/// <summary>
/// Checks objects equality.
/// Uses CompareDouble from RegularPolygonUtilityUtility class when comparing X and Y values.
/// <see cref="RegularPolygonUtility.CompareDouble(double, double)"/>
/// </summary>
/// <param name="other">Vertex for comparison</param>
/// <returns>True, if objects meet equality requirements. Otherwise, false.</returns>
public bool Equals(Vertex other)
{
if (Utility.CompareDouble(X, other.X) && Utility.CompareDouble(Y, other.Y))
{
return(true);
}
else
{
return(false);
}
}
private bool ValidateVertices(Vertex[] vertices)
{
if (vertices == null)
{
throw new RegularPolygonException("Cannot create polygon without vertices.");
}
if (vertices.Length <= 2)
{
throw new RegularPolygonException($"Cannot create polygon with {vertices.Length} vertices, at least 3 are needed.");
}
// check if vertices are unique;
for (int i = 0; i < vertices.Length; i++)
{
if (vertices.Count(v => v.Equals(vertices[i])) > 1) // if there are two equals vertices
{
throw new RegularPolygonException("Cannot create polygon with duplicated vertices.");
}
}
// check if sides lenghts are equal;
// distance between first and last will be used as reference side length value for other vertices distances.
double firstSideLength = vertices[0].GetDistanceFrom(vertices.Last());
for (int i = 0; i < vertices.Length - 1; i++)
{
double currentSideLength = vertices[i].GetDistanceFrom(vertices[i + 1]);
if (!Utility.CompareDouble(firstSideLength, currentSideLength))
{
throw new RegularPolygonException("Cannot create regular polygon with unequal side lengths.");
}
}
// check if vertices determine polygon that can be inscribed in a circle.;
double avgX = vertices.Average(v => v.X);
double avgY = vertices.Average(v => v.Y);
Vertex circleCenter = new Vertex(avgX, avgY);
double circleRadius = circleCenter.GetDistanceFrom(vertices[0]); // distance from first vertex as reference distance value
for (int i = 1; i < vertices.Length; i++)
{
if (!Utility.CompareDouble(circleCenter.GetDistanceFrom(vertices[i]), circleRadius))
{
throw new RegularPolygonException("Cannot create regular polygon that cannot be inscribed in circle.");
}
}
return(true);
}
