private int Split(Triangle t, ref List <Triangle> t1, ref List <Triangle> t2)
{
Vector3D normal = t.Normal;
int[] v = new int[3];
int val = 0;
int i = 0;
foreach (Vector3D pt in t.Points)
{
v[i] = TestPoint(pt);
val += v[i];
i++;
}
switch (val)
{
case 3:
t1.Add(t);
return(1);
case -3:
t2.Add(t);
return(1);
case 2:
t1.Add(t);
return(1);
case -2:
t2.Add(t);
return(1);
case 0:
if (v[0] != 0 || v[1] != 0 || v[2] != 0)
{
int pivot = 0, positive = 0, negative = 0;
if (0 == v[0])
{
pivot = 0;
if (v[1] > 0)
{
positive = 1; negative = 2;
}
else
{
positive = 2; negative = 1;
}
}
if (0 == v[1])
{
pivot = 1;
if (v[0] > 0)
{
positive = 0; negative = 2;
}
else
{
positive = 2; negative = 0;
}
}
if (0 == v[2])
{
pivot = 2;
if (v[0] > 0)
{
positive = 0; negative = 1;
}
else
{
positive = 1; negative = 0;
}
}
// here positive, pivot and negative are ready
Vector3D ptInter = Vector3D.Zero;
TestLine(t.Points[positive], t.Points[negative], ref ptInter);
t1.Add(new Triangle(t.PickId, t.Points[positive], t.EdgeDrawn(positive, negative), ptInter, false, t.Points[pivot], t.EdgeDrawn(pivot, positive), t.ColorFill));
t2.Add(new Triangle(t.PickId, t.Points[negative], t.EdgeDrawn(negative, pivot), t.Points[pivot], false, ptInter, t.EdgeDrawn(positive, negative), t.ColorFill));
return(2);
}
else
{
t1.Add(t);
return(1);
}
case -1:
if (0 == v[0] * v[1] * v[2])
{
t2.Add(t);
return(1);
}
{
int positive = 0, negative1 = 0, negative2 = 0;
if (v[0] == 1)
{
positive = 0; negative1 = 1; negative2 = 2;
}
if (v[1] == 1)
{
positive = 1; negative1 = 0; negative2 = 2;
}
if (v[2] == 1)
{
positive = 2; negative1 = 0; negative2 = 1;
}
Vector3D ptInter1 = Vector3D.Zero, ptInter2 = Vector3D.Zero;
TestLine(t.Points[negative1], t.Points[positive], ref ptInter1);
TestLine(t.Points[negative2], t.Points[positive], ref ptInter2);
Triangle t11 = new Triangle(t.PickId, t.Points[positive], t.EdgeDrawn(positive, negative1), ptInter1, false, ptInter2, t.EdgeDrawn(negative2, positive), t.ColorFill);
Triangle t21 = new Triangle(t.PickId, t.Points[negative2], t.EdgeDrawn(negative2, positive), ptInter2, false, ptInter1, false, t.ColorFill);
Triangle t22 = new Triangle(t.PickId, t.Points[negative2], false, ptInter1, t.EdgeDrawn(positive, negative1), t.Points[negative1], t.EdgeDrawn(negative1, negative2), t.ColorFill);
if (!t11.IsFlat)
{
t1.Add(AlignNormal(t11, normal));
}
if (!t21.IsFlat)
{
t2.Add(AlignNormal(t21, normal));
}
if (!t22.IsFlat)
{
t2.Add(AlignNormal(t22, normal));
}
return(3);
}
case 1:
if (0 == v[0] * v[1] * v[2])
{
t1.Add(t);
return(1);
}
{
int negative = 0, positive1 = 0, positive2 = 0;
if (v[0] == -1)
{
negative = 0; positive1 = 1; positive2 = 2;
}
if (v[1] == -1)
{
negative = 1; positive1 = 0; positive2 = 2;
}
if (v[2] == -1)
{
negative = 2; positive1 = 0; positive2 = 1;
}
Vector3D ptInter1 = Vector3D.Zero, ptInter2 = Vector3D.Zero;
TestLine(t.Points[positive1], t.Points[negative], ref ptInter1);
TestLine(t.Points[positive2], t.Points[negative], ref ptInter2);
Triangle t11 = new Triangle(t.PickId, t.Points[positive1], t.EdgeDrawn(positive1, negative), ptInter1, false, ptInter2, false, t.ColorFill);
Triangle t12 = new Triangle(t.PickId, t.Points[positive1], false, ptInter2, t.EdgeDrawn(negative, positive2), t.Points[positive2], t.EdgeDrawn(positive2, positive1), t.ColorFill);
Triangle t21 = new Triangle(t.PickId, t.Points[negative], t.EdgeDrawn(negative, positive2), ptInter2, false, ptInter1, t.EdgeDrawn(positive1, negative), t.ColorFill);
if (!t11.IsFlat)
{
t1.Add(AlignNormal(t11, normal));
}
if (!t12.IsFlat)
{
t1.Add(AlignNormal(t12, normal));
}
if (!t21.IsFlat)
{
t2.Add(AlignNormal(t21, normal));
}
return(3);
}
default:
{
StringBuilder sb = new StringBuilder();
foreach (Vector3D pt in t.Points)
{
sb.AppendLine(pt.ToString());
}
throw new Exception(sb.ToString());
}
}
}
public BSPNodeTri(Triangle t)
{
Triangle = t;
InitEquation(t, ref A, ref B, ref C, ref D);
}
public void AddTriangle(Triangle triangle) => Triangles.Add(triangle);