| 1 | <?xml version="1.0" encoding="UTF-8"?> |
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| 4 | <?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><link rel="stylesheet" type="text/css" href="opengl-man.css" /><title>gl_PointSize - OpenGL Shading Language (GLSL)</title><meta name="generator" content="DocBook XSL Stylesheets V1.69.1" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="gl_PointSize"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>gl_PointSize — contains size of rasterized points, in pixels</p></div><div class="refsynopsisdiv"><h2>Declaration</h2><p> |
| 5 | <code class="function">gl_PointSize</code> is a member of the <code class="function">gl_PerVertex</code> |
| 6 | named block: |
| 7 | </p><div class="funcsynopsis"><pre class="programlisting"> out gl_PerVertex { |
| 8 | vec4 gl_Position; |
| 9 | float gl_PointSize; |
| 10 | float gl_ClipDistance[]; |
| 11 | };</pre></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p> |
| 12 | In the vertex, tessellation evaluation and geoemtry languages, a single |
| 13 | global instance of the <code class="function">gl_PerVertex</code> named block is available and |
| 14 | its <code class="function">gl_PointSize</code> member is an output that receives the |
| 15 | intended size of the point to be rasterized, in pixels. It may be written at any time |
| 16 | during shader execution. If <code class="constant">GL_PROGRAM_POINT_SIZE</code> is enabled, |
| 17 | <code class="function">gl_PointSize</code> is used to determine the size of rasterized |
| 18 | points, otherwise it is ignored by the rasterization stage. |
| 19 | </p><p> |
| 20 | In the tessellation control language, the <code class="function">gl_PerVertex</code> named block |
| 21 | is used to construct an array, <code class="function">gl_out[]</code>, whose members become |
| 22 | available as inputs to the subsequent tessellation evaluation shader. |
| 23 | </p><p> |
| 24 | The value of <code class="function">gl_PointSize</code> (or the <code class="function">gl_PointSize</code> member of the <code class="function">gl_out[]</code> |
| 25 | array, in the case of the tessellation control shader) |
| 26 | is undefined after the vertex, tessellation control, and tessellation evaluation |
| 27 | shading stages if the corresponding shader executable does |
| 28 | not write to gl_PointSize. It is also undefined after the geometry processing stage if the geometry shader executable calls |
| 29 | <a href="EmitVertex.xml"><span class="citerefentry"><span class="refentrytitle">EmitVertex</span></span></a> without having |
| 30 | written <code class="function">gl_PointSize</code> since the last call to <a href="EmitVertex.xml"><span class="citerefentry"><span class="refentrytitle">EmitVertex</span></span></a> |
| 31 | (or hasn't written it at all). |
| 32 | </p><p> |
| 33 | In the tessellation control, tessellation evaluation and geoemetry languages, |
| 34 | the <code class="function">gl_PerVertex</code> named block is used to construct an array, <code class="function">gl_in[]</code> |
| 35 | of per-vertex or per-control point inputs whose content represents the corresponding |
| 36 | outputs written by the previous stage. |
| 37 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="versions"></a><h2>Version Support</h2><div class="informaltable"><table border="1"><colgroup><col align="left" /><col align="center" /><col align="center" /><col align="center" /><col align="center" /><col align="center" /><col align="center" /><col align="center" /><col align="center" /><col align="center" /><col align="center" /></colgroup><thead><tr><th align="left"><span class="bold"><strong>Variable</strong></span></th><th align="left"><span class="bold"><strong>Version 1.10</strong></span></th><th align="left"><span class="bold"><strong>Version 1.20</strong></span></th><th align="left"><span class="bold"><strong>Version 1.30</strong></span></th><th align="left"><span class="bold"><strong>Version 1.40</strong></span></th><th align="left"><span class="bold"><strong>Version 1.50</strong></span></th><th align="left"><span class="bold"><strong>Version 3.30</strong></span></th><th align="left"><span class="bold"><strong>Version 4.00</strong></span></th><th align="left"><span class="bold"><strong>Version 4.10</strong></span></th><th align="left"><span class="bold"><strong>Version 4.20</strong></span></th><th align="center"><span class="bold"><strong>Version 4.30</strong></span></th></tr><tr><th align="left">gl_PointSize (vertex shader)</th><th align="center"><span class="emphasis"><em>Y</em></span></th><th align="center"><span class="emphasis"><em>Y</em></span></th><th align="center"><span class="emphasis"><em>Y</em></span></th><th align="center"><span class="emphasis"><em>Y</em></span></th><th align="center"><span class="emphasis"><em>Y</em></span></th><th align="center"><span class="emphasis"><em>Y</em></span></th><th align="center"><span class="emphasis"><em>Y</em></span></th><th align="center"><span class="emphasis"><em>Y</em></span></th><th align="center"><span class="emphasis"><em>Y</em></span></th><th align="center"><span class="emphasis"><em>Y</em></span></th></tr><tr><th align="left">gl_PointSize (geometry shader)</th><th align="center"><span class="emphasis"><em>-</em></span></th><th align="center"><span class="emphasis"><em>-</em></span></th><th align="center"><span class="emphasis"><em>-</em></span></th><th align="center"><span class="emphasis"><em>-</em></span></th><th align="center"><span class="emphasis"><em>Y</em></span></th><th align="center"><span class="emphasis"><em>Y</em></span></th><th align="center"><span class="emphasis"><em>Y</em></span></th><th align="center"><span class="emphasis"><em>Y</em></span></th><th align="center"><span class="emphasis"><em>Y</em></span></th><th align="center"><span class="emphasis"><em>Y</em></span></th></tr></thead></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p> |
| 38 | <a href="gl_Position.xml"><span class="citerefentry"><span class="refentrytitle">gl_Position</span></span></a>, <a href="gl_ClipDistance.xml"><span class="citerefentry"><span class="refentrytitle">gl_ClipDistance</span></span></a> |
| 39 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p> |
| 40 | Copyright <span class="trademark"></span>© 2011 Khronos Group. |
| 41 | This material may be distributed subject to the terms and conditions set forth in |
| 42 | the Open Publication License, v 1.0, 8 June 1999. |
| 43 | <a href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>. |
| 44 | </p></div></div></body></html> |