private void CalculateTangentArray(int vertexCount, Vertex[] vertex, Vector[] normal, Texcoord[] texcoord,
int triangleCount, Face[] triangles, out Vector[] Bitangent, out Vector[] Normals, out Vector[] Tangent)
{
Vector3[] tan1 = new Vector3[vertexCount];
Vector3[] tan2 = new Vector3[vertexCount];
Normals = new Vector[vertexCount];
for (int a = 0; a < triangleCount; a++)
{
//Store Vertex Index's
int i1 = triangles[a].VertexIndices[0];
int i2 = triangles[a].VertexIndices[1];
int i3 = triangles[a].VertexIndices[2];
int n1 = triangles[a].NormalIndices[0];
int n2 = triangles[a].NormalIndices[1];
int n3 = triangles[a].NormalIndices[2];
int vt1 = triangles[a].TexcoordIndices[0];
int vt2 = triangles[a].TexcoordIndices[1];
int vt3 = triangles[a].TexcoordIndices[2];
//From Vertex Array Copy Coordinates of Vertex's
Vertex v1 = vertex[i1];
Vertex v2 = vertex[i2];
Vertex v3 = vertex[i3];
//From Texture Array Copy Coordinates of Vertex's
Texcoord w1 = texcoord[vt1];
Texcoord w2 = texcoord[vt2];
Texcoord w3 = texcoord[vt3];
//Make Relative to Vertex 1
//Vertex Coordinates
float x1 = v2.Position.X - v1.Position.X;
float x2 = v3.Position.X - v1.Position.X;
float y1 = v2.Position.Y - v1.Position.Y;
float y2 = v3.Position.Y - v1.Position.Y;
float z1 = v2.Position.Z - v1.Position.Z;
float z2 = v3.Position.Z - v1.Position.Z;
//Texture Coordinates
float s1 = w2.Coordinates.X - w1.Coordinates.X;
float s2 = w3.Coordinates.X - w1.Coordinates.X;
float t1 = w2.Coordinates.Y - w1.Coordinates.Y;
float t2 = w3.Coordinates.Y - w1.Coordinates.Y;
float r = 1.0F / (s1 * t2 - s2 * t1);
Vector3 sdir = new Vector3((t2 * x1 - t1 * x2) * r, (t2 * y1 - t1 * y2) * r, (t2 * z1 - t1 * z2) * r);
Vector3 tdir = new Vector3((s1 * x2 - s2 * x1) * r, (s1 * y2 - s2 * y1) * r, (s1 * z2 - s2 * z1) * r);
AngleFucker AF = new AngleFucker(v1.Position, v2.Position, v3.Position);
tan1[i1] += Vector3.Multiply(sdir, AF.Get_v1_Angle());
tan1[i2] += Vector3.Multiply(sdir, AF.Get_v2_Angle());
tan1[i3] += Vector3.Multiply(sdir, AF.Get_v3_Angle());
tan2[i1] += Vector3.Multiply(tdir, AF.Get_v1_Angle());
tan2[i2] += Vector3.Multiply(tdir, AF.Get_v2_Angle());
tan2[i3] += Vector3.Multiply(tdir, AF.Get_v3_Angle());
}
Tangent = new Vector[vertexCount];
Bitangent = new Vector[vertexCount];
for (int a = 0; a < vertexCount; a++)
{
Vector3 n = normal[a].Components;
Normals[a] = Round(normal[a]);
Vector3 b = tan2[a];
Vector3 t = tan1[a];
// Gram-Schmidt orthogonalize
Vector3 temp = Vector3.Subtract(t, Vector3.Multiply(n, Vector3.Dot(n, t)));
temp.Normalize();
Tangent[a] = new Vector(Vector3.Empty, Vector.VectorUsage.Tangent);
Tangent[a].Components = temp;
Tangent[a] = Round(Tangent[a]);
// Calculate handedness
float W = (Vector3.Dot(Vector3.Cross(n, t), b) < 0.0F) ? -1.0F : 1.0F;
//Calculate Bitangent
Bitangent[a] = new Vector(Vector3.Empty, Vector.VectorUsage.Bitangent);
Bitangent[a].Components = Vector3.Multiply((Vector3.Cross(n, temp)), W);
Bitangent[a] = Round(Bitangent[a]);
}
}
public VectorData(int vertexcount, Vertex[] vertices, Vector[] normals, Texcoord[] texcoords, int trianglecount, Face[] triangles)
{
Vector[] Tangents, Bitangents;
CalculateTangentArray(vertexcount, vertices, normals, texcoords, trianglecount, triangles, out Bitangents, out normals, out Tangents);
Size = (uint)(normals.Length * 3 * 4);
List<int> RawData = new List<int>((int)Size);
for (int Index = 0; Index < normals.Length; Index++)
{
RawData.Add(Compress(ref normals[Index]));
RawData.Add(Compress(ref Bitangents[Index]));
RawData.Add(Compress(ref Tangents[Index]));
}
RawVectorData = RawData.ToArray();
}
