土壤质地

Question

Here is the error message I am recieving from VS2010:

Unhandled exception at 0x77358dc9 in AzimuthalEqui.exe: 0xC0000005: Access violation writing location 0x00000014.

The line of code generating this error is:

texture[1] = SOIL_load_OGL_texture
    (
        texture_filename,
        SOIL_LOAD_AUTO,
        SOIL_CREATE_NEW_ID, // create ID automatically
        SOIL_flags
    );

before entering this function:

texture_filename = "Data/texture.jpg"

SOIL_LOAD_AUTO (= 0)

SOIL_CREATE_NEW_ID (=0)

SOIL_flags = 16 (=SOIL_FLAG_INVERT_Y)

The problem is that when I include a file I have written to parse some information in a text file an error is generated, otherwise the texture loads and is displayed. The prob is most likely caused by one function as when this particular function is removed the code loads and displays the texture. Here is the function that when added to my project makes the error occur:

[CODE]
void get_user_points(double *lats, double *longs){

    char buffer[BUFFSIZE_PARSE];
    char *p_buff = buffer;
    FILE *fp;
    const char *filename = "Points.txt";
    double temp;
    double *tmp_p = &temp;


    fp = fopen(filename,"r+");
    if (fp == NULL)
    {
        sprintf(buffer, "Can't Find File: %s", filename);
        MessageBoxA(NULL, buffer, "ERROR", MB_OK|MB_ICONEXCLAMATION);
        exit(0);
    }

    fgets(buffer, BUFFSIZE_PARSE, fp);

    while (*(p_buff+1) != '\0'){

        p_buff = get_next_letter(p_buff);

        switch (tolower(*p_buff)){
            case 'n':
                putchar(*p_buff);
                p_buff++;
                p_buff=get_next_double(lats, p_buff);
                printf(" = %f\n", *lats);
                break;
            case 's':
                ...
                ...
        }
    }
    putchar('\n');
    fclose(fp);
}

It has something to do with opening the file for reading... if I comment out these lines the texture loads correctly:

//fpr = fopen(filename2,"rb"); 
...
...
...
//fclose(fpr);

Here is my reduced code (i don't think this is the issue but just in case). [There may be some remanants of my full code]:

int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);

    {
        printf("Initialising...\n");
        glutInitWindowSize(700, 700);
        glutInitWindowPosition(0, 0);
        glutCreateWindow ("SOIL Texture Test");
    }

    InitGL();
    glutDisplayFunc(DrawGLScene);
    glutReshapeFunc(ReSizeGLScene);

    glutMainLoop();

    return 0;
}

int InitGL(GLvoid) // Setup OpenGL
{
    //Load textures
    if (!LoadGLTextures())                              // Jump To Texture Loading Routine ( NEW )
    {
        MessageBox(NULL,TEXT("Cannot Load Image for Texture Map"),TEXT("Error!"),MB_OK | MB_ICONINFORMATION);
        //return false;                                 // If Texture Didn't Load Return FALSE ( NEW )
    }
    else
        glEnable(GL_TEXTURE_2D);                        // Enable texture mapping


    glShadeModel(GL_SMOOTH);                            // Enable Smooth Shading
    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);               // Set the background colour (to black)

    glClearDepth(1.0f);                                 // Depth Buffer Setup
    glEnable(GL_DEPTH_TEST);                            // Enables Depth Testing
    glDepthFunc(GL_LEQUAL);                             // Select testing type


    //get_user_points(&user_lat[0], &user_long[0]);

    return true;                                        // Initialization went OK
}


void DrawGLScene(GLvoid) // OpenGL drawing function
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear the Screen and the Depth Buffer

    glLoadIdentity();
    glTranslatef(0.0f,0.0f,z);

    glBindTexture (GL_TEXTURE_2D, texture[filter]);
    glBegin (GL_QUADS);
        glNormal3f(0, 0, 1);

        glTexCoord2f (0,0);
        glVertex3f (-3,-3 ,0);
        glTexCoord2f (1,0 );
        glVertex3f (3,-3 , 0);
        glTexCoord2f (1, 1);
        glVertex3f (3,3 , 0);
        glTexCoord2f (0,1 );
        glVertex3f (-3,3 ,0 );
    glEnd();

    glFlush();
}

void ReSizeGLScene(int w, int h) // Code to resize (and initialise) the OpenGL scene (run once when in fullscreen mode)
{
    // Set up perspective view matrix
    glViewport(0, 0, w, h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45.0f, (GLfloat)w/(GLfloat)h, 0.1f, 100.0f);
    //glOrtho(-50.0, 50.0, -50.0, 50.0, -50.0, 50.0);

    // Set up modelview matrix
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
}

int LoadGLTextures(void) // Load Bitmaps And Convert To Textures
{
    unsigned int SOIL_flags;
    GLint mag_param;
    GLint min_param;

    printf("Loading Textures... ");

    SOIL_flags = SOIL_FLAG_INVERT_Y;
    mag_param = GL_NEAREST;
    min_param = GL_NEAREST;


    texture[1] = SOIL_load_OGL_texture
    (
        texture_filename,
        SOIL_LOAD_AUTO,
        SOIL_CREATE_NEW_ID, // create ID automatically
        SOIL_flags
    );

    if(texture[1] == 0)
        return false;

    glBindTexture(GL_TEXTURE_2D, texture[1]);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,mag_param);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,min_param);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

    printf("Textures Loaded\n");
    return true;
}

Answer 1

在项目中包含.c文件而不是.lib文件可解决此问题。