Commit | Line | Data |
---|---|---|
7faf1d71 AW |
1 | <?xml version="1.0" encoding="UTF-8"?> |
2 | <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd"> | |
3 | <!-- saved from url=(0013)about:internet --> | |
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_FragCoord - 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_FragCoord"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>gl_FragCoord — contains the window-relative coordinates of the current fragment</p></div><div class="refsynopsisdiv"><h2>Declaration</h2><div class="funcsynopsis"><code class="function">in vec4 gl_FragCoord;</code></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p> | |
5 | Available only in the fragment language, <code class="function">gl_FragCoord</code> is an input variable that contains the | |
6 | window relative coordinate (x, y, z, 1/w) values for the fragment. If multi-sampling, | |
7 | this value can be for any location within the pixel, or one of the fragment samples. | |
8 | This value is the result of fixed functionality that interpolates primitives after vertex | |
9 | processing to generate fragments. The z component is the depth value that would be used for the | |
10 | fragment's depth if no shader contained any writes to <a href="gl_FragDepth.xml"><span class="citerefentry"><span class="refentrytitle">gl_FragDepth</span></span></a>. | |
11 | </p><p> | |
12 | <code class="function">gl_FragCoord</code> may be redeclared with the additional layout qualifier identifiers | |
13 | <code class="function">origin_upper_left</code> or <code class="function">pixel_center_integer</code>. By | |
14 | default, <code class="function">gl_FragCoord</code> assumes a lower-left origin for window coordinates | |
15 | and assumes pixel centers are located at half-pixel centers. For example, the (x, y) location | |
16 | (0.5, 0.5) is returned for the lower-left-most pixel in a window. The origin of | |
17 | <code class="function">gl_FragCoord</code> may be changed by redeclaring <code class="function">gl_FragCoord</code> | |
18 | with the <code class="function">origin_upper_left</code> identifier. The values returned can also be | |
19 | shifted by half a pixel in both x and y by <code class="function">pixel_center_integer</code> so it | |
20 | appears the pixels are centered at whole number pixel offsets. This moves the (x, y) value returned by | |
21 | <code class="function">gl_FragCoord</code> of (0.5, 0.5) by default to (0.0, 0.0) with | |
22 | <code class="function">pixel_center_integer</code>. | |
23 | </p><p> | |
24 | If <code class="function">gl_FragCoord</code> is redeclared in any fragment shader in a program, it must be redeclared | |
25 | in all fragment shaders in that program that have static use of <code class="function">gl_FragCoord</code>. Redeclaring | |
26 | <code class="function">gl_FragCoord</code> with any accepted qualifier affects only <code class="function">gl_FragCoord.x</code> | |
27 | and <code class="function">gl_FragCoord.y</code>. It has no affect on rasterization, transformation or any other part | |
28 | of the OpenGL pipline or language features. | |
29 | </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_ClipDistance</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></thead></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p> | |
30 | <a href="gl_FragCoord.xml"><span class="citerefentry"><span class="refentrytitle">gl_FragCoord</span></span></a> | |
31 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p> | |
32 | Copyright <span class="trademark"></span>© 2011 Khronos Group. | |
33 | This material may be distributed subject to the terms and conditions set forth in | |
34 | the Open Publication License, v 1.0, 8 June 1999. | |
35 | <a href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>. | |
36 | </p></div></div></body></html> |