public void AssertThat_FromWorld_ToWorld_AreIdentityFunction()
{
//Generate a random load of points
var rand = new Random();
var points = new List <Vector2>();
for (int i = 0; i < 20; i++)
{
points.Add(rand.RandomNormalVector().XZ() * (float)rand.NextDouble() * 50);
}
//Calculate OABR
var oabr = OABR.Fit(points);
//Draw it
var svg = new SvgBuilder(2);
var hull = points.ConvexHull().ToArray();
svg.Outline(hull, "green");
svg.Outline((IReadOnlyList <Vector2>)oabr.Points(new Vector2[4]));
foreach (var vector2 in points)
{
svg.Circle(vector2, 1, oabr.Contains(vector2) ? "red" : "blue");
}
Console.WriteLine(svg.ToString());
//Assert that every point lies within the bounds
foreach (var vector2 in points)
{
var trans = oabr.FromWorld(vector2);
var world = oabr.ToWorld(trans);
Assert.IsTrue(vector2.TolerantEquals(world, 0.001f), string.Format("Expected {0} and {1} to be equal", vector2, world));
}
}
internal static OABR FitOabb(Parcel parcel, float nonOptimalityChance, float maximumNonOptimality, Func <double> random)
{
Contract.Requires(parcel != null);
Contract.Requires(random != null);
//Generate a set of OABBs, order by size
var oabbs = OABR.Fittings(parcel.Points()).OrderBy(a => a.Area).ToArray();
//Now select an OABB from this list, with the first (smallest) being the most likely
var selected = 0;
for (var i = 1; i < oabbs.Length; i++)
{
//Do not allow the area ratio between optimal and selected to go over the non optimality limit
if (oabbs[i].Area / (oabbs[0]).Area > maximumNonOptimality)
{
break;
}
//We're not breaking the non optimality limit, so what's the chance of selecting this?
var chance = Math.Pow(nonOptimalityChance, i);
selected = random() < chance ? i : selected;
}
return(oabbs[selected]);
}
public void AssertThat_AllPointsLiesInBounds_WithRandomShape()
{
//Generate a random load of points
var rand = new Random();
var points = new List <Vector2>();
for (int i = 0; i < 20; i++)
{
points.Add(rand.RandomNormalVector().XZ() * (float)rand.NextDouble() * 50);
}
//Calculate OABR
var oabr = OABR.Fit(points);
//Draw it
var svg = new SvgBuilder(2);
var hull = points.ConvexHull().ToArray();
svg.Outline(hull, "green");
svg.Outline((IReadOnlyList <Vector2>)oabr.Points(new Vector2[4]));
foreach (var vector2 in points)
{
svg.Circle(vector2, 1, oabr.Contains(vector2) ? "red" : "blue");
}
Console.WriteLine(svg.ToString());
//Assert that every point lies within the bounds
Assert.IsTrue(points.All(p => oabr.Contains(p)));
}
public float AspectRatio()
{
var oabb = OABR.Fit(Points());
var extents = oabb.Max - oabb.Min;
var ratio = Math.Max(extents.X, extents.Y) / Math.Min(extents.X, extents.Y);
return(ratio);
}
private IEnumerable <Parcel> Split(Parcel parcel, OABR oabb, Vector2 sliceDirection, Func <double> random, INamedDataCollection metadata)
{
Contract.Requires(parcel != null);
Contract.Requires(random != null);
Contract.Requires(metadata != null);
var extent = (oabb.Max - oabb.Min) / 2;
var point = oabb.Middle + Math.Max(extent.X, extent.Y) * sliceDirection.Perpendicular() * _splitPoint.SelectFloatValue(random, metadata);
var slices = parcel.Points().SlicePolygon(new Ray2(point, sliceDirection));
return(slices.Select(a => ToParcel(parcel, a)));
}
protected BasePolygonRegion(IReadOnlyList <Side> shape, OABR oabr)
{
Contract.Requires(shape != null);
Contract.Requires(shape.Count >= 3);
_shape = shape;
_bounds = BoundingRectangle.CreateFromPoints(Points);
_oabr = oabr;
Area = Points.Area();
OabrAreaError = _oabr.Area - Area;
}
public void AssertThat_CornerPoints_AreEqualToInputPoints_ForRectangularShape()
{
var points = new[] {
new Vector2(10, 10),
new Vector2(10, -10),
new Vector2(-10, -10),
new Vector2(-10, 10),
};
var oabr = OABR.Fit(points);
var corners = oabr.Points();
for (var i = 0; i < points.Length; i++)
{
Assert.AreEqual(points[i], corners[i]);
}
}
protected BasePolygonRegion(IReadOnlyList <Side> shape)
: this(shape, OABR.Fit(shape.Select(a => a.Start)))
{
Contract.Requires(shape != null);
Contract.Requires(shape.Count >= 3);
}
protected BasePolygonRegionContracts(IReadOnlyList <Side> shape, OABR oabr)
: base(shape, oabr)
{
}