bug fix in bi_assignment_ggp

include/rxmesh/matrix/nd_permute.cuh

@@ -134,7 +134,7 @@ void construct_a_simple_chordal_graph(Graph<T>& graph)
 
 /**
  * @brief construct patch neighbor graph which is the same as what we store in
- * PatchStash but in a different format 
+ * PatchStash but in a different format
  */
 template <typename T>
 void construct_patches_neighbor_graph(

include/rxmesh/rxmesh_dynamic.cu

@@ -1214,6 +1214,38 @@ __inline__ __device__ void bi_assignment_ggp(
  }
  }
  }
+ } else if (s_active_v(v) && !s_assigned_v(v)) {
+ // for active vertices that are not connected to anything
+ // other vertices, we will add then to one of the partitions
+ // at random (kinda) and put the vertex on the frontier so
+ // we don't encounter this if condition again
+ const uint16_t start = s_vv_offset[v];
+ const uint16_t end = s_vv_offset[v + 1];
+
+ // and we have to calculate the neighbors since we might be
+ // connected to in-active vertices
+ int num_neighbours = 0;
+
+ for (uint16_t vv = start; vv < end; ++vv) {
+
+ const uint16_t nv = s_vv[vv];
+
+ if (!s_active_v(nv)) {
+ continue;
+ }
+ num_neighbours++;
+ }
+ if (num_neighbours == 0) {
+ if (v % 2 == 0) {
+ s_partition_a_v.set(v, true);
+ ::atomicAdd(&s_num_A_vertices, 1);
+ } else {
+ s_partition_b_v.set(v, true);
+ ::atomicAdd(&s_num_B_vertices, 1);
+ }
+ s_next_frontier_v.set(v, true);
+ printf("\n reg growing %u", v);
+ }
  }
  }
 
@@ -1301,17 +1333,24 @@ __inline__ __device__ void bi_assignment_ggp(
  const uint16_t start = s_vv_offset[v];
  const uint16_t end = s_vv_offset[v + 1];
 
+
+ // put isolated vertices on the frontier right away so we
+ // don't have to deal with them again
+ // int num_neighbours = 0;
+
  for (uint16_t vv = start; vv < end; ++vv) {
  const uint16_t nv = s_vv[vv];
- if (is_a) {
- if (s_partition_b_v(nv)) {
- on_frontier = true;
- break;
- }
- } else {
- if (s_partition_a_v(nv)) {
- on_frontier = true;
- break;
+ if (s_active_v(nv)) {
+ if (is_a) {
+ if (s_partition_b_v(nv)) {
+ on_frontier = true;
+ break;
+ }
+ } else {
+ if (s_partition_a_v(nv)) {
+ on_frontier = true;
+ break;
+ }
  }
  }
  }
@@ -1422,6 +1461,11 @@ __inline__ __device__ void bi_assignment_ggp(
  init_interior();
  block.sync();
 
+ if (s_num_assigned_vertices == 0) {
+ // i.e., there is no frontier means we probably have a disconnected
+ // input
+ break;
+ }
  compute_interior();
  block.sync();
  }