Bresenham Line Drawing Algorithm in C Programming

#include< stdio.h>
#include< graphics.h>
#include< conio.h>
void BRESENHAM_LINE(int x1,int y1,int x2,int y2);
void main()
{
	int x1,y1,x2,y2,gdriver=DETECT,gmode;
	clrscr();
	initgraph(&gdriver,&gmode,"");

	printf("\nEnter point1(x1,y1):");
	scanf("%d %d",&x1,&y1);
	printf("\nEnter point2(x2,y2):");
	scanf("%d %d",&x2,&y2);
	BRESENHAM_LINE(x1,y1,x2,y2);
	getch();

}
void BRESENHAM_LINE(int x1,int y1,int x2,int y2)
{
	int dx=abs(x1-x2),dy=abs(y1-y2);
	int p=2*dy-dx;
	int twoDy=2*dy,twoDyDx=2*(dy-dx);
	int x,y,xEnd;

	if(x1>x2)
	{
		x=x2;
		y=y2;
		xEnd=x1;
	}

	else
	{
		x=x1;
		y=y1;
		xEnd=x2;
	}

	putpixel(x,y,WHITE);

	while(x < xEnd)
	{
		x++;
		if(p < 0)
			p+=twoDy;
		else
		{
			y++;
			p+=twoDyDx;
		}
		putpixel(x,y,WHITE);
	}
}

OUTPUT