glPolygonMode

GLPOLYGONMODE(3G)					    GLPOLYGONMODE(3G)



NAME
       glPolygonMode - select a polygon rasterization mode


C SPECIFICATION
       void glPolygonMode( GLenum face,
			   GLenum mode )


PARAMETERS
       face  Specifies	the  polygons that mode applies to.  Must be GL_FRONT
	     for front-facing polygons, GL_BACK for back-facing polygons,  or
	     GL_FRONT_AND_BACK for front- and back-facing polygons.

       mode  Specifies	how polygons will be rasterized.  Accepted values are
	     GL_POINT, GL_LINE, and GL_FILL.  The initial  value  is  GL_FILL
	     for both front- and back-facing polygons.

DESCRIPTION
       glPolygonMode  controls	the interpretation of polygons for rasteriza-
       tion.  face describes which polygons  mode  applies  to:	 front-facing
       polygons	 (GL_FRONT),  back-facing  polygons  (GL_BACK),	 or  both  (-
       GL_FRONT_AND_BACK).  The polygon mode affects only the final  rasteri-
       zation  of  polygons.  In particular, a polygon’s vertices are lit and
       the polygon is clipped and possibly  culled  before  these  modes  are
       applied.

       Three modes are defined and can be specified in mode:

       GL_POINT	     Polygon  vertices	that  are  marked  as  the start of a
		     boundary edge are drawn  as  points.   Point  attributes
		     such  as  GL_POINT_SIZE  and GL_POINT_SMOOTH control the
		     rasterization  of	the  points.   Polygon	rasterization
		     attributes other than GL_POLYGON_MODE have no effect.

       GL_LINE	     Boundary  edges  of  the  polygon are drawn as line seg-
		     ments.  They are treated as connected line segments  for
		     line stippling; the line stipple counter and pattern are
		     not reset between segments	 (see  glLineStipple).	 Line
		     attributes such as GL_LINE_WIDTH and GL_LINE_SMOOTH con-
		     trol the rasterization of the lines.  Polygon rasteriza-
		     tion  attributes  other  than  GL_POLYGON_MODE  have  no
		     effect.

       GL_FILL	     The  interior  of	the  polygon  is   filled.    Polygon
		     attributes	    such     as	    GL_POLYGON_STIPPLE	  and
		     GL_POLYGON_SMOOTH control the rasterization of the poly-
		     gon.

EXAMPLES
       To draw a surface with filled back-facing polygons and outlined front-
       facing polygons, call glPolygonMode(GL_FRONT, GL_LINE);

NOTES
       Vertices are marked as boundary or  nonboundary	with  an  edge	flag.
       Edge flags are generated internally by the GL when it decomposes poly-
       gons; they can be set explicitly using glEdgeFlag.

ERRORS
       GL_INVALID_ENUM is generated if either face or mode is not an accepted
       value.

       GL_INVALID_OPERATION is generated if glPolygonMode is executed between
       the execution of glBegin and the corresponding execution of glEnd.

ASSOCIATED GETS
       glGet with argument GL_POLYGON_MODE

SEE ALSO
       glBegin(3G),   glEdgeFlag(3G),	glLineStipple(3G),   glLineWidth(3G),
       glPointSize(3G), glPolygonStipple(3G)



							    GLPOLYGONMODE(3G)