public bool GetIntersection(Vec3 start, Vec3 end, ref Vertex intersection, ref float percentage)
{
Vec3 direction = end - start;
float num;
float denom;
direction.Normalize();
denom = Vec3.Dot(this.Normal, direction);
if (Math.Abs(denom) < Constants.Epsilon)
{
return(false);
}
num = -DistanceToPlane(start);
percentage = num / denom;
intersection = new Vertex(start + (direction * percentage));
percentage = percentage / (end - start).Magnitude();
return(true);
}
public void SortVerticesCW()
{
// calculate center of polygon
Vec3 center = Vec3.zero;
for (int i = 0; i < NumberOfVertices; i++)
{
center += Verts[i].P;
}
center /= NumberOfVertices;
// sort vertices
for (int i = 0; i < NumberOfVertices - 2; i++)
{
Vec3 a = Vec3.zero;
Plane p;
float smallestAngle = -1;
int smallest = -1;
a = Verts[i].P - center;
a.Normalize();
p = new Plane(Verts[i].P, center, center + P.Normal);
for (int j = i + 1; j < NumberOfVertices; j++)
{
if (p.ClassifyPoint(Verts[j].P) != PointClassification.BACK)
{
Vec3 b = Vec3.zero;
float angle;
b = Verts[j].P - center;
b.Normalize();
angle = Vec3.Dot(a, b);
if (angle > smallestAngle)
{
smallestAngle = angle;
smallest = j;
}
}
}
if (smallest == -1)
{
//throw new MalformedPolyException("Polygon has less than 3 vertices!");
return;
}
Vertex t = Verts[smallest];
Verts[smallest] = Verts[i + 1];
Verts[i + 1] = t;
}
// check if vertex order needs to be reversed for back-facing polygon
Plane oldPlane = P;
CalculatePlane();
if (Vec3.Dot(P.Normal, oldPlane.Normal) < 0)
{
int j = NumberOfVertices;
for (int i = 0; i < j / 2; i++)
{
Vertex v = Verts[i];
Verts[i] = Verts[j - i];
Verts[j - i] = v;
}
}
}