Experiment-1 Computer Graphics (DDA Line Drawing Algorithm).cpp

#include <iostream.h>
#include <stdio.h>
#include <conio.h>
#include <math.h>
#include <stdlib.h>
#include <dos.h>
#include <graphics.h>



void dda (int x1,int y1, int x2, int y2);
void dda (int x1,int y1, int x2, int y2)
{
 int i,dx,dy,steps;
 float x,y;
 float xinc,yinc;
 dx=(x2-x1);
 dy=(y2-y1);
 if(abs(dx)>=abs(dy))
 {
  steps=dx;
 }
 else
 steps=dy;
 xinc=(float)dx/steps;
 yinc=(float)dy/steps;
 x=x1;
 y=y1;
 putpixel(x,y,WHITE);
 for(i=1;i<steps;i++)
 {
  x=x+xinc;
  y=y+yinc;
  putpixel(x,y,WHITE) ;

 }
}

void dda_dotted(int x1, int y1, int x2, int y2);
void dda_dotted(int x1,int y1, int x2, int y2){
  int i,dx,dy,steps;
  float x,y;
  float xinc,yinc;
  dx=(x2-x1);
  dy=(y2-y1);
  if ( abs(dx)>= abs(dy))
  steps=dx;
  else
  steps=dy;
  xinc=(float)dx/steps;
  yinc=(float)dy/steps;
  x=x1;
  y=y1;
  putpixel(x,y,WHITE);
  for( i=1; i<steps; i++){
  	if(i%2==0)
  	{
  	putpixel(x,y,WHITE);
  	}
    x= x+ xinc;
    y= y+yinc;
    }
}

void dda_dashed(int x1, int y1, int x2, int y2);
void dda_dashed(int x1,int y1, int x2, int y2){
  int i,dx,dy,steps;
  float x,y;
  float xinc,yinc;
  dx=(x2-x1);
  dy=(y2-y1);
  if ( abs(dx)>= abs(dy))
  steps=dx;
  else
  steps=dy;
  xinc=(float)dx/steps;
  yinc=(float)dy/steps;
  x=x1;
  y=y1;
  putpixel(x,y,WHITE);
  for( i=1; i<steps; i++){
  	if(i%4==0)
  	{
  	putpixel(x,y,WHITE);
  	}
    x= x+ xinc;
    y= y+yinc;
    }
}

void main()
{
 int gd=DETECT,gm;
 int x1,y1,x2,y2,option;
 initgraph(&gd,&gm,"C:\\TURBOC3\\BGI");
 cleardevice();
 cout<< "DDA Line Generation Algorithm";
 cout<<"\n Enter the starting co-ordinates for drawing a line";
 cin>>x1>>y1;
 cout<<"\n Enter the ending co-ordinates";
 cin>>x2>>y2;
 cout<<"\nEnter your options:\n1) Normal DDA\n2) Dotted \n3) Dashed\n";
 cin>>option;

 switch(option){
   case 1: dda(x1,y1,x2,y2);
   break;
   case 2:dda_dotted(x1,y1,x2,y2);
   break;
   case 3:dda_dashed(x1,y1,x2,y2);
   break;
   default: cout<<"\n Invalid option";
   break;
 }


 getch();
 closegraph();
 }