Draw a Line using Equation y=mx+c in C

#include<stdio.h>
#include<conio.h>
#include<graphics.h>
#include<math.h>

void draw_line(float,float,float,float);
int round(float);

void main()
{

int gdriver,gmode;
float x1,y1,x2,y2;

clrscr();
printf(“Enter the two end-points of the line:”);
printf(“nx1 =”);
scanf(“%f”,&x1);
printf(“y1 =”);
scanf(“%f”,&y1);
printf(“x2 =”);
scanf(“%f”,&x2);
printf(“y2 =”);
scanf(“%f”,&y2);

gdriver = DETECT;
initgraph(&gdriver,&gmode,”c:\\tc\\bgi”);
draw_line(x1,y1,x2,y2);
getch();
closegraph();
}

void draw_line(float x1,float y1,float x2,float y2)
{
float m,c,x,y;
m = (y2 – y1)/(x2 – x1);
c = y1 – m * x1;
for(x = x1;x<x2;x++)
    {        
y = m * x + c;
        y = round(y);
        putpixel(x,(int)y,EGA_WHITE);
    }
}
int round(float x)
{
int val = (x + 0.5);
return (val);
}