C - Program to Implement DDA and Bresenhams Line and Circle Drawing Algorithm
#include<iostream.h>
#include<stdio.h>
#include<conio.h>
#include<graphics.h>
#include<math.h>
#include<stdlib.h>
#include<dos.h>
class shape // Declare a class
shape
{
float x1,y1,x2,y2;
public:
void dda(float x1,float x2,float
y1,float y2); // pass
rthe parameters to draw a line
void Bresenhamsline(float x1,float
x2,float y1,float y2); //
pass the co-ordinates to draw the line
using bresenhamsline drawing
algorithm
void Bresenhamscircle(); //pass
the co-ordinates to draw the circle using bresenhams circle drawing
algorithm
};
void
shape::dda(float x1,float x2,float y1,float y2 )
{
int dx,dy,step,xinc,yinc;
float slop,x3,y3;
dx=x2-x1; //passing
the parameters to starting and
ending points of parameter
dy=y2-y1;
if(abs(dx)>abs(dy))
step=abs(dx); // calculate the absolute value
else
step=abs(dy);
if(dx==0)
slop=float(dy/(dx+0.1)); //find the slope of line
else
slop=float(dy/dx);
putpixel(x1,y1,WHITE);
x3=x1;
y3=y1;
for(int i=1;i<step;i++)
{
If(abs(dx)>abs(dy)&&x3<x2)
{
x3=x3+1;
y3=float(y3+slop);
}
else
if(abs(dx)>abs(dy) && x3>x2)
{
x3=x3-1;
y3=y3-slop;
}
else
if(abs(dx)<abs(dy) && y3<y2)
{
x3=float(x3+(1/slop));
y3=y3+1;
}
else
if(abs(dx)<abs(dy) && y3>y2)
{
x3=float(x3-(1/slop));
y3=y3-1;
}
xinc=(x3+0.5);
yinc=(y3+0.5);
putpixel(xinc,yinc,WHITE);
}
}
void
shape::Bresenhamsline(float x1,float x2,float y1,float y2)
{
float Dx,Dy,x,y,e;
Dx = x2 - x1;
Dy = y2 - y1;
Dx = fabs(Dx);
Dy = fabs(Dy);
x = x1;
y = y1;
e = 2 * (Dy-Dx);
int i;
i = 1;
cleardevice();
do
{
putpixel(x,y,15);
while(e>=0)
{
y = y + 1;
e = e - (2*Dx);
}
x = x + 1;
e = e + (2 * Dy);
i = i + 1;
}while(i<=Dx);
}
void shape::Bresenhamscircle()
{
float r,d,x,y;
cout<<"\n\tEnter the radius of
a circle->";
cin>>r;
clrscr();
cleardevice();
x = 0;
y = r;
d = 3 - (2 * r);
do
{
putpixel(200+x,200+y,15);
putpixel(200+y,200+x,15);
putpixel(200+y,200-x,15);
putpixel(200+x,200-y,15);
putpixel(200-x,200-y,15);
putpixel(200-y,200-x,15);
putpixel(200-y,200+x,15);
putpixel(200-x,200+y,15);
if(d<=0)
{
d = d + (4*x) + 6;
}
else
{
d = d + (4*(x-y)) + 10;
y = y - 1;
}
x = x +1;
delay(10);
}while(x<y);
}
void main()
{
int ch;
float
x1,x2,y1,y2;
shape s;
int gdriver = DETECT, gmode, errorcode;
initgraph(&gdriver, &gmode,
"c:\\tc\\bgi");
errorcode = graphresult();
if (errorcode != grOk)
{
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to
halt:");
getch();
exit(1);
}
do
{
cout<<"\n\n\t\tMENU";
cout<<"\n\t1:DDA
line drawing";
cout<<"\n\t2:Bresenhamsline";
cout<<"\n\t3:Bresenhamscircle;";
cout<<"\n\nEnter
Your choice";
cin>>ch;
switch(ch)
{
case
1:cout<<"\nEnter (x1,y1) point";
cin>>x1>>y1;
cout<<"\nEnter (x2,y2)
point";
cin>>x2>>y2; ;
clrscr();
s.dda(x1,x2,y1,y2);
break;
case 2:
cout<<"\nEnter (x1,y1)
point";
cin>>x1>>y1;
cout<<"\nEnter (x2,y2)
point";
cin>>x2>>y2; ;
clrscr();
s.Bresenhamsline(x1,x2,y1,y2);
break;
case 3: clrscr();
s.Bresenhamscircle();
break;
}
}while(ch!=4);
getch();
}
