Program to implement DDA Line Drawing Algorithm

Program to implement DDA Line Drawing Algorithm #include<iostream.h> #include<graphics.h> #include<conio.h> #include<math.h> #include<dos.h> #include<stdlib.h> #include<stdio.h> class lines { private: int length,x1,y1,x2,y2,x,y,dx,dy,wx,wy,w,width; public: lines(); //Constructor void showline(); int sign(int); }; int lines::sign(int xx) { if(xx<0) return -1; if(xx==0) return 0; if(xx>0) return 1; return 0; } lines::lines() { x=0;y=0; cout<<" "Enter The Co-Ordinates (x1,y1) ":="; cin>>x1>>y1; cout<<" "Enter The Co-Ordinates (x2,y2) ":="; cin>>x2>>y2; cout<<" "Enter The Width Of The Line ":="; cin>>width; } void lines::showline() { char *s,*s1; if(abs(x2-x1)>=abs(y2-y1)) length=abs(x2-x1); else length=abs(y2-y1); w=width; wx=((w-1)/2)*(sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1))/abs(y2-y1)); wy=((w-1)/2)*(sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1))/abs(x2-x1)); dx=(x2-x1)/length; dy=(y2-y1)/length; if(dy>dx) wy=wx; x=x1+0.5*sign(dx); y=y1+0.5*sign(dy); int i=1; setcolor(0); while(i<=length) { for(int j=0;j<wy;j++) putpixel((x+320),480-(y+240+j),6); for(j=0;j<wy;j++) putpixel((x+320),480-(y+240-j),6); putpixel((x+320),480-(y+240),6); x+=dx; y+=dy; i++; } setcolor(15); outtextxy(40,10,"The Points Are:="); sprintf(s,"A(%d,%d)",x1,y1); outtextxy(40,20,s); sprintf(s,"B(%d,%d)",x2,y2); outtextxy(40,30,s); getch(); } void main() { int gd=DETECT,gm,i,j,xx=240,xxx=380; clrscr(); lines a; char *mess[]={"D","D","A"," ","A","L","G","O","R","I","T","H","M"}; initgraph(&gd,&gm,"..\bgi"); cleardevice(); rectangle(120,40,320,240); rectangle(320,40,520,240); rectangle(120,240,320,440); rectangle(320,240,520,440); for(i=0,j=12;i<8,j>=6;i++,j--) { xx+=10; outtextxy(xx,10,mess[i]); xxx-=10; outtextxy(xxx,10,mess[j]); delay(100); } for(i=130;i<=510;i+=10) for(j=50;j<=430;j+=10) putpixel(i,j,15); for(i=130;i<=510;i+=10) { if(i==320) continue; outtextxy(i,237,"+"); } for(i=50;i<=430;i+=10) { if(i==240) continue; outtextxy(317,i,"-"); } outtextxy(310,230,"O"); outtextxy(530,240,"X"); outtextxy(320,450,"-Y"); outtextxy(100,240,"-X"); outtextxy(320,30,"Y"); a.showline(); closegraph(); }