/// <summary>
/// Get the vertices along the specified edge of a square topography.
/// </summary>
/// <param name="direction">The edge of vertices to return.</param>
/// <returns>A collection of vertices.</returns>
public Vertex[] GetEdgeVertices(Units.CardinalDirection direction)
{
var range = Enumerable.Range(0, this.RowWidth);
var start = 0;
var increment = 1;
switch (direction)
{
case Units.CardinalDirection.North:
start = this.Mesh.Vertices.Count - this.RowWidth;
break;
case Units.CardinalDirection.South:
start = 0;
break;
case Units.CardinalDirection.East:
start = this.RowWidth - 1;
increment = this.RowWidth;
break;
case Units.CardinalDirection.West:
start = 0;
increment = this.RowWidth;
break;
default:
return(null);
}
return(range.Select(i => this.Mesh.Vertices[start + i * increment]).ToArray());
}
/// <summary>
/// Average the vertex placement along the specified edge
/// of this topography with the vertex placement along the
/// corresponding edge of a target topography.
/// </summary>
/// <param name="target"></param>
/// <param name="edgeToAverage"></param>
public void AverageEdges(Topography target, Units.CardinalDirection edgeToAverage)
{
if (this.RowWidth != target.RowWidth)
{
throw new ArgumentException("The specified topographies do not have the same number of vertices.");
}
Vertex[] e1 = null;
Vertex[] e2 = null;
switch (edgeToAverage)
{
case Units.CardinalDirection.North:
e1 = this.GetEdgeVertices(Units.CardinalDirection.North);
e2 = target.GetEdgeVertices(Units.CardinalDirection.South);
break;
case Units.CardinalDirection.South:
e1 = this.GetEdgeVertices(Units.CardinalDirection.South);
e2 = target.GetEdgeVertices(Units.CardinalDirection.North);
break;
case Units.CardinalDirection.East:
e1 = this.GetEdgeVertices(Units.CardinalDirection.East);
e2 = target.GetEdgeVertices(Units.CardinalDirection.West);
break;
case Units.CardinalDirection.West:
e1 = this.GetEdgeVertices(Units.CardinalDirection.West);
e2 = target.GetEdgeVertices(Units.CardinalDirection.East);
break;
}
for (var i = 0; i < e1.Length; i++)
{
var pos = e1[i].Position.Average(e2[i].Position);
e1[i].Position = pos;
e2[i].Position = pos;
}
}