#include <stdio.h>
#include <conio.h>
#include <math.h>
#pragma inline //Allows to use  386 code
void hor(int x,int y,int x1,char col) // Draws one horizontal line
{
	int temp;
	if(x>x1){
	temp=x;
	x=x1;
	x1=temp;
	}
	asm{
	mov ax,0a000h
	mov es,ax
	mov ax,320
	mov bx,y
	mul bx
	add ax,x
	mov di,ax
	mov cx,x1
	sub cx,x
	mov al,col
	rep stosb
	}
}


void Circle(int x,int y,int r,int col)
{
	int i,xx,lx=r;
	for(i=0;i<r+1;i++){   //Repeats only one quarter
	xx=sqrt((r*r)-(i*i)); //This is the circle engine (not the fastest one but it works)
			      //Look more info from ceh.doc
	hor(x+xx,y+i,lx+x+1,col);
	hor(x+xx,y-i,lx+x+1,col);
	hor(x-xx,y+i,-lx+x-1,col);
	hor(x-xx,y-i,-lx+x-1,col);
	lx=xx;
	}
}
void Ellipse(int x,int y,int a,int b,int col)
{
	int i,xx,lx=a;
	for(i=0;i<b+1;i++){
	xx=sqrt((double)(a*a)*((b*b)-(i*i)));
	xx=xx/b;
	hor(x+xx,y+i,lx+x+1,col);
	hor(x+xx,y-i,lx+x+1,col);
	hor(x-xx,y+i,-lx+x-1,col);
	hor(x-xx,y-i,-lx+x-1,col);
	lx=xx;
	}
}
void Hyperbeli(int x,int y,int a,int b,int col)
{
	int i,xx,lx=a;
	for(i=0;i<b+1;i++){
	xx=sqrt((double)(a*a)*((b*b)+(i*i)));
	xx=xx/b;
	hor(x+xx,y+i,lx+x+3,col);
	hor(x+xx,y-i,lx+x+3,col);
	hor(x-xx,y+i,-lx+x-3,col);
	hor(x-xx,y-i,-lx+x-3,col);
	lx=xx;
	}
}
void Clr()
{
	asm{
	mov ax,0a000h
	mov es,ax
	xor ax,ax
	xor di,di
	mov cx,16000
	rep stosd   //Clears 4 pixel per time
	}
}
int main(void)
{
	int i;
	asm mov ax,13h  // Puts 320*200*256 Mode on
	asm int 10h
	Circle(160,100,5,1);
	getch();
	for(i=0;i<90;i++){
	Circle(160,100,i+5,i+1);
	}
	getch();Clr();
	Ellipse(160,100,10,5,1);
	getch();
	for(i=0;i<40;i++){
	Ellipse(160,100,i*2+10,i+5,i+1);
	}
	getch();Clr();
	Hyperbeli(160,100,10,5,1);
	getch();
	for(i=0;i<40;i++){
	Hyperbeli(160,100,i*2+10,i+5,i+1);
	}
	getch();

	asm mov ax,03 //Puts text mode back
	asm int 10h
	return 0;
}