private static void ChooseEdgeNearCell(S2Cell cell, out S2Point a, out S2Point b)
{
S2Cap cap = cell.GetCapBound();
if (S2Testing.Random.OneIn(5))
{
// Choose a point anywhere on the sphere.
a = S2Testing.RandomPoint();
}
else
{
// Choose a point inside or somewhere near the cell.
a = S2Testing.SamplePoint(new S2Cap(cap.Center, 1.5 * cap.RadiusAngle()));
}
// Now choose a maximum edge length ranging from very short to very long
// relative to the cell size, and choose the other endpoint.
double max_length = Math.Min(100 * Math.Pow(1e-4, S2Testing.Random.RandDouble()) *
cap.Radius.Radians(), S2.M_PI_2);
b = S2Testing.SamplePoint(new S2Cap(a, S1Angle.FromRadians(max_length)));
if (S2Testing.Random.OneIn(20))
{
// Occasionally replace edge with antipodal edge.
a = -a;
b = -b;
}
}
public void AddEdges(S2Cap index_cap, int num_edges, MutableS2ShapeIndex index)
{
var fractal = new S2Testing.Fractal();
fractal.SetLevelForApproxMaxEdges(num_edges);
index.Add(new S2Loop.Shape(
fractal.MakeLoop(S2Testing.GetRandomFrameAt(index_cap.Center),
index_cap.RadiusAngle())));
}
public void AddPoints(S2Cap index_cap, int num_points, TestIndex index)
{
var points = S2Testing.MakeRegularPoints(
index_cap.Center, index_cap.RadiusAngle(), num_points);
for (int i = 0; i < points.Length; ++i)
{
index.Add(points[i], i);
}
}
public void AddPoints(S2Cap index_cap, int num_points, TestIndex index)
{
S2Testing.Fractal fractal = new();
fractal.SetLevelForApproxMaxEdges(num_points);
fractal.FractalDimension = (1.5);
var loop = (
fractal.MakeLoop(S2Testing.GetRandomFrameAt(index_cap.Center),
index_cap.RadiusAngle()));
for (int i = 0; i < loop.NumVertices; ++i)
{
index.Add(loop.Vertex(i), i);
}
}
public void Test_S2ShapeIndexRegion_GetCapBound()
{
var id = S2CellId.FromDebugString("3/0123012301230123012301230123");
// Add a polygon that is slightly smaller than the cell being tested.
MutableS2ShapeIndex index = new();
index.Add(NewPaddedCell(id, -kPadding));
S2Cap cell_bound = new S2Cell(id).GetCapBound();
S2Cap index_bound = index.MakeS2ShapeIndexRegion().GetCapBound();
Assert.True(index_bound.Contains(cell_bound));
// Note that S2CellUnion.GetCapBound returns a slightly larger bound than
// S2Cell.GetBound even when the cell union consists of a single S2CellId.
Assert.True(index_bound.RadiusAngle() <= 1.00001 * cell_bound.RadiusAngle());
}
public void AddPoints(S2Cap index_cap, int num_points, TestIndex index)
{
int sqrt_num_points = (int)Math.Ceiling(Math.Sqrt(num_points));
S2PointVector3 frame = S2Testing.GetRandomFrameAt(index_cap.Center);
double radius = index_cap.RadiusAngle().Radians;
double spacing = 2 * radius / sqrt_num_points;
for (int i = 0; i < sqrt_num_points; ++i)
{
for (int j = 0; j < sqrt_num_points; ++j)
{
S2Point point = new(Math.Tan((i + 0.5) * spacing - radius),
Math.Tan((j + 0.5) * spacing - radius), 1.0);
index.Add(S2.FromFrame(frame, point.Normalize()),
i * sqrt_num_points + j);
}
}
}
public void AddEdges(S2Cap index_cap, int num_edges, MutableS2ShapeIndex index)
{
index.Add(new S2Loop.Shape(S2Loop.MakeRegularLoop(
index_cap.Center, index_cap.RadiusAngle(), num_edges)));
}