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Contains size of rasterized points, in pixels.



In the vertex, tessellation evaluation and geometry languages, a single global instance of thegl_PerVertexnamed block is available and itsgl_PointSizemember 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_PointSizeis used to determine the size of rasterized points, otherwise it is ignored by the rasterization stage.

In the tessellation control language, thegl_PerVertexnamed block is used to construct an array,gl_out[], whose members become available as inputs to the subsequent tessellation evaluation shader.

The value ofgl_PointSize(or thegl_PointSizemember of thegl_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 writtengl_PointSizesince the last call to EmitVertex (or hasn't written it at all).

In the tessellation control, tessellation evaluation and geometry languages, thegl_PerVertexnamed 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[edit]

gl_PointSize (vertex shader) 1.1+
gl_PointSize (geometry shader) 1.5+
gl_PointSize (tessellation evaluation shader) 4.0+

See Also[edit]

 gl_Position , gl_ClipDistance 


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.