gl_PointSize

contains size of rasterized points, in pixels

Signature

gl_PointSize( )->

Description

In the vertex, tessellation evaluation and geometry languages, a single global instance of the
gl_PerVertex
named block is available and its
gl_PointSize
member is an output that receives the intended size of the point to be rasterized, in pixels. It may be written at any time during shader execution. If GL_PROGRAM_POINT_SIZE is enabled,
gl_PointSize
is used to determine the size of rasterized points, otherwise it is ignored by the rasterization stage.
In the tessellation control language, the
gl_PerVertex
named block is used to construct an array,
gl_out[]
, whose members become available as inputs to the subsequent tessellation evaluation shader.
The value of
gl_PointSize
(or the
gl_PointSize
member of the
gl_out[]
array, in the case of the tessellation control shader) is undefined after the vertex, tessellation control, and tessellation evaluation shading stages if the corresponding shader executable does not write to gl_PointSize. It is also undefined after the geometry processing stage if the geometry shader executable calls EmitVertex without having written
gl_PointSize
since the last call to EmitVertex (or hasn't written it at all).
In the tessellation control, tessellation evaluation and geometry languages, the
gl_PerVertex
named block is used to construct an array,
gl_in[]
of per-vertex or per-control point inputs whose content represents the corresponding outputs written by the previous stage.

Version Support

gl_PointSize (vertex shader)
gl_PointSize (geometry shader)
gl_PointSize (tessellation evaluation shader)

See Also

Copyright

Copyright
2011-2014 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. .