code: public static int findEdge(Poly node, MeshData tile, float value, int comp) {
  		float error = Float.MAX_VALUE;
  		int edge = 0;
  		for (int i = 0; i < node.vertCount; i++) {
  			int j = (i + 1) % node.vertCount;
  			float v1 = tile.verts[3 * node.verts[i] + comp] - value;
  			float v2 = tile.verts[3 * node.verts[j] + comp] - value;
  			float d = v1 * v1 + v2 * v2;
  			if (d < error) {
  				error = d;
  				edge = i;
  			}
  		}
  		return edge;
  	}
docs: Find edge closest to the given coordinate