private Vector3 Barycentre(Triangle triangle, float p1, float p2, float p3)
{
float x = (triangle.P1.X * p1 + triangle.P2.X * p2 + triangle.P3.X * p3) / p1 + p2 + p3;
float y = (triangle.P1.Y * p1 + triangle.P2.Y * p2 + triangle.P3.Y * p3) / p1 + p2 + p3;
float z = (triangle.P1.Z * p1 + triangle.P2.Z * p2 + triangle.P3.Z * p3) / p1 + p2 + p3;
return new Vector3(x, y, z);
}
public ITriangleInstance AddTriangle(Triangle triangle)
{
var instance = new TriangleInstance(this);
m_instances.Add(instance);
instance.P1 = triangle.P1;
instance.P2 = triangle.P2;
instance.P3 = triangle.P3;
instance.Color = triangle.Color;
return instance;
}
private Vector3 Barycentre2(Triangle triangle, float p1, float p2, float p3)
{
return new Vector3(p1 * triangle.P1.X + p2 * triangle.P2.X + p3 * triangle.P3.X,
p1 * triangle.P1.Y + p2 * triangle.P2.Y + p3 * triangle.P3.Y,
p1 * triangle.P1.Z + p2 * triangle.P2.Z + p3 * triangle.P3.Z);
}
private Vector3 Normal(Triangle t)
{
var u = new Vector3(
t.P2.X - t.P1.X,
t.P2.Y - t.P1.Y,
t.P2.Z - t.P1.Z
);
var v = new Vector3(
t.P3.X - t.P1.X,
t.P3.Y - t.P1.Y,
t.P3.Z - t.P1.Z
);
var normal = new Vector3(
u.Y * v.Z - v.Y * u.Z,
-(u.X * v.Z - v.X * u.Z),
u.X * v.Y - v.X * u.Y);
return normal.Normalize();
}
private List<Triangle> BuildIco(double R)
{
float phi = (float)((Math.Sqrt(5.0) - 1.0) / 2.0);
float radius = (float)Math.Sqrt((5 - Math.Sqrt(5)) / 2.0);
float A = (float)R / radius;
float B = phi * A;
var I0 = new Vector3(A, B, 0);
var I1 = new Vector3(-A, B, 0);
var I2 = new Vector3(-A, -B, 0);
var I3 = new Vector3(A, -B, 0);
var J0 = new Vector3(0, A, B);
var J1 = new Vector3(0, -A, B);
var J2 = new Vector3(0, -A, -B);
var J3 = new Vector3(0, A, -B);
var K0 = new Vector3(B, 0, A);
var K1 = new Vector3(B, 0, -A);
var K2 = new Vector3(-B, 0, -A);
var K3 = new Vector3(-B, 0, A);
var list = new List<Triangle>();
var t = new Triangle(I3, I0, K0);
list.Add(t);
t = new Triangle(I0, I3, K1);
list.Add(t);
t = new Triangle(I2, I1, K2);
list.Add(t);
t = new Triangle(I1, I2, K3);
list.Add(t);
t = new Triangle(J3, J0, I0);
list.Add(t);
t = new Triangle(J0, J3, I1);
list.Add(t);
t = new Triangle(J2, J1, I2);
list.Add(t);
t = new Triangle(J1, J2, I3);
list.Add(t);
t = new Triangle(K3, K0, J0);
list.Add(t);
t = new Triangle(K0, K3, J1);
list.Add(t);
t = new Triangle(K2, K1, J2);
list.Add(t);
t = new Triangle(K1, K2, J3);
list.Add(t);
t = new Triangle(I0, J0, K0);
list.Add(t);
t = new Triangle(I0, K1, J3);
list.Add(t);
t = new Triangle(I3, K0, J1);
list.Add(t);
t = new Triangle(I3, J2, K1);
list.Add(t);
t = new Triangle(I1, K3, J0);
list.Add(t);
t = new Triangle(I1, J3, K2);
list.Add(t);
t = new Triangle(I2, J1, K3);
list.Add(t);
t = new Triangle(I2, K2, J2);
list.Add(t);
return list;
}