C PROGRAM TO DEMONSTRATE 3D REFLECTION

/* C PROGRAM TO DEMONSTRATE 3D REFLECTION *//* AUTHOR : DEEPAK MAHAKALE 3RD YEAR IT SRCOEM, NAGPUR*/

#include <stdio.h>
#include <graphics.h>
#include <math.h>
#include <stdlib.h>
#include <dos.h>
#include <conio.h>

#define ORG -50

double face1[5][2] = {
   { 250, 125 },
   { 350, 125 },
   { 350, 225 },
   { 250, 225 },
   { 250, 125 }
          };

double face2[5][2] = {
   { 250+ORG, 125-ORG },
   { 350+ORG, 125-ORG },
   { 350+ORG, 225-ORG },
   { 250+ORG, 225-ORG },
   { 250+ORG, 125-ORG }
          };

double angle = 5.0 * M_PI / 180;
double midx1, midy1, midx2, midy2;

void rotate (void)
{
    int i;
    for (i=0; i<5; i++)
    {
double xnew, ynew;

xnew = midx1 + (face1[i][0] - midx1) * cos (angle) -
      (face1[i][1] - midy1) * sin (angle);
ynew = midy1 + (face1[i][0] - midx1) * sin (angle) +
(face1[i][1] - midy1) * cos (angle);

face1[i][0] = xnew;
face1[i][1] = ynew;

xnew = midx2 + (face2[i][0] - midx2) * cos (angle) -
(face2[i][1] - midy2) * sin (angle);
ynew = midy2 + (face2[i][0] - midx2) * sin (angle) +
(face2[i][1] - midy2) * cos (angle);

face2[i][0] = xnew;
face2[i][1] = ynew;
    }

    cleardevice();

    for (i=0; i<4; i++)
    {
setcolor(7);
line (face1[i][0], face1[i][1], face1[i+1][0], face1[i+1][1]);
setcolor(8);
line (face2[i][0], face2[i][1], face2[i+1][0], face2[i+1][1]);
setcolor(9);
line (face1[i][0], face1[i][1], face2[i][0], face2[i][1]);
    }

    delay (125);
}

void main()
{
    int gd = DETECT, gm;

    midx1 = (face1[0][0] + face1[1][0]) / 2.0;
    midy1 = (face1[1][1] + face1[2][1]) / 2.0;
    midx2 = (face2[0][0] + face2[1][0]) / 2.0;
    midy2 = (face2[1][1] + face2[2][1]) / 2.0;

    initgraph (&gd, &gm, "..\\bgi");

    while (!kbhit())
rotate();

    closegraph();
}