public void ClassifyPoint(BSPVertex vert, Vector3 planePoint, Vector3 planeNorm)
{
if (PointOnPlane(vert.Point, planePoint, planeNorm))
{
vert.Classification = BSPClassification.OnPlane;
}
else if (PointInFront(vert.Point, planePoint, planeNorm))
{
vert.Classification = BSPClassification.Front;
}
else
{
vert.Classification = BSPClassification.Back;
}
}
public void SplitPolygon(BSPFace face, Vector3 planePoint, Vector3 planeNorm, ref BSPFace front, ref BSPFace back)
{
front.TextureID = face.TextureID;
back.TextureID = face.TextureID;
BSPVertex firstPoint = face.Points[0];
if (firstPoint.Classification == BSPClassification.OnPlane)
{
front.Points.Add(firstPoint);
back.Points.Add(firstPoint);
}
else if (firstPoint.Classification == BSPClassification.Front)
{
front.Points.Add(firstPoint);
}
else
{
back.Points.Add(firstPoint);
}
int current = 0;
BSPVertex vert1, vert2;
for (int i = 1; i < face.Points.Count + 1; i++)
{
if (i == face.Points.Count)
{
current = 0;
}
else
{
current = i;
}
vert1 = face.Points[i - 1];
vert2 = face.Points[current];
ClassifyPoint(vert2, planePoint, planeNorm);
if (vert2.Classification == BSPClassification.OnPlane)
{
front.Points.Add(vert2);
back.Points.Add(vert2);
}
else
{
Vector3 intersect = new Vector3();
float percentage = 0.0f;
bool split = SplitEdge(vert1.Point, vert2.Point, planePoint, planeNorm, ref percentage, ref intersect);
if (split)
{
Vector3 texDelta = vert2.UVs - vert1.UVs;
BSPVertex newVert = new BSPVertex
{
Classification = BSPClassification.OnPlane,
Point = intersect,
UVs = texDelta * percentage + vert1.UVs
};
if (vert2.Classification == BSPClassification.Front)
{
back.Points.Add(newVert);
front.Points.Add(newVert);
front.Points.Add(vert2);
}
else if (vert2.Classification == BSPClassification.Back)
{
front.Points.Add(newVert);
back.Points.Add(newVert);
back.Points.Add(vert2);
}
}
else
{
if (vert2.Classification == BSPClassification.Front)
{
front.Points.Add(vert2);
}
else if (vert2.Classification == BSPClassification.Back)
{
back.Points.Add(vert2);
}
}
}
}
//TODO: This isn't always accurate at extreme splits.
front.Normal = face.Normal;
back.Normal = face.Normal;
//front.CalculateNormal();
front.CalculateCenter();
//back.CalculateNormal();
back.CalculateCenter();
}