#include <cmath>
#include <ctime>
#include <string>
#include <iostream>
using namespace std;
#include <GL/glut.h>

void display();
void myinit();
void processSpecialKeys(int, int, int);

/* globals */
GLsizei wh = 500, ww = 600; /* initial window size */
GLdouble vw = 100;

void myinit()
{
   glViewport(0, 0, (GLsizei) ww, (GLsizei) wh);
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
   glOrtho(-100.0, 100.0, -100.0, 100.0, -100.0, 100.0);
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();

   glEnable(GL_DEPTH_TEST);

}

void display()
{
    glClearColor (1.0, 1.0, 1.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glColor3f(0.0, 0.0, 0.0);

    glBegin(GL_POLYGON);
	    glVertex3f(0.0,-5.0,0.0);
        glVertex3f(50.0,-5.0,0.0);
        glVertex3f(50.0,5.0,0.0);
        glVertex3f(0.0,5.0,0.0);
    glEnd();
    glBegin(GL_POLYGON);
	    glVertex3f(0.0,-5.0,0.0);
        glVertex3f(0.0,-5.0,5.0);
        glVertex3f(0.0,5.0,5.0);
        glVertex3f(0.0,5.0,0.0);
    glEnd();
    glBegin(GL_POLYGON);
	    glVertex3f(0.0,-5.0,5.0);
        glVertex3f(50.0,-5.0,5.0);
        glVertex3f(50.0,5.0,5.0);
        glVertex3f(0.0,5.0,5.0);
    glEnd();
    glBegin(GL_POLYGON);
	    glVertex3f(0.0,-5.0,0.0);
        glVertex3f(0.0,-5.0,5.0);
        glVertex3f(50.0,-5.0,5.0);
        glVertex3f(50.0,-5.0,0.0);
    glEnd();
    glBegin(GL_POLYGON);
        glVertex3f(50.0,5.0,0.0);
        glVertex3f(50.0,5.0,5.0);
        glVertex3f(0.0,5.0,5.0);
        glVertex3f(0.0,5.0,0.0);
    glEnd();
    // Arrow
    glBegin(GL_TRIANGLES);
        glVertex3f(50.0,-10,0.0);
	    glVertex3f(60.0,0.0,0.0);
	    glVertex3f(50.0,10.0,0.0);
    glEnd();
    glBegin(GL_TRIANGLES);
        glVertex3f(50.0,-10,5.0);
	    glVertex3f(60.0,0.0,5.0);
	    glVertex3f(50.0,10.0,5.0);
    glEnd();
    glBegin(GL_POLYGON);
        glVertex3f(50.0,-10,0.0);
	    glVertex3f(50.0,-10,5.0);
	    glVertex3f(60.0,0.0,5.0);
        glVertex3f(60.0,0.0,0.0);
    glEnd();
    glBegin(GL_POLYGON);
        glVertex3f(50.0,10,0.0);
	    glVertex3f(50.0,10,5.0);
	    glVertex3f(60.0,0.0,5.0);
        glVertex3f(60.0,0.0,0.0);
    glEnd();

    glFlush();
}

void processSpecialKeys(int key, int x, int y)
{
    switch(key) {
        case GLUT_KEY_F7:
                gluPerspective(45.0, ww/wh, 20, 50);
                break;
        case GLUT_KEY_F8:
                glRotatef(3.0, 0.0, 1.0, 0.0);
                break;
        case GLUT_KEY_PAGE_UP:
                glRotatef(-3.0, 1.0, 0.0, 0.0);
                break;
        case GLUT_KEY_PAGE_DOWN:
                glRotatef(3.0, 1.0, 0.0, 0.0);
                break;
        case GLUT_KEY_UP:
                glScalef((1/1.1), (1/1.1), (1/1.1));
                break;
        case GLUT_KEY_DOWN:
                glScalef(1.1, 1.1, 1.1);
                break;
        case GLUT_KEY_LEFT:
                glRotatef(3.0, 0.0, 0.0, 1.0);
                break;
        case GLUT_KEY_RIGHT:
                glRotatef(-3.0, 0.0, 0.0, 1.0);
                break;
    }
    glutPostRedisplay();
}


int main(int argc, char** argv)
{
    glutInit(&argc,argv);
    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize(ww, wh);
    glutCreateWindow("3D Arrow");
    glutDisplayFunc(display);
    myinit();
    glutSpecialFunc(processSpecialKeys);
    glutMainLoop();
}