OpenGL Quad不是绘图

时间:2013-10-03 09:23:30

标签: c++ opengl

我正在使用visual c ++ 2012和opengl而我无法绘制四边形,我没有收到任何错误。是因为我没有更新方法吗?这是我的代码:

#define WIN32_LEAN_AND_MEAN

#include <Windows.h>

#include <gl/GL.h>

HWND hwnd;
int clientWidth = 800;
int clientHeight = 600;

bool InitMainWindow(HINSTANCE hInstance);
LRESULT CALLBACK MsgProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    if(!InitMainWindow(hInstance))
    {
        return 1;
    }

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(0, 800, 0, 600, 1, -1);
    glMatrixMode(GL_MODELVIEW);

    MSG msg = {0};
    while(WM_QUIT != msg.message)
    {
        if(PeekMessage(&msg, NULL, NULL, NULL, PM_REMOVE))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
        else
        {
            glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 

            glColor3f(0.5f,0.5f,1.0f);

            glPushMatrix();
            glTranslatef(0,0,-20.0f);
            glBegin(GL_QUADS);
                glVertex3f(-10.0f, -10.0f, 5.0f);
                glVertex3f(-10.0f, 10.0f, 5.0f);
                glVertex3f(10.0f, 10.0f, 5.0f);
                glVertex3f(10.0f, -10.0f, 5.0f);
            glEnd();
            glPopMatrix();
        }
    }

    return static_cast<int>(msg.wParam);
}

bool InitMainWindow(HINSTANCE hInstance)
{
    WNDCLASSEX wcex;
    ZeroMemory(&wcex, sizeof(WNDCLASSEX));
    wcex.cbClsExtra = 0;
    wcex.cbWndExtra = 0;
    wcex.cbSize = sizeof(WNDCLASSEX);
    wcex.style = CS_HREDRAW | CS_VREDRAW;
    wcex.hInstance = hInstance;
    wcex.lpfnWndProc = MsgProc;
    wcex.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcex.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
    wcex.lpszClassName = "Project2DClass";
    wcex.lpszMenuName = NULL;
    wcex.hIconSm = LoadIcon(NULL, IDI_APPLICATION);

    if(!RegisterClassEx(&wcex))
    {
        MessageBox(NULL, "Failed to register window class", NULL, NULL);
        return false;
    }

    RECT r = { 0, 0, clientWidth, clientHeight };
    DWORD style = WS_OVERLAPPEDWINDOW;
    AdjustWindowRect(&r, style, false);
    int width = r.right - r.left;
    int height = r.bottom - r.top;
    int x = GetSystemMetrics(SM_CXSCREEN)/2 - width/2;
    int y = GetSystemMetrics(SM_CYSCREEN)/2 - height/2;

    hwnd = CreateWindow("Project2DClass", "Project 2D", style, x, y, width, height, NULL, NULL, hInstance, NULL);
    if(!hwnd)
    {
        MessageBox(NULL, "Failed to create window", NULL, NULL);
        return false;
    }

    ShowWindow(hwnd, SW_SHOW); 

    return true;
}

LRESULT CALLBACK MsgProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch(msg)
    {
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }

    return DefWindowProc(hwnd, msg, wParam, lParam);
}

我该如何解决这个问题以及我做错了什么?

另外,我如何创建更新和同步方法?

1 个答案:

答案 0 :(得分:1)

我修好了!!!

这是我的代码:

/*
 *      This Code Was Created By Jeff Molofee 2000
 *      A HUGE Thanks To Fredric Echols For Cleaning Up
 *      And Optimizing This Code, Making It More Flexible!
 *      If You've Found This Code Useful, Please Let Me Know.
 *      Visit My Site At nehe.gamedev.net
 */

#include <windows.h>        // Header File For Windows
#include <gl\gl.h>          // Header File For The OpenGL32 Library
#include <gl\glu.h>         // Header File For The GLu32 Library

HDC         hDC=NULL;       // Private GDI Device Context
HGLRC       hRC=NULL;       // Permanent Rendering Context
HWND        hWnd=NULL;      // Holds Our Window Handle
HINSTANCE   hInstance;      // Holds The Instance Of The Application

bool    keys[256];          // Array Used For The Keyboard Routine
bool    active=TRUE;        // Window Active Flag Set To TRUE By Default
bool    fullscreen=TRUE;    // Fullscreen Flag Set To Fullscreen Mode By Default

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);   // Declaration For WndProc

GLvoid ReSizeGLScene(GLsizei width, GLsizei height)     // Resize And Initialize The GL Window
{
    if (height==0)                                      // Prevent A Divide By Zero By
    {
        height=1;                                       // Making Height Equal One
    }

    glViewport(0,0,width,height);                       // Reset The Current Viewport

    glMatrixMode(GL_PROJECTION);                        // Select The Projection Matrix
    glLoadIdentity();                                   // Reset The Projection Matrix

    // Calculate The Aspect Ratio Of The Window
    gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);

    glMatrixMode(GL_MODELVIEW);                         // Select The Modelview Matrix
    glLoadIdentity();                                   // Reset The Modelview Matrix
}

int InitGL(GLvoid)                                      // All Setup For OpenGL Goes Here
{
    glShadeModel(GL_SMOOTH);                            // Enable Smooth Shading
    glClearColor(0.0f, 0.0f, 0.0f, 0.5f);               // Black Background
    glClearDepth(1.0f);                                 // Depth Buffer Setup
    glEnable(GL_DEPTH_TEST);                            // Enables Depth Testing
    glDepthFunc(GL_LEQUAL);                             // The Type Of Depth Testing To Do
    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);  // Really Nice Perspective Calculations
    return TRUE;                                        // Initialization Went OK
}

int DrawGLScene(GLvoid)                                 // Here's Where We Do All The Drawing
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear Screen And Depth Buffer
    glLoadIdentity();                                   // Reset The Current Modelview Matrix

    //glClearColor(0.5f, 0.5f, 0, 0);

    glColor3f(0.5f,0.5f,0);

    glPushMatrix();
    glTranslatef(0,0,-20.0f);
    glBegin(GL_QUADS);
        glVertex3f(-5.0f, -5.0f, 2.5f);
        glVertex3f(-5.0f, 5.0f, 2.5f);
        glVertex3f(5.0f, 5.0f, 2.5f);
        glVertex3f(5.0f, -5.0f, 2.5f);
    glEnd();
    glPopMatrix();

    return TRUE;                                        // Everything Went OK
}

GLvoid KillGLWindow(GLvoid)                             // Properly Kill The Window
{
    if (fullscreen)                                     // Are We In Fullscreen Mode?
    {
        ChangeDisplaySettings(NULL,0);                  // If So Switch Back To The Desktop
        ShowCursor(TRUE);                               // Show Mouse Pointer
    }

    if (hRC)                                            // Do We Have A Rendering Context?
    {
        if (!wglMakeCurrent(NULL,NULL))                 // Are We Able To Release The DC And RC Contexts?
        {
            MessageBox(NULL,"Release Of DC And RC Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
        }

        if (!wglDeleteContext(hRC))                     // Are We Able To Delete The RC?
        {
            MessageBox(NULL,"Release Rendering Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
        }
        hRC=NULL;                                       // Set RC To NULL
    }

    if (hDC && !ReleaseDC(hWnd,hDC))                    // Are We Able To Release The DC
    {
        MessageBox(NULL,"Release Device Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
        hDC=NULL;                                       // Set DC To NULL
    }

    if (hWnd && !DestroyWindow(hWnd))                   // Are We Able To Destroy The Window?
    {
        MessageBox(NULL,"Could Not Release hWnd.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
        hWnd=NULL;                                      // Set hWnd To 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
    }
}

/*  This Code Creates Our OpenGL Window.  Parameters Are:                   *
 *  title           - Title To Appear At The Top Of The Window              *
 *  width           - Width Of The GL Window Or Fullscreen Mode             *
 *  height          - Height Of The GL Window Or Fullscreen Mode            *
 *  bits            - Number Of Bits To Use For Color (8/16/24/32)          *
 *  fullscreenflag  - Use Fullscreen Mode (TRUE) Or Windowed Mode (FALSE)   */

BOOL CreateGLWindow(char* title, int width, int height, int bits, bool fullscreenflag)
{
    GLuint      PixelFormat;            // Holds The Results After Searching For A Match
    WNDCLASS    wc;                     // Windows Class Structure
    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

    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;                                    // Success
}

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
            {
                active=TRUE;                        // Program Is Active
            }
            else
            {
                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?
        {
            keys[wParam] = TRUE;                    // If So, Mark It As TRUE
            return 0;                               // Jump Back
        }

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

        case WM_SIZE:                               // Resize The OpenGL Window
        {
            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);
}

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)
    {
        fullscreen=FALSE;                           // Windowed Mode
    }

    // Create Our OpenGL Window
    if (!CreateGLWindow("NeHe's OpenGL Framework",640,480,16,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 (active)                             // Program Active?
            {
                if (keys[VK_ESCAPE])                // Was ESC Pressed?
                {
                    done=TRUE;                      // ESC Signalled A Quit
                }
                else                                // Not Time To Quit, Update Screen
                {
                    DrawGLScene();                  // Draw The Scene
                    SwapBuffers(hDC);               // Swap Buffers (Double Buffering)
                }
            }

            if (keys[VK_F1])                        // Is F1 Being Pressed?
            {
                keys[VK_F1]=FALSE;                  // If So Make Key FALSE
                KillGLWindow();                     // Kill Our Current Window
                fullscreen=!fullscreen;             // Toggle Fullscreen / Windowed Mode
                // Recreate Our OpenGL Window
                if (!CreateGLWindow("NeHe's OpenGL Framework",640,480,16,fullscreen))
                {
                    return 0;                       // Quit If Window Was Not Created
                }
            }
        }
    }

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

http://nehe.gamedev.net/tutorial/creating_an_opengl_window_%28win32%29/13001/