public override bool Equals(object obj)
{
TriangleEdge other = obj as TriangleEdge;
if (other != null)
{
return((a == other.a && b == other.b) || (a == other.b && b == other.a));
}
return(false);
}
/**
* Compute the normal of the border edge.
* */
private Vector3 ComputeBorderEdgeNormal(TriangleEdge edge, ITriangleMesh mesh)
{
Vector3 v0 = mesh.GetVertex(edge.A);
Vector3 v1 = mesh.GetVertex(edge.B);
Vector3 e = Vector3.Subtract(v1, v0);
Vector3 n = Vector3.Cross(e, Vector3.UnitZ);
n.Normalize();
return(n);
}
/*
* Create the VBO for the border
* */
void CreateBorderVBO()
{
borderVBO = new VertexBufferObject();
List <TriangleEdge> borderEdges = mesh.GetBorder();
Color4 borderColor = Color4.Pink;
List <RenderVertex> renderVertices = new List <RenderVertex>();
for (int i = 0; i < borderEdges.Count; i++)
{
TriangleEdge edge = borderEdges[i];
Vector3 a = mesh.GetVertex(edge.A);
Vector3 b = mesh.GetVertex(edge.B);
renderVertices.Add(new RenderVertex(a, new Vector3(0, 1, 0), borderColor));
renderVertices.Add(new RenderVertex(b, new Vector3(0, 1, 0), borderColor));
}
borderVBO.Setup(renderVertices, PrimitiveType.Lines);
}
private ITriangleMesh CreateBoundary(ITriangleMesh mesh, float height, float borderHeightTop, float borderHeightBottom, Vector3 offset, Vector2[] cornerTexCoords)
{
List <TriangleEdge> border = mesh.GetBorder();
int vertsPerBorderEdge = 3;
ITriangleMesh borderMesh = new TriangleMesh();
for (int i = 0; i < border.Count; i++)
{
borderMesh.AddVertex(mesh.GetVertex(border[i].A));
}
for (int i = 0; i < border.Count; i++)
{
TriangleEdge borderEdge = border[i];
TriangleEdge prevEdge = border[(i + border.Count - 1) % border.Count];
Vector3 v = borderMesh.GetVertex(i);
// v0
Vector3 edgeNormal = ComputeBorderEdgeNormal(borderEdge, mesh);
Vector3 prevEdgeNormal = ComputeBorderEdgeNormal(prevEdge, mesh);
Vector3 borderNormal = Vector3.Add(edgeNormal, prevEdgeNormal);
borderNormal.Normalize();
borderNormal = Vector3.Multiply(borderNormal, Math.Max(borderHeightTop, borderHeightBottom) / (float)Math.Sin(30.0 / 180.0 * Math.PI));
Vector3 v0 = Vector3.Add(Vector3.Add(v, borderNormal), new Vector3(0, 0, -borderHeightTop));
borderMesh.AddVertex(v0);
// v1
Vector3 v1 = Vector3.Add(v0, Vector3.Multiply(Vector3.UnitZ, -(height - (borderHeightTop + borderHeightBottom))));
borderMesh.AddVertex(v1);
// v2
Vector3 v2 = Vector3.Add(v, Vector3.Multiply(Vector3.UnitZ, -height));
borderMesh.AddVertex(v2);
}
float alpha = (float)(borderHeightTop * Math.Sqrt(2) / (borderHeightTop * Math.Sqrt(2) + borderHeightBottom * Math.Sqrt(2) + height));
float beta = 1 - (float)(borderHeightBottom * Math.Sqrt(2) / (borderHeightTop * Math.Sqrt(2) + borderHeightBottom * Math.Sqrt(2) + height));
int ti0 = borderMesh.AddTextureCoordinate(cornerTexCoords[0]);
int ti1 = borderMesh.AddTextureCoordinate(Vector2.Add(Vector2.Multiply(cornerTexCoords[0], 1 - alpha), Vector2.Multiply(cornerTexCoords[1], alpha)));
int ti2 = borderMesh.AddTextureCoordinate(Vector2.Add(Vector2.Multiply(cornerTexCoords[0], 1 - beta), Vector2.Multiply(cornerTexCoords[1], beta)));
int ti3 = borderMesh.AddTextureCoordinate(cornerTexCoords[1]);
int ti_0 = borderMesh.AddTextureCoordinate(cornerTexCoords[2]);
int ti_1 = borderMesh.AddTextureCoordinate(Vector2.Add(Vector2.Multiply(cornerTexCoords[2], 1 - alpha), Vector2.Multiply(cornerTexCoords[3], alpha)));
int ti_2 = borderMesh.AddTextureCoordinate(Vector2.Add(Vector2.Multiply(cornerTexCoords[2], 1 - beta), Vector2.Multiply(cornerTexCoords[3], beta)));
int ti_3 = borderMesh.AddTextureCoordinate(cornerTexCoords[3]);
// Triangles
for (int i = 0; i < border.Count; i++)
{
TriangleEdge borderEdge = border[i];
int vi0 = border.Count + vertsPerBorderEdge * i + 0;
int vi1 = border.Count + vertsPerBorderEdge * i + 1;
int vi2 = border.Count + vertsPerBorderEdge * i + 2;
int vi_0 = border.Count + vertsPerBorderEdge * ((i + 1) % border.Count) + 0;
int vi_1 = border.Count + vertsPerBorderEdge * ((i + 1) % border.Count) + 1;
int vi_2 = border.Count + vertsPerBorderEdge * ((i + 1) % border.Count) + 2;
// A
Triangle t = new Triangle(i, vi0, (i + 1) % border.Count, ti0, ti1, ti_1);
borderMesh.AddTriangle(t);
// B
t = new Triangle((i + 1) % border.Count, vi0, vi_0, ti_0, ti1, ti_1);
borderMesh.AddTriangle(t);
// C
t = new Triangle(vi0, vi1, vi_0, ti1, ti2, ti_1);
borderMesh.AddTriangle(t);
// D
t = new Triangle(vi1, vi_1, vi_0, ti2, ti_2, ti_1);
borderMesh.AddTriangle(t);
// E
t = new Triangle(vi1, vi2, vi_1, ti2, ti3, ti_2);
borderMesh.AddTriangle(t);
// F
t = new Triangle(vi2, vi_2, vi_1, ti3, ti_3, ti_2);
borderMesh.AddTriangle(t);
}
return(borderMesh);
}
public List <TriangleEdge> GetBorder()
{
List <TriangleEdge> border = new List <TriangleEdge>();
foreach (Triangle t in triangles)
{
for (int i = 0; i < 3; i++)
{
TriangleEdge e = new TriangleEdge(t.GetVertexIndex(i), t.GetVertexIndex((i + 1) % 3));
if (!border.Contains(e))
{
border.Add(e);
}
else
{
border.Remove(e);
}
}
}
Console.WriteLine("Mesh border: " + border.Count + " edges.");
// Sort
List <TriangleEdge> sortedBorder = new List <TriangleEdge>();
while (border.Count > 0)
{
TriangleEdge start = border[0];
sortedBorder.Add(start);
border.Remove(start);
int endIdx = start.B;
bool found = true;
int borderPolySize = 1;
while (found)
{
found = false;
for (int i = 0; i < border.Count; i++)
{
TriangleEdge e = border[i];
if (e.A == endIdx)
{
sortedBorder.Add(e);
border.Remove(e);
endIdx = e.B;
found = true;
borderPolySize++;
}
else if (e.B == endIdx)
{
sortedBorder.Add(e);
border.Remove(e);
e.Flip();
endIdx = e.A;
found = true;
borderPolySize++;
}
}
}
Console.WriteLine("Border polygon found: " + ((start.A == sortedBorder[sortedBorder.Count - 1].B) ? "closed" : "open") + ", " + borderPolySize + " edges");
}
return(sortedBorder);
}