public void SubDivide(List <Triangle> triList, List <PositionTexture> vertexList)
{
Vector3d a1 = Vector3d.Lerp(vertexList[B].Position, vertexList[C].Position, .5f);
Vector3d b1 = Vector3d.Lerp(vertexList[C].Position, vertexList[A].Position, .5f);
Vector3d c1 = Vector3d.Lerp(vertexList[A].Position, vertexList[B].Position, .5f);
Vector2d a1uv = Vector2d.Lerp(new Vector2d(vertexList[B].Tu, vertexList[B].Tv), new Vector2d(vertexList[C].Tu, vertexList[C].Tv), .5);
Vector2d b1uv = Vector2d.Lerp(new Vector2d(vertexList[C].Tu, vertexList[C].Tv), new Vector2d(vertexList[A].Tu, vertexList[A].Tv), .5);
Vector2d c1uv = Vector2d.Lerp(new Vector2d(vertexList[A].Tu, vertexList[A].Tv), new Vector2d(vertexList[B].Tu, vertexList[B].Tv), .5);
a1.Normalize();
b1.Normalize();
c1.Normalize();
int aIndex = vertexList.Count;
int bIndex = vertexList.Count + 1;
int cIndex = vertexList.Count + 2;
vertexList.Add(new PositionTexture(a1, a1uv.X, a1uv.Y));
vertexList.Add(new PositionTexture(b1, b1uv.X, b1uv.Y));
vertexList.Add(new PositionTexture(c1, c1uv.X, c1uv.Y));
triList.Add(new Triangle(A, cIndex, bIndex));
triList.Add(new Triangle(B, aIndex, cIndex));
triList.Add(new Triangle(C, bIndex, aIndex));
triList.Add(new Triangle(aIndex, bIndex, cIndex));
}
public Vector2d PointToRaDec(Vector2d point) // point is between 0 and 1 inclusive
{
int indexX = (int)(point.X / subDivSize);
int indexY = (int)(point.Y / subDivSize);
if (indexX > ((int)Math.Pow(2, subDivisions) - 1))
{
indexX = ((int)Math.Pow(2, subDivisions) - 1);
}
if (indexY > ((int)Math.Pow(2, subDivisions) - 1))
{
indexY = ((int)Math.Pow(2, subDivisions) - 1);
}
double xDist = (point.X - ((double)indexX * subDivSize)) / subDivSize;
double yDist = (point.Y - ((double)indexY * subDivSize)) / subDivSize;
Vector2d interpolatedTop = Vector2d.Lerp(raDecMap[indexX, indexY], raDecMap[indexX + 1, indexY], xDist);
Vector2d interpolatedBottom = Vector2d.Lerp(raDecMap[indexX, indexY + 1], raDecMap[indexX + 1, indexY + 1], xDist);
Vector2d result = Vector2d.Lerp(interpolatedTop, interpolatedBottom, yDist);
return(result);
}