在类中渲染OpenGL对象？

我正在尝试学习现代OpenGL并为各种原始类型（例如多维数据集，球体等）创建类。但是，我遇到了一个问题，即我的多维数据集类在其Draw()函数中未呈现任何内容，但是如果我将其移动，所有到我的main()功能，它工作正常。

这是cube.cpp的代码：

#include "cube.h"

#include <iostream>
GLuint Cube::indexArr[36] = {
    0, 1, 2, // front face
    2, 3, 1,
    4, 5, 6,
    6, 7, 4,
    7, 3, 0,
    0, 4, 7,
    6, 2, 1,
    1, 5, 6,
    0, 1, 5,
    5, 4, 0,
    3, 2, 6,
    6, 7, 3
};

bool    Cube::cubeSetUp = false;
GLuint  Cube::cubeVBO = 0;
GLuint  Cube::cubeVAO = 0;
GLuint  Cube::cubeEBO = 0;

Cube::Cube()
{
    if (!cubeSetUp)
        SetUpCube();

    //define the 8 vertices that make up a cube
    objectVerts = new GLfloat[24] {
        -0.5f, -0.5f, -0.5f, // front bottom left  0
         0.5f, -0.5f, -0.5f, // front bottom right 1
         0.5f,  0.5f, -0.5f, // front top right    2
        -0.5f,  0.5f, -0.5f, // front top left     3
        -0.5f, -0.5f, 0.5f, // back bottom left   4
         0.5f, -0.5f, 0.5f, // back bottom right  5
         0.5f,  0.5f, 0.5f, // back top right     6
        -0.5f,  0.5f, 0.5f  // back top left      7
    };
}

void Cube::Draw()
{
    glBindVertexArray(cubeVAO);

    //GLfloat modelMatrix[16];
    //transform.affine.ConvertToOpenGLMatrix(modelMatrix);

    //glUniformMatrix4fv(modelMatrixLoc, 1, GL_FALSE, modelMatrix);

    glDrawElements(GL_TRIANGLES, 36, GL_UNSIGNED_INT, 0);   
    glBindVertexArray(0);
}


void Cube::SetUpCube()
{
    cubeSetUp = true;
    glGenVertexArrays(1, &cubeVAO);
    glGenBuffers(1, &cubeVBO);
    glGenBuffers(1, &cubeEBO);

    glBindVertexArray(cubeVAO);

    glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(objectVerts), objectVerts, GL_STATIC_DRAW);

    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, cubeEBO);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indexArr), indexArr, GL_STATIC_DRAW);

    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(GLfloat), (GLvoid*)0);
    glEnableVertexAttribArray(0);

    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glBindVertexArray(0);
}

的代码cube.h：

#ifndef __CUBE__H_
#define __CUBE__H_

#include "scene_object.h"

class Cube : public SceneObject
{
    public:
        /***************
         * Constructor *
         ***************/
        Cube();

        /***********************
         * Overloaded Function *
         ***********************/
        void Draw();

    private:
        static GLuint  indexArr[36];
        static bool    cubeSetUp;
        static GLuint  cubeVBO, cubeVAO, cubeEBO;

        void SetUpCube();
};

#endif

难道我做错了什么？OpenGL是否不同意为索引数组使用静态数组？我尝试摆脱了元素缓冲区对象，而只使用glDrawArrays(...)，但是它也没有用。如果需要，我也可以提供主要代码。

另外，顶点着色器什么也没做。它仅接收顶点信息并将其提供给gl_Position。

谢谢你的帮助。

的代码main.cpp：

#define GLEW_STATIC
#include <GL/glew.h>
#include <GLFW/glfw3.h>

#include <iostream>
#include <fstream>
#include <string>

#include "shader.h"
#include "cube.h"
#include "camera.h"

using namespace std;

int main(int argc, char* argv[])
{
    if (argc != 3)
    {
        cout << "Incorrect number of arguments!" << endl;
        cout << "Usage: [executable] vertexShader fragmentShader" << endl;
        return -1;
    }

    glfwInit();
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
    glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);

    GLFWwindow* window = glfwCreateWindow(800, 600, "Scene Description Language Generator", nullptr, nullptr);
    if (window == nullptr)
    {
        std::cout << "Failed to create the GLFW window" << std::endl;
        glfwTerminate();
        return -1;
    }

    glfwMakeContextCurrent(window);
    glewExperimental = GL_TRUE;
    if (glewInit() != GLEW_OK)
    {
        std::cout << "Failed to initialize GLEW" << std::endl;
        return -1;
    }

    glEnable(GL_DEPTH_TEST);

    int width, height;
    glfwGetFramebufferSize(window, &width, &height);

    glViewport(0, 0, width, height);

    Shader shader(argv[1], argv[2]);

    Cube c;

    GLuint modelMat = glGetUniformLocation(shader.GetProgram(), "model");

    c.SetModelMatrixLoc(modelMat);

    while (!glfwWindowShouldClose(window))
    {
        glfwPollEvents();

        glClearColor(0.2f, 0.3f, 0.3f, 1);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        shader.Use();
        c.Draw();

        glfwSwapBuffers(window);
    }

    glfwTerminate();
    return 0;
}

编辑：为main.cpp和cube.h添加了代码，以防万一。