opengl - 不能包含

Question

我正在使用 Visual Studio 2010。
我正在尝试在 OpenGL 中编写简单的 Camera 类。
我需要在 Camera.h 中包含 gl/gl.h
gl/gl.h 已经包含在 main.cpp 中，Camera.h 包含在 main.cpp 中
当我放

#include <gl/gl.h>

在 Camera.h 中，我遇到了一堆这样的错误: Error 11 error C2086: 'int APIENTRY' : redefinition C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\include\gl\GL.h 1153 1 Gaz 3D
文件:
相机.h

#include <math.h>
#include <gl/gl.h>

#ifndef _CAMERA_H
#define _CAMERA_H

class Camera
{
private:
    Camera();
public:
    static Camera& getCamera();
    float x, y, z, rotv, roth;
    void moveForward(float n);
    void moveBackward(float n);
    void moveLeft(float n);
    void moveRight(float n);
    void lookUp(float n);
    void lookDown(float n);
    void lookLeft(float n);
    void lookRight(float n);
};

#endif

主.cpp:

#include <windows.h>
#include <gl\gl.h>
#include <gl\glu.h>
#include <gl\glaux.h>
#include <math.h>
#include "Camera.h"

// ... some variables ...

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,  
                   LPSTR lpCmdLine, int nCmdShow)
{
    // main code ...
}

我究竟做错了什么？

Answer 1

只需先包含 windows.h。

#include <windows.h>

正如 OpenGL FAQ 中所说:

Also, note that you'll need to put an #include <windows.h> statement before the #include<GL/gl.h>. Microsoft requires system DLLs to use a specific calling convention that isn't the default calling convention for most Win32 C compilers, so they've annotated the OpenGL calls in gl.h with some macros that expand to nonstandard C syntax. This causes Microsoft's C compilers to use the system calling convention. One of the include files included by windows.h defines the macros.

资源:

social.msdn.microsoft.com - OpenGL problems

OpenGL FAQ - Why am I getting compile, link, and runtime errors?