DEMO

#include <windows.h> //Don't include this for Ubuntu OS
#include <GL/glut.h> //OpenGL library
#include <stdio.h> //Standard Input Output
#include <math.h> //For mathematical operations

void display(){
    glClearColor(0,0,0,0);  //sets color glClearColor(R,G,B,alpha);
    glClear(GL_COLOR_BUFFER_BIT);   //set color sent the buffer

    glPointSize(30);    //setting the size of the point
    glColor3f(1,0,1);   //you can set it here and all the objects will have the same color
    glBegin(GL_POINTS);
    glVertex2d(-1,-1);
    glVertex2d(-0.7,0.3);
    glColor3f(1,1,1);
    glVertex2d(-0.6,0.4);
    glColor3f(1,1,0);
    glVertex2d(-0.5,0.5);
    glColor3f(1,0,0);
    glVertex2d(-0.4,0.4);
    glColor3f(0,1,1);
    glVertex2d(-0.5,0.3);
    glEnd();

    glBegin(GL_LINES);
    glColor3f(0,1,1);
    glVertex2d(-0.6,-0.6);
    glColor3f(1,1,0);
    glVertex2d(-0.3,-0.6);
    glColor3f(1,1,1);
    glVertex2d(-0.6,-0.3);
    glColor3f(1,0,0);
    glVertex2d(-0.3,-0.3);
    glEnd();

    glBegin(GL_LINE_STRIP);
    glColor3f(1,1,0);
    glVertex2d(0.3,0.6);
    glColor3f(0,1,1);
    glVertex2d(0.6,0.6);
    glColor3f(1,1,1);
    glVertex2d(0.6,0.3);
    glColor3f(1,0,0);
    glVertex2d(0.3,0.3);
    glEnd();

    glBegin(GL_LINE_LOOP);
    glColor3f(1,1,0);
    glVertex2d(0.3,-0.6);
    glColor3f(0,1,1);
    glVertex2d(0.6,-0.6);
    glColor3f(1,1,1);
    glVertex2d(0.6,-0.3);
    glColor3f(1,0,0);
    glVertex2d(0.3,-0.3);
    glEnd();

    glBegin(GL_POLYGON);
    glColor3f(1,1,0);
    glVertex2d(0,0.5);
    glColor3f(0,1,1);
    glVertex2d(0.5,0);
    glColor3f(1,1,1);
    glVertex2d(0,-0.5);
    glColor3f(1,0,0);
    glVertex2d(-0.5,0);
    glEnd();

    glFlush();  //used to push/display the information stored in the buffer to the screen
}

int main(int argc,char **argv){

    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB|GLUT_SINGLE);
    glutInitWindowSize(1000,1000); //initilizing the window size
    glutInitWindowPosition(0,0);    //initilizing the position
    glutCreateWindow("Demo");       //naming the window
    glutDisplayFunc(display);       //displaying the function
    glutMainLoop();                 //
    return 0;
}

//argc - argument count
//argv - argument value
//used to pass arguments when you run the program
//for example /a.out hello
//it will print hello if