c program for dda line

c program for dda line

void main()

{

int gd=detect, gm;

int  x, y, x1, y1, x2, y2;

float  m, dx, dy;

printf(“enter x1 and y1 :”);

scanf(“%d %d”,&x1,&y1);

printf(“enter x2 and y2 :”);

scanf(“%d %d”,&x2,&y2);

dx = x2 – x1;

dy = y2 – y1;

m = dy / dx;

initgraph(&gd,&gm,””);

if(abs(m)<=1)

{

if(x1>x2)

{

     swap(x1,x2);    // use appropriate function

     swap(y1,y2);

}

for(x=x1,y=y1;x<=x2;)

{

     putpixel(x,y,2);

     x++;

     y=round(m+y);

}

}

else

{

if(y1>y2)

{

     swap(x1,x2);    // use appropriate function

     swap(y1,y2);

}

for(x=x1,y=y1;y<=y2;)

{

     putpixel(x,y,2);

     y++;

     x=round(x+(1/m));

}

}

getch();

closegraph();

}