#include <graphics.h>	
#include <stdlib.h>	
#include <stdio.h>	
#include <conio.h>	
#include <math.h>	
#include <dos.h>	
#define Pi 3.1415926536	
enum Action{move,draw};	
struct Point3D	
{	
  int x;	
  int y;	
  int z;	
  Action action;	
};	
// this function initializes graphics mode	
// it will work only if you're using Borland C++ compiler & BGI drivers	
// if you're using another compiler you should overwrite body of this function	
void init_gr(void)	
{	
  /* request autodetection */	
  int gdriver = DETECT, gmode, errorcode;	
  /* initialize graphics mode */	
  initgraph(&gdriver, &gmode, "");	
  /* read result of initialization */	
  errorcode = graphresult();	
  if (errorcode != grOk)    /* an error occurred */	
  {	
     printf("Graphics error: %s\n", grapherrormsg(errorcode));	
     printf("Press any key to halt:");	
     getch();	
     exit(1);               /* return with error code */	
  }	
}	
// this function shuts graphics mode down	
// it will work only if you're using Borland C++ compiler & BGI drivers	
// if you're using another compiler you should overwrite body of this function	
void end_gr(void)	
{	
  closegraph();	
}	
// this function moves CP to (x,y) position	
// it will work only if you're using Borland C++ compiler & BGI drivers	
// if you're using another compiler you should overwrite body of this function	
void MoveTo(int x, int y)	
{	
  moveto(x,y);	
}	
// this function draws a line to (x,y) position	
// it will work only if you're using Borland C++ compiler & BGI drivers	
// if you're using another compiler you should overwrite body of this function	
void LineTo(int x, int y)	
{	
  lineto(x,y);	
}	
void draw3Dobject(Point3D *object, int N, float rho, float theta,	
                  float phi, float dist_to_screen, int xshift, int yshift)	
{	
  int x,y;	
  float xe,ye,ze,costh,sinph,cosph,sinth,v11,v12,v13,v21,v22,v32,v33,v23,v43;	
  // calculating coefficients	
  costh=cos(theta);	
  sinth=sin(theta);	
  cosph=cos(phi);	
  sinph=sin(phi);	
  v11=-sinth; v12=-cosph*costh; v13=-sinph*costh;	
  v21=costh;  v22=-cosph*sinth; v23=-sinph*sinth;	
              v32=sinph;        v33=-cosph;	
                                v43=rho;	
  for (int i=0;i<N;i++)	
  {	
     // calculating eye coordinates	
     xe=v11*(object+i)->x+v21*(object+i)->y;	
     ye=v12*(object+i)->x+v22*(object+i)->y+v32*(object+i)->z;	
     ze=v13*(object+i)->x+v23*(object+i)->y+v33*(object+i)->z+v43;	
 
     // calculating screen coordinates	
     x=dist_to_screen*xe/ze+xshift;	
     y=dist_to_screen*ye/ze+yshift;	
     // drawing	
     if((object+i)->action==move)	
       MoveTo(x,y);	
     else	
       LineTo(x,y);	
  }	
}	
int main(void)	
{	
  const int n=4; // number of cubes segments +1	
  Point3D cube[15*n]; // coordinates for cubes points	
  float rho=1900,theta=Pi/3,phi=2*Pi/3,dist_to_screen=600; // view point	
  int xshift=300, yshift=140; // picture offset	
  float side=300; // cubes parameters	
  float delta;// auxulary variable	
  // initializing graphics mode	
  init_gr();	
  // generating cube	
  delta=side/(n-1);	
  for (int i=0;i<n;i++)	
  {	
    for(int j=i*5;j<i*5+5;j++)	
    {	
      cube[j].x=i*delta;	
      cube[j].action=draw;	
    }	
    cube[i*5].y=0;	
    cube[i*5].z=0;	
    cube[i*5].action=move;	
    cube[i*5+1].y=side;	
    cube[i*5+1].z=0;	
    cube[i*5+2].y=side;	
    cube[i*5+2].z=side;	
    cube[i*5+3].y=0;	
    cube[i*5+3].z=side;	
    cube[i*5+4].y=0;	
    cube[i*5+4].z=0;	
  }	
  int c=5*n;	
  for (i=0;i<n;i++)	
  {	
    for(int j=i*5;j<i*5+5;j++)	
    {	
      cube[c+j].y=i*delta;	
      cube[c+j].action=draw;	
    }	
    cube[c+i*5].x=0;	
    cube[c+i*5].z=0;	
    cube[c+i*5].action=move;	
    cube[c+i*5+1].x=side;	
    cube[c+i*5+1].z=0;	
    cube[c+i*5+2].x=side;	
    cube[c+i*5+2].z=side;	
    cube[c+i*5+3].x=0;	
    cube[c+i*5+3].z=side;	
    cube[c+i*5+4].x=0;	
    cube[c+i*5+4].z=0;	
  }	
  c=10*n;	
  for (i=0;i<n;i++)	
  {	
    for(int j=i*5;j<i*5+5;j++)	
    {	
       cube[c+j].z=i*delta;	
       cube[c+j].action=draw;	
    }	
    cube[c+i*5].y=0;	
    cube[c+i*5].x=0;	
    cube[c+i*5].action=move;	
    cube[c+i*5+1].y=side;	
    cube[c+i*5+1].x=0;	
    cube[c+i*5+2].y=side;	
    cube[c+i*5+2].x=side;	
    cube[c+i*5+3].y=0;	
    cube[c+i*5+3].x=side;	
    cube[c+i*5+4].y=0;	
    cube[c+i*5+4].x=0;	
  }	
  // drawing	
  draw3Dobject(cube,15*n,rho,theta,phi,dist_to_screen,xshift,yshift);	
  /* clean up */	
  getch();	
  end_gr();	
  return 0;	
}