glLineWidth -	specify	the width of rasterized	lines

	  void glLineWidth( GLfloat width )

	  width	 Specifies the width of	rasterized lines.  The initial
		 value is 1.

	  glLineWidth specifies	the rasterized width of	both aliased
	  and antialiased lines.  Using	a line width other than	1 has
	  different effects, depending on whether line antialiasing is
	  enabled.  To enable and disable line antialiasing, call
	  glEnable and glDisable with argument GL_LINE_SMOOTH. Line
	  antialiasing is initially disabled.

	  If line antialiasing is disabled, the	actual width is
	  determined by	rounding the supplied width to the nearest
	  integer.  (If	the rounding results in	the value 0, it	is as
	  if the line width were 1.)  If
	  | DELTA x | >= | DELTA y |,
	  i pixels are filled in each column that is rasterized, where
	  i is the rounded value of width.  Otherwise, i pixels	are
	  filled in each row that is rasterized.

	  If antialiasing is enabled, line rasterization produces a
	  fragment for each pixel square that intersects the region
	  lying	within the rectangle having width equal	to the current
	  line width, length equal to the actual length	of the line,
	  and centered on the mathematical line	segment.  The coverage
	  value	for each fragment is the window	coordinate area	of the
	  intersection of the rectangular region with the
	  corresponding	pixel square.  This value is saved and used in
	  the final rasterization step.

	  Not all widths can be	supported when line antialiasing is
	  enabled. If an unsupported width is requested, the nearest
	  supported width is used.  Only width 1 is guaranteed to be
	  supported; others depend on the implementation.  To query
	  the range of supported widths	and the	size difference
	  between supported widths within the range, call glGet	with

	  The line width specified by glLineWidth is always returned
	  when GL_LINE_WIDTH is	queried.  Clamping and rounding	for
	  aliased and antialiased lines	have no	effect on the
	  specified value.
	  Nonantialiased line width may	be clamped to an
	  implementation-dependent maximum.  Although this maximum
	  cannot be queried, it	must be	no less	than the maximum value
	  for antialiased lines, rounded to the	nearest	integer	value.

	  GL_INVALID_VALUE is generated	if width is less than or equal
	  to 0.

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

	  glGet	with argument GL_LINE_WIDTH
	  glGet	with argument GL_LINE_WIDTH_RANGE
	  glGet	with argument GL_LINE_WIDTH_GRANULARITY
	  glIsEnabled with argument GL_LINE_SMOOTH