Function getShellAssignments

js/meshValidation.js:472–497

(adjacency, triCount)

/**
 * Return per-triangle shell ID (0-based) via BFS on the adjacency graph.
 *
 * @param {Array<Array<{neighbor:number}>>} adjacency
 * @param {number} triCount
 * @returns {Uint32Array}  shellId[t] = 0-based shell index for triangle t
 */
export function getShellAssignments(adjacency, triCount) {
  const shellId = new Uint32Array(triCount); // default 0
  const visited = new Uint8Array(triCount);
  let nextShell = 0;
  for (let seed = 0; seed < triCount; seed++) {
    if (visited[seed]) continue;
    const id = nextShell++;
    const queue = [seed];
    visited[seed] = 1;
    shellId[seed] = id;
    let head = 0;
    while (head < queue.length) {
      const cur = queue[head++];
      const neighbors = adjacency[cur];
      if (!neighbors) continue;
      for (const { neighbor } of neighbors) {
        if (!visited[neighbor]) {
          visited[neighbor] = 1;
          shellId[neighbor] = id;
          queue.push(neighbor);
        }
      }
    }
  }