GLUTINIT(3)                      Local Manual                      GLUTINIT(3)

NAME
     glutInit -- Initialize OpenGLUT data structures.

LIBRARY
     OpenGLUT - mainloop

SYNOPSIS
     #include <openglut.h>

     void
     glutInit(int *pargc, char **argv);

PARAMETERS
      pargc     Pointer to something like main()'s  argc.

      argv      Something like main()'s  argv.

DESCRIPTION
     This function should be called once, near the start of any GLUT, freeg-
     lut, or OpenGLUT program.  It serves two vital roles:

      - It allows OpenGLUT to initialize internal structures.
      - It allows OpenGLUT to process command-line arguments to control the
     initial window position, etc.

     You should take note of the interaction between glutInit() and the
     related functions such as glutInitWindowPosition().  OpenGLUT always uses
     the most recent configuration information, so if you call glutInit(),
     then glutInitWindowPosition(), you prevent the user from controlling the
     initial window position via a command-line parameter.

     glutInit() will remove from  pargc,   argv  any parameters that it recog-
     nizes in the command line.  The following command-line parameters are
     suported:

      -  -display   display-id  This allows connection to an alternate X
     server.
      -  -geometry   geometry-spec  This takes width, height, and window posi-
     tion.  The position is given as a signed value (negative values being
     distance from the far boundary of the screen).  For example, a window
     geometry of 5x7+11-17 is 5 pixels wide, 7 pixels tall, 11 pixels from the
     left, and 17 pixels from the bottom edge of the screen.
      -  -direct  Insist on only OpenGL direct rendering.  Direct rendering is
     normally requested but indirect is normally accepted.   -direct  is not
     always available.  See  -indirect.
      -  -indirect  Attempt only indirect OpenGL rendering.   -indirect  is
     always available.  See  -direct.
      -  -iconic  Open the window in iconized form.
      -  -gldebug  Print any detected OpenGL errors via glutReportErrors().
     Presently done at the bottom of glutMainLoopEvent().
      -  -sync  Synchronize the window system communications heavily.

     Additionally, this function checks whether the environment variable
     GLUT_FPS  is defined (only on UNIX_X11); if so, OpenGLUT will periodi-
     cally print the average number of times per second that your program
     calls glutSwapBuffers().

CAVEATS
     You really should always call this, even if you are a WIN32 user.  It
     provides a way for the user to directly inform OpenGLUT about preferences
     without the application needing to explicitly deal with those issues.
     This is also where OpenGLUT retrieves your program's name to help disam-
     biguate error and warning messages it may be forced to emit.

     Option  -sync  sets a flag, but is not actually used at this time.

     Lots of code does XFlush() on the X server, regardless of whether  -sync
     is specified.  Much of that appears to be required in order to support
     direct client invocation of  glutMainLoopEvent(), regrettably. However,
     if one calls glutMainLoop(), instead, we might avoid gratuitous XFlush()
     calls.  (That last sentence isn't particularly germain to this function,
     but there's no better place to make this remark at this time.) Even for
     glutMainLoopEvent(), we may be able to coalesce many XFlush() calls.

SEE ALSO
     glutInitWindowPosition(3) glutInitWindowSize(3) glutInitDisplayMode(3)
     glutInitDisplayString(3) glutCreateWindow(3) glutDisplayFunc(3)
     glutMainLoop(3) glutMainLoopEvent(3) glutReportErrors(3)
     glutSwapBuffers(3)




NetBSD 2.0                           Epoch                          NetBSD 2.0
