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GLPOINTSIZE()                                                    GLPOINTSIZE()

NAME
       glPointSize - specify the diameter of rasterized points

C SPECIFICATION
       void glPointSize( GLfloat size )

PARAMETERS
       size  Specifies the diameter of rasterized points.  The initial value
             is 1.

DESCRIPTION
       glPointSize specifies the rasterized diameter of both aliased and
       antialiased points.  Using a point size other than 1 has different
       effects, depending on whether point antialiasing is enabled.  To enable
       and disable point antialiasing, call glEnable and glDisable with
       argument GL_POINT_SMOOTH. Point antialiasing is initially disabled.

       If point antialiasing is disabled, the actual size is determined by
       rounding the supplied size to the nearest integer.  (If the rounding
       results in the value 0, it is as if the point size were 1.)  If the
       rounded size is odd, then the center point (x, y) of the pixel fragment
       that represents the point is computed as

                                          (
       |_ x_w _| +.5, |_ y_w _| +.5)

       where w subscripts indicate window coordinates.  All pixels that lie
       within the square grid of the rounded size centered at (x, y) make up
       the fragment.  If the size is even, the center point is

                                          (
       |_ x_w +.5 _|, |_ y_w +.5 _|)

       and the rasterized fragment's centers are the half-integer window
       coordinates within the square of the rounded size centered at (x, y).
       All pixel fragments produced in rasterizing a nonantialiased point are
       assigned the same associated data, that of the vertex corresponding to
       the point.

       If antialiasing is enabled, then point rasterization produces a
       fragment for each pixel square that intersects the region lying within
       the circle having diameter equal to the current point size and centered
       at the point's (x_w, y_w).  The coverage value for each fragment is the
       window coordinate area of the intersection of the circular region with
       the corresponding pixel square.  This value is saved and used in the
       final rasterization step.  The data associated with each fragment is
       the data associated with the point being rasterized.

       Not all sizes are supported when point antialiasing is enabled.  If an
       unsupported size is requested, the nearest supported size is used.
       Only size 1 is guaranteed to be supported; others depend on the
       implementation.  To query the range of supported sizes and the size
       difference between supported sizes within the range, call glGet with
       arguments GL_POINT_SIZE_RANGE and GL_POINT_SIZE_GRANULARITY.

NOTES
       The point size specified by glPointSize is always returned when
       GL_POINT_SIZE is queried.  Clamping and rounding for aliased and
       antialiased points have no effect on the specified value.

       A non-antialiased point size 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 points, rounded to the
       nearest integer value.

ERRORS
       GL_INVALID_VALUE is generated if size is less than or equal to 0.

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

ASSOCIATED GETS
       glGet with argument GL_POINT_SIZE
       glGet with argument GL_POINT_SIZE_RANGE
       glGet with argument GL_POINT_SIZE_GRANULARITY
       glIsEnabled with argument GL_POINT_SMOOTH

SEE ALSO
       glEnable

                                                                 GLPOINTSIZE()