/* Program to show Animation  */

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

int dx,dy,s1,s2,dp,swap=0;

void bressenham(int x1,int x2,int y1,int y2)
{
	dx=abs(x2-x1);
	dy=abs(y2-y1);
	if(x2<x1) s1=-1;
	else if(x2>x1) s1=1;
		else s1=0;
	if(y2<y1) s2=-1;
	else if(y2>y1) s2=1;
		else s2=0;
	dp=2*dy-dx;
	if(dy>dx)
	{
		int temp=dy;
		dy=dx;
		dx=temp;
		swap=1;
	}
}

void erase(int x,int y,int r,int x3,int y3,int x4,int y4
				,int x5,int y5,int x6,int y6)
{
	setcolor(BLACK);
	circle(x,y,r);
	line(x3,y3,x4,y4);
	line(x5,y5,x6,y6);
}

void main()
{
	clrscr();
	int gd=DETECT,gm;
	initgraph(&gd,&gm,"");
	setcolor(WHITE);

	int x1=100,y1=100,h,b,x3,y3,x4,y4,x5,y5,x6,y6,x,y,r;
	printf("Enter the height of the wedge : ");
	scanf("%d",&h);
	printf("Enter the width of the edge : ");
	scanf("%d",&b);
	printf("Enter the radius of the circle : ");
	scanf("%d",&r);
	int x2=x1+b,y2=y1+h;
	cleardevice();
	line(x1,y1,x2,y2);
	line(x1,y1,x1,y2);
	line(x1,y2,x2,y2);
	float angle=atan((float)(y2-y1)/(x2-x1));
	x=x1+r*sin(angle);
	y=y1-r*cos(angle);
	x3=x; y3=y+r;
	x4=x; y4=y-r;
	x5=x+r; y5=y;
	x6=x-r; y6=y;
	line(x3,y3,x4,y4);
	line(x5,y5,x6,y6);
	circle(x,y,r);
	float ang=1/r;
	bressenham(x1,x2,y1,y2);
	while(x<(x2+r*sin(angle)) && y<(y2-r*cos(angle)))
	{
		ang+=(float)1/r;
		erase(x,y,r,x3,y3,x4,y4,x5,y5,x6,y6);
		setcolor(WHITE);
		line(x1,y1,x2,y2);
		if(dp<0)
		{
			if(swap) y=y+s2;
			else x=x+s1;
			dp+=2*dy;
		}
		else
		{
			x=x+s1;
			y=y+s2;
			dp=dp+2*dy-2*dx;
		}
		x3=x+(float)r*cos(-ang);
		x4=x-(float)r*cos(-ang);
		y3=y-(float)r*sin(-ang);
		y4=y+(float)r*sin(-ang);
		x5=x-(float)r*sin(+ang);
		x6=x+(float)r*sin(+ang);
		y5=y+(float)r*cos(+ang);
		y6=y-(float)r*cos(+ang);
		line(x3,y3,x4,y4);
		line(x5,y5,x6,y6);
		circle(x,y,r);
		delay(10);
	}
	getch();
}