Contains the routing graph data for a single tile.

The graph topology is stored in compressed sparse row graph format. It also contains information on how the graph partitions are interconnected, i.e. graph edges from this tile to another.

Vertex indices 0 through firstEdgeIndices.length - 2 refer to internal vertices (vertices in this partition).

The last entry of firstEdgeIndices is always edges.length.

Thus, each entry in firstEdgeIndices is the index of the edge after the last edge of the previous vertex.

That means, the edges starting at a given internal vertex with index idx, are determined by the index range from firstEdgeIndices(idx) (inclusive) to firstEdgeIndices(idx + 1) (exclusive).

Vertex indices firstEdgeIndices.length - 1 through firstEdgeIndices.length + externalVertexIndices.length - 2 refer to external vertices (vertices outside this partition that are referred to from inside this partition).

Therefore, the number of external vertices is externalVertexIndices.length.

When looking up a vertex v with index idx:

• If idx < firstEdgeIndices.length - 1, v is in the current graph partition.
• Otherwise, v belongs to the tile with ID externalVertexTileIds(idx - firstEdgeIndices.length + 1) and its index in that partition is externalVertexIndices(idx - firstEdgeIndices.length + 1).

See also

• TiledGraph
• The section on "The Compressed Sparse Row Format" in the Location Library developer guide