Initialize the Start Point

Land Desktop Map 3D Samples

 
Initialize the Start Point
 
 
 

This method takes three arguments: the start point, the ready list, and the not ready list. It does the following:

NoteThe start point in this case has coordinates (1905927, 472596).
  1. Sets the CurrentDistance and Index properties of the start point to 0 and adds the start point to the ready list.
  2. Gets the links whose envelopes intersect the start point. This is described in topic Get Neighbor Links.
    NoteIn this case, there is one link, whose start point is (1905922, 472443) and whose end point is 1905927, 472596). This link is labeled ‘A’ in the graphic.
  3. For each link returned by previous step do the following:
    • Get the next point from the link. This is described in the topic Get Next Point From Link. The arguments passed in are the start point, the neighboring link, true indicating the first argument is a start or end point, and two null point references. The GetNextPointFromLink method will decide whether one or both of the link boundary points needs to be considered and will set one or both null point references to point to a link boundary point.
      NoteThe only non-null point reference returned is the boundary point of link ‘A’, whose coordinates are (1905922, 472443).
    • Sets properties on non-null point references set by GetNextPointFromLink. The point’s current distance is set to the distance between the start point and the point, and its previous point is set to refer to the start point and its index is set to 1.
      NoteThe distance property of the point whose coordinates are (1905922, 472443) is set to 156. Its previous point property is set to the start point and its index property is set to 1.
    • Adds a non-null point reference to the not ready list and this list is sorted.