#include <iostream>

#  include <GL/glew.h>
#  include <GL/freeglut.h>
#  include <GL/glext.h>

using namespace std;

// Globals.
float Xvalue,
      Yvalue,
      Zvalue;
float rotX, rotY,rotZ;
bool Hidden;

void cube() {
   // front
   glColor3f(1.0, 0.0, 0.0);
   glBegin(GL_POLYGON) ;
       glVertex3f(0,0,0);
       glVertex3f(0,1,0);
       glVertex3f(1,1,0);
       glVertex3f(1,0,0);
   glEnd();
   
   //bottom 
   glColor3f(0.0, 1.0, 0.0);
   glBegin(GL_POLYGON) ;
       glVertex3f(0,0,0);
       glVertex3f(0,0,1);
       glVertex3f(1,0,1);
       glVertex3f(1,0,0);
   glEnd();

   // top
   glColor3f(0.0, 0.0, 1.0);
   glBegin(GL_POLYGON) ;
       glVertex3f(0,1,0);
       glVertex3f(0,1,1);
       glVertex3f(1,1,1);
       glVertex3f(1,1,0);
   glEnd();

   //left
   glColor3f(1.0, 1.0, 0.0);
   glBegin(GL_POLYGON) ;
       glVertex3f(0,0,0);
       glVertex3f(0,0,1);
       glVertex3f(0,1,1);
       glVertex3f(0,1,0);
   glEnd();

   //left
   glColor3f(1.0, 0.0, 1.0);
   glBegin(GL_POLYGON) ;
       glVertex3f(1,0,0);
       glVertex3f(1,0,1);
       glVertex3f(1,1,1);
       glVertex3f(1,1,0);
   glEnd();

   // top
   glColor3f(1.0, 0.0, 1.0);
   glBegin(GL_POLYGON) ;
       glVertex3f(0,0,1);
       glVertex3f(0,1,1);
       glVertex3f(1,1,1);
       glVertex3f(1,0,1);
   glEnd();
}
// Drawing routine.
void drawScene(void) {
   glClear(GL_COLOR_BUFFER_BIT| GL_DEPTH_BUFFER_BIT);

   glLoadIdentity();

   // draw an axis, that stays put.
   glTranslatef(0.0,0.0,-5.0);
   glColor3f(0.0,0.0,0.0);
   glBegin(GL_LINES);
       glVertex3f(-2,0,0);
       glVertex3f(2,0,0);
       glVertex3f(0,-2,0);
       glVertex3f(0,2,0);
       glVertex3f(0,0,-2);
       glVertex3f(0,0,2);
   glEnd();

   glTranslatef(Xvalue, Yvalue, Zvalue);
   glRotatef(rotX, 1.0, 0.0, 0.0);
   glRotatef(rotY, 0.0, 1.0, 0.0);
   glRotatef(rotZ, 0.0, 0.0, 1.0);

   if(Hidden) {
       glEnable(GL_DEPTH_TEST);
   }

   cube();

   if(Hidden) {
       glDisable(GL_DEPTH_TEST);
   }

   glutSwapBuffers();
}

void reset(void) {
     Xvalue = 0;
     Yvalue = 0;
     Zvalue = -5.0;
     rotX = rotY= rotZ = 0;
     Hidden = true;
     return;
}

// Initialization routine.
void setup(void) {
   reset();
   glPolygonMode(GL_FRONT_AND_BACK, GL_POLYGON);
   //glFrontFace(GL_CW);
   glClearColor(1.0, 1.0, 1.0, 0.0);  
}

// OpenGL window reshape routine.
void resize(int w, int h) {
   glViewport(0, 0, w, h); 
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
   glFrustum(-1.0, 1.0, -1.0, 1.0, 1.5, 20.0);
   glMatrixMode(GL_MODELVIEW);
}

// Keyboard input processing routine.
void keyInput(unsigned char key, int x, int y) {
   switch (key) {
      case 'a':
          rotX -= 10.0;
	  break;
      case 'A':
          rotX += 10.0;
	  break;
      case 'b':
          rotY -= 10.0;
	  break;
      case 'B':
          rotY += 10.0;
	  break;
      case 'c':
          rotZ -= 10.0;
	  break;
      case 'C':
          rotZ += 10.0;
	  break;
      case 'h':
          
	  if (Hidden) {
	      Hidden = false;
	      cout << "Hidden is off" << endl;
	  } else {
	      Hidden=true;
	      cout << "Hidden is on" << endl;
	  }
	  break;
      case 'r':
          reset();
	  break;

      case 'x':
          Xvalue -= .1;
	  break;
      case 'X':
          Xvalue += .1;
	  break;
      case 'y':
          Yvalue -= .1;
	  break;
      case 'Y':
          Yvalue += .1;
	  break;
      case 'Z':
          Zvalue += .1;
	  break;
      case 'z':
          Zvalue -= .1;
	  break;
      case 27:
      case 'q':
         exit(0);
         break;
      default:
         break;
   }
         glutPostRedisplay();
}

// Callback routine for non-ASCII key entry.
void specialKeyInput(int key, int x, int y) {
   if(key == GLUT_KEY_UP) Yvalue += 0.1;
   if(key == GLUT_KEY_DOWN) Yvalue -= 0.1;
   if(key == GLUT_KEY_LEFT) Xvalue -= 0.1;
   if(key == GLUT_KEY_RIGHT) Xvalue += 0.1;
   glutPostRedisplay();
}

// Main routine.
int main(int argc, char **argv) {
   glutInit(&argc, argv);

   glutInitContextVersion(3, 0); 
   glutInitContextProfile(GLUT_COMPATIBILITY_PROFILE); 

   glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH); 
   glutInitWindowSize(500, 500);
   glutInitWindowPosition(100, 100); 
   glutCreateWindow("Teapot");
   glutDisplayFunc(drawScene); 
   glutReshapeFunc(resize);  
   glutKeyboardFunc(keyInput);

   // Register the callback function for non-ASCII key entry.
   glutSpecialFunc(specialKeyInput);

   glewExperimental = GL_TRUE; 
   glewInit(); 
   
   setup(); 

   glutMainLoop();
}