LINE USING SLOPE METHOD

/*CSEMATTER.BLOGSPOT.IN
PROGRAM NAME-PROGRAM TO DRAW A LINE USING SLOPE*/

#include<stdio.h>
#include<conio.h>
#include<graphics.h>
int main()
{int gd=DETECT,gm;
float x1,x2,y1,y2;
float m,c,x,y,i;
printf("enter the first coordinatse");
scanf("%f %f",&x1,&y1);
printf("enter the second coordinatse");
scanf("%f %f",&x2,&y2);
m=(y2-y1)/(x2-x1);
c=y1-(m*x1);
initgraph(&gd,&gm,"C:\tc\bgi");
  if(x2!=x1)
   { x=x1;
     y=y1;
       while(x<=x2)
       {y=(m*x)+c;
        putpixel(x,y,15);
        x++;}
    }
else
   printf("ERROR!!!!!!");
   getch();
closegraph();}