private static void RequirePortalMorph(Morph.Id morph, string paramName)
{
switch (morph)
{
case Morph.Portal.Down:
case Morph.Portal.Left:
case Morph.Portal.Right:
case Morph.Portal.Up:
break;
default:
throw new ArgumentException("The given morph is not a portal morph.", paramName);
}
}
public static Direction PerformPortalTransformation(this Direction direction, Morph.Id sourcePortalMorph,
Morph.Id targetPortalMorph)
{
RequirePortalMorph(sourcePortalMorph, nameof(sourcePortalMorph));
RequirePortalMorph(targetPortalMorph, nameof(targetPortalMorph));
var source = (int) sourcePortalMorph;
var target = (int) targetPortalMorph;
// No transformation required if morphs are same for both portals
if (source == target)
return direction;
if (source < target)
source += 4;
var dir = source - target;
switch (dir)
{
case 1:
return direction.RotatedClockWise();
case 2:
return direction.Flipped();
case 3:
return direction.RotatedCounterClockWise();
default:
return direction;
}
}
