DDA

#include<stdio.h>
#include<conio.h>
#include<graphics.h>
#include<dos.h>
int xround(float m){
    int p=int(m);
    if(m-p>=0.5)
    return p+1;
    else
    return p;
}
void dda(int x1,int y1,int x2,int y2,int color){
    int i,dx=x2-x1,dy=y2-y1;
    float steps;
    if(dx>dy)
    steps=dx;
    else
    steps=dy;
    float xinc=float(dx)/steps;
    float x=x1;
    float y=y1;
    float yinc=float(dy)/steps;
    putpixel(xround(x),xround(y),color);
    for(i=0 ; i<steps ; i++){
        x=x+xinc;
        y=y+yinc;
        putpixel(xround(x),xround(y),color);
    }
}
void main(){
    clrscr();
    int x1,x2,y1,y2;
    int gd=DETECT, gm;
    initgraph(&gd,&gm,"c:\\tC\\bgi");
    dda(50,100,100,50,WHITE);
    dda(100,50,300,50,WHITE);
    dda(100,50,150,100,WHITE);
    dda(300,50,350,100,WHITE);
    dda(150,100,350,100,WHITE);
    dda(50,100,50,250,WHITE);
    dda(150,100,150,250,WHITE);
    dda(350,100,350,250,WHITE);
    dda(50,250,350,250,WHITE);
    dda(75,150,125,150,WHITE);
    dda(75,150,75,250,WHITE);
    dda(125,150,125,250,WHITE);
    dda(200,150,300,150,WHITE);
    dda(200,150,200,200,WHITE);
    dda(200,200,300,200,WHITE);
    dda(300,150,300,200,WHITE);
    getch();
}