Free OpenGL Fortran 77 and C++ environment for Windows

Components

The following components were used as a start point for our kit:
  1. Borland C++ Builder compiler (free command line tools)
  2. GLUT source for F77 binding headers
  3. f2c - fortran to c translator recompiled with BCC
  4. Fortran binding for GLUT, GL and GLUT
  5. No Fortran GL examples were available so I wrote some to verify success of the idea

Motivation

For teaching graphics with the free tools which can be given to students for home use without violating the license. Primarily this kit is intended for Fortran 77 users as there is no simple and free solution for use on MS Windows. With simple solution I mean the kit size, ease of installation, ease of use and portability of the executables. This prerequisites ruled out free tools on Windows such as Cygnus, djgpp, mingw as they require a lot of unix tools and runtime dlls (portability). Our executables run with the prerequisite of glut32.dll installed or placed with executable in the same directory. The use of GLUT is mandatory for OpenGL window programming abstraction in F77 on Windows.

Installation

  1. Download C++ Builder Compiler command line tools from Borland
  2. Download our kit of headers, libraries, binaries, batch files and F77 examples
  3. Install BCC command line tools in directory c:\bcc55
  4. Create c:\bcc55\bin\ilink32.cfg with the link path switches:
    -L"c:\bcc55\lib;c:\bcc55\lib\psdk"
  5. Create c:\bcc55\bin\bcc32.cfg and add include directory search
    -I"c:\bcc55\include"
    -L"c:\bcc55\lib"
  6. Extract zip contents into c:\. This will overlay c:\bcc55 installation with:
    bcc55/bin/f77.bat
    bcc55/bin/f2c.exe
    bcc55/include/GL/glutf90.h
    bcc55/include/GL/fglu.h
    bcc55/include/GL/fglut.h
    bcc55/include/GL/glut.h
    bcc55/include/GL/fgl.h
    bcc55/include/f2c.h
    bcc55/lib/fopengl32.lib
    bcc55/lib/glut32.dll
    bcc55/lib/glut32.lib
    bcc55/lib/libf77.lib
    bcc55/lib/libi77.lib
    bcc55/f90gl/gl/cwrap.c
    bcc55/f90gl/glu/cwrapglu.c
    bcc55/f90gl/glut/cwrapglt.c
    bcc55/examples/line.f
    bcc55/examples/teapot.f
    bcc55/examples/unproject.f
    bcc55/examples/tblight.f
    bcc55/examples/trackball.c
    bcc55/examples/...
  7. Copy/move glut32.dll from lib into system directory (eg. c:\windows\system32 or c:\winnt\system32)
  8. Update Windows search to point to c:\bcc55\bin. For 98/ME update autoexec.bat, NT/2000 System/Envitonment/Path

Usage

Fortran compiling comes with f77 batch script that eases two step procedure of converting fortran source into ANSI C and then proceeding with C compiling and linking into executable. Compilation should be initiated with Fortran file without extension i.e..:

f77 teapot

Of course, usage of the f77.bat is limited to simple projects/users. Use it as template for Makefile. To support modular programming several files can be compiled/linked with one command. The first file should contain program statement. Precompiled modules should be specified as .obj files. Example command line:


f77 mainprog module1 module2 module3.c module4.obj module5.obj

Rebuilding sources

f90gl subdirectory is provided for rebuilding fopengl32.lib from source. No makefile is provided but you can compile fortran bindery with simple C compile command eg. bcc32 -c cwrap.c
You can build the library with tlib fopengl32.lib +- ..\f90gl\gl\cwrap.obj in the lib subdir. Maybe someone will properly patch the files and submitted it to f90gl project or to me. For rebuilding glut with proper fortran callbacks please use sources from f90gl. You will need MS Visual C++ for that. As usual user command implib glut32.lib glut32.dll for building bcc library extract from .dll.

Bugs

There are differences in internal handling of the string type between different fortran implementations. f2c is no exception. So if you get exception violation message from a function this may be the case. Not many glut routines accept strings. Please send bug reports to me an I will see what I can do.

Documentation

For F77 you can use fortran specification, f2c and binding for OpenGL and GLUT. For convenience I collected and converted into PDF GL and GLU fortran binding specification for off-line reading. For GLUT we use f prefix naming convention as suggested by ARB.

Examples

line.f

You should start with this hello sample with minimal code needed for GLUT windowing application. It consist of two compilation units: Subroutine display and main program named line. Every program unit needs include files at the beginning of the code. Usually this is GL/fglut.h for main and additionally GL/fgl.h and GL/fglu.h for callback routines. Default callback routines are assumed except for display. Window area is (-1,-1) (1,1) and anamorphical resize.

teapot.f

Adds keyboard event demo and glut predefined object. Note that every callback function needs to be specified with external otherwise this name will be treated as variable. I strongly suggest to use implicit none for every program unit.

unproject.f

Mouse events are captured and then viewport coordinates are back projected into world coordinates which are then drawn as polyline. This is 2D demo as the z is assumed.

cube-f.f

Shaded cube with their sides marked with stoked font text.

tblight.f

Lighting demo and quaternion rotation example with external C source routine and builtin Fortran binding.
Compile this demo with: f77 tblight trackball.c

mm.f

MadMax highway animation of 5 vehicles.
Leon Kos
LECAD
University of Ljubljana
Created: March 2002