public IEnumerable <Vec> Trace()
{
if ((Width > 1) && (Height > 1))
{
// trace all four sides
foreach (Vec top in Row(TopLeft, Width - 1))
{
yield return(top);
}
foreach (Vec right in Column(TopRight.OffsetX(-1), Height - 1))
{
yield return(right);
}
foreach (Vec bottom in Row(Width - 1))
{
yield return(BottomRight.Offset(-1, -1) - bottom);
}
foreach (Vec left in Column(Height - 1))
{
yield return(BottomLeft.OffsetY(-1) - left);
}
}
else if ((Width > 1) && (Height == 1))
{
// a single row
foreach (Vec pos in Row(TopLeft, Width))
{
yield return(pos);
}
}
else if ((Height >= 1) && (Width == 1))
{
// a single column, or one unit
foreach (Vec pos in Column(TopLeft, Height))
{
yield return(pos);
}
}
// otherwise, the rect doesn't have a positive size, so there's nothing to trace
}