// File: box2a.C
//  Second implementation of class Box.

#include <iostream.h>
#include <stdlib.h>

#include "box2a.h"

// Local function prototypes
static void swap(float &, float &) ;

// Local function implementations
static void swap(float &x, float &y) {
   float temp ;

   temp = x ;
   x = y ;
   y = temp ;
}


// The default constructor initializes
// the new box with default dimensions

Box::Box() {
   length = 1.0 ;
   height = 2.0 ;
   width =  3.0 ;
   top = up ;
}


// Alternate constructor, allows client to specify
// the dimensions of the box.

Box::Box(float x, float y, float z) {
   length = x ;
   height = y ;
   width =  z ;
   top = up ;
}


// Report vital stats
void Box::identify() {

   if (length == 0.0 || height == 0.0  || width == 0.0) {
      cout << "I am an invisible box\n" ;
   } else {
      cout << "I am a box with length=" << length
      << ", height=" << height << " and width=" << width << "\n" ;
   }

   cout << "I am pointing " ;
   switch(top) {
      case front: cout << "to the front" ; break ;
      case back:  cout << "to the back"  ; break ;
      case left:  cout << "to the left"  ; break ;
      case right: cout << "to the right" ; break ;
      case up:    cout << "up" ; break ;
      case down:  cout << "down" ; break ;
      default:
         cerr << "Oops. Bad direction\n" ;
         exit(1) ;
   }
   cout << "\n" ;
}


// Compute box volume
float Box::volume() {
   return length * height * width ;
}


// Double each dimension
void Box::grow() {
   length = length * 2 ;
   height = height * 2 ;
   width  = width  * 2 ;
}


// Halve each dimension
void Box::shrink() {
   length = length / 2 ;
   height = height / 2 ;
   width  = width  / 2 ;
}


// turn around x axis
void Box::turn() {
   swap(height, width) ;

   switch(top) {
       case front :
          top = down ;
          break ;
       case back :
          top = up ;
          break ;
       case left :
          break ;
       case right :
          break ;
       case up :
          top = front ;
          break ;
       case down :
          top = back ;
          break ;
       default :
          cerr << "Oops, internal error in turn\n" ;
          exit(1) ;
   }

}

// spin around y axis
void Box::spin() {
   swap(length, width) ;

   switch(top) {
       case front :
          top = right ;
          break ;
       case back :
          top = left ;
          break ;
       case left :
          top = front ;
          break ;
       case right :
          top = back ;
          break ;
       case up :
          break ;
       case down :
          break ;
       default :
          cerr << "Oops, internal error in spin\n" ;
          exit(1) ;
   }
}


// rotate around z axis
void Box::rotate() {
   swap(length, height) ;

   switch(top) {
       case front :
          break ;
       case back :
          break ;
       case left :
          top = down ;
          break ;
       case right :
          top = up ;
          break ;
       case up :
          top = left ;
          break ;
       case down :
          top = right ;
          break ;
       default :
          cerr << "Oops, internal error in rotate\n" ;
          exit(1) ;
   }
}