OpenGL (SDL,C++) - tutorial 1

//http://www.youtube.com/user/thecplusplusguy
//OpenGL tutorial 1
#include <iostream>
#include <SDL/SDL.h>
#include <GL/gl.h>
#include <GL/glu.h>

void init()
{
    glClearColor(0.0,0.0,0.0,1.0);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45.0,640.0/480.0,1.0,500.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
}

void display()
{
    glClear(GL_COLOR_BUFFER_BIT);
    glBegin(GL_TRIANGLES);
        glVertex3f(0.0,2.0,-5.0);
        glVertex3f(-2.0,-2.0,-5.0);
        glVertex3f(2.0,-2.0,-5.0);
    glEnd();
}

int main(int main,char** argv)
{
    SDL_Init(SDL_INIT_EVERYTHING);
    SDL_Surface* screen=SDL_SetVideoMode(640,480,32,SDL_SWSURFACE|SDL_OPENGL);
    bool running=true;
    Uint32 start;
    SDL_Event event;
    init();
    while(running)
    {
        start=SDL_GetTicks();
        while(SDL_PollEvent(&event))
        {
            switch(event.type)
            {
                case SDL_QUIT:
                    running=false;
                    break;
            }
        }
        display();
        SDL_GL_SwapBuffers();
        if(1000/30>(SDL_GetTicks()-start))
            SDL_Delay(1000/30-(SDL_GetTicks()-start));
    }
    SDL_Quit();
    return 0;
}