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GLPOINTSIZE(3G)                                                                              GLPOINTSIZE(3G)



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

                                                (xw + .5, yw + .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

                                                (xw + .5, yw + .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 nonan-tialiased nonantialiased
       tialiased 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 ( xw , yw).  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_SMOOTH_POINT_SIZE_RANGE   and
       GL_SMOOTH_POINT_SIZE_GRANULARITY.  For aliased points, query the  supported  range  with  glGet  with
       arguments GL_ALIASED_POINT_SIZE_RANGE and

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.

       GL_POINT_SIZE_RANGE and GL_POINT_SIZE_GRANULARITY are deprecated in  GL  versions  1.2  and  greater.
       Their      functionality      has     been     replaced     by     GL_SMOOTH_POINT_SIZE_RANGE     and
       GL_SMOOTH_POINT_SIZE_GRANULARITY.

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_ALIASED_POINT_SIZE_RANGE
       glGet with argument GL_SMOOTH_POINT_SIZE_RANGE
       glGet with argument GL_SMOOTH_POINT_SIZE_GRANULARITY
       glIsEnabled with argument GL_POINT_SMOOTH

SEE ALSO
       glEnable(3G)




                                                                                             GLPOINTSIZE(3G)