fglIntro(3G)

NAME
     - Introduction to OpenGL FORTRAN Bindings



OVERVIEW
     OpenGL is a high-performance 3D-oriented renderer that supersedes IrisGL.
     It is supported on all SGI graphics adaptors except for the G, GT and
     GTX. A number of other workstation and personal computer vendors also
     support OpenGL.

     This manpage contains OpenGL FORTRAN binding specific information.


NOTES
     The FORTRAN bindings naming convention for routines is to prefix each
     OpenGL call with fgl. GL_ prefix is used for the constants.

     The OpenGL FORTRAN bindings header files consist of /usr/include/GL/fgl.h
     and /usr/include/GL/fglu.h, the OpenGL FORTRAN bindings libraries are
     /usr/lib/libfGL.a and /usr/lib/libfGLU.a.

     There are no FORTRAN bindings for X and GLX.

     To determine if a pointer is null, compare it to GL_NULL (which is
     actually an 8-character string).

     Beware of problems with the commands that return strings of potentially
     unlimited length, such as fglGetString. The FORTRAN bindings support only
     limited length strings. If you need to deal with longer strings, you will
     need to write an interface routine that copies the result string into a
     buffer and then returns a token at a time.


EXAMPLES
     Compile with f77 -o sphere sphere.f -lfglut -lfGLU -lfGL -lglut -lGLU
     -lGL -lXmu -lXext -lXi -lX11

     C  GLUT Fortran program to draw red light sphere.

             subroutine display #include "GL/fgl.h"
             call fglclear(GL_COLOR_BUFFER_BIT + GL_DEPTH_BUFFER_BIT)
             call fglcalllist(1)
             call glutswapbuffers
             end

             subroutine gfxinit #include "GL/fgl.h"
             real diffuse(4),pos(4)
             data diffuse /1.0, 0.0, 0.0, 1.0/
             data pos /1.0, 1.0, 1.0, 0.0/
             call fglnewlist(1, GL_COMPILE)
             call glutsolidsphere(dble(1.0), 20, 20)
             call fglendlist
             call fgllightfv(GL_LIGHT0, GL_DIFFUSE, diffuse)
             call fgllightfv(GL_LIGHT0, GL_POSITION, pos)
             call fglenable(GL_LIGHTING)
             call fglenable(GL_LIGHT0)
             call fglenable(GL_DEPTH_TEST)
             call fglmatrixmode(GL_PROJECTION)
             call fgluperspective(dble(40.0), dble(1.0),
          2                       dble(1.0), dble(10.0))
             call fglmatrixmode(GL_MODELVIEW)
             call fglulookat(dble(0.0), dble(0.0), dble(5.0),
          2                  dble(0.0), dble(0.0), dble(0.0),
          3                  dble(0.0), dble(1.0), dble(1.0))
             call fgltranslatef(0.0, 0.0, -1.0)
             end

             program main #include "GL/fglut.h"
             external display
             external reshape
             external submenu
             external mainmenu
             call glutinit
             call glutinitdisplaymode(GLUT_DOUBLE+GLUT_RGB+GLUT_DEPTH)
             call glutcreatewindow('Fortran GLUT sphere')
             call gfxinit
             call glutdisplayfunc(display)
             call glutmainloop
             end


BUGS
     OpenGL FORTRAN bindings may contain unresolved symbols. Adding
     -ignore_unresolved to your compile command line will eliminate the error.


SEE ALSO
     glIntro