c++ - main.cpp のコードは機能しますが、クラスに入れると機能しません

Question

画面に 30x30 のボールを描画する簡単なコードがあります。すべてが main.cpp 内にあるときは完全に機能しましたが、独自の別のクラスに入れると、代わりに画面の右上を占める非常にかすかな灰色のボックスが表示されました。Ball クラス内にある正確なコードを main.cpp に貼り付けると、再び完全に機能します。

コードが Ball クラスにある場合:

Ball クラスのすべてのコードを main に貼り付けると (および Ball クラスの前の状態):

コードはここにあります。

main.cpp

#include "Includes.hpp"

static unsigned int Width = 800;
static unsigned int Height = 600;


int main()
{   

bool CursorEnabled = true;
bool PolygonMode = false;

//Camera.CameraInit(45.0f , Width , Height , Model);   use ortho instead \/
Camera.CameraInit (Width, Height, glm::mat4 (1.0f));

GLuint vao;
glGenVertexArrays (1 , &vao);
glBindVertexArray(vao);

Ball ball;

float LastTime = glfwGetTime(); // (for deltatime)

while (true)
{
    float DeltaTime = glfwGetTime() - LastTime; // Deltatime init
    LastTime = glfwGetTime(); // update for deltatime

    glClearColor (0.0f , 0.0f , 0.0f , 1.0f);
    glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    ball.Draw();

    glfwSwapBuffers();

    if (glfwGetKey (GLFW_KEY_ESC) || !glfwGetWindowParam(GLFW_OPENED))
    {
        std::cout << "\nShutdown command. Exiting...\n" << std::flush;
        return 0;
    }


}

}

ボール.hpp

#ifndef BALL
#define BALL

class Ball
{
private:
//Vertices and UV coordiantes.
std::vector <glm::vec2> ballVert;
std::vector <glm::vec2> ballUV;

//Buffers
GLuint vertBuf;
GLuint uvBuf;

//Image
GLuint ballTex;

//IDs for the shader.
GLuint shader;
GLuint MVPid;
GLuint sampler;
GLuint coord;
GLuint uv;

public:
//Constructor
Ball();

void Draw();

};

#endif

ボール.cpp

#include "Includes.hpp"

Ball::Ball()
{
//Create ball vertices and UV coords
ballVert.push_back(glm::vec2(0 , 0));                                       /*left      /\*/
ballVert.push_back(glm::vec2(0 , 30));                                      /*right    /  \*/
ballVert.push_back(glm::vec2(30 , 0));                                      /*top     ------*/

ballVert.push_back(glm::vec2(0 , 30));                                       /*left      /\*/
ballVert.push_back(glm::vec2(30 , 30));                                      /*right    /  \*/
ballVert.push_back(glm::vec2(30 , 0));                                       /*top     ------*/

ballUV.push_back(glm::vec2(0 , 1));
ballUV.push_back(glm::vec2(0 , 0));
ballUV.push_back(glm::vec2(1 , 1));

ballUV.push_back(glm::vec2(0 , 0));
ballUV.push_back(glm::vec2(1 , 0));
ballUV.push_back(glm::vec2(1 , 1));

//Load the image
ballTex = SOIL_load_OGL_texture (
"img/ball.png",
SOIL_LOAD_AUTO,
SOIL_CREATE_NEW_ID, SOIL_FLAG_MIPMAPS | SOIL_FLAG_INVERT_Y | SOIL_FLAG_NTSC_SAFE_RGB | SOIL_FLAG_COMPRESS_TO_DXT);

//Generate buffers
glGenBuffers (1 , &vertBuf);
glBindBuffer (GL_ARRAY_BUFFER , vertBuf);
glBufferData (GL_ARRAY_BUFFER , ballVert.size() * sizeof(glm::vec2) , &ballVert[0] , GL_STATIC_DRAW);

glGenBuffers (1 , &uvBuf);
glBindBuffer (GL_ARRAY_BUFFER , uvBuf);
glBufferData (GL_ARRAY_BUFFER , ballUV.size() * sizeof (glm::vec2) , &ballUV[0] , GL_STATIC_DRAW);

shader = Game.LoadShaders ("src/glsl/ball.vert" , "src/glsl/ball.frag");
MVPid = glGetUniformLocation (shader , "MVP");
sampler = glGetUniformLocation (shader, "sampler");
coord = glGetAttribLocation(shader, "coord");
uv = glGetAttribLocation (shader, "uv");


}

void Ball::Draw()
{
glUseProgram (shader);
    glUniformMatrix4fv(MVPid, 1, GL_FALSE, &Camera.GetMVP()[0][0]); // Send MVP     to shader

    glActiveTexture (GL_TEXTURE0); // bind the ball texture
    glBindTexture (GL_TEXTURE_2D, ballTex);
    glUniform1i (sampler , 0);
        glEnableVertexAttribArray (coord); // sending the vertex data
            glBindBuffer(GL_ARRAY_BUFFER, vertBuf);
                glVertexAttribPointer(
                    coord, // The attribute we want to configure
                    2,                  // size
                    GL_FLOAT,           // type
                    GL_FALSE,           // normalized?
                    0,                  // stride
                    (void*)0            // array buffer offset
                    );

        glEnableVertexAttribArray (uv);
            glBindBuffer (GL_ARRAY_BUFFER , uvBuf);
                glVertexAttribPointer (uv, 2, GL_FLOAT, GL_FALSE, 0,     (void*)0);

    // Draw the triangle !
            glDrawArrays(GL_TRIANGLES, 0, ballVert.size()); 

        glDisableVertexAttribArray(coord);
        glDisableVertexAttribArray(uv);
}