Question

the purpose of my program is to load and display a simple cube with the same texture on each face. the problem is the 2 first faces (front, rear) are good. I tried several combinations of vertices in the textures array but it doesn’t work. I don’t know if I need to add more vertices in the textures array or change the order or change the indices array.

#define OFFSET_BUFFER(bytes) ((GLfloat *)NULL + bytes)

float vertices[] =
{
    -1.0f, -1.0f, 1.0f, // 0 
    1.0f, -1.0f, 1.0f,  // 1 
    -1.0f, 1.0f, 1.0f,  // 2 
    1.0f, 1.0f, 1.0f,   // 3 

    -1.0f, -1.0f, -1.0f,// 4 
    1.0f, -1.0f, -1.0f, // 5 
    -1.0f, 1.0f, -1.0f, // 6 
    1.0f, 1.0f, -1.0f,  // 7 
}; 

GLubyte indices[] =
{
    0,1,2, 1,3,2, //front face
    6,7,5, 6,5,4, //rear face
    1,5,3, 5,7,3, //problem on the right face
    //2,3,6, 3,6,7,
    //2,4,0, 2,4,6
    0,5,1, 5,4,0
}; 

float textures[] =
{
    0.0f, 1.0f,//0
    1.0f, 1.0f,//1
    0.0f, 0.0f,//2
    1.0f, 0.0f,//3

    0.0f, 1.0f,//0
    1.0f, 1.0f,//1
    0.0f, 0.0f,//2
    1.0f, 0.0f,//3
}; 

int main(int argc, char *argv[])
{
    SDL_Init(SDL_INIT_VIDEO);
    SDL_WM_SetCaption("Texture Mapping",NULL);
    SDL_SetVideoMode(500, 500, 32, SDL_OPENGL);

    bool continuer = true;
    SDL_Event event;
    GLuint texCube;

    glClearDepth(1.0f);
    glClearColor(0.1f, 0.1f, 0.1f, 0.1f);
    glEnable(GL_DEPTH_TEST);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(70.0f, (float)500.0f / (float)500.0f, 1.0f, 3000.0f);
    glewInit();

    texCube = loadTexture("caisse.jpg");
    glBindTexture(GL_TEXTURE_2D, texCube);

    glEnable(GL_TEXTURE_2D);

    while (continuer)
    {
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        SDL_WaitEvent(&event);
        switch(event.type)
        {
            case SDL_QUIT:
                continuer = false;
        }

        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();

        gluLookAt(0.0f, 0.0f, 3.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f);

        //Draw Cube ---------------------------------------

        glPushMatrix();
        glRotatef(90.0f, 1.0f, 1.0f, 0.0f);

        glEnableClientState(GL_VERTEX_ARRAY);
        glVertexPointer(3, GL_FLOAT, 0, vertices);

        glEnableClientState(GL_TEXTURE_COORD_ARRAY);
        glTexCoordPointer(2, GL_FLOAT, 0, textures);

        glDrawElements(GL_TRIANGLES, 24, GL_UNSIGNED_BYTE, indices);

        glDisableClientState(GL_VERTEX_ARRAY);
        glDisableClientState(GL_TEXTURE_COORD_ARRAY);

        //-------------------------------------------------

        glPopMatrix();

        glFlush();
        SDL_GL_SwapBuffers();
    }

    glDisable(GL_TEXTURE_2D);
    SDL_Quit();

    return 0;
}

Answer 1

Your corners are sharing texture coordinates, which just isn’t going to work.
you should have 4 vertices for each face, as the texture coordinates for each corner will be different depending on the face.