%mathent; ]> 2011-2014 Khronos Group gl_Position 3G gl_Position contains the position of the current vertex out highp vec4 gl_Position The variable gl_Position is intended for writing the homogeneous vertex position. It can be written at any time during vertexshader execution. This value will be used by primitive assembly, clipping, culling, and other fixed functionality operations, if present, that operate on primitives after vertex processing has occurred. Its value is undefined after the vertex processing stage if the vertex shader executable does not write gl_Position. gl_Position gl_PointSize 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/.