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

#define lin(a,b,c,d) line(320+(a),240-(b),320+(c),240-(d))

void writepixel(int x,int y,int cx,int cy,int sangle,int eangle)
{
 double p;
 p=atan2(y,x)*180/M_PI;
 if(p<0) p+=360;

if((sangle<=eangle && p>=sangle && p<=eangle)
 ||(sangle>eangle && (p>=sangle || p<=eangle))
   )
    putpixel(320+x+cx,240-(y+cy),WHITE);
}

void circlepoints(int x,int y,int cx,int cy,int sangle,int eangle)
{
// printf("%2d %2d ",x,y);
 writepixel(x,y,cx,cy,sangle,eangle);
 writepixel(-x,y,cx,cy,sangle,eangle);
 writepixel(x,-y,cx,cy,sangle,eangle);
 writepixel(-x,-y,cx,cy,sangle,eangle);
 writepixel(y,x,cx,cy,sangle,eangle);
 writepixel(-y,x,cx,cy,sangle,eangle);
 writepixel(y,-x,cx,cy,sangle,eangle);
 writepixel(-y,-x,cx,cy,sangle,eangle);
// printf("\n");
}

void mparc(int rad,int cx,int cy,int sangle,int eangle)
{
 int x=0;
 int y=rad;

 double d= 5.0/ 4.0 - rad;

 circlepoints(x,y,cx,cy,sangle,eangle);

 while(y>x)
 {
   if(d<0) /* select E */
     d+= 2.0 * x + 3.0;
   else
   { d+= 2.0 * (x-y) + 5.0;
     y--;
   }
   x++;
   circlepoints(x,y,cx,cy,sangle,eangle);
 }
}


void mpcircle(int r,int cx,int cy)
{  mparc(r,cx,cy,0,360);
}

void mpsector(int r,int cx,int cy,int sangle,int eangle)
{
  mparc(r,cx,cy,sangle,eangle);
  lin(0,0,r*cos(M_PI*sangle/180),r*sin(M_PI*sangle/180));
  lin(0,0,r*cos(M_PI*eangle/180),r*sin(M_PI*eangle/180));
}

main()
{
int gd=DETECT,gm;
initgraph(&gd,&gm,"c:\\tcpp30\\bgi");

//the axes

lin(-60,-60,60,60);
lin(0,60,0,-60);   //y
lin(-60,60,60,-60);
lin(-60,0,60,0); // x

//all angles are positively mentioned and are in [0-360]

//mpsector(50,0,0,0,270);
mpsector(50,0,0,330,20);
//mpcircle(40,10,10);

getch();
return 0;
}