#include 
#include 
#include 
#include 
#include 

void reset (int h[][2])
{
    int val[9][2] = {
			{ 50, 50 },{ 75, 50 },{ 75, 75 },{ 100, 75 },
			{ 100, 50 },{ 125, 50 },{ 125, 100 },{ 87, 125 },{ 50, 100 }
		    };
    int i;
    for (i=0; i<9; i++)
    {
	h[i][0] = val[i][0]-50;
	h[i][1] = val[i][1]-50;
    }
}
void draw (int h[][2])
{
    int i;
    setlinestyle (DOTTED_LINE, 0, 1);
    line (320, 0, 320, 480);
    line (0, 240, 640, 240);
    setlinestyle (SOLID_LINE, 0, 1);
    for (i=0; i<8; i++)
	line (320+h[i][0], 240-h[i][1], 320+h[i+1][0], 240-h[i+1][1]);
    line (320+h[0][0], 240-h[0][1], 320+h[8][0], 240-h[8][1]);
}
void rotate (int h[][2], float angle)
{
    int i;
    for (i=0; i<9; i++)
    {
	int xnew, ynew;
	xnew = h[i][0] * cos (angle) - h[i][1] * sin (angle);
	ynew = h[i][0] * sin (angle) + h[i][1] * cos (angle);
	h[i][0] = xnew; h[i][1] = ynew;
    }
}
void scale (int h[][2], int sx, int sy)
{
    int i;
    for (i=0; i<9; i++)
    {
	h[i][0] *= sx;
	h[i][1] *= sy;
    }
}
void translate (int h[][2], int dx, int dy)
{
    int i;
    for (i=0; i<9; i++)
    {
	h[i][0] += dx;
	h[i][1] += dy;
    }
}
void reflect (int h[][2], int m, int c)
{
	int i;
	float angle;
	for (i=0; i<9; i++)
		h[i][1] -= c;
	angle = M_PI/2 - atan (m);
	rotate (h, angle);
	for (i=0; i<9; i++)
		h[i][0] = -h[i][0];
	angle = -angle;
	rotate (h, angle);
	for (i=0; i<9; i++)
		h[i][1] += c;
}

void ini()
{
	int gd=DETECT,gm;
	initgraph(&gd,&gm,"..\\bgi");
}
void dini()
{
	getch();
	closegraph();
}
void main()
{

	int h[9][2],sx,sy,x,y,m,c,choice;
	do
	{
		clrscr();
		printf("1. Scaling about the origin.\n");
		printf("2. Scaling about an arbitrary point.\n");
		printf("3. Reflection about the line y = mx + c.\n");
		printf("4. Exit\n");
		printf("Enter the choice: ");
		scanf("%d",&choice);
		switch(choice)
		{
			case 1: printf ("Enter the x- and y-scaling factors: ");
				scanf ("%d%d", &sx, &sy);
				ini();
				reset (h);
				draw (h);getch();
				scale (h, sx, sy);
				cleardevice();
				draw (h);
				dini();
				break;

			case 2: printf ("Enter the x- and y-scaling factors: ");
				scanf ("%d%d", &sx, &sy);
				printf ("Enter the x- and y-coordinates of the point: ");
				scanf ("%d%d", &x, &y);
				ini();
				reset (h);
				translate (h, x, y);// Go to arbitrary point
				draw(h); getch();//Show its arbitrary position
				cleardevice();
				translate(h,-x,-y);//Take it back to origin
				draw(h);
				getch();
				cleardevice();
				scale (h, sx, sy);//Now Scale it
				draw(h);
				getch();
				translate (h, x, y);//Back to Arbitrary point
				cleardevice();
				draw (h);
				putpixel (320+x, 240-y, WHITE);
				dini();
				break;

			case 3: printf ("Enter the values of m and c: ");
				scanf ("%d%d", &m, &c);
				ini();
				reset (h);
				draw (h); getch();
				reflect (h, m, c);
				cleardevice();
				draw (h);
				dini();
				break;
			
			case 4: exit(0);
		}
	}while(choice!=4);
}

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