/// <summary>
/// Performs a brute-force comparison of every segment in each <see cref="ISegmentString" />.
/// This has n^2 performance.
/// </summary>
/// <param name="e0"></param>
/// <param name="e1"></param>
private void ComputeVertexSnaps(INodableSegmentString e0, INodableSegmentString e1)
{
var pts0 = e0.Coordinates;
var pts1 = e1.Coordinates;
for (int i0 = 0; i0 < pts0.Length - 1; i0++)
{
var hotPixel = new HotPixel(pts0[i0], _scaleFactor, _li);
for (int i1 = 0; i1 < pts1.Length - 1; i1++)
{
// don't snap a vertex to itself
if (e0 == e1)
{
if (i0 == i1)
{
continue;
}
}
bool isNodeAdded = //AddSnappedNode(hotPixel, e1, i1);
hotPixel.AddSnappedNode(e1, i1);
// if a node is created for a vertex, that vertex must be noded too
if (isNodeAdded)
{
e0.AddIntersection(pts0[i0], i0);
}
}
}
}
/// <summary>
/// Snaps (nodes) all interacting segments to this hot pixel.
/// The hot pixel may represent a vertex of an edge,
/// in which case this routine uses the optimization
/// of not noding the vertex itself
/// </summary>
/// <param name="hotPixel">The hot pixel to snap to.</param>
/// <param name="parentEdge">The edge containing the vertex, if applicable, or <c>null</c>.</param>
/// <param name="hotPixelVertexIndex"></param>
/// <returns><c>true</c> if a node was added for this pixel.</returns>
public bool Snap(HotPixel hotPixel, ISegmentString parentEdge, int hotPixelVertexIndex)
{
var pixelEnv = hotPixel.GetSafeEnvelope();
var hotPixelSnapAction = new HotPixelSnapAction(hotPixel, parentEdge, hotPixelVertexIndex);
_index.Query(pixelEnv, new QueryVisitor(pixelEnv, hotPixelSnapAction));
return(hotPixelSnapAction.IsNodeAdded);
}
/// <summary>
/// Snaps segments to nodes created by segment intersections.
/// </summary>
/// <param name="snapPts"></param>
private void ComputeIntersectionSnaps(IEnumerable <Coordinate> snapPts)
{
foreach (var snapPt in snapPts)
{
var hotPixel = new HotPixel(snapPt, _scaleFactor, _li);
_pointSnapper.Snap(hotPixel);
}
}
/// <summary>
///
/// </summary>
/// <param name="ss"></param>
/// <param name="snapPts"></param>
private void ComputeSnaps(INodableSegmentString ss, IEnumerable <Coordinate> snapPts)
{
foreach (var snapPt in snapPts)
{
var hotPixel = new HotPixel(snapPt, _scaleFactor, _li);
for (int i = 0; i < ss.Count - 1; i++)
{
//AddSnappedNode(hotPixel, ss, i);
hotPixel.AddSnappedNode(ss, i);
}
}
}
/// <summary>
/// Snaps segments to the vertices of a Segment String.
/// </summary>
/// <param name="e"></param>
private void ComputeVertexSnaps(INodableSegmentString e)
{
var pts0 = e.Coordinates;
for (int i = 0; i < pts0.Length; i++)
{
var hotPixel = new HotPixel(pts0[i], _scaleFactor, _li);
bool isNodeAdded = _pointSnapper.Snap(hotPixel, e, i);
// if a node is created for a vertex, that vertex must be noded too
if (isNodeAdded)
{
e.AddIntersection(pts0[i], i);
}
}
}
/// <summary>
/// Snaps (nodes) all interacting segments to this hot pixel.
/// The hot pixel may represent a vertex of an edge,
/// in which case this routine uses the optimization
/// of not noding the vertex itself
/// </summary>
/// <param name="hotPixel">The hot pixel to snap to.</param>
/// <returns><c>true</c> if a node was added for this pixel.</returns>
public bool Snap(HotPixel hotPixel)
{
return(Snap(hotPixel, null, -1));
}
/// <summary>
/// Initializes a new instance of the <see cref="HotPixelSnapAction"/> class.
/// </summary>
/// <param name="hotPixel"></param>
/// <param name="parentEdge"></param>
/// <param name="hotPixelVertexIndex"></param>
public HotPixelSnapAction(HotPixel hotPixel, ISegmentString parentEdge, int hotPixelVertexIndex)
{
_hotPixel = hotPixel;
_parentEdge = parentEdge;
_hotPixelVertexIndex = hotPixelVertexIndex;
}