برنامه سورس محافظ صفحه نمایش سی پلاس

#include<graphics.h>
#include<stdlib.h>
#include<dos.h>
#include<math.h>
#include<conio.h>
class box
{
private:
float x[4],y[4],centerx,centery;
int r,deg;
public:
box()
{
r=rand()%50;
centerx=rand()%640;centery=rand()%480;
deg=0;
}
void cal()
{
x[0]=centerx-r*sin(deg*(3.14/180));
y[0]=centery-r*cos(deg*(3.14/180));
x[1]=centerx+r*sin(deg*(3.14/180));
y[1]=centery-r*cos(deg*(3.14/180));
x[2]=centerx+r*sin(deg*(3.14/180));
y[2]=centery+r*cos(deg*(3.14/180));
x[3]=centerx-r*sin(deg*(3.14/180));
y[3]=centery+r*cos(deg*(3.14/180));
deg++;
if(deg>=90)
{
centerx=rand()%640;
centery=rand()%480;
sound(centerx+centery);
r=rand()%50;
if(centerx-r<=0)
centerx=centerx+r;
if(centerx+r>=640)
centerx=centerx-r;
if(centery-r<=0)
centery=centery+r;
if(centery+r>=480)
centery=centery-r;
cleardevice();
deg=0;
}
}
void disp(int col)
{
setcolor(col);
line(x[0],y[0],x[1],y[1]);
line(x[1],y[1],x[2],y[2]);
line(x[2],y[2],x[3],y[3]);
line(x[3],y[3],x[0],y[0]);

}