DDA Line Drawing Algorithm in C

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

void main()
{
	int i, gd, gm;
	float x, y, x1, y1, x2, y2, x_incr, y_incr, length, dx, dy, m;
	printf("enter the value of x1:");
	scanf("%f", &x1);
	printf("\n enter the value of y1:");
	scanf("%f", &y1);
	printf("\n enter the value of x2:");
	scanf("%f", &x2);
	printf("\n enter the value of y2:");
	scanf("%f", &y2);

	detectgraph(&gd, &gm);
	initgraph(&gd, &gm, " ");
	setbkcolor(7);

	dx = abs(x2 - x1);
	dy = abs(y2 - y1);
	m = dy / dx;
	printf("Slope=%f", m);
	if (dx >= dy)
	{
		length = dx;
	}
	else
	{
		length = dy;
	}

	x_incr = abs(x2 - x1) / length;
	y_incr = abs(y2 - y1) / length;
	x = x1;
	y = y1;
	putpixel(x, y, 12);

	i = 1;
	while (i <= length)
	{
		x = x + x_incr;
		y = y + y_incr;
		putpixel(x, y, 12);
		printf("\n %f %f", x, y);
		i = i + 1;
		delay(50);
	}

	getch();
	closegraph();
}