BresLine

#include<stdio.h>
#include<conio.h>
#include<graphics.h>
#include<math.h>
int one(int p){
    int p1;
    if(p<0)
    p1=-1;
    else p1=1;
    return p1;
}
void bres(int x1,int y1,int x2,int y2,int color){
    int dx,i,dy,p,x,y,xend,yend;
    int xinc=one(x2-x1);
    int yinc=one(y2-y1);
    dx=abs(x2-x1);
    dy=abs(y2-y1);
    x=x1; y=y1;
    if(dx>dy){
        p=2*dy-dx;
        putpixel(x,y,color);
        for(i=0;i<dx;i++){
            x+=xinc;
            if(p<0)
            p=p+2*dy;
            else{
                y+=yinc;
                p=p+2*(dy-dx);
            }
            putpixel(x,y,color);
        }
    }
    else{
        p=2*dx-dy;
        putpixel(x,y,color);
        for(i=0;i<dy;i++){
            y+=yinc;
            if(p<0)
            p=p+2*dx;
            else{
                x+=xinc;
                p=p+2*(dx-dy);
            }
            putpixel(x,y,color);
        }
    }
}
void main(){
    int gd=DETECT,gm;
    clrscr();
    initgraph(&gd, &gm, "C:\\tc\\bgi");
    bres(150,100,200,50,WHITE);
    bres(150,100,200,150,WHITE);
    bres(200,150,250,100,WHITE);
    bres(250,100,200,50,WHITE);
    bres(100,150,200,150,WHITE);
    bres(100,150,50,200,WHITE);
    bres(50,200,150,200,WHITE);
    bres(150,200,200,150,WHITE);
    bres(200,150,300,150,WHITE);
    bres(200,150,250,200,WHITE);
    bres(250,200,350,200,WHITE);
    bres(350,200,300,150,WHITE);
    getch();
}