Index: trbs.html =================================================================== --- trbs.html (revision 538) +++ trbs.html (revision 539) @@ -31,7 +31,7 @@ The TRBS performs these operations on a mixed model: it takes the input geometry (vias, obstacles, board size) and triangulates it. Then 2nets are routed between the endpoint vertices through edges on this -triangulation. However, this routing is abstract, topological: the exact +triangulation (Figure 1). However, this routing is abstract, topological: the exact coordinates of the 2nets are not considered, only the order of 2nets crossing triangulation edges.
@@ -49,7 +49,7 @@ which case an alternate (longer) detour is searched or ultimately network ordering is changed.
-Finally, of the TRBS finished routing, the result is a list of topological edge +Finally, of the TRBS finished routing (Figure 2), the result is a list of topological edge crossing for each triangulation edge for each 2net on its way between its start and end vertex. The last step is translating these crossings back to physical geometry, introducing new edges (spokes) and moving the @@ -145,7 +145,7 @@ inserted between edge end vertices or existing crossings). In case of target vertex, the output is a boolean, whether that vertex is visible or not.
-The algorithm for determining visibility is: +The algorithm for determining visibility (e.g. on Figure 3) is:
-A CW search from S2 first reaches vertex PA then will jump to the edge PA-PC, +On Figure 4, a CW search from S2 first reaches vertex PA then will jump to the edge PA-PC, which is the target edge.
Case 2: -On case 1, tracing CCW: because of 3b., the search reaches target edge after +On Figure 4, tracing CCW from S2: because of 3b., the search reaches target edge after tracing S2's edge, vertex PB and the blue path.
Case 3: visibility blocked @@ -205,6 +205,6 @@
-Starting from S2, tracing CCW: trace S2's edge to PB, then switch edge +On Figure 5, starting from S2, tracing CCW: trace S2's edge to PB, then switch edge by 3c, bumping into the blue path by 4, tracing it to edge PA-PB; this edge is the edge S2 is on. By 5, return failure.