#include <iostream.h>
#include <dos.h>
#include <conio.h>
#include <graphics.h>
#include <math.h>

void DDALine(unsigned, unsigned, unsigned, unsigned);

void Line(int, int, int, int);
void set_mode(char mode)
{

  union REGS regs;

  regs.h.ah = 0;
  regs.h.al = mode;
  int86(0x10, &regs, &regs);
/*
	asm mov ah, 0x0;
	asm mov al, mode;
	asm int 0x10;
 */
}

//void Putpixel(unsigned x, unsigned y, char color)
void Putpixel(int x, int y, char color)
{
  union REGS regs;

  regs.h.ah = 0x0c;
  regs.h.al = color;
  regs.x.cx = x;
  regs.x.dx = y;
  int86(0x10, &regs, &regs);
/*
  asm mov ah, 0x0c;
  asm mov al, color;
  asm mov cx, x;
  asm mov dx, y;
  asm int 0x10;
  */
}
template <class T>
T Abs(T x)
{
	if(x < 0)
		return ((-1) * x);
	else
		return x;
}
/*
unsigned Abs(int x)
{
	if(x < 0)
		return (-1 * x);
	else
		return x;
} */
int Round(float x)
{
	return ((x * 10 + 5) / 10);
}

char Getch()
{
	char C;
	asm mov ah, 0x07;
	asm int 0x21;
	asm mov C,al;
	return C;
}
void main()
{
//	set_mode(0x12);
 /*
	int gdriver = DETECT, gmode, errorcode;
	initgraph(&gdriver, &gmode, "");
   */
	clrscr();
	Line(1, 2, 4, 9);
/*
//	Line(0, 0, 639, 479);
	getch();
	getch();
	line(479, 0, 0, 479);
//	DDALine(0, 0, 63, 47);
	getch();
	getch();
//	line(0, 0, 639, 479);*/
	getch();
	getch();
//	closegraph();
//	set_mode(0x03);

}


void Line(int x1, int y1, int x2, int y2)
{
	int x, y, dx, dy, p, end, inc;
	dx = Abs(x1 - x2);
	dy = Abs(y1 - y2);
	if(dx > dy)
	{
		p  = 2 * dy - dx;
		if(x1 > x2)
		{
			x = x2;
			y = y2;
			end = x1;
			if(y2 > y1)
				inc = -1;
			else
				inc = 1;
		}
		else
		{
			x = x1;
			y = y1;
			end = x2;
			if(y1 > y2)
				inc = -1;
			else
				inc = 1;
		}
//		Putpixel(x , y, 1);
		cout<<x<<"\t"<<y<<"\t"<<p<<endl;
		for(;x < end;)
		{
			x = x + 1;
			if(p < 0)
				p = p + 2 * dy;
			else
			{
				y = y + inc;
				p = p + 2 * (dy - dx);
			}
//			Putpixel(x,y,1);
			cout<<x<<"\t"<<y<<"\t"<<p<<endl;

		}

	}
	else
	{
		p  = 2 * dx - dy;
		if(y1 > y2)
		{
			x = x2;
			y = y2;
			end = y1;
			if(x2 > x1)
				inc = -1;
			else
				inc = 1;
		}
		else
		{
			x = x1;
			y = y1;
			end = y2;
			if(x1 > x2)
				inc = -1;
			else
				inc = 1;
		}
//		Putpixel(x, y, 1);
		cout<<x<<"\t"<<y<<"\t"<<p<<endl;
		for(;y < end;)
		{
			y = y + 1;
			if(p < 0)
				p = p + 2 * dx;
			else
			{
				x = x + inc;
				p = p + 2 * (dx - dy);
			}
//			Putpixel(x,y,1);
		cout<<x<<"\t"<<y<<"\t"<<p<<endl;
		}
	}
}
void DDALine(unsigned x1, unsigned y1, unsigned x2, unsigned y2)
{
	float x, y,  incx, incy;
	int dx, dy, step;
	dx = x2 - x1;
	dy = y2 - y1;

	if(abs(dx) > abs(dy))
		step = abs(dx);
	else
		step = abs(dy);
	if(step != 0)
	{
		incx = (float) dx/step;
		incy = (float) dy/step;
	}
	x = x1;
	y = y1;

	Putpixel(x, y, 4);
//	cout<<x<<"\t\t"<<y<<endl;
	for(int i=0; i < step; i++)
	{
		x = x + incx;
		y = y + incy;
		Putpixel(Round(x), Round(y), 4);
//		cout<<x<<"\t\t"<<y<<endl;

	}
}

void Polygon(int xc, int yc, int r, int sides, double angle, int color)
{
	double x, y, inc;
	inc = (double) 360.0/sides;
	for(int i=0; i<sides; i++)
	{
		x = r * cos(angle * 3.14/180.0) + xc;
		y = r * sin(angle * 3.14/180.0) + yc;

	}
}