G95 Fortran interface to OpenGL and GLUT

I developed the direct G95 fortran bindings to OpenGL+GLUT libraries. This is much faster and uses much less memory than does the traditional import library method, expecially when linking large libraries or applications. This version implements the interface for OpenGL 1.2+, GLU 1.2+, GLUT 3.7, FreeGlut/OpenGlut and several extensions. It supports several Unix workstations and Windows 98/NT/2000/Me/XP.

The G95 bindings for OpenGL are an alternative to the older Fortran 90 bindings. This increases the similarity between the Fortran and C interfaces to OpenGL.

Unix Fortran sources	Win32 Fortran sources
Unix OpenGL module	Windows OpenGL module

Character strings should come to an end in zero byte as in C.
glutInit command you should use in the next way
```
call glutinit(1,loc('thePgm'//char(0)))
```

For functions, which return a character string, you should use pointer. See example:

        character(100), pointer :: str
        ..............................
        str=>glGetString(GL_VERSION)
        l=min(len(str),index(str,char(0)))
        print *, 'OpenGL version is ',str(1:l)

In some commands you have to pass pointers of the different types. Use function loc to get address.Example
```
 call glVertexPointer( 2, GL_FLOAT, 0, loc(P) ) 
```
where P is a real array of vertices with coordinates x,y.
In GLU some functions return the pointer on structure. I remade it in integer(C_INTPTR_T). Example
```
        integer(C_INTPTR_T) :: nurb
        nurb = gluNewNurbsRenderer()
```
See details in molehill.f90
Some GLUT commands begin with underscoring, for example __glutInitWithExit (old glut 3.7). Use g_glutInitWithExit instead.

CALLBACK subroutines. If the callback subroutine has arguments, you have to pass it by value (as in C). Example:

        subroutine motion(x, y) bind(c)
        integer(GLint), intent(in), value :: x, y
        ....................................
        end subroutine motion

Rest. View examples.

What you need

For compiling you need in file opengl.mod. You have to get the OpenGLu.f03 file for Unix32/64 platform or OpenGLw.f03 for Windows platform. You have to create opengl.mod with command line

For Windows platform you need in FGlut32.dll. In principle, this is the same as FreeGlut/OpenGlut, but I remade CALLBACKs for stdcall calling convention. If you have MinGW gcc, you can make it very easy:

G95 Fortran interface to OpenGL and GLUT

What you need

Compiling