The difference and relationship between glew, glee and GL Glu glut GLX glext

 GLEW It's a cross platform C++ expanded memory bank , be based on OpenGL Graphic interface . Use OpenGL Our friends all know ,window Currently only supported OpenGL1.1 Number of culverts , but OpenGL Now it has developed to 2.0 Above , To use these OpenGL Advanced features of , You have to download the latest extensions , in addition , Different video card companies , Will also release some only own graphics card to support The extension function of the , If you want to use this number to contain , Have to look for the latest glext.h, With GLEW expanded memory bank , You don't have to worry about not finding an interface to a function anymore , because GLEW Can automatically recognize Don't all that your platform supports OpenGL Advanced extension number . in other words , Just include one glew.h The header file , You can use gl,glu,glext,wgl,glx Of all the Partial function .GLEW Support various popular operating systems （including Windows, Linux, Mac OS X, FreeBSD, Irix, and Solaris）.

Project home page ： http://glew.sourceforge.net/
Document address ： http://glew.sourceforge.net/install.html
Download address ： https://sourceforge.net/project/downloading.php?group_id=67586&filename=glew-1.5.1-src.zip

glu It's a utility library , contains 43 A function , Function names are prefixed with glu.Glu In order to reduce the heavy programming work , Encapsulates the OpenGL function ,Glu Function by calling the core library function , Provides relatively simple usage for developers , Implement some more complex operations .
glaux yes OpenGL Auxiliary Library , contains 31 A function , The function name is prefixed with aux. This part of the function provides window management 、 Input and output processing and drawing some simple three-dimensional objects .
glut It's the utility library , It is basically used for window interface , And cross platform （ So sometimes you like to do simple demo Words , It can be used only glut Just ok 了 ）

GLX:OpenGL extension for X.

about X Window system , It uses OpenGL Expand （GLX） As a OpenGL Provided by an attachment to , be-all GLX All functions use the prefix glX.

common OpenGL The header file is as follows ：（Windows The case difference can be ignored in the system , I didn't pay much attention to case myself . meanwhile , The path of the file may change , For example, not <GL/gl.h> It is "gl.h", The specific situation depends on where you put the header file ）

<GL/gl.h>：OpenGL The functions and constants used are declared .

<GL/glu.h>：GLU（OpenGL Utility library ） The functions and constants used are declared .GLU Library belongs to OpenGL Part of the standard .（ The following libraries do not belong to ）

<GL/glaux.h>：GLAUX（OpenGL Auxiliary Library ） The functions and constants used are declared . This library provides a creation window , Handle keyboard and mouse events , Set palette, etc OpenGL Itself does not provide , But I'm writing OpenGL Functions often used in the program . At present, this library is out of date , Only a few compilation environments provide , for example VC series . stay VC In the series compiler , Before using this header file, you must use #include <windows.h> Or header files with similar functions .

<GL/glut.h>：GLUT（OpenGL Utility Kit ） The functions and constants used are declared . The functions of this library are roughly the same as GLAUX similar , At present many OpenGL The tutorial uses this library to write demo programs . Some compilation systems may not provide this library directly （ for example VC series ）, Need to download and install separately . This header file automatically contains <GL/gl.h> and <GL/glu.h>, You don't have to include them again when programming .

<GL/glext.h>： Extended header file . Because Microsoft is interested in OpenGL Your support is not very positive ,VC Although the series compiler has <GL/gl.h> This header file , But there's only OpenGL 1.1 What is specified in the version , But not OpenGL 1.2 And later . For the current computer configuration , Almost all support OpenGL 1.4 edition , The higher is to 1.5, 2.0, 2.1, and VC These functions cannot be used directly . To solve this problem , And then there is <GL/glext.h> The header file . This header file provides a higher version OpenGL Various constant declarations and function pointer declarations required .

<GL/wglext.h>： Extended header file . And <GL/glext.h> similar , But this header file only provides information applicable to Windows Various aspects of the system OpenGL Functions and constants used by extensions , Not applicable to other operating systems .

"glee.h"：GLEE Header file of open source library . It's there because <GL/glext.h> Although you can use a higher version OpenGL function , But the form of use is not very convenient .GLEE The library allows higher versions of OpenGL Functions and others OpenGL Functions are also convenient to use . It should be noted that , This header file is related to <GL/gl.h> It's conflicting , Include in "glee.h" Before , Should not contain <GL/gl.h>.
#include <GL/glut.h>
#include "glee.h"   // error , because glut.h contains gl.h, It is associated with glee.h Conflict
                    // But if you put two include Sequence switching , Right
"glos.h"： Although this is often seen , But I don't know what it is , It may be various functions related to the system , Or maybe it's just a file written by yourself . I once saw a glos.h There is only one sentence in the header file #include <GL/glut.h>.