#include <windows.h>
#include <cmath>

int main() {
	system("start c:\\windows\\system32\\mspaint.exe");
	HWND paint;

	do {
		paint = FindWindow("MSPaintApp", "Untitled - Paint");
		Sleep(10);
	} while (paint == NULL);

	Sleep(200);
	RECT r;
	GetWindowRect(paint, &r);
	RECT cr;
	GetClientRect(paint, &cr);

	int x = r.left + (cr.right / 2);
	int y = r.top + (cr.bottom / 2);

	SetCursorPos(x,y);

	POINT p;
	GetCursorPos(&p);
	paint = WindowFromPoint(p);

	GetWindowRect(paint, &r);
	GetClientRect(paint, &cr);

	x = r.left + (cr.right / 2);
	y = r.top + (cr.bottom / 2);

	SetCursorPos(x,y);

	int radius = 0;
	double angle = 0;

	int max = min(cr.right/2,cr.bottom/2);

	mouse_event(MOUSEEVENTF_LEFTDOWN, 0, 0, 0, 0);

	for (; radius < max; radius++, angle += 0.1) {
		SetCursorPos(x+(cos(angle)*radius), y+(sin(angle)*radius));
		Sleep(20);
	}

	mouse_event(MOUSEEVENTF_LEFTUP, x, y, 0, 0);

	return 0;
}