internal override void CalculateTangents(TangentMixer t, TangentMixer b)
{
throw new NotImplementedException();
}
internal virtual void CalculateTangents(TangentMixer t, TangentMixer b)
{
//throw new System.NotImplementedException();
}
internal override void CalculateTangents(TangentMixer t, TangentMixer b)
{
switch (this.VertexSourceType)
{
case VertexSourceType.QuadList:
this.CalculateTangentsQuadList(t, b);
return;
case VertexSourceType.TriangleList:
this.CalculateTangentsTrianleList(t, b);
return;
case VertexSourceType.TriangleStrip:
this.CalculateTangentsTrianleStrip(t, b);
return;
}
}
private void CalculateTangentsTrianleStrip(TangentMixer t, TangentMixer b)
{
throw new NotImplementedException();
}
private void CalculateTangentsTrianleList(TangentMixer t, TangentMixer b)
{
for (int i = 0; i < this.indices.Count; i += 3)
{
Vector3 p2 = this.Mesh.Vertices[this.indices[i + 2].Vertex];
Vector3 p1 = this.Mesh.Vertices[this.indices[i + 1].Vertex];
Vector3 p0 = this.Mesh.Vertices[this.indices[i].Vertex];
Vector3 n2 = this.Mesh.Normals[this.indices[i + 2].Normal];
Vector3 n1 = this.Mesh.Normals[this.indices[i + 1].Normal];
Vector3 n0 = this.Mesh.Normals[this.indices[i].Normal];
Vector3 v1 = p1 - p0;
Vector3 v2 = p2 - p0;
var pu0 = this.Mesh.IsUV0StreamAvailable?this.Mesh.UV0[this.indices[i].UV0]:Vector2.Zero;
var pu1 = this.Mesh.IsUV0StreamAvailable?this.Mesh.UV0[this.indices[i + 1].UV0]:Vector2.Zero;
var pu2 = this.Mesh.IsUV0StreamAvailable ? this.Mesh.UV0[this.indices[i + 2].UV0] : Vector2.Zero;
var u1 = pu1 - pu0;
var u2 = pu2 - pu0;
var det = u1.X * u2.Y - u2.X * u1.Y;
if (det == 0)
{
det = 1;
}
det = 1 / det;
var tangent =
Vector3.Normalize(
new Vector3(
(v1.X * u2.Y - v2.X * u1.Y) * det, (v1.Y * u2.Y - v2.Y * u1.Y) * det, (v1.Z * u2.Y - v2.Z * u1.Y) * det));
var bitangent =
Vector3.Normalize(
new Vector3(
(-v1.X * u2.X + v2.X * u1.X) * det, (-v1.Y * u2.X + v2.Y * u1.X) * det, (-v1.Z * u2.X + v2.Z * u1.X) * det));
var key0 = new TangentKey(p0, pu0);
var key1 = new TangentKey(p1, pu1);
var key2 = new TangentKey(p2, pu2);
{
var old = this.indices[i];
old.Tangent = t.Add(key0, ref n0, tangent);
old.Binormal = b.Add(key0, ref n0, bitangent);
this.indices[i] = old;
}
{
var old = this.indices[i+1];
old.Tangent = t.Add(key1, ref n1, tangent);
old.Binormal = b.Add(key1, ref n1, bitangent);
this.indices[i+1] = old;
}
{
var old = this.indices[i + 2];
old.Tangent = t.Add(key2, ref n2, tangent);
old.Binormal = b.Add(key2, ref n2, bitangent);
this.indices[i + 2] = old;
}
}
}
private void CalculateTangentsQuadList(TangentMixer t, TangentMixer b)
{
throw new NotImplementedException();
}