lab5_src

#include <GL/glut.h>
#include <stdlib.h>


void display(void)
{
    glClear(GL_COLOR_BUFFER_BIT);   //flush gl
    glColor3f(1.0, 0.0, 0.0);       //red line color

    //outer pentagram, clockwise
    glBegin(GL_LINE_LOOP);
        glVertex2i(20,80);
        glVertex2i(70,120);
        glVertex2i(120,80);
        glVertex2i(100,20);
        glVertex2i(40,20);
    glEnd();

    //inner pentagram
    glBegin(GL_LINE_LOOP);
        glVertex2i(70,100);
        glVertex2i(90,40);
        glVertex2i(40,70);
        glVertex2i(100,70);
        glVertex2i(50,40);
    glEnd();

    //connectors
    glBegin(GL_LINES);
        //north
        glVertex2i(70,120);
        glVertex2i(70,100);
        //north-east
        glVertex2i(120,80);
        glVertex2i(100,70);
        //south-east
        glVertex2i(100,20);
        glVertex2i(90,40);
        //south-west
        glVertex2i(40,20);
        glVertex2i(50,40);
        //north-west
        glVertex2i(20,80);
        glVertex2i(40,70);
    glEnd();

    glFlush();  //force immidiate display
}

int main(int argc,char *argv[])
{
    glutInit(&argc,argv);                   //prepare glut
    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);       //set the display mode
    glutInitWindowSize (500, 500);          //the size of the program window
    glutInitWindowPosition (100, 100);      //initial position for the window
    glutCreateWindow ("points and lines");  //create window with a title

    glClearColor(255,255,255,0.0);          //background color
    glMatrixMode (GL_PROJECTION);           //2d envyronment
    gluOrtho2D (0.0, 200.0, 0.0, 150.0);    //matrix dimensions

    glutDisplayFunc(display);               //show thee actual program
    glutMainLoop();

    return EXIT_SUCCESS;                    //exit the program
}