/// <summary>
/// Create a sphere (or one of it's domes) at 'position' with radius specified
/// </summary>
/// <param name="position"></param>
/// <param name="radius"></param>
/// <param name="steps"></param>
/// <param name="domes"></param>
public Sphere(Point3F position, double radius, int steps = 45, Domes domes = Domes.Both) : this(radius, steps, domes)
{
Transform.Translate(position);
ApplyTransformation();
Transform = Matrix4x4F.Identity;
}
private void BuildDomes(double radius, int steps, Domes domes)
{
Polyline curve = new Circle(0, 0, radius).ToPolyline();
// we need steps to be dividable by 4 !!
steps = ((steps / 4) + ((steps % 4) != 0 ? 4 : 0)) * 4;
// the circle acts as our equator being positioned at 0,0,0
List <Point3F> equator = new List <Point3F>(steps + 1);
// fill the equator
for (double i = 0; i <= 1; i = i + 1 / (double)steps)
{
equator.Add(curve.GetParametricPoint(i));
}
// close the point count
equator.Add(curve.GetParametricPoint(0));
int equ = equator.Count;
int num = 0;
// here our top dome will have it's points
LinkedList <Point3F> spherePointsTop = new LinkedList <Point3F>();
double height = 0;
double factor = 1;
// Domes.Top starts at the first increment
if (domes == Domes.Top)
{
// insert the equator
foreach (Point3F p in equator)
{
spherePointsTop.AddFirst(p);
}
num++;
}
if (domes == Domes.Both || domes == Domes.Top)
{
// build the top dome
for (int stp = 0; stp != (steps / 4); stp++)
{
// use the equator's points to build the height rings
height = (equator[stp < (equ - 1) ? stp + 1 : 0].Y);
factor = (equator[stp < (equ - 1) ? stp + 1 : 0].X) / radius;
for (int cnt = 0; cnt != equ; cnt++)
{
Point3F item = equator[cnt];
item.X *= factor;
item.Y *= factor;
item.Z = height;
spherePointsTop.AddFirst(item);
}
num++;
}
}
// here our bottom dome will have it's points
LinkedList <Point3F> spherePointsBottom = new LinkedList <Point3F>();
if (domes == Domes.Both || domes == Domes.Bottom)
{
// build the bottom dome
for (int stp = ((steps / 2) + (steps / 4)) - 1; stp != steps; stp++)
{
// use the equator's points to build the height rings
height = (equator[stp < (equ - 1) ? stp + 1 : 0].Y);
factor = (equator[stp < (equ - 1) ? stp + 1 : 0].X) / radius;
for (int cnt = 0; cnt != equ; cnt++)
{
Point3F item = equator[cnt];
item.X *= factor;
item.Y *= factor;
item.Z = height;
spherePointsBottom.AddFirst(item);
}
num++;
}
}
// combine top and bottom dome into our points list
Points.AddRange(spherePointsTop.ToArray());
Points.AddRange(spherePointsBottom.ToArray());
// build triange list
List <TriangleFace> faces = new List <TriangleFace>(Points.Count * 2);
for (int stp = 0; stp != (num - 1); stp++)
{
for (int k = 0; k < (equ - 1); k++)
{
int idxp = (stp * equ) + k;
faces.Add(new TriangleFace(idxp, idxp + 1, idxp + equ + 1));
faces.Add(new TriangleFace(idxp, idxp + equ + 1, idxp + equ));
}
}
Faces = faces.ToArray();
}
/// <summary>
/// Create a sphere (or one of it's domes) at 0,0,0 with radius specified
/// </summary>
/// <param name="radius"></param>
/// <param name="steps"></param>
/// <param name="domes"></param>
public Sphere(double radius, int steps = 45, Domes domes = Domes.Both) : this()
{
BuildDomes(radius, steps, domes);
}
