public CSG_Model(List <CSG_Polygon> list)
{
this.vertices = new List <CSG_Vertex>();
this.indexes = new List <int>();
int p = 0;
for (int i = 0; i < list.Count; i++)
{
CSG_Polygon poly = list[i];
for (int j = 2; j < poly.vertices.Count; j++)
{
this.vertices.Add(poly.vertices[0]);
this.indexes.Add(p++);
this.vertices.Add(poly.vertices[j - 1]);
this.indexes.Add(p++);
this.vertices.Add(poly.vertices[j]);
this.indexes.Add(p++);
}
}
}
// Split `polygon` by this plane if needed, then put the polygon or polygon
// fragments in the appropriate lists. Coplanar polygons go into either
// `coplanarFront` or `coplanarBack` depending on their orientation with
// respect to this plane. Polygons in front or in back of this plane go into
// either `front` or `back`.
public void SplitPolygon(CSG_Polygon polygon, List <CSG_Polygon> coplanarFront, List <CSG_Polygon> coplanarBack, List <CSG_Polygon> front, List <CSG_Polygon> back)
{
// Classify each point as well as the entire polygon into one of the above
// four classes.
EPolygonType polygonType = 0;
List <EPolygonType> types = new List <EPolygonType>();
for (int i = 0; i < polygon.vertices.Count; i++)
{
float t = Vector3.Dot(this.normal, polygon.vertices[i].position) - this.w;
EPolygonType type = (t < -CSG.EPSILON) ? EPolygonType.Back : ((t > CSG.EPSILON) ? EPolygonType.Front : EPolygonType.Coplanar);
polygonType |= type;
types.Add(type);
}
// Put the polygon in the correct list, splitting it when necessary.
switch (polygonType)
{
case EPolygonType.Coplanar:
{
if (Vector3.Dot(this.normal, polygon.plane.normal) > 0)
{
coplanarFront.Add(polygon);
}
else
{
coplanarBack.Add(polygon);
}
}
break;
case EPolygonType.Front:
{
front.Add(polygon);
}
break;
case EPolygonType.Back:
{
back.Add(polygon);
}
break;
case EPolygonType.Spanning:
{
List <CSG_Vertex> f = new List <CSG_Vertex>();
List <CSG_Vertex> b = new List <CSG_Vertex>();
for (int i = 0; i < polygon.vertices.Count; i++)
{
int j = (i + 1) % polygon.vertices.Count;
EPolygonType ti = types[i], tj = types[j];
CSG_Vertex vi = polygon.vertices[i], vj = polygon.vertices[j];
if (ti != EPolygonType.Back)
{
f.Add(vi);
}
if (ti != EPolygonType.Front)
{
b.Add(vi);
}
if ((ti | tj) == EPolygonType.Spanning)
{
float t = (this.w - Vector3.Dot(this.normal, vi.position)) / Vector3.Dot(this.normal, vj.position - vi.position);
CSG_Vertex v = CSG_VertexUtility.Mix(vi, vj, t);
f.Add(v);
b.Add(v);
}
}
if (f.Count >= 3)
{
front.Add(new CSG_Polygon(f));
}
if (b.Count >= 3)
{
back.Add(new CSG_Polygon(b));
}
}
break;
} // End switch(polygonType)
}
