@graphty/layout/dist/src/algorithms/planarity/check.js

graph layout algorithms based on networkx

/**
 * Main planarity checking function
 */
import { isK5, isK33 } from './special-graphs';
import { lrPlanarityTest } from './lr-test';
import { createTriangulationEmbedding } from './embedding';
/**
 * Check if graph is planar using a simplified version of Boyer-Myrvold algorithm.
 * Returns planarity and embedding information.
 *
 * @param G - Graph
 * @param nodes - List of nodes
 * @param edges - List of edges
 * @returns Object containing isPlanar flag and embedding
 */
export function checkPlanarity(G, nodes, edges, seed = null) {
    // For small graphs (n <= 4), all are planar
    if (nodes.length <= 4) {
        return { isPlanar: true, embedding: createTriangulationEmbedding(nodes, edges, seed) };
    }
    // For K5 (complete graph with 5 nodes) and K3,3 (complete bipartite with 3,3 nodes)
    // these are not planar by Kuratowski's theorem
    if (isK5(nodes, edges) || isK33(nodes, edges)) {
        return { isPlanar: false, embedding: null };
    }
    // For other graphs, use LR algorithm (Left-Right Planarity Test)
    const result = lrPlanarityTest(nodes, edges, seed);
    return result;
}
//# sourceMappingURL=check.js.map