linux - 无法在 Linux(Ubuntu)上使用 glew.h

Question

最近，我从 Windows 转到 Linux 并尝试学习 Udemy 类(class)，该类(class)最初是在 Windows 上使用 Visual Studio 教授的。

我需要使用两个头文件 glfw3.h 和 glew.h 在类中。

我可以导入 glfw3.h 并使用它就好了，但是 glew.h 函数显示一些错误。

我使用了代码 sudo apt-get install libglew-dev 获取库文件。但仍然会弹出错误。

代码:

    #include <GLFW/glfw3.h>
    #include <GL/glew.h>

    int main(void)
    {}

错误消息:

In file included from Lesson01.cpp:2:0:
/usr/include/GL/glew.h:85:2: error: #error gl.h included before glew.h
#error gl.h included before glew.h
^~~~~

In file included from Lesson01.cpp:2:0:
/usr/include/GL/glew.h:16088:93: error: conflicting declaration     
‘typedef void (* PFNGLFRAGMENTLIGHTMODELFVSGIXPROC)(GLenum, GLfloat*)’
LAPIENTRY * PFNGLFRAGMENTLIGHTMODELFVSGIXPROC) (GLenum pname, GLfloat*    
params);
     ^

In file included from /usr/include/GL/gl.h:2055:0,
             from /usr/include/GLFW/glfw3.h:171,
             from Lesson01.cpp:1:
/usr/include/GL/glext.h:12070:25: note: previous declaration as  
‘typedef void (* PFNGLFRAGMENTLIGHTMODELFVSGIXPROC)(GLenum, const     
GLfloat*)’typedef void (APIENTRYP PFNGLFRAGMENTLIGHTMODELFVSGIXPROC)   
(GLenum pname, const GLfloat *params);
                                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In file included from Lesson01.cpp:2:0:
/usr/include/GL/glew.h:16090:91: error: conflicting declaration 
‘typedef void (* PFNGLFRAGMENTLIGHTMODELIVSGIXPROC)(GLenum, GLint*)’
(GLAPIENTRY * PFNGLFRAGMENTLIGHTMODELIVSGIXPROC) (GLenum pname, GLint*  
params);
     ^

In file included from /usr/include/GL/gl.h:2055:0,
             from /usr/include/GLFW/glfw3.h:171,
             from Lesson01.cpp:1:
/usr/include/GL/glext.h:12072:25: note: previous declaration as   
‘typedef void (* PFNGLFRAGMENTLIGHTMODELIVSGIXPROC)(GLenum, const 
GLint*)’ typedef void (APIENTRYP PFNGLFRAGMENTLIGHTMODELIVSGIXPROC) 
(GLenum pname, const GLint *params);
                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Answer 1

正如您的编译器所建议的，包含文件的顺序很重要:

error: #error gl.h included before glew.h

只需反转前两行:

#include <GL/glew.h>
#include <GLFW/glfw3.h>

int main(void)
{ 
    return 0;
}