OpenGL 3.3 can not draw anything

Question

i can not draw anything on my gl screen. It just clears the screen. Here is my Main, Display, and Cube classes.

main.cpp

Display d(800, 600, "Hi");
while (!d.IsClosed()) {
    d.Clear();
    d.Update();
}
return 0;

display.cpp

Constructor initializes glfw and glew.

void Display::Update() {
    glfwPollEvents();
    m_shader->UseProgram();
    m_renderer->Render(*m_cube);
    glfwSwapBuffers(m_window);
}

UseProgram function is from Shader class and just glUseProgram(m_programID);.

Also m_renderer->Render() is just calls Render function from object in the parameter.

cube.cpp

void Cube::Init() {
//cube vertices - colors
GLfloat data[] = {
    -0.5f,  0.5f,  0.0f, m_color.r, m_color.g, m_color.b, m_color.a,
    -0.5f, -0.5f,  0.0f, m_color.r, m_color.g, m_color.b, m_color.a,
     0.5f, -0.5f,  0.0f, m_color.r, m_color.g, m_color.b, m_color.a,
     0.5f,  0.5f,  0.0f, m_color.r, m_color.g, m_color.b, m_color.a,

    -0.5f,  0.5f, -0.5f, m_color.r, m_color.g, m_color.b, m_color.a,
    -0.5f, -0.5f, -0.5f, m_color.r, m_color.g, m_color.b, m_color.a,
     0.5f, -0.5f, -0.5f, m_color.r, m_color.g, m_color.b, m_color.a,
     0.5f,  0.5f, -0.5f, m_color.r, m_color.g, m_color.b, m_color.a
};

//cube indices
GLuint indices[] = {
    //front
    0, 1, 2,
    0, 2, 3,

    //top
    4, 0, 3,
    4, 3, 7,

    //bottom
    1, 3, 6,
    1, 6, 2,

    //left
    4, 3, 1,
    4, 1, 0,

    //right
    3, 2, 6,
    3, 6, 7,

    //back
    4, 5, 6,
    4, 6, 7,
};

m_vertexCount = sizeof(indices) / sizeof(GLuint);

//Generate buffers
glGenVertexArrays(1, &m_vaoID);
glGenBuffers(1, &m_vboID);
glGenBuffers(1, &m_eboID);

//Bind vertex array object
glBindVertexArray(m_vaoID);

//Bind vertex buffer object
glBindBuffer(GL_ARRAY_BUFFER, m_vboID);
glBufferData(GL_ARRAY_BUFFER, sizeof(data), data, GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glEnableVertexAttribArray(1);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(GL_FLOAT), (GLvoid*)0);
glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, 4 * sizeof(GL_FLOAT), (GLvoid*)(3 * sizeof(GL_FLOAT)));

//Unbind vertex buffer object
glBindBuffer(GL_ARRAY_BUFFER, 0);

//Bind Element buffer object
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_eboID);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
//Unbind Element buffer object
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

//Unbind vertex array object 
glBindVertexArray(0);
}

Init() function is called from constructor. This is all cube initialization code. Just binding and unbinding arrays.

void Cube::Render() {
glBindVertexArray(m_vaoID);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_eboID);
glDrawElements(GL_TRIANGLES, m_vertexCount, GL_UNSIGNED_INT, 0);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
glBindVertexArray(0);
}

I can't figure out what problem is. It just doesn't shows anything on screen. If you want i can post my Shader class too.

Answer 1

The stride parameters are wrong. Each consecutive position start 7 floats away from the start of the last one. Same goes for colors. The correct code would be

glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 7 * sizeof(GL_FLOAT), (GLvoid*)0);
glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, 7 * sizeof(GL_FLOAT), (GLvoid*)(3 * sizeof(GL_FLOAT)));

Another thing is that you are unbinding the index buffer before unbinding the VAO, thus you effectively remove the binding. The last lines of the VAO setup have to be:

//Bind Element buffer object
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_eboID);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);

//Unbind vertex array object 
glBindVertexArray(0);

//Unbind Element buffer object
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

Additionally, the binding/unbinding of the GL_ELEMENT_ARRAY_BUFFER in the Render() function should be removed.