void Form1_MouseWheel(object sender, MouseEventArgs e)
{
double factor = 1.0;
if (e.Delta > 0)
{
factor = Math.Pow(ZOOM_FACTOR_IN, (double)e.Delta / (double)WHEEL_DELTA);
}
else if (e.Delta < 0)
{
factor = Math.Pow(ZOOM_FACTOR_OUT, (double)-e.Delta / (double)WHEEL_DELTA);
}
currentRenderer.Zoom(e.X, e.Y, factor);
}
