5 replies to this topic

[MindOfCorruption97]

Sorry to ask but for some reason my OpenGL application does not seem to work. When I try to run/debug my application it stops and shows a message that my application stopped working. I tried to find ways to fix it, but I don't know what is causing to to stop working.

 

I listed all the classes and files associated with my application.

 

MainWindow.cpp

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

#include "EditorLink.h"

const char g_szClassName[] = "Window";
BOOL quit = FALSE;

void EnableOpenGL(HWND hWnd,HDC * hDc,HGLRC * hRc);
void DisableOpenGL(HWND hWnd,HDC hDc,HGLRC hRc);

Editor Edit;

LRESULT CALLBACK WndProc(HWND hWnd,UINT msg,WPARAM wParam,LPARAM lParam)
{
    switch(msg)
    {
        case WM_CLOSE:
            quit = TRUE;
            break;
        case WM_DESTROY:
            PostQuitMessage(0);
            break;
        default:
            return DefWindowProc(hWnd,msg,wParam,lParam);
    }
}

int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR CmdLine,int nCmdShow)
{
    WNDCLASS wc;
    HWND hWnd;
    HGLRC hRc;
    HDC hDc;
    MSG msg;
    
    wc.lpszClassName = g_szClassName;
    wc.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
    wc.hInstance = hInstance;
    wc.style = CS_OWNDC;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.lpfnWndProc = WndProc;
    wc.lpszMenuName = NULL;
    wc.hCursor = LoadCursor(NULL,IDC_ARROW);
    wc.hIcon = LoadIcon(NULL,NULL);
    RegisterClass(&wc);
    
    hWnd = CreateWindow(
            g_szClassName,
            "OPENGL PRACTICE",
            WS_OVERLAPPEDWINDOW | WS_CAPTION | WS_POPUP | WS_VISIBLE,
            CW_USEDEFAULT,CW_USEDEFAULT,800,700,
            NULL,NULL,hInstance,NULL
            );
    
    EnableOpenGL(hWnd,&hDc,&hRc);
    Edit.init(hInstance);
    
    ShowWindow(hWnd,nCmdShow);
    UpdateWindow(hWnd);
    
    while(!quit)
    {
        if(PeekMessage(&msg,NULL,0,0,PM_REMOVE))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
        else
        {
            Edit.display();
            SwapBuffers(hDc);
        }
    }
    
    DisableOpenGL(hWnd,hDc,hRc);
    DestroyWindow(hWnd);
    
    return msg.wParam;
}


void EnableOpenGL(HWND hWnd,HDC * hDc,HGLRC * hRc)
{
    *hDc = GetDC(hWnd);
    int nFormat;
    
    PIXELFORMATDESCRIPTOR pfd =
    {
        sizeof(PIXELFORMATDESCRIPTOR),
        1,
        PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER,
        PFD_TYPE_RGBA,
        0,0,0,0,0,0,0,0,0,0,0,0,0,
        24,
        8,
        0,
        PFD_MAIN_PLANE,
        0,0,0,0
    };
    
    nFormat = ChoosePixelFormat(*hDc,&pfd);
    SetPixelFormat(*hDc,nFormat,&pfd);
    
    *hRc = wglCreateContext(*hDc);
    wglMakeCurrent(*hDc,*hRc);
}

void DisableOpenGL(HWND hWnd,HDC hDc,HGLRC hRc)
{
    wglMakeCurrent(NULL,NULL);
    wglDeleteContext(hRc);
    ReleaseDC(hWnd,hDc);
}

Editor.h

#include <windows.h>

#ifndef EDITORLINK_H
#define	EDITORLINK_H

class Editor
{
public:
    void init(HINSTANCE hInstance);
    void display();
private:
};

#endif

 

Editor.cpp

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

#include "EditorLink.h"
#include "Texture.h"

unsigned int tex;
Bitmap *bitmap;

void Editor::init(HINSTANCE hInstance)
{
    glClearColor(0.0,0.0,0.0,1.0);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45,640.0/480.0,1.0,500.0);
    glMatrixMode(GL_MODELVIEW);
    glEnable(GL_DEPTH_TEST);
    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    glEnable(GL_TEXTURE_2D);
    
    float dif[] = {1.0,1.0,1.0,1.0};
    glLightfv(GL_LIGHT0,GL_DIFFUSE,dif);
    float amb[] = {0.2,0.2,0.2,1.0};
    glLightfv(GL_LIGHT0,GL_AMBIENT,amb);
    
    tex = bitmap->loadTexture("Practice.bmp");
}

void Editor::display()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glLoadIdentity();
    
    float pos[] = {-2.0,2.0,-3.0,1.0,};
    glLightfv(GL_LIGHT0,GL_POSITION,pos);
    
    glTranslatef(0.0,0.0,-5.0);
    
    glBindTexture(GL_TEXTURE_2D,tex);
    glBegin(GL_QUADS);
    glTexCoord2f(0.0,1.0);
    glVertex3f(-2.0,2.0,0.0);
    glTexCoord2f(0.0,0.0);
    glVertex3f(-2.0,-2.0,0.0);
    glTexCoord2f(1.0,0.0);
    glVertex3f(2.0,-2.0,0.0);
    glTexCoord2f(1.0,1.0);
    glVertex3f(2.0,2.0,0.0);
    glEnd();
}

 

Texture.h

#include <windows.h>
#include <cstdio>

#ifndef TEXTURE_H
#define	TEXTURE_H

class Bitmap
{    
public:
    RGBQUAD getColors(){return *colors;}
    BYTE getPixelData(){return *pixelData;}
    bool getLoaded(){return loaded;}
    LONG getWidth(){return width;}
    LONG getHeight(){return height;}
    WORD getBpp(){return bpp;}
    bool loadBmp(const char * FileName);
    unsigned int loadTexture(const char * FileName);
private:
    RGBQUAD *colors;
    BYTE *pixelData;
    bool loaded;
    LONG width,height;
    WORD bpp;
    BITMAPFILEHEADER bmfh;
    BITMAPINFOHEADER bmih;
};

#endif

Texture.cpp

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

#include "Texture.h"

bool Bitmap::loadBmp(const char* FileName)
{
    int numColors,offset;
    DWORD size,diff;
    BYTE *tempPixelData;
    LONG byteWidth,padWidth;
    
    FILE *in;
    in = fopen(FileName,"rb");
    fread(&bmfh,sizeof(BITMAPFILEHEADER),1,in);
    fread(&bmih,sizeof(BITMAPINFOHEADER),1,in);
    
    numColors = 1 << bmih.biBitCount;
    
    size = bmfh.bfSize - bmfh.bfOffBits;
    tempPixelData = new BYTE[size];
    byteWidth = padWidth = (LONG)((float)width * (float)bpp/8.0);
    
    height = bmih.biHeight;
    diff = height * byteWidth;
    
    if(bmih.biBitCount == 8)
    {
        colors = new RGBQUAD[numColors];
        fread(colors,sizeof(RGBQUAD),numColors,in);
    }
    if(tempPixelData == NULL)
    {
        fclose(in);
        return false;
    }
    fread(tempPixelData,sizeof(BYTE),size,in);
    
    while(padWidth % 4 != 0)
    {
        padWidth++;
    }
    if(height > 0)
    {
        int j = size - 3;
        offset = padWidth - byteWidth;
        for(int i = 0;i < size;i += 3)
        {
            if((i + 1) % padWidth == 0)
            {
                i += offset;
            }
            *(pixelData + j + 2) = *(tempPixelData + i);
            *(pixelData + j + 1) = *(tempPixelData + i + 1);
            *(pixelData + j) = *(tempPixelData + i + 2);
            j++;
        }
    }
    else
    {
        height = height* - 1;
        offset = 0;
        do{
            memcpy((pixelData + (offset * byteWidth)),
                    (tempPixelData + (offset * byteWidth)),
                    byteWidth);
            offset++;
        }while(offset < height);
    }
}

unsigned int Bitmap::loadTexture(const char * FileName)
{
    if(loadBmp(FileName))
    {
        unsigned int id;
        glGenTextures(1,&id);
        glBindTexture(GL_TEXTURE_2D,id);
        glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,width,height,0,GL_RGB,GL_UNSIGNED_BYTE,pixelData);
        
        glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
        
        return id;
    }
}

 

Thank you, sorry to waste your time.

Also can you guys tell me what causes an application to stop working? Since I want to make sure I could prevent this from happening in the future.

[fastcall22]

There are a lot of reasons why an application can stop working. Perhaps you should use your debugger and break while your program isn't responding and examine what it is doing and/or stuck on.

One thing I noticed is that your WndProc routine isn't returning a value when the default case isn't reached. However, that only applies to WM_CLOSE and WM_QUIT, so I doubt that is the issue here...

[Cornstalks]

It's a lot of code to go through, so I just skimmed it, but this looks suspicious:

Bitmap *bitmap;
...
    tex = bitmap->loadTexture("Practice.bmp");

I don't see you ever initializing bitmap. My guess is that it's an invalid pointer and you aren't setting it/allocating a Bitmap. Perhaps it shouldn't be a pointer and should just be a regular Bitmap instead of a Bitmap*? I see no reason to make it a pointer. I'm also unsure of why you made bitmap and tex global variables instead of member variables of Editor...
 
But yes, as fastcall22 said, now would be a great time to get familiar with your debugger.

Edited by Cornstalks, 31 December 2012 - 04:24 PM.

[MindOfCorruption97]

Well I made Tex and Bitmap no longer a global variable.

I also checked the debugger and it says the problem is this section of the code.

 if((i + 1) % padWidth == 0)
{
i += offset;
}
*(pixelData + j + 2) = *(tempPixelData + i);
*(pixelData + j + 1) = *(tempPixelData + i + 1);
*(pixelData + j) = *(tempPixelData + i + 2);
j++;

I tried deleting that part of the code and it worked but it didn't show the texture.

Any idea what could be wrong?

[Cornstalks]

Well, for one, you're never setting pixelData. This is the same problem that I said bitmap had. The thing about pointers is, if you don't give them a chunk of valid memory to point to, they're just pointing off into oblivion, and using them is a great way to crash your program. You need to allocate memory for pixelData if you're going to write to it.

Also, this:

while(padWidth % 4 != 0)
{
    padWidth++;
}

can be simplified to:

padWidth += padWidth % 4; // round up to multiple of 4

Actually, the more I look at it there's a whole bunch of problems with your code. colors and tempPixelData leak memory because you never delete [] what you new [] (there could be other leaks elsewhere; I haven't checked too thoroughly). You're mixing C with C++ when you shouldn't (for example, don't use FILEs, use std::fstreams, and use  std::copy instead of memcpy). But even if you keep using FILEs, you're not fclose()ing what you fopen().

 

And this if statement is useless:

 

if(tempPixelData == NULL)
{
    fclose(in);
    return false;
}

 

If new fails, it will throw an exception (std::bad_alloc), so there's no point in checking it for NULL.

 

Also, you should place your #includes inside of your inclusion guards (this isn't necessarily a problem, but it's "best practice").

Edited by Cornstalks, 31 December 2012 - 05:46 PM.

[NewDisplayName]

Check first if your j and i are getting initialised to 0, everytime before you enter this pieace of code, and then look for any reason why you might be hitting an out-of-bounds failure while doing pointer arithmetic.