.IPLOTLABELS.EQ.1)THEN
  !## associated file drawn
  DO IASSF=1,NIPFLIST
   !## active based upon selection
   IF(IPFDLIST(5,IASSF).EQ.0)CYCLE
   !## part of selected ipf
   IIPF=IPFDLIST(1,IASSF) !ASSF(IASSF)%IIPF
   !## selected in menu-field
   IF(IPFPLOT(IIPF)%ISEL.EQ.0.OR.IPFLISTINDEX(IASSF,3).EQ.0)CYCLE
   IF(ISELECTED.EQ.IASSF)THEN
    CALL IMOD3D_SETCOLOR(WRGB(255,0,0))
   ELSE
    CALL IMOD3D_SETCOLOR(LCOLOR)
   ENDIF
   CALL GLCALLLIST(IPFLISTINDEX(IASSF,3))
  ENDDO
 ENDIF

 CALL IMOD3D_ERROR('IMOD3D_DISPLAY_IPF')

 END SUBROUTINE IMOD3D_DISPLAY_IPF

 !###======================================================================
 SUBROUTINE IMOD3D_DISPLAY_IDF(IMODE)
 !###======================================================================
 IMPLICIT NONE
 INTEGER :: I,J
 INTEGER,INTENT(IN) :: IMODE

 DO I=1,SIZE(IDFLISTINDEX) 
  IF(IDFPLOT(I)%ISEL.NE.1.OR.IDFLISTINDEX(I).EQ.0)CYCLE
 
  IF(IDFPLOT(I)%IFILL.EQ.1.OR.IDFPLOT(I)%IFILL.EQ.3)THEN

   !## opaque mode
   CALL GLBLENDFUNC(GL_ONE,GL_ZERO)  !## (1) source (2) destination
   
   CALL GLPOLYGONMODE(GL_BACK, GL_FILL); CALL GLPOLYGONMODE(GL_FRONT,GL_FILL)

   IF(IDFPLOT(I)%ILEG.EQ.1)THEN
    CALL IMOD3D_SETCOLOR(IDFPLOT(I)%ICOLOR)
   ELSEIF(IDFPLOT(I)%ILEG.EQ.2)THEN  !## legend colour - reread as not yet filled with legend-colouring
    !## do not change colour since colour is inside display-list
   ENDIF
   !## turn on light if neccessary
   IF(IDFPLOT(I)%ISHADED.EQ.1)THEN

    !## set material ...

    !## one single colour used
    IF(IDFPLOT(I)%ILEG.EQ.1)THEN
     !## show shaded surface
!     CALL IMOD3D_RETURNCOLOR(IDFPLOT(I)%ICOLOR,AMBIENT)
!     CALL GLMATERIALFV(GL_FRONT_AND_BACK,GL_AMBIENT_AND_DIFFUSE,AMBIENT)
    ENDIF

    !## flat shading
    CALL GLSHADEMODEL(GL_FLAT) !## heeft te maken met invullen kleuren
    CALL GLENABLE(GL_LIGHTING)

   ENDIF

   CALL GLCALLLIST(IDFLISTINDEX(I))

   !## turn of light
   IF(IDFPLOT(I)%ISHADED.EQ.1)THEN
    CALL GLDISABLE(GL_LIGHTING)
   ENDIF
  
  ENDIF

  !## draw mesh
  IF(IDFPLOT(I)%IFILL.EQ.2.OR.IDFPLOT(I)%IFILL.EQ.3)THEN

   !## blend mode
   CALL GLBLENDFUNC(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA)  !## (1) source (2) destination

   !## show lines to represent rectangles/triangles
   IF(IDFPLOT(I)%IFILL.EQ.2)CALL IMOD3D_SETCOLOR(IDFPLOT(I)%ICOLOR)
   IF(IDFPLOT(I)%IFILL.EQ.3)CALL IMOD3D_SETCOLOR(WRGB(0,0,0))
   CALL GLLINEWIDTH(1.0_GLFLOAT)
   !## outline (showing rectangles)
   CALL GLPOLYGONMODE(GL_FRONT,GL_LINE); CALL GLPOLYGONMODE(GL_BACK, GL_LINE)

   CALL GLCALLLIST(IDFLISTINDEX(I))

  ENDIF

 END DO

 !## default
 CALL GLPOLYGONMODE(GL_BACK, GL_FILL); CALL GLPOLYGONMODE(GL_FRONT,GL_FILL)
 
 END SUBROUTINE IMOD3D_DISPLAY_IDF

 !###======================================================================
 SUBROUTINE IMOD3D_DISPLAY_IFF()
 !###======================================================================
 IMPLICIT NONE
 INTEGER :: I
 REAL(KIND=GLFLOAT) :: XW

 !## opaque mode
 CALL GLBLENDFUNC(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA)  !## (1) source (2) destination

 DO I=1,NIFFLIST
  IF(IFFPLOT(I)%ISEL.NE.1.OR.IFFLISTINDEX(I).EQ.0)CYCLE

  IF(MP(IFFPLOT(I)%IPLOT)%ILEG.EQ.0)THEN
   CALL IMOD3D_SETCOLOR(MP(IFFPLOT(I)%IPLOT)%SCOLOR)
  ENDIF
  XW=REAL(IFFPLOT(I)%ITHICKNESS)
  CALL GLLINEWIDTH(XW)
  CALL GLCALLLIST(IFFLISTINDEX(I))

 END DO

 END SUBROUTINE IMOD3D_DISPLAY_IFF

 !###======================================================================
 SUBROUTINE IMOD3D_DISPLAY_SOL()
 !###======================================================================
 IMPLICIT NONE
 INTEGER :: I

 !## opaque mode
 !CALL GLBLENDFUNC(GL_ONE,GL_ZERO)  !## (1) source (2) destination

 !## no lightning ... difficult to draw in correct seqence/order

 CALL GLENABLE(GL_LIGHTING)
 CALL GLSHADEMODEL(GL_FLAT) !## heeft te maken met invullen kleuren

 DO I=1,NSOLLIST

  IF(SOLPLOT(I)%ISEL.EQ.0)CYCLE
  IF(SOLPLOT(I)%IBITMAP.EQ.1)CYCLE
  IF(SOLLISTINDEX(I,1).EQ.0)CYCLE
  CALL GLBLENDFUNC(GL_ONE,GL_ZERO)  !## (1) source (2) destination
  IF(SOLPLOT(I)%IINTERFACE.EQ.0)THEN 
   CALL GLENABLE(GL_LIGHTING)
   IF(SOLPLOT(I)%IBLEND.EQ.1)THEN
    CALL GLBLENDFUNC(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA)  !## (1) source (2) destination
   ENDIF
  ELSE
   CALL GLDISABLE(GL_LIGHTING)
  ENDIF
  CALL GLCALLLIST(SOLLISTINDEX(I,1))
 END DO

 CALL GLDISABLE(GL_LIGHTING)

! IF(ITRANSPARANCYBITMAP.EQ.1)THEN
!  CALL GLBLENDFUNC(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA)
! ELSE
  CALL GLDISABLE(GL_BLEND)
! ENDIF

 CALL GLCOLOR4F(1.0_GLFLOAT,1.0_GLFLOAT,1.0_GLFLOAT,1.0_GLFLOAT)

 DO I=1,NSOLLIST
  IF(SOLPLOT(I)%ISEL.EQ.0)CYCLE
  IF(SOLPLOT(I)%IBITMAP.EQ.0)CYCLE
  IF(SOLLISTINDEX(I,2).EQ.0)CYCLE
  IF(SOLPLOT(I)%IINTERFACE.EQ.1)THEN
   CALL GLPOLYGONMODE(GL_FRONT,GL_LINE); CALL GLPOLYGONMODE(GL_BACK, GL_LINE)
  ELSE
   CALL GLPOLYGONMODE(GL_BACK, GL_FILL); CALL GLPOLYGONMODE(GL_FRONT,GL_FILL)
  ENDIF
  CALL GLCALLLIST(SOLLISTINDEX(I,2))
 ENDDO
 
 CALL GLENABLE(GL_BLEND)
 
 END SUBROUTINE IMOD3D_DISPLAY_SOL

 !###======================================================================
 SUBROUTINE IMOD3D_DISPLAY_CLP()
 !###======================================================================
 IMPLICIT NONE
 INTEGER :: I

 DO I=1,NCLPLIST
  IF(CLPPLOT(I)%ISEL.EQ.1)THEN
   CALL GLCALLLIST(CLPLISTINDEX(I))
  ENDIF
 END DO

 END SUBROUTINE IMOD3D_DISPLAY_CLP

 !###======================================================================
 SUBROUTINE IMOD3D_DISPLAY_GEN()
 !###======================================================================
 IMPLICIT NONE
 INTEGER :: I
 REAL(KIND=GLFLOAT) :: XW,XR,XG,XB
 INTEGER :: IR,IG,IB

 !## blend mode
 CALL GLBLENDFUNC(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA)  !## (1) source (2) destination

 DO I=1,NGENLIST
  IF(GENPLOT(I)%ISEL.NE.1.OR.GENLISTINDEX(I).EQ.0)CYCLE
  
  IF(GENPLOT(I)%L3D)THEN
   !## show shaded surface
   CALL IMOD3D_SETCOLOR(GENPLOT(I)%ICOLOR,GENPLOT(I)%ITRANSPARANCY)
  ELSE
   CALL IMOD3D_SETCOLOR(GENPLOT(I)%ICOLOR)
   XW=REAL(GENPLOT(I)%ITHICKNESS)
   CALL GLLINEWIDTH(XW)
  ENDIF
  CALL GLCALLLIST(GENLISTINDEX(I))

 END DO

 END SUBROUTINE IMOD3D_DISPLAY_GEN

 !###======================================================================
 SUBROUTINE IMOD3D_DISPLAY_BMP()
 !###======================================================================
 IMPLICIT NONE
 INTEGER :: I

 !## not background bitmap plotting
 IF(IACTBITMAP.EQ.0)RETURN

 IF(ITRANSPARANCYBITMAP.EQ.1)THEN
  CALL GLBLENDFUNC(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA)
 ELSE
  CALL GLDISABLE(GL_BLEND)
 ENDIF

 CALL GLCOLOR4F(1.0_GLFLOAT,1.0_GLFLOAT,1.0_GLFLOAT,1.0_GLFLOAT)

 I=1
 CALL GLCALLLIST(BMPLISTINDEX(I))

 CALL GLENABLE(GL_BLEND)

 END SUBROUTINE IMOD3D_DISPLAY_BMP

 !###======================================================================
 SUBROUTINE IMOD3D_DISPLAY_LEGEND() 
 !###======================================================================
 IMPLICIT NONE
 INTEGER :: I,N,M

 IF(LEGENDINDEX.EQ.0)RETURN

 !## save projection transformation matrix
 CALL GLMATRIXMODE(GL_PROJECTION); CALL GLPUSHMATRIX()
 !## set new projection transformation matrix
 CALL GLLOADIDENTITY()
 CALL GLORTHO(0.0_GLDOUBLE,100.0_GLDOUBLE,0.0_GLDOUBLE,100.0_GLDOUBLE,-1.0_GLDOUBLE,1.0_GLDOUBLE)
 !## save modelview transformation matrix
 CALL GLMATRIXMODE(GL_MODELVIEW); CALL GLPUSHMATRIX()
 !## set new modelview transformation matrix
 CALL GLLOADIDENTITY()

 CALL GLDISABLE(GL_BLEND)
 CALL GLDISABLE(GL_LIGHT0)
 CALL GLPOLYGONMODE(GL_FRONT_AND_BACK,GL_FILL)
 CALL GLDISABLE(GL_DEPTH_TEST)

 CALL GLCALLLIST(LEGENDINDEX)

 CALL GLENABLE(GL_BLEND)
 CALL GLENABLE(GL_LIGHT0) 
 CALL GLDEPTHFUNC(GL_LESS)
 CALL GLENABLE(GL_DEPTH_TEST)
  
 !## restore transformations matrices
 CALL GLMATRIXMODE(GL_MODELVIEW);  CALL GLPOPMATRIX()
 CALL GLMATRIXMODE(GL_PROJECTION); CALL GLPOPMATRIX()

 END SUBROUTINE IMOD3D_DISPLAY_LEGEND

 !###======================================================================
 SUBROUTINE IMOD3D_DISPLAY_SAVE(ID)
 !###======================================================================
 IMPLICIT NONE
 INTEGER,INTENT(IN) :: ID
 INTEGER(KIND=GLSIZEI) :: NDX,NDY 
 INTEGER(GLINT) :: IVIEWPORT(4) 
 REAL(KIND=GLFLOAT),DIMENSION(:),ALLOCATABLE :: FRGB
 INTEGER,DIMENSION(:),ALLOCATABLE :: IRGB 
 INTEGER :: IHANDLE,I
 CHARACTER(LEN=256) :: FNAME
 REAL(KIND=GLFLOAT),DIMENSION(3) :: GLCOLOR
 
 IF(ID.EQ.ID_SAVEAS)THEN
  IF(.NOT.UTL_WSELECTFILE('All Known Files (*.bmp;*.pcx;*.png;*.jpg)|*.bmp;*.pcx;*.png;*.jpg|BitMap (*.bmp)|*.bmp| &
                           ZSoft PC Paintbrush (*.pcx)|*.pcx|Portable Network Graphic image (*.png)|*.png|JPEG Image (*.jpg)|*.jpg|',&
                   SAVEDIALOG+PROMPTON+DIRCHANGE+APPENDEXT,FNAME,&
                   'Save Current Image to BitMap (*.bmp;*.pcx;*.png;*.jpg)'))RETURN
 ENDIF
 
 !## capture entire screen
 CALL GLGETINTEGERV(GL_VIEWPORT,IVIEWPORT)
 NDX=IVIEWPORT(3); NDY=IVIEWPORT(4)
 ALLOCATE(FRGB(NDX*NDY*3),IRGB(NDX*NDY))
 
 CALL GLREADBUFFER(GL_FRONT)
 CALL GLREADPIXELS(0_GLINT,0_GLINT,NDX,NDY,GL_RGB,GL_FLOAT,FRGB)
 
 DO I=0,(NDX*NDY)-1
  GLCOLOR(1)=FRGB(I*3+1); GLCOLOR(2)=FRGB(I*3+2); GLCOLOR(3)=FRGB(I*3+3)
  CALL IMOD3D_GETCOLOR(IRGB(I+1),GLCOLOR)
 ENDDO
 
 CALL WBITMAPCREATE(IHANDLE,NDX,NDY)  
 CALL WBITMAPGETDATA(IHANDLE,IRGB)   
 !## switch vertically
 CALL WBITMAPMIRROR(IHANDLE,1)

 IF(ID.EQ.ID_SAVEAS)THEN
  CALL WBITMAPSAVE(IHANDLE,FNAME)
 ELSE
  CALL WBITMAPCLIPBOARD(IHANDLE)
 ENDIF
 CALL WBITMAPDESTROY(IHANDLE)
 
 DEALLOCATE(FRGB,IRGB)
 CALL GLREADBUFFER(GL_BACK)
 
 IF(ID.EQ.ID_SAVEAS)THEN
  CALL WMESSAGEBOX(OKONLY,INFORMATIONICON,COMMONOK,'Succesfully saved the current image to'//CHAR(13)//TRIM(FNAME),'Information')
 ELSE
  CALL WMESSAGEBOX(OKONLY,INFORMATIONICON,COMMONOK,'Succesfully copied the current image to'//CHAR(13)//'the Windows Clipboard','Information')
 ENDIF
 
 END SUBROUTINE IMOD3D_DISPLAY_SAVE
 
 !###======================================================================
 SUBROUTINE IMOD3D_ANAGLYPHS()
 !###======================================================================
 IMPLICIT NONE

!   STEP      =MINSTEP
!   HEADING   =HEADING+PERP
!   LOOKFROM%X=LOOKFROM%X-COS(HEADING)*STEP
!   LOOKFROM%Y=LOOKFROM%Y-SIN(HEADING)*STEP
!   LOOKAT%X  =LOOKAT%X-COS(HEADING)*STEP
!   LOOKAT%Y  =LOOKAT%Y-SIN(HEADING)*STEP
!   HEADING   =HEADING-PERP

! LOOKAT%X=LOOKFROM%X+COS(HEADING)*DX
! LOOKAT%Y=LOOKFROM%Y+SIN(HEADING)*DX 
! LOOKAT%Z=LOOKFROM%Z+SIN(TILT)*DZ 

 !## set transformation parameters according to the lookfrom() and lookat() variables
! CALL IMOD3D_RESET_TO_INIT()
! CALL IMOD3D_DISPLAY(1)

 END SUBROUTINE IMOD3D_ANAGLYPHS

 !###======================================================================
 SUBROUTINE IMOD3D_RESET_VIEW() 
 !###======================================================================
 IMPLICIT NONE
 
 CALL GLTRANSLATED(SHIFT%X, SHIFT%Y, SHIFT%Z)
 CALL GLROTATED(ANGLE%X, 0.0_GLDOUBLE, 0.0_GLDOUBLE, 1.0_GLDOUBLE)
 CALL GLROTATED(ANGLE%Y, COS(PI*ANGLE%X/180.0_GLDOUBLE), &
                -SIN(PI*ANGLE%X/180.0_GLDOUBLE), 0.0_GLDOUBLE)
 CALL GLTRANSLATED(-LOOKAT%X, -LOOKAT%Y, -LOOKAT%Z)
 CALL GLSCALED(XSCALE_FACTOR,YSCALE_FACTOR,ZSCALE_FACTOR)
 
 CALL IMOD3D_ERROR('IMOD3D_RESET_VIEW')

 END SUBROUTINE IMOD3D_RESET_VIEW

END MODULE MOD_3D_DISPLAY