Index for Section 3G

Alphabetical listing for G

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glLineWidth(3G)
NAME
  glLineWidth - specify the width of rasterized lines

SYNOPSIS
  void glLineWidth(
	  GLfloat width );

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

DESCRIPTION
  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.
  Likewise, there is a range for aliased line widths as well. To query the
  range of supported widths and the size difference between supported widths
  within the range, call glGet() with arguments GL_ALIASED_LINE_WIDTH_RANGE,
  GL_SMOOTH_LINE_WIDTH_RANGE, GL_SMOOTH_LINE_WIDTH_GRANULARITY.

NOTES
  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.  Call glGet() with GL_ALIASED_LINE_WIDTH_RANGE to determine the
  maximum width.

ERRORS
  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().

ASSOCIATED GETS
       glGet() with argument GL_LINE_WIDTH
       glGet() with argument GL_ALIASED_LINE_WIDTH_RANGE
       glGet() with argument GL_SMOOTH_LINE_WIDTH_RANGE
       glGet() with argument GL_SMOOTH_LINE_WIDTH_GRANULARITY
       glIsEnabled() with argument GL_LINE_SMOOTH

SEE ALSO
  glEnable(3)

Index for Section 3G

Alphabetical listing for G

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