/// <summary>
/// A step in building the attention map
/// </summary>
/// <param name="position">The location shown</param>
/// <param name="size">The size of the visible part</param>
/// <param name="duration">Duration at that point</param>
/// <param name="shouldRemove">Is positive or negative change, for UNDO</param>
public void BuildActivationMap(PointF position,
SizeF size,
TimeSpan duration,
bool shouldRemove)
{
if (AttentionMap != null)
{
ImageProxy <double> imageProxy = AttentionMap?.Proxy(
new Rectangle((int)(position.X - size.Width / 2), (int)(position.Y - size.Height / 2),
(int)size.Width, (int)size.Height));
//Apply a change to every pixel
imageProxy?.ApplyFilter((value, location) =>
{
var ix = (location.X / size.Width) * 2 - 1;
var iy = (location.Y / size.Height) * 2 - 1;
if (ix * ix + iy * iy > 1)//out of circle = original pixel
{
return(value);
}
var distance = Math.Pow((ix * ix + iy * iy), 0.5);
//=2*(1- 1.5^(8*dist-1) / (1.5^(8*dist-1)+1))
const double _base = 1.5d;
const double _mult_dist = 8;
const double _off = -1;
const double _mult = 2;
var distanceFactor = _mult * (1 - Math.Pow(_base, _mult_dist * distance + _off) / (Math.Pow(_base, _mult_dist * distance + _off) + 1));
//If remove(subtract) multiply by minus one
var removeFactor = shouldRemove ? -1 : 1;
return(value += duration.TotalMilliseconds * distanceFactor * removeFactor);
});
}
}