DDA algorithm : Define the nodes, i.e end points in form of (x1,y1) and (x2,y2). Calculate the distance between the two end points vertically and horizontally, i.e dx=|x1-x2| and dy=|y1-y2|. Define new variable name ‘pixel’, and compare dx and dy values, if dx > dy then pixel=dx else pixel =dy. dx=dx/pixel and dy=dy/pixel x=x1; y=y1; while (i<=pixel) compute the pixel and plot the pixel with x=x+dx and y=y+dy. c program for dda algorithm : #include <graphics.h> #include <stdio.h> #include <math.h> int main( ) { float x,y,x1,y1,x2,y2,dx,dy,pixel; int i,gd,gm; printf("Enter the value of x1 : "); scanf("%f",&x1); printf("Enter the value of y1 : "); scanf("%f",&y1); printf("Enter the value of x2 : "); scanf("%f",&x2); printf("Enter the value of y1 : "); scanf("%f",&y2); detectgraph(&gd,&gm); ...