Pemerograman C++ with OpenGL (3-Lines)

//PEMBUATAN BANYAK GARIS

#include <windows.h>
#include <GL\glut.h>
void display(void)
{
//membersihkan buffer
glClear(GL_COLOR_BUFFER_BIT);
//menggambar garis
glBegin(GL_LINES);
glColor3f(1.0,0.0,0.0); //merah
glVertex2f(10.0,10.0);
glVertex2f(10.0,110.0);
glVertex2f(50.0,10.0);
glVertex2f(50.0,110.0);
glVertex2f(90.0,10.0);
glVertex2f(90.0,110.0);
glVertex2f(130.0,10.0);
glVertex2f(130.0,110.0);

glEnd();

glBegin(GL_LINES);
glColor3f(0.0,0.0,1.0); //biru
glVertex2f(20.0,10.0);
glVertex2f(20.0,110.0);
glVertex2f(60.0,10.0);
glVertex2f(60.0,110.0);
glVertex2f(100.0,10.0);
glVertex2f(100.0,110.0);
glVertex2f(140.0,10.0);
glVertex2f(140.0,110.0);
glEnd();

glBegin(GL_LINES);
glColor3f(0.0,1.0,0.0); //hijau
glVertex2f(30.0,10.0);
glVertex2f(30.0,110.0);
glVertex2f(70.0,10.0);
glVertex2f(70.0,110.0);
glVertex2f(110.0,10.0);
glVertex2f(110.0,110.0);
glVertex2f(150.0,10.0);
glVertex2f(150.0,110.0);
glEnd();

glBegin(GL_LINES);
glColor3f(1.0,1.0,0.0); //kuning
glVertex2f(40.0,10.0);
glVertex2f(40.0,110.0);
glVertex2f(80.0,10.0);
glVertex2f(80.0,110.0);
glVertex2f(120.0,10.0);
glVertex2f(120.0,110.0);
glVertex2f(160.0,10.0);
glVertex2f(160.0,110.0);
glEnd();

glFlush();
}
void reshape(int w, int h){
glViewport (0,0, (GLsizei) w, (GLsizei) h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluOrtho2D(0.0,160.0,0.0,120.0);
}
void init(void){
//membuat background warna merah
glClearColor(0.0,0.0,0.0,0.0);
//set viewport dengan nilai 320 x 240, inisialisasi windowsize
glViewport(0,0,320,240);
// set the 2D clipping area
gluOrtho2D(0.0, 170.0,0.0, 120.0);
glPointSize(5.0);
}
/* Deklarasi window size, position, dan display mode(single buffer and RGBA).
* Pemanggilan routin inisialisasi.
* Memanggil fungsi untuk manampilkan objek di layar
*/
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize (320, 240);
glutInitWindowPosition (200, 100);
glutCreateWindow ("Garis Lurus");
init ();
glutDisplayFunc(display);
glutMainLoop();
return 0;
}


//hasilnya