#include <gl/glew.h>

#include <gl/freeglut.h>

#include <iostream>

int window_width = ;

int window_height = ;

float rtri = 0.0;

float rquad = 0.0;

void init();

void display();

void resize(int w, int h);

int main(int argc, char ** argv)

{

   glutInit(&argc, argv);

   glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE);

   glutInitWindowSize(, );

   glutCreateWindow("OpenGL");

   GLenum res = glewInit();

   if (res != GLEW_OK)

   {

       std::cout << glewGetErrorString(res) << std::endl;

   }

   init();

   glutDisplayFunc(display);

   glutReshapeFunc(resize);

   glutMainLoop();

   return EXIT_SUCCESS;

}

void init()

{

    glClearColor(0.0, 0.0, 0.0, 1.0);

}

void display()

{

    glClear(GL_COLOR_BUFFER_BIT);

    glLoadIdentity();

    for (int loop = ; loop < ; ++loop)

    {

        if ( == loop)

        {

           glViewport(, , window_width/, window_height/);

           glMatrixMode(GL_PROJECTION);

           glLoadIdentity();

           gluOrtho2D(-, , -, );

        }

        if ( == loop)

        {

            glViewport(window_width/, , window_width, window_height/);

            glMatrixMode(GL_PROJECTION);

            glLoadIdentity();

            gluOrtho2D(-, , -, );

        }

        if ( == loop)

        {

            glViewport(, window_height/, window_width/, window_height);

            glMatrixMode(GL_PROJECTION);

            glLoadIdentity();

            gluOrtho2D(-, , -, );

        }

        if ( == loop)

        {

           glViewport(window_width/, window_height/, window_width, window_height) ;

           glMatrixMode(GL_PROJECTION);

           glLoadIdentity();

           gluOrtho2D(-, , -, );

        }

        glMatrixMode(GL_MODELVIEW);

        glLoadIdentity();

        glClear(GL_DEPTH_BUFFER_BIT);

        if ( == loop)

        {

            glBegin(GL_QUADS);

                glVertex2f(-, -);

                glVertex2f(, -);

                glVertex2f(, );

                glVertex2f(-, );

            glEnd();

        }

        if ( == loop)

        {

            glBegin(GL_QUADS);

                glVertex2f(-, -);

                glVertex2f(, -);

                glVertex2f(, );

                glVertex2f(-, );

            glEnd();

        }

        if ( == loop)

        {

            glBegin(GL_QUADS);

                glVertex2f(-, -);

                glVertex2f(, -);

                glVertex2f(, );

                glVertex2f(-, );

            glEnd();

        }

        if ( == loop)

        {

            glBegin(GL_QUADS);

                glVertex2f(-, -);

                glVertex2f(, -);

                glVertex2f(, );

                glVertex2f(-, );

            glEnd();

        }

    }

    glutSwapBuffers();

}

void resize(int w, int h)

{

     window_height = h;

     window_width = w;

}