embedding_demo.4.js

#include "assert.js"
#include "util.js"
#include "undirected_graph.js"
#include "ps.js"

var K4me = [[1, 2], [2, 0, 3], [0, 3, 1], [1, 2]];
var K4noemb = [[3, 1, 2], [2, 0, 3], [0, 3, 1], [1, 2, 0]];
var F = [K4me, K4noemb];

var acoords = [[[0.5, 0, -0.3, 0.7], [-0.8, 0.9, -0.8, -0.6]], [[0.9, 0, -0.9, 0.8], [-0.8, 0.9, -0.8, 0]]];

function draw(x) {
    var coords = acoords[x];

    var G = from_adjacency_list(F[x]);

    var size = 592;
    var r = 12;
    var last_face;
    var cnt;
    var pftv;
    var da = 15;

    ps.set_(size, r);

    ps.straight_line_drawing(G, coords, [], size, r, [], false);

    function draw_vertex_edge_label(G, v, e, coords, l) {
        var w = opposite(G, v, e);
        var deg = r2d(Math.atan2(coords[1][v] - coords[1][w], coords[0][w] - coords[0][v]));
        var cx = (ps.scrx(coords[0][v]) + ps.scrx(coords[0][w])) / 2;
        var cy = (ps.scry(coords[1][v]) + ps.scry(coords[1][w])) / 2;
        console.log("12 " + ps.frm(deg) + " (" + l + ") " + ps.frm(cx) + " " + ps.frm(cy) + " txtdistdeg");
        ps.vertex_indicator(G, v, e, coords, r, da);
    }

    r = 18;
    last_face = -1;
    cnt = -1;
    pftv = planar_face_traversal_visitor();
    pftv.begin_face = function () {
        last_face += 1;
        cnt = 0;
    };
    pftv.next_vertex_edge = function (v, e) {
        draw_vertex_edge_label(G, v, e, coords, last_face + "_" + String.fromCharCode(97 + cnt));
        cnt += 1;
    };
    planar_face_traversal(G, pftv);

    console.log("0 0 (is_embedding=" + is_embedding(G) + ",");
    console.log(" n_faces_planar=" + n_faces_planar(G) + ",");
    console.log(" traversed faces=" + (last_face + 1) + ") 300 20 txtdistdeg");
    console.log("0 0 (from_adjacency_list( " + JSON.stringify(F[x]) + " )) 300 570 txtdistdeg");

    console.log("showpage");
}

ps.header();
ps.header2();
draw(0);