OpenGL rendering problem

This is a discussion on OpenGL rendering problem within the Game Programming forums, part of the General Programming Boards category; Hey all, I want to know how I can create a window and use OpenGL only in a certain portion ...

  1. #1
    Registered User
    Join Date
    Apr 2007
    Posts
    102

    OpenGL rendering problem

    Hey all, I want to know how I can create a window and use OpenGL only in a certain portion of the window(The rendering area, not just the viewport.) Meaning if I created a window, I want the window background to show on half the screen and the OpenGL rendering planes and screen on the other half. How would I go about doing this?
    My Favorite Programming Line:
    Code:
    #define true ((rand() % 2) ? true : false)

  2. #2

    Join Date
    May 2005
    Posts
    1,041
    All you need to do is call glViewPort before each render call. The first x and y coordinates specify the lower left corner, the next specify the dimensions of the window.
    I'm not immature, I'm refined in the opposite direction.

  3. #3
    Registered User
    Join Date
    Apr 2007
    Posts
    102
    will that limit the actual size of the openGL drawing state. Meaning, if I call glViewport(which I have) will it be visible without drawing that it will not fill the entire window. Will the Clear screen color still be spanned across the window?
    My Favorite Programming Line:
    Code:
    #define true ((rand() % 2) ? true : false)

  4. #4

    Join Date
    May 2005
    Posts
    1,041
    It will draw to the viewport defined by glViewport without drawing on the rest of the window. You've said you've already done it, so why are you re-asking me?
    I'm not immature, I'm refined in the opposite direction.

  5. #5
    Registered User
    Join Date
    Apr 2007
    Posts
    102
    Hmm.. Let me try to explain this.. I've used GlViewport and the results do only draw on the specified portion of the window yes, however the black/whatever color background remains the same. I want to display a portion of the windows backcolor while the entire opengl portion of the window is on the other side. The current way I use GlViewport or any other way I use it doesn't affect the entire OpenGL portion of the window.
    My Favorite Programming Line:
    Code:
    #define true ((rand() % 2) ? true : false)

  6. #6
    Ethernal Noob
    Join Date
    Nov 2001
    Posts
    1,901
    You'd have to do something like
    Code:
    glViewport(0, 0, w/2, h);
    .
    .
    .//projection and rendering settings for first half of window
    glViewport(w/2, 0, w, h);
    .
    .
    .//projection and rendering settings for second half.
    You're essentially telling OpenGL to draw two viewports in one window, each taking half of the screen's width. You'd have to give each one a projection setting and rendering settings. I'm not sure if you can connect one viewport with another, i.e. have one viewport project one angle of a scene while the other projects another.

  7. #7
    Registered User
    Join Date
    Apr 2007
    Posts
    102
    Quote Originally Posted by indigo0086 View Post
    You'd have to do something like
    Code:
    glViewport(0, 0, w/2, h);
    .
    .
    .//projection and rendering settings for first half of window
    glViewport(w/2, 0, w, h);
    .
    .
    .//projection and rendering settings for second half.
    You're essentially telling OpenGL to draw two viewports in one window, each taking half of the screen's width. You'd have to give each one a projection setting and rendering settings. I'm not sure if you can connect one viewport with another, i.e. have one viewport project one angle of a scene while the other projects another.

    I appreciate your response, however I don't think you have understood what I want to do. I'm creating an editor for some levels for a game I'm making. However the only area I want to be OpenGL used is the center left side of the screen. I want the entire right side of the window to basically be window controls(Text boxes, etc..) If you've seen a modeling program, that's basically what I want. Rendering in one portion. Window background with windows texts and controls in the other.
    I've already got menus, however I think if i put any controls, they will just be hidden due to OpenGLs background clearscreen color.

    Maybe my code will help explain what I want to do:
    Code:
    #define WIN32_LEAN_AND_MEAN
    #define WIN32_EXTRA_LEAN
    
    #include <windows.h>
    #include <gl/gl.h>
    #include <gl/glu.h>
    
    #include "MenuIds.h"
    
    bool exiting = false;
    long windowWidth = 800;
    long windowHeight = 600;
    long windowBits = 32;
    bool fullscreen = false;
    HDC hDC;
    
    char ClassName[] = {"WindowsClassName1"};
    
    void SetupPixelFormat(HDC hDC)
    {
        int pixelFormat;
    
        PIXELFORMATDESCRIPTOR pfd =
        {   
            sizeof(PIXELFORMATDESCRIPTOR),  // size
                1,                          // version
                PFD_SUPPORT_OPENGL |        // OpenGL window
                PFD_DRAW_TO_WINDOW |        // render to window
                PFD_DOUBLEBUFFER,           // support double-buffering
                PFD_TYPE_RGBA,              // color type
                32,                         // prefered color depth
                0, 0, 0, 0, 0, 0,           // color bits (ignored)
                0,                          // no alpha buffer
                0,                          // alpha bits (ignored)
                0,                          // no accumulation buffer
                0, 0, 0, 0,                 // accum bits (ignored)
                16,                         // depth buffer
                0,                          // no stencil buffer
                0,                          // no auxiliary buffers
                PFD_MAIN_PLANE,             // main layer
                0,                          // reserved
                0, 0, 0,                    // no layer, visible, damage masks
        };
    
        pixelFormat = ChoosePixelFormat(hDC, &pfd);
        SetPixelFormat(hDC, pixelFormat, &pfd);
    }
    
    LRESULT CALLBACK MainWindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
    {
        static HDC hDC;
        static HGLRC hRC;
        int height, width;
    
        // dispatch messages
        switch (uMsg)
        {   
        case WM_CREATE:         // window creation
            hDC = GetDC(hWnd);
            
            SetupPixelFormat(hDC);
            
            hRC = wglCreateContext(hDC);
            
            wglMakeCurrent(hDC, hRC);
                                
            HMENU MainMenu;
            HMENU FileMenu;
                    
            MainMenu=CreateMenu();  
            FileMenu=CreateMenu();  
            AppendMenu(FileMenu,MF_STRING,ID_New,"&New");  
            AppendMenu(FileMenu,MF_STRING,ID_Load,"&Load");  
            AppendMenu(FileMenu,MF_STRING,ID_Close,"&Close");
            AppendMenu(FileMenu,MF_STRING,ID_Save, "&Save");
            AppendMenu(FileMenu,MF_STRING,ID_SaveAs, "S&ave As..");
            AppendMenu(FileMenu,MF_SEPARATOR,0,"");  
            AppendMenu(FileMenu,MF_STRING,ID_Exit,"E&xit"); 
            InsertMenu(MainMenu,ID_File,MF_POPUP,(UINT)FileMenu,"File");  
                    
            HMENU SubMenus;
            SubMenus = CreateMenu();
                    
            AppendMenu(SubMenus,MF_STRING,ID_Wall,"&Wall");  
            AppendMenu(SubMenus,MF_STRING,ID_Floor,"&Floor");  
            AppendMenu(SubMenus,MF_STRING,ID_Stair,"&Stair");
            InsertMenu(MainMenu,ID_Create,MF_POPUP,(UINT)SubMenus,"Create");  
                    
            HMENU SubMenus2;
            SubMenus2 = CreateMenu();
                    
            AppendMenu(SubMenus2,MF_STRING,ID_Undo,"&Undo");  
            AppendMenu(SubMenus2,MF_STRING,ID_Redo,"&Redo");
            AppendMenu(SubMenus2,MF_SEPARATOR,0,"");
            AppendMenu(SubMenus2,MF_STRING,ID_Properties,"&Properties");
            InsertMenu(MainMenu,ID_Edit,MF_POPUP,(UINT)SubMenus2,"Edit"); 
                    
            HMENU SubMenus3;
            SubMenus3 = CreateMenu();
                    
            AppendMenu(SubMenus3,MF_STRING,ID_Wireframe,"&Wireframe");  
            AppendMenu(SubMenus3,MF_STRING | MF_CHECKED,ID_Textured,"&Textured");  
            AppendMenu(SubMenus3,MF_STRING,ID_Regular,"&Regular");
            AppendMenu(SubMenus3,MF_SEPARATOR,0,"");  
            AppendMenu(SubMenus3,MF_STRING,ID_ResetView,"R&eset View"); 
            AppendMenu(SubMenus3,MF_SEPARATOR,0,"");   
            AppendMenu(SubMenus3,MF_STRING,ID_TopView,"&Top View");  
            AppendMenu(SubMenus3,MF_STRING,ID_XView,"&X View");
            AppendMenu(SubMenus3,MF_STRING,ID_ZView,"&Z View");
            InsertMenu(MainMenu,ID_View,MF_POPUP,(UINT)SubMenus3,"View");   
                    
            HMENU SubMenus4;
            SubMenus4 = CreateMenu();
                    
            AppendMenu(SubMenus4,MF_STRING,ID_Overview,"&Overview");  
            InsertMenu(MainMenu,ID_Help,MF_POPUP,(UINT)SubMenus4,"Help"); 
                    
            if (!SetMenu(hWnd,MainMenu)) {    return FALSE; }
            
            break;
    
        case WM_DESTROY:            // window destroy
        case WM_QUIT:
        case WM_CLOSE:                  // windows is closing
    
            // deselect rendering context and delete it
            wglMakeCurrent(hDC, NULL);
            wglDeleteContext(hRC);
    
            // send WM_QUIT to message queue
            PostQuitMessage(0);
            break;
    
        case WM_SIZE:
            windowHeight = HIWORD(lParam);        // retrieve width and height
            windowWidth = LOWORD(lParam);
            
            >>>>> Does not solve problem >>> glViewport(0, 0, windowWidth - 300, windowHeight);        // reset the viewport to new dimensions
            glMatrixMode(GL_PROJECTION);            // set projection matrix current matrix
            glLoadIdentity();                       // reset projection matrix
    
            // calculate aspect ratio of window
            gluPerspective(52.0f,(GLfloat)windowWidth/(GLfloat)windowHeight,1.0f,1000.0f);
    
            break;
    
        case WM_ACTIVATEAPP:        // activate app
            break;
    
        case WM_PAINT:              // paint
            PAINTSTRUCT ps;
            BeginPaint(hWnd, &ps);
            EndPaint(hWnd, &ps);
            break;
    
        case WM_LBUTTONDOWN:        // left mouse button
            break;
    
        case WM_RBUTTONDOWN:        // right mouse button
            break;
    
        case WM_MOUSEMOVE:          // mouse movement
            break;
    
        case WM_LBUTTONUP:          // left button release
            break;
    
        case WM_RBUTTONUP:          // right button release
            break;
    
        case WM_KEYUP:
            break;
    
        case WM_KEYDOWN:
    
            break;
    
        default:
            break;
        }
        return DefWindowProc(hWnd, uMsg, wParam, lParam);
    }
    
    int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
    {
        WNDCLASSEX windowClass;     // window class
        HWND       hwnd;            // window handle
        MSG        msg;             // message
        DWORD      dwExStyle;       // Window Extended Style
        DWORD      dwStyle;         // Window Style
        RECT       windowRect;
    
        windowRect.left=(long)0;                        // Set Left Value To 0
        windowRect.right=(long)windowWidth; // Set Right Value To Requested Width
        windowRect.top=(long)0;                         // Set Top Value To 0
        windowRect.bottom=(long)windowHeight;   // Set Bottom Value To Requested Height
    
        // fill out the window class structure
        windowClass.cbSize          = sizeof(WNDCLASSEX);
        windowClass.style           = CS_HREDRAW | CS_VREDRAW;
        windowClass.lpfnWndProc     = MainWindowProc;
        windowClass.cbClsExtra      = 0;
        windowClass.cbWndExtra      = 0;
        windowClass.hInstance       = hInstance;
        windowClass.hIcon           = LoadIcon(NULL, IDI_APPLICATION);  // default icon
        windowClass.hCursor         = LoadCursor(NULL, IDC_ARROW);      // default arrow
        windowClass.hbrBackground   = NULL;                             // don't need background
        windowClass.lpszMenuName    = NULL;                             // no menu
        windowClass.lpszClassName   = ClassName;
        windowClass.hIconSm         = LoadIcon(NULL, IDI_WINLOGO);      // windows logo small icon
    
        // register the windows class
        if (!RegisterClassEx(&windowClass))
            return 0;
    
        if (fullscreen)                             // fullscreen?
        {
            DEVMODE dmScreenSettings;                   // device mode
            memset(&dmScreenSettings,0,sizeof(dmScreenSettings));
            dmScreenSettings.dmSize = sizeof(dmScreenSettings); 
            dmScreenSettings.dmPelsWidth = windowWidth;         // screen width
            dmScreenSettings.dmPelsHeight = windowHeight;           // screen height
            dmScreenSettings.dmBitsPerPel = windowBits;             // bits per pixel
            dmScreenSettings.dmFields=DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;
    
            // 
            if (ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN) != DISP_CHANGE_SUCCESSFUL)
            {
                // setting display mode failed, switch to windowed
                MessageBox(NULL, "Display mode failed", NULL, MB_OK);
                fullscreen = 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
    
        // class registered, so now create our window
        hwnd = CreateWindowEx(NULL,                                 // extended style
            ClassName,                          // class name
            "Level Designer",      // app name
            dwStyle | WS_CLIPCHILDREN |
            WS_CLIPSIBLINGS,
            0, 0,                               // x,y coordinate
            windowRect.right - windowRect.left,
            windowRect.bottom - windowRect.top, // width, height
            NULL,                               // handle to parent
            NULL,                               // handle to menu
            hInstance,                          // application instance
            NULL);                              // no extra params
    
        hDC = GetDC(hwnd);
    
        // check if window creation failed (hwnd would equal NULL)
        if (!hwnd)
            return 0;
        
        >> Does not solve problem >> glViewport(0, 0, windowWidth - 500, windowHeight);        // reset the viewport to new   dimensions
        glMatrixMode(GL_PROJECTION);            // set projection matrix current matrix
        glLoadIdentity();                       // reset projection matrix
    
        // calculate aspect ratio of window
        gluPerspective(52.0f,(GLfloat)windowWidth/(GLfloat)windowHeight,1.0f,1000.0f);
    
        glMatrixMode(GL_MODELVIEW);             // set modelview matrix
        glLoadIdentity();                       // reset modelview matrix
    
        ShowWindow(hwnd, SW_SHOW);          // display the window
        UpdateWindow(hwnd);                 // update the window
    
        while (!exiting)
        {
            SwapBuffers(hDC);
    
            while (PeekMessage (&msg, NULL, 0, 0, PM_NOREMOVE))
            {
                if (!GetMessage (&msg, NULL, 0, 0))
                {
                    exiting = true;
                    break;
                }
    
                TranslateMessage (&msg);
                DispatchMessage (&msg);
            }
        }
    
        if (fullscreen)
        {
            ChangeDisplaySettings(NULL,0);          // If So Switch Back To The Desktop
            ShowCursor(TRUE);                       // Show Mouse Pointer
        }
    
        return (int)msg.wParam;
    }
    That's the main source file obviously
    Last edited by JJFMJR; 08-31-2007 at 07:25 PM. Reason: Recent post.
    My Favorite Programming Line:
    Code:
    #define true ((rand() % 2) ? true : false)

  8. #8

    Join Date
    May 2005
    Posts
    1,041
    I've already got menus, however I think if i put any controls, they will just be hidden due to OpenGLs background clearscreen color.
    Why don't you try it out? I remember writing chemistry programs that have had buttons on the right side of the screen that showed up even though OpenGL was actually being rendered to the entire background, and I don't believe I did anything special for it. I believe we have given you the answer already, and that is you simply need to call glViewport when setting up OpenGL with dimensions smaller than the size of the Win32 window you are drawing on. This will limit anything OpenGL wants to do to that portion of the screen.

    EDIT:
    If it does not work you will need to create a parent window that is purely for Windows, and then create a child window which uses OpenGL. You have the code for doing that above.
    Last edited by BobMcGee123; 08-31-2007 at 05:35 PM.
    I'm not immature, I'm refined in the opposite direction.

  9. #9
    Registered User
    Join Date
    Apr 2007
    Posts
    102
    Well, using gl Viewport, I still do not receive the results I strived for, if that's the only answer that can be given, which won't work. I guess I just have live without it. Thanks for your input all. If you still think you can get it to work, please let me know.
    My Favorite Programming Line:
    Code:
    #define true ((rand() % 2) ? true : false)

Popular pages Recent additions subscribe to a feed

Similar Threads

  1. Opengl masking problem
    By kaptenkraek in forum Game Programming
    Replies: 1
    Last Post: 03-14-2008, 12:26 PM
  2. Memory problem with Borland C 3.1
    By AZ1699 in forum C Programming
    Replies: 16
    Last Post: 11-16-2007, 10:22 AM
  3. SDL_ttf and OpenGL
    By sand_man in forum Game Programming
    Replies: 2
    Last Post: 12-01-2004, 05:06 PM
  4. Problem with OpenGL tutorial
    By 2Biaz in forum Windows Programming
    Replies: 18
    Last Post: 09-16-2004, 11:02 AM
  5. OpenGL lighting
    By BabyG in forum Game Programming
    Replies: 3
    Last Post: 08-29-2004, 09:58 AM

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21