VBO

#include <OpenGL/OpenGL.h>
#include <GLUT/glut.h>
#include <iostream>
#include <vector>

using namespace std;

const float width= 800, height=600;
vector<GLfloat> data;
GLuint buffer;

void init(void)
{
    glEnable(GL_DEPTH_TEST);
    glViewport(0,0,width,height);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45.0, width/height , 1.0, 1000.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    gluLookAt(0.0, 0.0, 100.0, width/2, height/2, 0.0, 0.0, 1.0, 0.0);

    data= vector<GLfloat> {
        width/2+20,height/2+20,0.0,
        width/2+20,height/2-20,0.0,
        width/2-20, height/2-20,0.0,
        width/2-20, height/2+20,0.0
    };
    glGenBuffers(1, &buffer);
    glBindBuffer(GL_ARRAY_BUFFER, buffer);
    glBufferData(GL_ARRAY_BUFFER, 12*sizeof(GLfloat), data.data(), GL_STATIC_DRAW);
    glBindBuffer(GL_ARRAY_BUFFER, 0);
}

void display(void)
{
    glClearColor(1.0, 1.0, 1.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glColor3f(1, 0, 0);
    glBindBuffer(GL_ARRAY_BUFFER, buffer);
    glEnableClientState(GL_VERTEX_ARRAY);
    glVertexPointer(3, GL_FLOAT, 0, data.data());
    glDrawArrays(GL_QUADS, 0, 4);
    glDisableClientState(GL_VERTEX_ARRAY);
    glBindBuffer(GL_ARRAY_BUFFER, 0);

    glutSwapBuffers();
}

int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitWindowPosition(100, 100);
    glutInitWindowSize(width,height);
    glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH);
    glutCreateWindow("Interaction");
    glutDisplayFunc(display);
    init();
    glutMainLoop();
    return 0;
}