Segmentation fault using OpenGL

[Tron Thomas]

Here is the code:
#include <windows.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <math.h>
#include <il/il.h>

void SetupOpenGL();
void SetupRenderingContext();
void SetupTexture();
void SetProjection();

LRESULT WINAPI WinProc(HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lParam);
void Render();
void FreeResources();

HWND g_hWnd = NULL;
HGLRC g_hContext = NULL;

GLuint g_nTexture = 0;

int WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR, int)
{
    char szClassName[] = "TestIL";
    char szTitle[] = "Test DevIL";

    WNDCLASS wndClass;
    wndClass.style = CS_HREDRAW | CS_VREDRAW;
    wndClass.lpfnWndProc = reinterpret_cast<WNDPROC>(WinProc);
    wndClass.cbClsExtra = 0;
    wndClass.cbWndExtra = 0;
    wndClass.hInstance = ::GetModuleHandle(NULL);
    wndClass.hIcon = ::LoadIcon(NULL, IDI_APPLICATION);
    wndClass.hCursor = ::LoadCursor(NULL, IDC_ARROW);
    wndClass.hbrBackground = reinterpret_cast<HBRUSH>(COLOR_WINDOW + 1);
    wndClass.lpszMenuName = NULL;
    wndClass.lpszClassName = szClassName;

    if(!::RegisterClass(&wndClass)){
        return 0;
    }

    g_hWnd = ::CreateWindow(szClassName, szTitle, WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT, 640, 480, NULL, NULL, 
wndClass.hInstance,
        NULL);

    if(NULL == g_hWnd){
        return 0;
    }
   
    ::SetupOpenGL();

    ::SetupTexture();

    ::ShowWindow(g_hWnd, SW_SHOWNORMAL);
    ::UpdateWindow(g_hWnd);

    MSG msg;
    ZeroMemory(&msg, sizeof(msg));
    while(WM_QUIT != msg.message){
        if(::PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)){
            ::TranslateMessage(&msg);
            ::DispatchMessage(&msg);
        }
        else{
            ::Render();
        }
    }

    ::FreeResources();

    ::UnregisterClass(szClassName, wndClass.hInstance);

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

void SetupOpenGL()
{
    ::SetupRenderingContext();

    ::SetProjection();

    ::glClearColor(0.0, 0.0, 0.0, 0.0);
    ::glEnable(GL_TEXTURE_2D);
}

void SetupRenderingContext()
{
    HDC hDC = ::GetDC(g_hWnd);

    PIXELFORMATDESCRIPTOR thePixelFormat;
    ZeroMemory(&thePixelFormat, sizeof(thePixelFormat));
    thePixelFormat.nSize = sizeof(thePixelFormat);
    thePixelFormat.nVersion = 1;
    thePixelFormat.dwFlags =
        PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
    thePixelFormat.iPixelType = PFD_TYPE_RGBA;
    thePixelFormat.cColorBits = 16;
    thePixelFormat.cDepthBits = 16;
    thePixelFormat.iLayerType = PFD_MAIN_PLANE;

    int nFormat = ::ChoosePixelFormat(hDC, &thePixelFormat);
    ::SetPixelFormat(hDC, nFormat, &thePixelFormat);

    g_hContext = ::wglCreateContext(hDC);
    ::wglMakeCurrent(hDC, g_hContext);

    ::ReleaseDC(g_hWnd, hDC);
}

void SetupTexture()
{
    ::ilInit();

    ILuint nImage;
    ::ilGenImages(1, &nImage);
    ::ilBindImage(nImage);

    ::ilLoadImage("BARK4.JPG");

    ::glGenTextures(1, &g_nTexture);
    ::glBindTexture(GL_TEXTURE_2D, g_nTexture);

    ILint nWidth = ::ilGetInteger(IL_IMAGE_WIDTH);
    ILint nHeight = ::ilGetInteger(IL_IMAGE_HEIGHT);
    ::ilConvertImage(IL_RGBA, IL_UNSIGNED_BYTE);

    unsigned char* pData = ::ilGetData();
    ::glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, nWidth, nHeight, 0, GL_RGBA,
        GL_UNSIGNED_BYTE, pData);

    ::ilDeleteImages(1, &nImage);
    ::ilShutDown();

    ::glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);    
::glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    // Specify how to filter the texture when it is stretch or shrunk
    ::glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    ::glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
}

void SetProjection()
{
    RECT rect;
    ::GetClientRect(g_hWnd, &rect);
    int nWidth = rect.right- rect.left;
    int nHeight = rect.bottom - rect.top;

    ::glViewport(0, 0, nWidth, nHeight);

    ::glMatrixMode(GL_PROJECTION);
    ::glLoadIdentity();
    GLdouble dAspect = static_cast<GLdouble>(nWidth) / nHeight;
    ::gluPerspective(45.0, dAspect, 0.1, 100.0);

    ::gluLookAt(0.0, 0.0, -10.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
}

LRESULT WINAPI WinProc
(
    HWND hWnd,
    UINT nMsg,
    WPARAM wParam,
    LPARAM lParam
)
{
    switch(nMsg){

        case WM_CREATE:
            return 0;

        case WM_SIZE:
            ::SetProjection();
            return 0;

        case WM_PAINT:
            ::Render();
            ::ValidateRect(hWnd, NULL);
            return 0;

        case WM_DESTROY:
            ::PostQuitMessage(0);
            return 0;
    }

    return ::DefWindowProc(hWnd, nMsg, wParam, lParam);
}         

void Render()
{
    HDC hDC = ::GetDC(g_hWnd);

    ::wglMakeCurrent(hDC, g_hContext);
    ::glClear(GL_COLOR_BUFFER_BIT);

    ::glMatrixMode(GL_MODELVIEW);
    ::glLoadIdentity();

    ::glBindTexture(GL_TEXTURE_2D, g_nTexture);
    ::glBegin(GL_QUADS);

    ::glTexCoord2f(0.0f, 1.0f);
    ::glVertex3f(-2.5f, 2.5f, 0.0f);

    ::glTexCoord2f(0.0f, 0.0f);
    ::glVertex3f(-2.5f, -2.5f, 0.0f);

    ::glTexCoord2f(1.0f, 0.0f);
    ::glVertex3f(2.5f, -2.5f, 0.0f);

    ::glTexCoord2f(1.0f, 1.0f);
    ::glVertex3f(2.5f, 2.5f, 0.0f);

    ::glEnd();

    ::SwapBuffers(hDC);

    ::ReleaseDC(g_hWnd, hDC);
}

void FreeResources()
{
    ::glBindTexture(GL_TEXTURE_2D, 0);

    ::glDeleteTextures(1, &g_nTexture);

    ::wglMakeCurrent(NULL, NULL);
    ::wglDeleteContext(g_hContext);   
}

It is trying to test the DevIL image library.


Reid Thompson wrote:

>posting the code might get someone interested in looking at the issue
>
>--
>thanks,
>reid
>
>
>-----Original Message-----
>From: Tron Thomas [mailto:tron.thomas@verizon.net] 
>Sent: Friday, March 21, 2003 3:57 PM
>To: cygwin@cygwin.com
>Subject: Segmentation fault using OpenGL
>
>
>I have written a Windows OpenGL program which I can successfully build 
>and run using both the Borland and Microsoft compilers.  When I try to 
>run the same program after building it with the Cygwin GCC compiler, I 
>get a segmentation fault.  I'm very puzzled by this as the program works
>
>fine when built with other compilers.
>
>Does anyone have experieince with Cygwin and OpenGL and might know what 
>could be causing this problem?  The fault occur when I call glTexImage2D
>
>to create a 2 dimensional texture.
>
>
>
>--
>Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
>Bug reporting:         http://cygwin.com/bugs.html
>Documentation:         http://cygwin.com/docs.html
>FAQ:                   http://cygwin.com/faq/
>
>
>  
>



--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Bug reporting:         http://cygwin.com/bugs.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/