computeEdgeCostAtVertex static method

void computeEdgeCostAtVertex(Vertex v)

Implementation

static void computeEdgeCostAtVertex(Vertex v ) {
  // compute the edge collapse cost for all edges that start
  // from vertex v.  Since we are only interested in reducing
  // the object by selecting the min cost edge at each step, we
  // only cache the cost of the least cost edge at this vertex
  // (in member variable collapse) as well as the value of the
  // cost (in member variable collapseCost).

  if ( v.neighbors.length == 0 ) {
    // collapse if no neighbors.
    v.collapseNeighbor = null;
    v.collapseCost = -0.01;
    return;
  }

  v.collapseCost = 100000;
  v.collapseNeighbor = null;

  // search all neighboring edges for "least cost" edge
  for (int i = 0; i < v.neighbors.length; i ++ ) {
    final collapseCost = computeEdgeCollapseCost( v, v.neighbors[ i ] );

    if(v.collapseNeighbor == null){
      v.collapseNeighbor = v.neighbors[i];
      v.collapseCost = collapseCost;
      v.minCost = collapseCost;
      v.totalCost = 0;
      v.costCount = 0;
    }

    v.costCount++;
    v.totalCost += collapseCost;

    if ( collapseCost < v.minCost ) {
      v.collapseNeighbor = v.neighbors[ i ];
      v.minCost = collapseCost;
    }
  }

  // we average the cost of collapsing at this vertex
  v.collapseCost = v.totalCost / v.costCount;
  // v.collapseCost = v.minCost;
}