Man page or keyword search:   man All Sections 1 - General Commands 2 - System Calls 3 - Subroutines, Functions 4 - Special Files 5 - File Formats 6 - Games and Screensavers 7 - Macros and Conventions 8 - Maintenence Commands 9 - Kernel Interface New Commands Server 4.4BSD AIX Alpinelinux Archlinux Aros BSDOS BSDi Bifrost CentOS Cygwin Darwin Debian DigitalUNIX DragonFly ElementaryOS Fedora FreeBSD Gentoo GhostBSD HP-UX Haiku Hurd IRIX Inferno JazzOS Kali Knoppix LinuxMint MacOSX Mageia Mandriva Manjaro Minix MirBSD NeXTSTEP NetBSD OPENSTEP OSF1 OpenBSD OpenDarwin OpenIndiana OpenMandriva OpenServer OpenSuSE OpenVMS Oracle PC-BSD Peanut Pidora Plan9 QNX Raspbian RedHat Scientific Slackware SmartOS Solaris SuSE SunOS Syllable Tru64 UNIXv7 Ubuntu Ultrix UnixWare Xenix YellowDog aLinux   29550 pages apropos Keyword Search (all sections) Output format html ascii pdf view pdf save postscript

GLUTESSVERTEX(3G)		 OpenGL Manual		     GLUTESSVERTEX(3G)

NAME
       gluTessVertex - specify a vertex on a polygon

C SPECIFICATION
       void gluTessVertex(GLUtesselator* tess, GLdouble * location,
			  GLvoid* data);

PARAMETERS
       tess
	   Specifies the tessellation object (created with gluNewTess()).

       location
	   Specifies the location of the vertex.

       data
	   Specifies an opaque pointer passed back to the program with the
	   vertex callback (as specified by gluTessCallback()).

DESCRIPTION
       gluTessVertex describes a vertex on a polygon that the program defines.
       Successive gluTessVertex calls describe a closed contour. For example,
       to describe a quadrilateral, gluTessVertex should be called four times.
       gluTessVertex can only be called between gluTessBeginContour() and
       gluTessEndContour().

       data normally points to a structure containing the vertex location, as
       well as other per-vertex attributes such as color and normal. This
       pointer is passed back to the user through the GLU_TESS_VERTEX or
       GLU_TESS_VERTEX_DATA callback after tessellation (see the
       gluTessCallback() reference page).

EXAMPLE
       A quadrilateral with a triangular hole in it can be described as
       follows:

	   gluTessBeginPolygon(tobj, NULL);
	      gluTessBeginContour(tobj);
		 gluTessVertex(tobj, v1, v1);
		 gluTessVertex(tobj, v2, v2);
		 gluTessVertex(tobj, v3, v3);
		 gluTessVertex(tobj, v4, v4);
	      gluTessEndContour(tobj);
	      gluTessBeginContour(tobj);
		 gluTessVertex(tobj, v5, v5);
		 gluTessVertex(tobj, v6, v6);
		 gluTessVertex(tobj, v7, v7);
	      gluTessEndContour(tobj);
	   gluTessEndPolygon(tobj);

NOTES
       It is a common error to use a local variable for location or data and
       store values into it as part of a loop. For example:

	   for (i = 0; i < NVERTICES; ++i) {
	      GLdouble data[3];
	      data[0] = vertex[i][0];
	      data[1] = vertex[i][1];
	      data[2] = vertex[i][2];
	      gluTessVertex(tobj, data, data);
	   }

       This doesn't work. Because the pointers specified by location and data
       might not be dereferenced until gluTessEndPolygon() is executed, all
       the vertex coordinates but the very last set could be overwritten
       before tessellation begins.

       Two common symptoms of this problem are when the data consists of a
       single point (when a local variable is used for data) and a
       GLU_TESS_NEED_COMBINE_CALLBACK error (when a local variable is used for
       location).

SEE ALSO
       gluNewTess(), gluTessBeginContour(), gluTessBeginPolygon(),
       gluTessCallback(), gluTessEndPolygon(), gluTessNormal(),
       gluTessProperty()

COPYRIGHT
       Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed
       under the SGI Free Software B License. For details, see
       http://oss.sgi.com/projects/FreeB/.

AUTHORS
       opengl.org

opengl.org			  03/16/2013		     GLUTESSVERTEX(3G)

Vote for polarhome