gluTessProperty man page on YellowDog

Man page or keyword search:  
man Server   18644 pages
apropos Keyword Search (all sections)
Output format
YellowDog logo
[printable version]

GLUTESSPROPERTY(3G)					   GLUTESSPROPERTY(3G)

NAME
       gluTessProperty - set a tessellation object property

C SPECIFICATION
       void gluTessProperty( GLUtesselator* tess,
			     GLenum which,
			     GLdouble data )

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

       which  Specifies	  the	property   to	be   set.   Valid  values  are
	      GLU_TESS_WINDING_RULE,		       GLU_TESS_BOUNDARY_ONLY,
	      GLU_TESS_TOLERANCE.

       data   Specifies the value of the indicated property.

DESCRIPTION
       gluTessProperty	is used to control properties stored in a tessellation
       object. These properties affect the way that the	 polygons  are	inter‐
       preted and rendered.  The legal values for which are as follows:

       GLU_TESS_WINDING_RULE
		      Determines  which parts of the polygon are on the "inte‐
		      rior".  data may be set to one of	 GLU_TESS_WINDING_ODD,
		      GLU_TESS_WINDING_NONZERO,	 GLU_TESS_WINDING_POSITIVE, or
		      GLU_TESS_WINDING_NEGATIVE,			    or
		      GLU_TESS_WINDING_ABS_GEQ_TWO.

		      To  understand how the winding rule works, consider that
		      the input contours partition the plane into regions. The
		      winding  rule  determines	 which	of  these  regions are
		      inside the polygon.

		      For a single contour C, the winding number of a point  x
		      is  simply  the  signed  number  of  revolutions we make
		      around x as we travel once around C (where CCW is	 posi‐
		      tive).  When  there are several contours, the individual
		      winding numbers are summed. This procedure associates  a
		      signed  integer  value  with  each point x in the plane.
		      Note that the winding number is the same for all	points
		      in a single region.

		      The  winding rule classifies a region as "inside" if its
		      winding number belongs  to  the  chosen  category	 (odd,
		      nonzero,	positive,  negative,  or  absolute value of at
		      least two). The previous GLU tessellator (prior  to  GLU
		      1.2)  used the "odd" rule. The "nonzero" rule is another
		      common way to define the interior. The other three rules
		      are useful for polygon CSG operations.

       GLU_TESS_BOUNDARY_ONLY
		      Is  a boolean value ("value" should be set to GL_TRUE or
		      GL_FALSE). When set to GL_TRUE, a set of closed contours
		      separating   the	 polygon  interior  and	 exterior  are
		      returned instead of a  tessellation.  Exterior  contours
		      are  oriented  CCW  with respect to the normal; interior
		      contours	are  oriented  CW.  The	  GLU_TESS_BEGIN   and
		      GLU_TESS_BEGIN_DATA  callbacks use the type GL_LINE_LOOP
		      for each contour.

       GLU_TESS_TOLERANCE
		      Specifies a tolerance for merging features to reduce the
		      size  of the output.  For example, two vertices that are
		      very close to each other might be replaced by  a	single
		      vertex. The tolerance is multiplied by the largest coor‐
		      dinate magnitude of any input vertex; this specifies the
		      maximum distance that any feature can move as the result
		      of a single merge operation. If a single	feature	 takes
		      part  in	several	 merge	operations, the total distance
		      moved could be larger.

		      Feature merging is completely optional; the tolerance is
		      only  a  hint.   The  implementation is free to merge in
		      some cases and not in others, or to never merge features
		      at all. The initial tolerance is 0.

		      The  current implementation merges vertices only if they
		      are exactly coincident, regardless of the current toler‐
		      ance.  A	vertex	is  spliced  into  an edge only if the
		      implementation is unable to distinguish  which  side  of
		      the  edge	 the vertex lies on. Two edges are merged only
		      when both endpoints are identical.

SEE ALSO
       gluGetTessProperty(3G), gluNewTess(3G)

							   GLUTESSPROPERTY(3G)
[top]

List of man pages available for YellowDog

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net