mirror of
https://github.com/Perlmint/glew-cmake.git
synced 2024-11-23 07:05:07 +00:00
148981e1a4
git-svn-id: https://glew.svn.sourceforge.net/svnroot/glew/trunk/glew@18 783a27ee-832a-0410-bc00-9f386506c6dd
413 lines
13 KiB
HTML
413 lines
13 KiB
HTML
<!--
|
|
Copyright (C) 2002 Milan Ikits
|
|
This documentation may not be modified or redistributed in any
|
|
form, except by the copyright holder.
|
|
-->
|
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
|
|
"http://www.w3.org/TR/html/4/loose.dtd">
|
|
<html>
|
|
<head>
|
|
<title>
|
|
GLEW: The OpenGL Extension Wrangler Library
|
|
</title>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
|
|
</head>
|
|
<body bgcolor="#ffffff" text="#000000" link="#1010f0" vlink="#000080" alink="#800000">
|
|
|
|
<center>
|
|
<table border=0 width="50%" cellpadding="5" cellspacing="10">
|
|
<tr>
|
|
<td align=center><img src="./glew.png" alt="glew" width="97" height="75"></td>
|
|
</tr>
|
|
<tr>
|
|
<td align=center><font size="+2"><b>The OpenGL Extension Wrangler Library</b></font></td>
|
|
</tr>
|
|
<tr>
|
|
<td width="80%">
|
|
<table border=0 cellpadding=0 cellspacing=0 align=center>
|
|
<tr><td align=center><a href="#Introduction"><font size="-1">Introduction</font></a></td></tr>
|
|
<tr><td align=center><a href="#Download"><font size="-1">Obtaining GLEW</font></a></td></tr>
|
|
<tr><td align=center><a href="#Supported"><font size="-1">Supported Extensions</font></a></td></tr>
|
|
<tr><td align=center><a href="#Build"><font size="-1">How to Build Your Project with GLEW</font></a></td></tr>
|
|
<tr><td align=center><a href="#Install"><font size="-1">How to Install GLEW</font></a></td></tr>
|
|
<tr><td align=center><a href="#Use"><font size="-1">How to Use GLEW</font></a></td></tr>
|
|
<tr><td align=center><a href="#Issues"><font size="-1">Known Issues</font></a></td></tr>
|
|
<tr><td align=center><a href="#Credits"><font size="-1">Credits, Copyright</font></a></td></tr>
|
|
</table>
|
|
<br>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td bgcolor="#FFF0D0" align="center"><a
|
|
name="Introduction"><font size="+1"><b>Introduction</b></font></a>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>
|
|
The goal of the OpenGL Extension Wrangler Library (GLEW) is to assist
|
|
C/C++ OpenGL developers with two tedious tasks: initializing and
|
|
using extensions and writing portable applications. GLEW provides
|
|
an efficient run-time mechanism to determine whether a certain
|
|
extension is supported by the driver or not. OpenGL core and
|
|
extension functionality is exposed via a single header file. GLEW
|
|
currently supports the products of two commodity graphics card
|
|
vendors, NVIDIA and ATI, on two operating systems, Windows and Linux.
|
|
<p>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td bgcolor="#FFF0D0" align="center"><a
|
|
name="Download"><font size="+1"><b>Obtaining GLEW</b></font></a>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>
|
|
The source and precompiled binaries are available at the <a
|
|
href="http://glew.sourceforge.net/">project website</a>.
|
|
|
|
<p>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td bgcolor="#FFF0D0" align="center"><a
|
|
name="Supported"><font size="+1"><b>Supported Extensions</b></font></a>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>
|
|
<table border=0 cellpadding="0" cellspacing="0">
|
|
<tr>
|
|
<td>GLEW currently supports <a href="glew.html">OpenGL</a>,
|
|
<a href="wglew.html">WGL</a>, and <a href="glxew.html">GLX</a>
|
|
extensions.
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
<p>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td bgcolor="#FFF0D0" align="center"><a
|
|
name="Build"><font size="+1"><b>How to Build Your Project with GLEW</b></font></a>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>
|
|
|
|
There are two ways to build your project with GLEW.
|
|
<p>
|
|
|
|
<font size="+1"><b>Including the source files / project file</b></font>
|
|
<p>
|
|
|
|
The simpler but less flexible way is to include <tt>glew.h</tt> and
|
|
<tt>glew.c</tt> into your project and define the <tt>GLEW_STATIC</tt>
|
|
preprocessor constant for the static library or executable you are
|
|
building together with GLEW. You also need to replace
|
|
<tt><GL/gl.h></tt> and <tt><GL/glu.h></tt> with
|
|
<tt><glew.h></tt> and set the appropriate include flag
|
|
(<tt>-I</tt>) to tell the compiler where to look for it.
|
|
For example:
|
|
|
|
<blockquote><pre>#include <glew.h>
|
|
#include <GL/glut.h>
|
|
<gl, glu, and glut functionality is available here>
|
|
</pre></blockquote>
|
|
|
|
Note that if you are using GLEW together with GLUT, you have to
|
|
include <tt>glew.h</tt> first. In addition, <tt>glew.h</tt> includes
|
|
<tt>glu.h</tt>, so you don't need to include it separately.
|
|
|
|
<p>
|
|
On Windows you can also add the supplied project file
|
|
(<tt>glew.dsp</tt> or <tt>glew.vcproj</tt>) to your workspace or
|
|
solution and compile it together with your other projects. In this
|
|
case you need to change the <tt>GLEW_BUILD</tt> preprocessor constant
|
|
to <tt>GLEW_STATIC</tt>, otherwise you get build errors. <b>Note that
|
|
GLEW does not use the C runtime library, so it does not matter
|
|
which version (single-threaded, multi-threaded or multi-threaded DLL) it
|
|
is linked with</b>.
|
|
|
|
<p>
|
|
|
|
<font size="+1"><b>Using GLEW as a shared library</b></font>
|
|
<p>
|
|
|
|
Alternatively, you can use the provided project files / makefile to
|
|
build a separate shared library you can link your projects with later.
|
|
In this case the best practice is to install <tt>glew.h</tt>,
|
|
<tt>glew32.lib</tt>, and <tt>glew32.dll</tt> / <tt>libGLEW.so</tt> to
|
|
where the OpenGL equivalents <tt>gl.h</tt>, <tt>opengl32.lib</tt>, and
|
|
<tt>opengl32.dll</tt> / <tt>libGL.so</tt> are located. Note that you
|
|
need administrative privileges to do this. If you do not have
|
|
administrator access and your system administrator will not do it for
|
|
you, you can install GLEW into your own lib and include subdirectories
|
|
and tell the compiler where to find it. Then you can just replace
|
|
<tt><GL/gl.h></tt> with <tt><GL/glew.h></tt> in your
|
|
program:
|
|
|
|
<blockquote><pre>#include <GL/glew.h>
|
|
#include <GL/glut.h>
|
|
<gl, glu, and glut functionality is available here>
|
|
</pre></blockquote>
|
|
|
|
or:
|
|
|
|
<blockquote><pre>#include <GL/glew.h>
|
|
<gl and glu functionality is available here>
|
|
</pre></blockquote>
|
|
|
|
<p>
|
|
Don't forget to link your project with <tt>glew32.lib</tt>,
|
|
<tt>glu32.lib</tt>, and <tt>opengl32.lib</tt> on Windows and
|
|
<tt>libGLEW.so</tt>, <tt>libGLU.so</tt>, and <tt>libGL.so</tt> on
|
|
Linux (<tt>-lGLEW -lGLU -lGL</tt>).
|
|
|
|
<p>
|
|
It is important to keep in mind that <tt>glew.h</tt> includes neither
|
|
<tt>windows.h</tt> nor <tt>gl.h</tt>. Also, GLEW will warn you by
|
|
issuing a preprocessor error in case you have included <tt>gl.h</tt>,
|
|
<tt>glext.h</tt>, or <tt>glATI.h</tt> before <tt>glew.h</tt>.
|
|
<p>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td bgcolor="#FFF0D0" align="center"><a
|
|
name="Install"><font size="+1"><b>How to Install GLEW</b></font></a>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>
|
|
|
|
<p>
|
|
To install the shared library version of GLEW you need to copy the
|
|
headers and libraries into their destination directories. On Windows
|
|
this boils down to copying (no, we will not write a Windows installer
|
|
for you).
|
|
<p>
|
|
|
|
<center>
|
|
<table border=0 cellpadding=0 cellspacing=0>
|
|
<tr><td><tt>lib/glew32.dll</tt></td><td> to </td>
|
|
<td><tt>%SystemRoot%/system32</tt>, usually <tt>C:/WINDOWS/system32</tt></td></tr>
|
|
<tr><td><tt>lib/glew32.lib</tt></td><td> to </td>
|
|
<td><tt>{VC Root}/Lib</tt></td></tr>
|
|
<tr><td><tt>include/GL/glew.h</tt></td><td> to </td>
|
|
<td><tt>{VC Root}/Include/GL</tt></td></tr>
|
|
<tr><td><tt>include/GL/wglew.h</tt></td><td> to </td>
|
|
<td><tt>{VC Root}/Include/GL</tt></td></tr>
|
|
</table>
|
|
</center>
|
|
<p>
|
|
|
|
where <tt>{VC Root}</tt> is your Visual C++ directory, typically
|
|
<tt>C:/Program Files/Microsoft Visual Studio/VC98</tt> for Visual
|
|
Studio 6.0 or <tt>C:/Program Files/Microsoft Visual
|
|
Studio/Vc7/PlatformSDK</tt> for Visual Studio .NET. <b>However, if you
|
|
build GLEW with Visual Studio .NET, the project file will
|
|
automatically install it into these directories, so you
|
|
don't have to worry about installation at all</b>.
|
|
|
|
<p>
|
|
On Linux, typing <tt>"make install"</tt> will attempt to install GLEW
|
|
into <tt>/usr/include/GL</tt> and <tt>/usr/lib</tt>. You can
|
|
customize the installation target via the <tt>GLEW_TARGET</tt>
|
|
environment variable if you do not have write access
|
|
to these directories.
|
|
<p>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td bgcolor="#FFF0D0" align="center"><a
|
|
name="Use"><font size="+1"><b>How to Use GLEW</b></font></a>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>
|
|
|
|
<font size="+1"><b>Initializing GLEW</b></font>
|
|
<p>
|
|
|
|
First you need to create a valid OpenGL rendering context and call
|
|
<tt>glewInit()</tt> to initialize the extension entry points. If
|
|
<tt>glewInit()</tt> returns <tt>GLEW_OK</tt> the initialization
|
|
succeeded and you can use the available extensions as well as core
|
|
OpenGL functionality. For example:
|
|
|
|
<blockquote><pre>#include <GL/glew.h>
|
|
#include <GL/glut.h>
|
|
...
|
|
glutInit(&argc, argv);
|
|
glutCreateWindow("GLEW Test");
|
|
int err = glewInit();
|
|
if (GLEW_OK != err)
|
|
{
|
|
/* problem: glewInit failed, something is seriously wrong */
|
|
fprintf(stderr, "Error: %s\n", glewGetErrorString(err));
|
|
...
|
|
}
|
|
</pre></blockquote>
|
|
|
|
<p>
|
|
|
|
<font size="+1"><b>Querying the available OpenGL extensions</b></font>
|
|
<p>
|
|
|
|
To find out if a particular extension is available on your
|
|
platform, use the globally defined structure <tt>glew</tt>:
|
|
|
|
<blockquote><pre>if (glew.ARB_vertex_program)
|
|
{
|
|
/* it is safe to use the ARB_vertex_program extension here */
|
|
glGenProgramsARB(...);
|
|
}
|
|
</pre></blockquote>
|
|
|
|
You can also check for core OpenGL functionality. For example, to
|
|
see if OpenGL 1.3 is supported you can use the following:
|
|
|
|
<blockquote><pre>if (glew.GL_13)
|
|
{
|
|
/* Yay! OpenGL 1.3 is supported! */
|
|
}
|
|
</pre></blockquote>
|
|
|
|
In general, you can check if <tt>glew.{extension_name}</tt> or
|
|
<tt>glew.GL_{version}</tt> is set or not. For extensions
|
|
<tt>glewGetExtension</tt> provides a slower alternative:
|
|
|
|
<blockquote><pre>if (GL_TRUE == glewGetExtension("GL_ARB_fragment_program"))
|
|
{
|
|
/* Looks like ARB_fragment_program is supported. */
|
|
}
|
|
</pre></blockquote>
|
|
|
|
<p>
|
|
|
|
<font size="+1"><b>Experimental drivers</b></font>
|
|
<p>
|
|
|
|
GLEW works by querying the supported extensions from the graphics
|
|
driver. Experimental drivers, however, might not report every
|
|
available extension through the standard mechanism, in which case GLEW
|
|
will report it unsupported. To circumvent this situation, the
|
|
<tt>glewExperimental</tt> global switch can be turned on by setting it
|
|
to <tt>GL_TRUE</tt> before calling <tt>glewInit()</tt>. This makes
|
|
sure that all extensions with valid entry points will be exposed.
|
|
|
|
<p>
|
|
|
|
<font size="+1"><b>Platform specific extensions</b></font>
|
|
<p>
|
|
|
|
Platform specific extensions are separated into two header files:
|
|
<tt>wglew.h</tt> and <tt>glxew.h</tt>. These files define the
|
|
available <tt>WGL</tt> and <tt>GLX</tt> extensions as well as the
|
|
global <tt>wglew</tt> and <tt>glxew</tt> structs, which work similarly
|
|
to the <tt>glew</tt> structure. To determine if a given <tt>WGL</tt> or
|
|
<tt>GLX</tt> extension is supported, query <tt>wglew.{extension name}</tt> or
|
|
<tt>glxew.{extension_name}</tt>. For example:
|
|
|
|
<blockquote><pre>#include <GL/wglew.h>
|
|
|
|
if (wglew.ARB_pbuffer)
|
|
{
|
|
/* OK, we can use pbuffers */
|
|
}
|
|
else
|
|
{
|
|
/* Sorry, pbuffers will not work on this platform */
|
|
}
|
|
</pre></blockquote>
|
|
|
|
<p>
|
|
|
|
<font size="+1"><b>glewinfo: a command line extension reporting utility</b></font>
|
|
<p>
|
|
|
|
GLEW comes with a command line utility called <tt>glewinfo</tt> that
|
|
allows you to make a list of the extensions supported on your platform.
|
|
The <tt>glewinfo</tt> utility uses GLEW to find out which extensions
|
|
and entry points are available and reports the results to a text file
|
|
called <tt>glewinfo.txt</tt>.
|
|
|
|
<p>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td bgcolor="#FFF0D0" align="center"><a
|
|
name="Issues"><font size="+1"><b>Known Issues</b></font></a>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>
|
|
|
|
GLEW requires GLX 1.2 to assure compatibility with GLUT. In addition,
|
|
the SGI GLX video extensions are not supported, because they depend on
|
|
external libraries.
|
|
<p>
|
|
Note that according to the <a
|
|
href="http://msdn.microsoft.com/library/default.asp?url=/library/en-us/opengl/ntopnglr_6yer.asp">WGL documentation</a> you have to initialize the entry points
|
|
for every rendering context you create. GLEW ignores this
|
|
requirement, and does not define per context entry points. This means
|
|
that you need to call <tt>glewInit()</tt> only once in your program,
|
|
or more precisely once per process. We have not noticed any problems
|
|
so far from ignoring the specification.
|
|
<p>
|
|
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td bgcolor="#FFF0D0" align="center"><a
|
|
name="Credits"><font size="+1"><b>Credits, Copyright</b></font></a>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td>
|
|
GLEW was developed by Milan Ikits. He also performs occasional
|
|
maintainance to make sure that GLEW stays in mint condition. Aaron
|
|
Lefohn, Joe Kniss, and Chris Wyman were the first users and also
|
|
assisted with the design and debugging process. The acronym
|
|
originates from Aaron Lefohn.
|
|
<p>
|
|
GLEW is derived from the EXTGL project by Lev Povalahev. It is
|
|
licensed under the LGPL, the BSD license, the SGI Free Software
|
|
License B, and the GLX Public License. We encourage those who are not
|
|
in favor of the LGPL to read <a
|
|
href="http://www.cs.utah.edu/~gk/teem/lgpl.html">this</a> excellent
|
|
tutorial.
|
|
|
|
<blockquote><pre></pre></blockquote>
|
|
|
|
<tr>
|
|
<td bgcolor="#FFF0D0">
|
|
<table border="0" cellspacing="0" cellpadding="0" width="100%">
|
|
<tr>
|
|
<td align="left">
|
|
<i>Last update: 12-21-02</i></td>
|
|
</tr>
|
|
</table>
|
|
</td>
|
|
</tr>
|
|
|
|
</table>
|
|
</center>
|
|
|
|
</body>
|