// possibly consider hilbert curve
// http://en.wikipedia.org/wiki/Hilbert_curve
// http://blog.notdot.net/2009/11/Damn-Cool-Algorithms-Spatial-indexing-with-Quadtrees-and-Hilbert-Curves
// if we actually use the range property in the query, this could be useful
private void CheckBattenberg(
char c,
double cx,
double cy,
int level,
IList <Cell> matches,
StringBuilder str,
IShape shape,
int maxLevel)
{
if (Debugging.AssertsEnabled)
{
Debugging.Assert(str.Length == level);
}
double w = levelW[level] / 2;
double h = levelH[level] / 2;
int strlen = str.Length;
IRectangle rectangle = m_ctx.MakeRectangle(cx - w, cx + w, cy - h, cy + h);
SpatialRelation v = shape.Relate(rectangle);
if (SpatialRelation.CONTAINS == v)
{
str.Append(c);
//str.append(SpatialPrefixGrid.COVER);
matches.Add(new QuadCell(this, str.ToString(), v.Transpose()));
}
else if (SpatialRelation.DISJOINT == v)
{
// nothing
}
else // SpatialRelation.WITHIN, SpatialRelation.INTERSECTS
{
str.Append(c);
int nextLevel = level + 1;
if (nextLevel >= maxLevel)
{
//str.append(SpatialPrefixGrid.INTERSECTS);
matches.Add(new QuadCell(this, str.ToString(), v.Transpose()));
}
else
{
Build(cx, cy, nextLevel, matches, str, shape, maxLevel);
}
}
str.Length = strlen;
}
protected void assertRelation(String msg, SpatialRelation expected, Shape a, Shape b)
{
msg = a + " intersect " + b; //use different msg
AssertIntersect(msg, expected, a, b);
//check flipped a & b w/ transpose(), while we're at it
AssertIntersect("(transposed) " + msg, expected.Transpose(), b, a);
}
protected virtual void AssertRelation(string msg, SpatialRelation expected, IShape a, IShape b)
{
AssertIntersect(msg, expected, a, b);
//check flipped a & b w/ transpose(), while we're at it
AssertIntersect(msg, expected.Transpose(), b, a);
}
protected void AssertRelation(String msg, SpatialRelation expected, Shape a, Shape b)
{
msg = a + " intersect " + b; //use different msg
AssertIntersect(msg, expected, a, b);
//check flipped a & b w/ transpose(), while we're at it
AssertIntersect("(transposed) " + msg, expected.Transpose(), b, a);
}