【原】OpenGL C++版

下面，我将NEHE的LESSON1中的代码改成C++版的。
代码如下：
第一部分是Opengl.h

#pragma once

#include "OpenGLModel.h"

class COpengl
{
public:
    COpengl(void);
    ~COpengl(void);
    int InitGL(GLvoid);
    int DrawGLScene(GLvoid);
    GLvoid ReSizeGLScene(GLsizei,GLsizei);
    GLvoid KillGLWindow(GLvoid);
    BOOL CreateGLWindow(char*,int,int,int,bool);
private:
    HDC hDC;             //设备描述表(Device Context)
    HGLRC hRC;            //着色描述表(Rendering Context)
    HWND hWnd;            //保存窗口句柄
    HINSTANCE hInstance; //保存程序的实例
public:
    bool keys[256];      //用于监控键盘动作的数组
    bool active;         //窗口是否处于最小化状态
    bool fullscreen;     //是否全屏显示
};

第二部分是Opengl.cpp

#include " Opengl.h "

extern LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

COpengl::COpengl()

{

hDC=NULL;

hRC=NULL;

hWnd=NULL;

active=TRUE;

fullscreen=TRUE;

}

COpengl:: ~ COpengl( void )

{

}

// 初始化OpenGL

int COpengl::InitGL(GLvoid)

{

glClearColor(0.0f,0.0f,1.0f,0.0f); //把颜色设置为蓝色

return TRUE; // 初始化成功

}

// 视口设置、投影变换

GLvoid COpengl::ReSizeGLScene(GLsizei width, GLsizei height)

{

//防止被0所除

if(height==0)

{

height=1;

}

//把视口设置为窗口的大小

glViewport(0,0,width,height);

//透视投影(重置坐标系统)

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);

//模型视图变换设置(重置坐标系统)

glMatrixMode(GL_MODELVIEW); // 选择模型观察矩阵

glLoadIdentity(); // 重置模型观察矩阵

}

int COpengl::DrawGLScene(GLvoid)

{

glClear(GL_COLOR_BUFFER_BIT); //用当前的清除色清除窗口(蓝色)

SwapBuffers(hDC);

return TRUE;

}

GLvoid COpengl::KillGLWindow(GLvoid)

{

if(fullscreen)

{

ChangeDisplaySettings(NULL,0);

ShowCursor(TRUE);

}

if(hRC)

{

if(!wglMakeCurrent(NULL,NULL))

{

MessageBox(NULL,"Release of DC And RC Failed.","SHUTDOWN ERROR",MB_OK|MB_ICONINFORMATION);

}

if(!wglDeleteContext(hRC))

{

MessageBox(NULL,"Release Rendering Context Failed.","SHUTDOWN ERROR",MB_OK|MB_ICONINFORMATION);

}

hRC=NULL;

}

if(hDC && !ReleaseDC(hWnd,hDC))

{

MessageBox(NULL,"Release Device Context Failed.","SHUTDOWN ERROR",MB_OK|MB_ICONINFORMATION);

hDC=NULL;

}

if(hWnd && !DestroyWindow(hWnd))

{

MessageBox(NULL,"Could Not Release hWnd.","SHUTDOWN ERROR",MB_OK|MB_ICONINFORMATION);

hWnd=NULL;

}

if (!UnregisterClass("OpenGL",hInstance)) // Are We Able To Unregister Class

{

MessageBox(NULL,"Could Not Unregister Class.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);

hInstance=NULL; // Set hInstance To NULL

}

BOOL COpengl::CreateGLWindow( char * title, int width, int height, int bits, bool fullscreenflag)

{

GLuint PixelFormat; // 保存查找匹配的结果

DWORD dwExStyle; // Window Extended Style

DWORD dwStyle; // Window Style

RECT WindowRect; // Grabs Rectangle Upper Left / Lower Right Values

WindowRect.left=(long)0; // Set Left Value To 0

WindowRect.right=(long)width; // Set Right Value To Requested Width

WindowRect.top=(long)0; // Set Top Value To 0

WindowRect.bottom=(long)height; // Set Bottom Value To Requested Height

fullscreen=fullscreenflag; // Set The Global Fullscreen Flag

//定义窗口类

WNDCLASS wc; // Windows Class Structure

hInstance = GetModuleHandle(NULL); // Grab An Instance For Our Window

wc.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC; // Redraw On Size, And Own DC For Window.

wc.lpfnWndProc = (WNDPROC) WndProc; // WndProc Handles Messages

wc.cbClsExtra = 0; // No Extra Window Data

wc.cbWndExtra = 0; // No Extra Window Data

wc.hInstance = hInstance; // Set The Instance

wc.hIcon = LoadIcon(NULL, IDI_WINLOGO); // Load The Default Icon

wc.hCursor = LoadCursor(NULL, IDC_ARROW); // Load The Arrow Pointer

wc.hbrBackground = NULL; // No Background Required For GL

wc.lpszMenuName = NULL; // We Don't Want A Menu

wc.lpszClassName = "OpenGL"; // Set The Class Name

if (!RegisterClass(&wc)) // Attempt To Register The Window Class

{

MessageBox(NULL,"Failed To Register The Window Class.","ERROR",MB_OK|MB_ICONEXCLAMATION);

return FALSE; // Return FALSE

}

if (fullscreen) // Attempt Fullscreen Mode?

{

DEVMODE dmScreenSettings; // Device Mode

memset(&dmScreenSettings,0,sizeof(dmScreenSettings)); // Makes Sure Memory's Cleared

dmScreenSettings.dmSize=sizeof(dmScreenSettings); // Size Of The Devmode Structure

dmScreenSettings.dmPelsWidth = width; // Selected Screen Width

dmScreenSettings.dmPelsHeight = height; // Selected Screen Height

dmScreenSettings.dmBitsPerPel = bits; // Selected Bits Per Pixel

dmScreenSettings.dmFields=DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;

// Try To Set Selected Mode And Get Results. NOTE: CDS_FULLSCREEN Gets Rid Of Start Bar.

if (ChangeDisplaySettings(&dmScreenSettings,CDS_FULLSCREEN)!=DISP_CHANGE_SUCCESSFUL)

{

// If The Mode Fails, Offer Two Options. Quit Or Use Windowed Mode.

if (MessageBox(NULL,"The Requested Fullscreen Mode Is Not Supported By\nYour Video Card. Use Windowed Mode Instead?","NeHe GL",MB_YESNO|MB_ICONEXCLAMATION)==IDYES)

{

fullscreen=FALSE; // Windowed Mode Selected. Fullscreen = FALSE

}

else

{

// Pop Up A Message Box Letting User Know The Program Is Closing.

MessageBox(NULL,"Program Will Now Close.","ERROR",MB_OK|MB_ICONSTOP);

return FALSE; // Return FALSE

}

if (fullscreen) // Are We Still In Fullscreen Mode?

{

dwExStyle=WS_EX_APPWINDOW; // Window Extended Style

dwStyle=WS_POPUP; // Windows Style

ShowCursor(FALSE); // Hide Mouse Pointer

}

else

{

dwExStyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE; // Window Extended Style

dwStyle=WS_OVERLAPPEDWINDOW; // Windows Style

}

AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle); // Adjust Window To True Requested Size

// Create The Window

if (!(hWnd=CreateWindowEx( dwExStyle, // Extended Style For The Window

"OpenGL", // Class Name

title, // Window Title

dwStyle | // Defined Window Style

WS_CLIPSIBLINGS | // Required Window Style

WS_CLIPCHILDREN, // Required Window Style

0, 0, // Window Position

WindowRect.right-WindowRect.left, // Calculate Window Width

WindowRect.bottom-WindowRect.top, // Calculate Window Height

NULL, // No Parent Window

NULL, // No Menu

hInstance, // Instance

NULL))) // Dont Pass Anything To WM_CREATE

{

KillGLWindow(); // Reset The Display

MessageBox(NULL,"Window Creation Error.","ERROR",MB_OK|MB_ICONEXCLAMATION);

return FALSE; // Return FALSE

}

static PIXELFORMATDESCRIPTOR pfd= // pfd Tells Windows How We Want Things To Be

{

sizeof(PIXELFORMATDESCRIPTOR), // Size Of This Pixel Format Descriptor

1, // Version Number

PFD_DRAW_TO_WINDOW | // Format Must Support Window

PFD_SUPPORT_OPENGL | // Format Must Support OpenGL

PFD_DOUBLEBUFFER, // Must Support Double Buffering

PFD_TYPE_RGBA, // Request An RGBA Format

bits, // Select Our Color Depth

0, 0, 0, 0, 0, 0, // Color Bits Ignored

0, // No Alpha Buffer

0, // Shift Bit Ignored

0, // No Accumulation Buffer

0, 0, 0, 0, // Accumulation Bits Ignored

16, // 16Bit Z-Buffer (Depth Buffer)

0, // No Stencil Buffer

0, // No Auxiliary Buffer

PFD_MAIN_PLANE, // Main Drawing Layer

0, // Reserved

0, 0, 0 // Layer Masks Ignored

};

if (!(hDC=GetDC(hWnd))) // Did We Get A Device Context?

{

KillGLWindow(); // Reset The Display

MessageBox(NULL,"Can't Create A GL Device Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);

return FALSE; // Return FALSE

}

if (!(PixelFormat=ChoosePixelFormat(hDC,&pfd))) // Did Windows Find A Matching Pixel Format?

{

KillGLWindow(); // Reset The Display

MessageBox(NULL,"Can't Find A Suitable PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);

return FALSE; // Return FALSE

}

if(!SetPixelFormat(hDC,PixelFormat,&pfd)) // Are We Able To Set The Pixel Format?

{

KillGLWindow(); // Reset The Display

MessageBox(NULL,"Can't Set The PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);

return FALSE; // Return FALSE

}

if (!(hRC=wglCreateContext(hDC))) // Are We Able To Get A Rendering Context?

{

KillGLWindow(); // Reset The Display

MessageBox(NULL,"Can't Create A GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);

return FALSE; // Return FALSE

}

if(!wglMakeCurrent(hDC,hRC)) // Try To Activate The Rendering Context

{

KillGLWindow(); // Reset The Display

MessageBox(NULL,"Can't Activate The GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);

return FALSE; // Return FALSE

}

ShowWindow(hWnd,SW_SHOW); // Show The Window

SetForegroundWindow(hWnd); // Slightly Higher Priority

SetFocus(hWnd); // Sets Keyboard Focus To The Window

ReSizeGLScene(width, height); // Set Up Our Perspective GL Screen

if (!InitGL()) // Initialize Our Newly Created GL Window

{

KillGLWindow(); // Reset The Display

MessageBox(NULL,"Initialization Failed.","ERROR",MB_OK|MB_ICONEXCLAMATION);

return FALSE; // Return FALSE

}

return TRUE;

}

第三部分是OpenGLModel.h

#ifndef OPENGLMODEL_H
#define OPENGLMODEL_H

#include < windows.h >

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

#endif OPENGLMODEL_H

第四部分是OpenGLModel.cpp

#include " OpenGLModel.h "
#include " Opengl.h "

COpengl theOpengl;

LRESULT    CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain(    HINSTANCE    hInstance,             // Instance
                    HINSTANCE    hPrevInstance,         // Previous Instance
                    LPSTR        lpCmdLine,             // Command Line Parameters
                     int             nCmdShow)             // Window Show State
{
    MSG        msg;                                     // Windows Message Structure
    BOOL    done = FALSE;                                 // Bool Variable To Exit Loop

     // Ask The User Which Screen Mode They Prefer
     if (MessageBox(NULL, " Would You Like To Run In Fullscreen Mode? " , " Start FullScreen? " ,MB_YESNO | MB_ICONQUESTION) == IDNO)
    {
        theOpengl.fullscreen = FALSE;                             // Windowed Mode
    }

     // Create Our OpenGL Window
     if ( ! theOpengl.CreateGLWindow( " NeHe's OpenGL Framework " , 640 , 480 , 16 ,theOpengl.fullscreen))
    {
         return 0 ;                                     // Quit If Window Was Not Created
    }

     while ( ! done)                                     // Loop That Runs While done=FALSE
    {
         if (PeekMessage( & msg,NULL, 0 , 0 ,PM_REMOVE))     // Is There A Message Waiting?
        {
             if (msg.message == WM_QUIT)                 // Have We Received A Quit Message?
            {
                done = TRUE;                             // If So done=TRUE
            }
             else                                      // If Not, Deal With Window Messages
            {
                TranslateMessage( & msg);                 // Translate The Message
                DispatchMessage( & msg);                 // Dispatch The Message
            }
        }
         else                                          // If There Are No Messages
        {
             // Draw The Scene.  Watch For ESC Key And Quit Messages From DrawGLScene()
             if ((theOpengl.active && ! theOpengl.DrawGLScene()) || theOpengl.keys[VK_ESCAPE])     // Active?  Was There A Quit Received?
            {
                done = TRUE;                             // ESC or DrawGLScene Signalled A Quit
            }
             if (theOpengl.keys[VK_F1])                         // Is F1 Being Pressed?
            {
                theOpengl.keys[VK_F1] = FALSE;                     // If So Make Key FALSE
                theOpengl.KillGLWindow();                         // Kill Our Current Window
                theOpengl.fullscreen =! theOpengl.fullscreen;                 // Toggle Fullscreen / Windowed Mode
                 // Recreate Our OpenGL Window
                 if ( ! theOpengl.CreateGLWindow( " NeHe's OpenGL Framework " , 640 , 480 , 32 ,theOpengl.fullscreen))
                {
                     return 0 ;                         // Quit If Window Was Not Created
                }
            }
        }
    }

     // Shutdown
    theOpengl.KillGLWindow();                                     // Kill The Window
     return (msg.wParam);                             // Exit The Program
}

LRESULT CALLBACK WndProc(    HWND    hWnd,             // Handle For This Window
                            UINT    uMsg,             // Message For This Window
                            WPARAM    wParam,             // Additional Message Information
                            LPARAM    lParam)             // Additional Message Information
{
     switch (uMsg)                                     // Check For Windows Messages
    {
         case WM_ACTIVATE:                             // Watch For Window Activate Message
        {
             if ( ! HIWORD(wParam))                     // Check Minimization State
            {
                theOpengl.active = TRUE;                         // Program Is Active
            }
             else
            {
                theOpengl.active = FALSE;                         // Program Is No Longer Active
            }

             return 0 ;                                 // Return To The Message Loop
        }

         case WM_SYSCOMMAND:                             // Intercept System Commands
        {
             switch (wParam)                             // Check System Calls
            {
                 case SC_SCREENSAVE:                     // Screensaver Trying To Start?
                 case SC_MONITORPOWER:                 // Monitor Trying To Enter Powersave?
                 return 0 ;                             // Prevent From Happening
            }
             break ;                                     // Exit
        }

         case WM_CLOSE:                                 // Did We Receive A Close Message?
        {
            PostQuitMessage( 0 );                         // Send A Quit Message
             return 0 ;                                 // Jump Back
        }

         case WM_KEYDOWN:                             // Is A Key Being Held Down?
        {
            theOpengl.keys[wParam] = TRUE;                     // If So, Mark It As TRUE
             return 0 ;                                 // Jump Back
        }

         case WM_KEYUP:                                 // Has A Key Been Released?
        {
            theOpengl.keys[wParam] = FALSE;                     // If So, Mark It As FALSE
             return 0 ;                                 // Jump Back
        }

         case WM_SIZE:                                 // Resize The OpenGL Window
        {
            theOpengl.ReSizeGLScene(LOWORD(lParam),HIWORD(lParam));   // LoWord=Width, HiWord=Height
             return 0 ;                                 // Jump Back
        }
    }

     // Pass All Unhandled Messages To DefWindowProc
     return DefWindowProc(hWnd,uMsg,wParam,lParam);
}

函数调用流程：
WinMain函数为入口函数，该函数调用CreateGLWindow函数。

CreateGLWindow函数中，定义窗口类，并注册窗口，然后调用CreateWindowEx函数创建窗口。之后设置像素格式，获得DC，并激活RC，然后显示窗口，再调用ReSizeGLScene函数设置OpenGL透视窗口，之后调用InitGL函数，对OpenGL窗口进行初始化。

OpenGL窗口创建成功并初始化后，进入消息循环。用PeekMessage函数检查是否有新的消息，若没有消息，则调用DrawGLScene函数绘制我们的OpenGL场景。

【原】OpenGL C++版

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