c++ - OpenGLクワッドがレンダリングされない

Question

私は本の例から持っています、私は色の黒いものGL_QUADSを投げました、そして私はまだそれを手に入れません、私が得るのは私の澄んだ白い画面だけです何が間違っているのでしょうか?

#include "SDL.h"
#include "SDL_opengl.h"
#include <iostream>
int main(int argc, char* args[])
{
    // Memory usage specifics
    SDL_Init(SDL_INIT_EVERYTHING);
    SDL_GL_SetAttribute( SDL_GL_RED_SIZE, 8 );
    SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, 8 );
    SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, 8 );
    SDL_GL_SetAttribute( SDL_GL_ALPHA_SIZE, 8 );
    SDL_GL_SetAttribute( SDL_GL_BUFFER_SIZE, 32 );
    SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16 );
    SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );

    // name on the window
    SDL_WM_SetCaption( "our first game", NULL );

    //set screen
    SDL_SetVideoMode(600,400,32, SDL_OPENGL);

    // when screen is clear
    glClearColor(1,1,1,1); //red, green, blue, alpha

    //portion to display
    glViewport(0,0,600,400);

    //shade
    glShadeModel(GL_SMOOTH);

    // 3D or 2D
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity(); //saves

    //if only 2D?
    glDisable(GL_DEPTH_TEST);
    //this handles the main loop
    bool isRunning = true;
    //this is for the events
    SDL_Event event;

    //main rectangle
    float myX = 300;
    float myY = 350;
    float width = 50;
    float height = 30;

    //main loop
    while ( isRunning )
    {
        //EVENTS
        while ( SDL_PollEvent(&event) )
        {
            //logic that should happen for certain events
            //quiting the window
            if ( event.type == SDL_QUIT )
            {
                isRunning = false;
            }
            // if ESC pressed
            if ( event.type == SDL_KEYUP && event.key.keysym.sym == SDLK_ESCAPE )
            {
                isRunning = false;
            }
        }
        //LOGIC

        //RENDERING TO THE SCREEN
         glClear(GL_COLOR_BUFFER_BIT);
         //start rendering phase
         glPushMatrix();
         //set the matix
         glOrtho(0,600,400,0,-1,1);
         //black color
         glColor4ub(0,0,0,255);

         //drawing
         //GL_QUADS, GL_POINTS, GL_LINES, GL_LINE_STRIP,
         //GL_LINE_LOOP, GL_QUADS, GL_TRIANGLES, GL_POLIGON

         glBegin(GL_QUADS);
            glVertex2f(myX,myY);
            glVertex2f(myX+width,myY);
            glVertex2f(myX+width,myY+height);
            glVertex2f(myX,myY+height);
         glEnd();



        //render
        SDL_GL_SwapBuffers();
    }
    //house keeping
    SDL_Quit();
    return 0;
}