###### Digital Differential Analyzer (DDA) Algorithm is the simple line generation algorithm. DDA is hardware or software used for interpolation of variables over an interval between start and end point. DDAs are used for rasterization of lines, triangles and polygons.

###### Below is a program written in C to draw a simple line using DDA Line Drawing Algorithm.

Code:#include#include#includevoid main(){int gd=DETECT,gm,x,y,x1,y1,x2,y2,dx,dy,i;float length,xinc,yinc;initgraph(&gd,&gm,"C:\\tc\\bgi");cleardevice();printf("Enter x1,y1,x2,y2:");scanf("%d%d%d%d",&x1,&y1,&x2,&y2);dx=x2-x1;dy=y2-y1;if(abs(dx)>=abs(dy))length=abs(dx);elselength=abs(dy);xinc=dx/length;yinc=dy/length;x=x1;y=y1;putpixel((int)x,(int)y,WHITE);i=0;while(i<=length){x=x+xinc;y=y+yinc;putpixel((int)x,(int)y,WHITE);delay(100);i=i+1;}getch();closegraph();restorecrtmode();}

__Output:__

###### Note: Just copy the files “CGA.bgi” & “EGAVGA.bgi” from bgi folder to bin. So, if you have copied these 2 files then you can skip writing “C:\\tc\\bgi” in initgraph with just “”(2 double quotes).

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