Provided by: opengl-4-man-doc_1.0~svn33624-1_all 
NAME
gl_PointSize - contains size of rasterized points, in pixels
DECLARATION
gl_PointSize is a member of the gl_PerVertex named block:
out gl_PerVertex {
vec4 gl_Position;
float gl_PointSize;
float gl_ClipDistance[];
};
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
┌──────────────┬───────────────────────────────────────────────────────────────────────────────────┐
│ │ OpenGL Shading Language Version │
├──────────────┼──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┤
│Variable │ 1.10 │ 1.20 │ 1.30 │ 1.40 │ 1.50 │ 3.30 │ 4.00 │ 4.10 │ 4.20 │ 4.30 │ 4.40 │ 4.50 │
│Name │ │ │ │ │ │ │ │ │ │ │ │ │
├──────────────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┤
│gl_PointSize │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │
│(vertex │ │ │ │ │ │ │ │ │ │ │ │ │
│shader) │ │ │ │ │ │ │ │ │ │ │ │ │
├──────────────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┤
│gl_PointSize │ - │ - │ - │ - │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │
│(geometry │ │ │ │ │ │ │ │ │ │ │ │ │
│shader) │ │ │ │ │ │ │ │ │ │ │ │ │
├──────────────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┤
│gl_PointSize │ - │ - │ - │ - │ - │ - │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │
│(tessellation │ │ │ │ │ │ │ │ │ │ │ │ │
│evaluation │ │ │ │ │ │ │ │ │ │ │ │ │
│shader) │ │ │ │ │ │ │ │ │ │ │ │ │
└──────────────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┘
SEE ALSO
gl_Position(), gl_ClipDistance()
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.
http://opencontent.org/openpub/.
COPYRIGHT
Copyright © 2011-2014 Khronos Group
[FIXME: source] 01/03/2018 GL_POINTSIZE(3G)