/// <summary>
/// Creates a new Circle Instance.
/// </summary>
/// <param name="radius">how large the circle is.</param>
/// <param name="vertexCount">
/// The number or vertex that will be generated along the perimeter of the circle.
/// This is for collision detection.
/// </param>
/// <param name="momentOfInertiaMultiplier">
/// How hard it is to turn the shape. Depending on the construtor in the
/// Body this will be multiplied with the mass to determine the moment of inertia.
/// </param>
public CircleShape(Scalar radius, int vertexCount, Scalar momentOfInertiaMultiplier)
: base(CreateCircle(radius, vertexCount), momentOfInertiaMultiplier)
{
if (radius <= 0)
{
throw new ArgumentOutOfRangeException("radius", "must be larger then zero");
}
this.radius = radius;
this.Normals = ShapeHelper.CalculateNormals(this.Vertexes);
}
private Vector2D[] CalculateNormals()
{
Vector2D[] result = new Vector2D[Vertexes.Length];
int offset = 0;
for (int index = 0; index < polygons.Length; ++index)
{
Vector2D[] polygon = polygons[index];
ShapeHelper.CalculateNormals(polygon, result, offset);
offset += polygon.Length;
}
return(result);
}
/// <summary>
/// Creates a new Polygon Instance.
/// </summary>
/// <param name="vertexes">the vertexes that make up the shape of the Polygon</param>
/// <param name="gridSpacing">
/// How large a grid cell is. Usualy you will want at least 2 cells between major vertexes.
/// The smaller this is the better precision you get, but higher cost in memory.
/// The larger the less precision and if it's to high collision detection may fail completely.
/// </param>
/// <param name="momentOfInertiaMultiplier">
/// How hard it is to turn the shape. Depending on the construtor in the
/// Body this will be multiplied with the mass to determine the moment of inertia.
/// </param>
public PolygonShape(Vector2D[] vertexes, Scalar gridSpacing, Scalar momentOfInertiaMultiplier)
: base(vertexes, momentOfInertiaMultiplier)
{
if (vertexes == null)
{
throw new ArgumentNullException("vertexes");
}
if (vertexes.Length < 3)
{
throw new ArgumentException("too few", "vertexes");
}
if (gridSpacing <= 0)
{
throw new ArgumentOutOfRangeException("gridSpacing");
}
this.Normals = ShapeHelper.CalculateNormals(this.Vertexes);
this.grid = new DistanceGrid(this, gridSpacing);
}