libsphere(3L)

NAME
     libsphere - the Sphere Library

SYNOPSIS
     #include <gl/fsphere.h>

          intger*4 function sphdra(params)
          real params(4);

          integer*4 sphgnp()

          subroutine sphfre()

          integer*4 function sphmode(attribute, value)
          integer*4 attribute, value;

          subroutine sphobj(objid)
          integer*4 objid;

          subroutine sphrma(mat)
          real mat(4,4);

          subroutine sphbbp(void)

          subroutine sphebp(void)

          subroutine sphclr(clr)
          real clr(4);

DESCRIPTION
     The Sphere Library renders spheres by issuing GL calls.  sphdra draws a
     sphere.  sphmod sets various attributes that affect the speed and quality
     of spheres rendered by sphdra. sphrma allows you to control the
     orientation of spheres by providing a rotation matrix.  sphgnp returns
     the number of polygons per sphere, in the mode currently selected by
     sphmod.  sphobj  operates like sphdra, except that, instead of
     immediately rendering a sphere, it creates and returns a GL object, which
     can be rendered using callob.  The routines sphbbp and sphebp are for
     drawing collections of spheres using a special bitmap image of a phong-
     shaded sphere.  The diffuse color of the bitmap spheres are set with the
     routine sphclr.

USAGE
     To link a program with libsphere, specify -lsphere on the compile line.
     When linking a program with libsphere, you must also specify the Graphics
     Library, -lfgl -lgl_s, and the Math Library, -lm.

CAVEAT
     In the current implementation, the Sphere Library maintains an internal
     cache of GL objects, one for each combination of sphere attributes for
     which sphdra or sphobj has been called.  The first call to sphdra, or
     sphobj, with a combination of attributes that has not yet been rendered
     will result in the creation of a new GL object and, thus, will take
     longer than subsequent calls with the same combination of sphere
     attributes.

     If your program uses the Sphere Library and also manipulates its own GL
     objects, you must be careful that your allocation of object identifiers
     does not conflict with the Sphere Library's allocation of object
     identifiers for its internal cache.  The Sphere Library calls genobj for
     its object identifier allocation.  If your program allocates object
     identifiers for its own use, you should either use genobj to allocate
     object identifiers or use isobj to verify that any object identifiers
     your program generates are not already being used by the Sphere Library.
     See makeob(3g) and genobj(3g) for further discussion of object
     identifiers.

     If you need to free the virtual memory used by the Sphere Library's
     internal cache, you can call sphfre to free all its GL objects and their
     associated memory.

SEE ALSO
     sphdra, sphgnp, sphfre, sphmod, sphobj, sphrma, sphbbp, sphebp, sphclr