/// <summary>
/// Creates a Polygon from an array of points.
/// </summary>
/// <param name="points"></param>
/// <param name="shared"></param>
/// <returns></returns>
public static Polygon createPolygon(Vector3[] points, System.Object shared = null)
{
if (points.Length < 2)
{
return null;
}
List<IVertex> vertices = new List<IVertex>();
foreach (Vector3 pos in points)
{
vertices.Add(new Vertex(pos));
}
Polygon polygon = new Polygon(vertices, shared);
return polygon;
}
/// <summary>
/// Extrudes a polygon.
/// </summary>
/// <param name="polygon">The polygon to extrude</param>
/// <param name="distance">Extrusion distance</param>
/// <param name="normal">Optional normal to extrude along, default is polygon normal</param>
/// <returns></returns>
public static List<Polygon> extrudePolygon(Polygon polygon, float distance, Vector3? normal = null)
{
normal = normal != null ? normal : polygon.plane.normal;
Vector3 du = normal.GetValueOrDefault();
IVertex[] vertices = polygon.vertices;
List<IVertex> top = new List<IVertex>();
List<IVertex> bot = new List<IVertex>();
List<Polygon> polygons = new List<Polygon>();
Vector3 invNormal = normal.GetValueOrDefault();
du *= distance;
invNormal *= -1f;
for (int i = 0; i < vertices.Length; i++)
{
int j = (i + 1) % vertices.Length;
Vector3 p1 = vertices[i].pos;
Vector3 p2 = vertices[j].pos;
Vector3 p3 = p2 + du;
Vector3 p4 = p1 + du;
Plane plane = Plane.fromPoints(p1, p2, p3);
Vertex v1 = new Vertex(p1, plane.normal);
Vertex v2 = new Vertex(p2, plane.normal);
Vertex v3 = new Vertex(p3, plane.normal);
Vertex v4 = new Vertex(p4, plane.normal);
Polygon poly = new Polygon(new List<IVertex>(new IVertex[] { v1, v2, v3, v4 }), polygon.shared);
polygons.Add(poly);
top.Add(new Vertex(p4, normal.GetValueOrDefault()));
bot.Insert(0, new Vertex(p1, invNormal));
}
polygons.Add(new Polygon(top, polygon.shared));
polygons.Add(new Polygon(bot, polygon.shared));
return polygons;
}
/// <summary>
/// Create CSG from array, does not clone the polygons
/// </summary>
/// <param name="polygon"></param>
/// <returns></returns>
private static CSG fromPolygons(Polygon[] polygons)
{
//TODO: Optimize polygons to share vertices
CSG csg = new CSG();
csg.polygons.AddRange(polygons);
return csg;
}
/// <summary>
/// Cube function, Untested but compiles
/// </summary>
/// <param name="center">world space center of the cube</param>
/// <param name="radius">size of the cube created at center</param>
/// <returns></returns>
public static CSG cube(Vector3? center, Vector3? radius)
{
Vector3 c = center.GetValueOrDefault(Vector3.zero);
Vector3 r = radius.GetValueOrDefault(Vector3.one);
//TODO: Test if this works
Polygon[] polygons = new Polygon[6];
int[][][] data = new int[][][] {
new int[][]{new int[]{0, 4, 6, 2}, new int[]{-1, 0, 0}},
new int[][]{new int[]{1, 3, 7, 5}, new int[]{1, 0, 0}},
new int[][]{new int[]{0, 1, 5, 4}, new int[]{0, -1, 0}},
new int[][]{new int[]{2, 6, 7, 3}, new int[]{0, 1, 0}},
new int[][]{new int[]{0, 2, 3, 1}, new int[]{0, 0, -1}},
new int[][]{new int[]{4, 5, 7, 6}, new int[]{0, 0, 1}}
};
for (int x = 0; x < 6; x++)
{
int[][] v = data[x];
Vector3 normal = new Vector3((float)v[1][0], (float)v[1][1], (float)v[1][2]);
IVertex[] verts = new IVertex[4];
for (int i = 0; i < 4; i++)
{
verts[i] = new Vertex(
new Vector3(
c.x + (r.x * (2 * (((v[0][i] & 1) > 0) ? 1 : 0) - 1)),
c.y + (r.y * (2 * (((v[0][i] & 2) > 0) ? 1 : 0) - 1)),
c.z + (r.z * (2 * (((v[0][i] & 4) > 0) ? 1 : 0) - 1))),
normal
);
}
polygons[x] = new Polygon(verts);
}
return CSG.fromPolygons(polygons);
}
/// <summary>
/// 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`
/// </summary>
/// <param name="polygon"></param>
/// <param name="coplanarFront"></param>
/// <param name="coplanarBack"></param>
/// <param name="front"></param>
/// <param name="back"></param>
public void splitPolygon(Polygon polygon,
ref List <Polygon> coplanarFront,
ref List <Polygon> coplanarBack,
ref List <Polygon> front,
ref List <Polygon> back)
{
//Debug.Log("splitPolygon: " + polygon.vertices[0].pos + ", " + polygon.vertices[1].pos + ", " + polygon.vertices[2].pos);
IVertex[] vertices = polygon.vertices;
int polygonType = 0;
List <int> types = new List <int>();
int type;
float t;
int i;
for (i = 0; i < vertices.Length; i++)
{
t = Vector3.Dot(this.normal, vertices[i].pos) - this.w;
if (t < -Plane.EPSILON)
{
type = BACK;
}
else if (t > Plane.EPSILON)
{
type = FRONT;
}
else
{
type = COPLANAR;
}
polygonType |= type;
types.Add(type);
}
// Put the polygon in the correct list, splitting it when necessary.
switch (polygonType)
{
case COPLANAR:
if (Vector3.Dot(this.normal, polygon.plane.normal) > 0)
{
coplanarFront.Add(polygon);
}
else
{
coplanarBack.Add(polygon);
}
break;
case FRONT:
front.Add(polygon);
break;
case BACK:
back.Add(polygon);
break;
default:
case SPANNING:
if (polygonType != SPANNING)
{
Debug.Log("Defaulting to spanning");
}
List <IVertex> f = new List <IVertex>();
List <IVertex> b = new List <IVertex>();
for (i = 0; i < vertices.Length; i++)
{
int j = (i + 1) % vertices.Length;
int ti = types[i];
int tj = types[j];
IVertex vi = vertices[i];
IVertex vj = vertices[j];
if (ti != BACK)
{
f.Add(vi);
}
if (ti != FRONT)
{
b.Add(ti != BACK ? vi.clone() : vi);
}
if ((ti | tj) == SPANNING)
{
t = (this.w - Vector3.Dot(this.normal, vi.pos)) /
Vector3.Dot(this.normal, vj.pos - vi.pos);
IVertex v = vi.interpolate(vj, t);
f.Add(v);
b.Add(v.clone());
}
}
if (f.Count >= 3)
{
front.Add(new Polygon(f, polygon.shared));
}
if (b.Count >= 3)
{
back.Add(new Polygon(b, polygon.shared));
}
break;
}
}
/// <summary>
/// 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`
/// </summary>
/// <param name="polygon"></param>
/// <param name="coplanarFront"></param>
/// <param name="coplanarBack"></param>
/// <param name="front"></param>
/// <param name="back"></param>
public void splitPolygon(Polygon polygon,
ref List<Polygon> coplanarFront,
ref List<Polygon> coplanarBack,
ref List<Polygon> front,
ref List<Polygon> back)
{
//Debug.Log("splitPolygon: " + polygon.vertices[0].pos + ", " + polygon.vertices[1].pos + ", " + polygon.vertices[2].pos);
IVertex[] vertices = polygon.vertices;
int polygonType = 0;
List<int> types = new List<int>();
int type;
float t;
int i;
for (i = 0; i < vertices.Length; i++)
{
t = Vector3.Dot(this.normal, vertices[i].pos) - this.w;
if (t < -Plane.EPSILON) { type = BACK; } else if (t > Plane.EPSILON) { type = FRONT; } else { type = COPLANAR; }
polygonType |= type;
types.Add(type);
}
// Put the polygon in the correct list, splitting it when necessary.
switch (polygonType)
{
case COPLANAR:
if (Vector3.Dot(this.normal, polygon.plane.normal) > 0)
{
coplanarFront.Add(polygon);
}
else
{
coplanarBack.Add(polygon);
}
break;
case FRONT:
front.Add(polygon);
break;
case BACK:
back.Add(polygon);
break;
default:
case SPANNING:
if (polygonType != SPANNING)
Debug.Log("Defaulting to spanning");
List<IVertex> f = new List<IVertex>();
List<IVertex> b = new List<IVertex>();
for (i = 0; i < vertices.Length; i++)
{
int j = (i + 1) % vertices.Length;
int ti = types[i];
int tj = types[j];
IVertex vi = vertices[i];
IVertex vj = vertices[j];
if (ti != BACK) f.Add(vi);
if (ti != FRONT) b.Add(ti != BACK ? vi.clone() : vi);
if ((ti | tj) == SPANNING)
{
t = (this.w - Vector3.Dot(this.normal, vi.pos)) /
Vector3.Dot(this.normal, vj.pos - vi.pos);
IVertex v = vi.interpolate(vj, t);
f.Add(v);
b.Add(v.clone());
}
}
if (f.Count >= 3) front.Add(new Polygon(f, polygon.shared));
if (b.Count >= 3) back.Add(new Polygon(b, polygon.shared));
break;
}
}
public Mesh toMesh()
{
List <Polygon> trisFromPolygons = new List <Polygon>();
// triangulate polygons
for (int i = this.polygons.Count - 1; i >= 0; i--)
{
if (this.polygons[i].vertices.Length > 3)
{
//Debug.Log("!!! Poly to Tri (order): " + this.polygons[i].vertices.Length);
for (int vi = 1; vi < this.polygons[i].vertices.Length - 1; vi++)
{
IVertex[] tri = new IVertex[] {
this.polygons[i].vertices[0],
this.polygons[i].vertices[vi],
this.polygons[i].vertices[vi + 1]
};
trisFromPolygons.Add(new Polygon(tri));
}
// the original polygon is replaced by a set of triangles
this.polygons.RemoveAt(i);
}
}
this.polygons.AddRange(trisFromPolygons);
// TODO: Simplify mesh - the boolean CSG algorithm leaves lots of coplanar
// polygons that share an edge that could be simplified.
// At this point, we have a soup of triangles without regard for shared vertices.
// We index these to combine any vertices with identical positions & normals
// (and maybe later UVs & vertex colors)
List <Vertex> vertices = new List <Vertex>();
int[] tris = new int[this.polygons.Count * 3];
for (int pi = 0; pi < this.polygons.Count; pi++)
{
Polygon tri = this.polygons[pi];
if (tri.vertices.Length > 3)
{
Debug.LogError("Polygon should be a triangle, but isn't !!");
}
for (int vi = 0; vi < 3; vi++)
{
Vertex vertex = tri.vertices[vi] as Vertex;
bool equivalentVertexAlreadyInList = false;
for (int i = 0; i < vertices.Count; i++)
{
if (vertices[i].pos.ApproximatelyEqual(vertex.pos) &&
vertices[i].normal.ApproximatelyEqual(vertex.normal))
{
equivalentVertexAlreadyInList = true;
vertex.index = vertices[i].index;
}
}
if (!equivalentVertexAlreadyInList)
{
vertices.Add(vertex);
vertex.index = vertices.Count - 1;
}
tris[(pi * 3) + vi] = vertex.index;
}
//Debug.Log(string.Format("Added tri {0},{1},{2}: {3},{4},{5}", pi, pi+1, pi+2, tris[pi], tris[pi+1], tris[pi+2]));
}
Vector3[] verts = new Vector3[this.polygons.Count * 3];
Vector3[] normals = new Vector3[this.polygons.Count * 3];
Mesh m = new Mesh();
for (int i = 0; i < vertices.Count; i++)
{
verts[i] = vertices[i].pos;
normals[i] = vertices[i].normal;
}
m.vertices = verts;
m.normals = normals;
m.triangles = tris;
//m.RecalculateBounds();
//m.RecalculateNormals();
//m.Optimize();
//Debug.Log("toMesh verts, normals, tris: " + m.vertices.Length + ", " +m.normals.Length+", "+m.triangles.Length);
return(m);
}
