Implementation Of 2D Transformations Computer Graphics

To write a C program to implement 2D transformations.
Step By Step Procedural Algorithm 
1. Enter the choice for transformation.
2. Perform the translation, rotation, scaling, reflection and shearing of 2D object.
3. Get the needed parameters for the transformation from the user.
4. Incase of rotation, object can be rotated about x or y axis.
5. Display the transmitted object in the screen.
Source Code Programming 2D Transformations
#include
#include
#include
#include
int ch,x,y,az,i,w,ch1,ch2,xa,ya,ra,a[10],b[10],da,db;
float x1,y1,az1,w1,dx,dy,theta,x1s,y1s,sx,sy,a1[10],b1[10];
void main()
{
int gm ,gr;
clrscr();
detectgraph(&gm,&gr);
initgraph(&gm,&gr,"d:\\tc\\BGI");
printf("Enter the upper left corner of the rectangle:\n");
scanf("%d%d",&x,&y);
printf("Enter the lower right corner of the rectangle:\n");
scanf("%d%d",&az,&w);
rectangle(x,y,az,w);
da=az-x;
db=w-y;
a[0]=x;
b[0]=y;
a[1]=x+da;
b[1]=y;
a[2]=x+da;
b[2]=y+db;
a[3]=x;b[3]=y+db;
while(1)
{
printf("******2D Transformations*******\n");
printf("1.Translation\n2.Rotation\n3.Scaling\n4.Reflection\n5.Shearing\n6.Exit\nEnter your choice:\n");
scanf("%d",&ch);
switch(ch)
{
case 1:
detectgraph(&gm,&gr);
initgraph(&gm,&gr,"d:\\tc\\BGI");
rectangle(x,y,az,w);
printf("*******Translation*******\n\n");
printf("Enter the value of shift vector:\n");
scanf("%f%f",&dx,&dy);
x1=x+dx;
y1=y+dy;
az1=az+dx;
w1=w+dy;
rectangle(x1,y1,az1,w1);
break;
case 2:
detectgraph(&gm,&gr);
initgraph(&gm,&gr,"d:\\tc\\BGI");
rectangle(x,y,az,w);
printf("*******Rotation*******\n\n");
printf("Enter the value of fixed point and angle of rotation:Enter the value of fixed point and angle of rotation:\n");
scanf("%d%d%d",&xa,&ya,&ra);
theta=(float)(ra*(3.14/180));
for(i=0;i<4;i++)
{
a1[i]=(xa+((a[i]-xa)*cos(theta)-(b[i]-ya)*sin(theta)));
b1[i]=(ya+((a[i]-xa)*sin(theta)+(b[i]-ya)*cos(theta)));
}
for(i=0;i<4;i++)
{
if(i!=3)
line(a1[i],b1[i],a1[i+1],b1[i+1]);
else
line(a1[i],b1[i],a1[0],b1[0]);
}
break;
case 3:
detectgraph(&gm,&gr);
initgraph(&gm,&gr,"d:\\tc\\BGI");
rectangle(x,y,az,w);
printf("********Scaling*******\n\n");
printf("Enter the value of scaling factor:\n");
scanf("%f%f",&sx,&sy);
x1=x*sx;
y1=y*sy;
az1=az*sx;
w1=w*sy;
rectangle(x1,y1,az1,w1);
break;
case 4:
detectgraph(&gm,&gr);
initgraph(&gm,&gr,"d:\\tc\\BGI");
rectangle(x,y,az,w);
printf("*******Reflection*********\n");
printf("1.About x-axis\n2.About y-axis\n3.About both axis\nEnter your choice:\n");
scanf("%d",&ch1);
switch(ch1)
{
case 1:
printf("Enter the fixed point\n");
scanf("%d%d",&xa,&ya);
theta=(float)(90*(3.14/180));
for(i=0;i<4;i++)
{
a1[i]=(xa+((a[i]-xa)*cos(theta)-(-b[i]-ya)*sin(theta)));
b1[i]=(ya+((a[i]-xa)*sin(theta)+(-b[i]-ya)*cos(theta)));
}
for(i=0;i<4;i++)
{
if(i!=3)
line(a1[i],b1[i],a1[i+1],b1[i+1]);
else
line(a1[i],b1[i],a1[0],b1[0]);
}
break;
case 2:
printf("Enter the fixed point\n");
scanf("%d%d",&xa,&ya);
theta=(float)(270*(3.14/180));
for(i=0;i<4;i++)
{
a1[i]=(xa+((-a[i]-xa)*cos(theta)-(b[i]-ya)*sin(theta)));
b1[i]=(ya+((-a[i]-xa)*sin(theta)+(b[i]-ya)*cos(theta)));
}
for(i=0;i<4;i++)
{
if(i!=3)
line(a1[i],b1[i],a1[i+1],b1[i+1]);
else
line(a1[i],b1[i],a1[0],b1[0]);
}
break;
case 3:
printf("Enter the fixed point\n");
scanf("%d%d",&xa,&ya);
theta=(float)(180*(3.14/180));
for(i=0;i<4;i++)
{
a1[i]=(xa+((-a[i]-xa)*cos(theta)-(-b[i]-ya)*sin(theta)));
b1[i]=(ya+((-a[i]-xa)*sin(theta)+(-b[i]-ya)*cos(theta)));
}
for(i=0;i<4;i++)
{
if(i!=3)
line(a1[i],b1[i],a1[i+1],b1[i+1]);
else
line(a1[i],b1[i],a1[0],b1[0]);
}
break;
}
break;
case 5:
detectgraph(&gm,&gr);
initgraph(&gm,&gr,"d:\\tc\\BGI");
rectangle(x,y,az,w);
printf("*******Shearing******\n\n");
printf("1.x-direction shear\n2.y-direction shear\nEnter your choice:\n");
scanf("%d",&ch2);
switch(ch2)
{
case 1:
printf("Enter the value of shear:\n");
scanf("%f",&x1s);
x1=x+(y*x1s);
y1=y;
az1=az+(w*x1s);
w1=w;
rectangle(x1,y1,az1,w1);
break;
case 2:
printf("Enter the value of shear:\n");
scanf("%f",&y1s);
x1=x;
y1=y+(x*y1s);
az1=az;
w1=w+(az*y1s);
rectangle(x1,y1,az1,w1);
break;
}
break;
case 6:
exit(0);
}
}
getch();
}
Example OUTPUT Result compuer Graphics

Enter the upper left corner of the rectangle:
100
100
Enter the lower right corner of the rectangle:
200
200
******2DTransformations*******
1.Translation
2.Rotation
3.Scaling
4.Reflection
5.Shearing
6.Exit

Enter your choice: 1

*******Translation******* Enter the value of shift vector:
150
150
******2DTransformations*******
1.Translation
2.Rotation
3.Scaling
4.Reflection
5.Shearing
6.Exit
Enter your choice: 2
*******Rotation*******
Enter the value of fixed point and angle of rotation:
300
300
70
******2DTransformations******* 1.Translation
2.Rotation
3.Scaling
4.Reflection
5.Shearing
6.Exit
Enter your choice: 3
********Scaling*******
Enter the value of scaling factor:
2
2
******2DTransformations*******
1.Translation
2.Rotation
3.Scaling
4.Reflection
5.Shearing
6.Exit

Enter your choice: 4
*******Reflection*********
1.About x-axis
2.About y-axis
3.About both axis
Enter your choice:1
Enter the fixed point
150
150
Enter your choice: 2
Enter the fixed point
150
150
Enter your choice: 3
Enter the fixed point
150
150
******2DTransformations******* 1.Translation
2.Rotation
3.Scaling
4.Reflection
5.Shearing
6.Exit
Enter your choice: 5
*******Shearing*********
1.x-direction shear
2.y-direction shear
Enter your choice: 1
Enter the value of shear : 2
Enter your choice: 2
Enter the value of shear : 2
RESULT: Thus the c program to implement 2D transformations was coded and executed successfully.