C++ program to implement shearing in graphics

A shear is a transformation that distorts the shape of an object along either or both of the axies. Like scale and translate, a shear can be done along just one or along both of the coordinate axes. A shear along one axis (say, the x-axis) is performed in terms of the point's coordinate in the other axis (the y-axis). Thus a shear of 1 in the x-axis will cause the x-coodinate of the point ot distort by 1*(y-coordinate). 

http://www.gomezconsultants.com/CSE5280/Transformations/2DTrans.html

Pogram

#include<iostream.h>
#include<conio.h>
#include<graphics.h>
#include<dos.h>
void main()
{
int gd=DETECT,gm;
initgraph(&gd,&gm,"C:\\Tc\\BGI");
float x1,y1,x2,y2;
float shx,shy;
char ch;
x1=50;y1=100;x2=100;y2=200;
rectangle(x1,y1,x2,y2);
delay(10);
cout<<"enter the direction of shear : ";
cin>>ch;
if(ch=='x')
{
cout<<"enter x-direction of shear : ";
cin>>shx;
y1=y1+shx*x1;
y2=y2+shx*x2;
setcolor(RED);
rectangle(x1,y1,x2,y2);
}
else
{
cout<<"enter y-direction of shear : ";
cin>>shy;
x1=x1+shy*y1;
x2=x2+shy*y2;
setcolor(RED);
rectangle(x1,y1,x2,y2);
}
getch();
closegraph();
}