/// <summary>
/// Subdivides the given list of triangles with the given list of vertices.
/// </summary>
/// <param name="triList">
/// List of triangles.
/// </param>
/// <param name="vertexList">
/// List of vertices.
/// </param>
public void SubDivide(Collection <Triangle> triList, Collection <PositionTexture> vertexList)
{
if (triList == null)
{
throw new ArgumentNullException("triList");
}
if (vertexList == null)
{
throw new ArgumentNullException("vertexList");
}
Vector3d first = Vector3d.Lerp(vertexList[this.B].Position, vertexList[this.C].Position, .5f);
Vector3d second = Vector3d.Lerp(vertexList[this.C].Position, vertexList[this.A].Position, .5f);
Vector3d third = Vector3d.Lerp(vertexList[this.A].Position, vertexList[this.B].Position, .5f);
Vector2d firstUV = Vector2d.Lerp(new Vector2d(vertexList[this.B].Tu, vertexList[this.B].Tv), new Vector2d(vertexList[this.C].Tu, vertexList[this.C].Tv), .5);
Vector2d secondUV = Vector2d.Lerp(new Vector2d(vertexList[this.C].Tu, vertexList[this.C].Tv), new Vector2d(vertexList[this.A].Tu, vertexList[this.A].Tv), .5);
Vector2d thirdUV = Vector2d.Lerp(new Vector2d(vertexList[this.A].Tu, vertexList[this.A].Tv), new Vector2d(vertexList[this.B].Tu, vertexList[this.B].Tv), .5);
first.Normalize();
second.Normalize();
third.Normalize();
int firstIndex = vertexList.Count;
int secondIndex = vertexList.Count + 1;
int thirdIndex = vertexList.Count + 2;
vertexList.Add(new PositionTexture(first, firstUV.X, firstUV.Y));
vertexList.Add(new PositionTexture(second, secondUV.X, secondUV.Y));
vertexList.Add(new PositionTexture(third, thirdUV.X, thirdUV.Y));
triList.Add(new Triangle(this.A, thirdIndex, secondIndex));
triList.Add(new Triangle(this.B, firstIndex, thirdIndex));
triList.Add(new Triangle(this.C, secondIndex, firstIndex));
triList.Add(new Triangle(firstIndex, secondIndex, thirdIndex));
}
/// <summary>
/// Converts a given point to RA-Dec coordinate space.
/// </summary>
/// <param name="point">
/// Point between 1 and 0 inclusive.
/// </param>
/// <returns>
/// Point in RA-Dec coordinates.
/// </returns>
public Vector2d PointToRaDec(Vector2d point)
{
int indexX = (int)(point.X / this.subDivSize);
int indexY = (int)(point.Y / this.subDivSize);
if (indexX > ((int)Math.Pow(2, this.subDivisions) - 1))
{
indexX = ((int)Math.Pow(2, this.subDivisions) - 1);
}
if (indexY > ((int)Math.Pow(2, this.subDivisions) - 1))
{
indexY = ((int)Math.Pow(2, this.subDivisions) - 1);
}
double distX = (point.X - ((double)indexX * this.subDivSize)) / this.subDivSize;
double distY = (point.Y - ((double)indexY * this.subDivSize)) / this.subDivSize;
Vector2d interpolatedTop = Vector2d.Lerp(this.mapRaDec[indexX, indexY], this.mapRaDec[indexX + 1, indexY], distX);
Vector2d interpolatedBottom = Vector2d.Lerp(this.mapRaDec[indexX, indexY + 1], this.mapRaDec[indexX + 1, indexY + 1], distX);
Vector2d result = Vector2d.Lerp(interpolatedTop, interpolatedBottom, distY);
return(result);
}