Walkthrough: show only the medial graph in panels C and D

Drop the faint base-graph (G') edges and the dotted restored base edge from the
medial panels, leaving just the medial graph (medial vertices at edge midpoints,
medial edges, colours, halos, and the restored-diagonal medial square). Panels A
and B still show the triangulation.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

papers/medial_tire_decompositions_of_plane_triangulations/experiments/draw_walkthrough.py

@@ -182,16 +182,12 @@ def draw_graph(ax, gr, pos, level=None, bold_cycle=None, shade_quad=None, wvert=
                         xytext=(11, 10), fontsize=6.5, color="#999999", zorder=6)
 
 def draw_medial(ax, pos, col, halo=None, restored=None):
-    for ed in gg.edges():
-        a, b = tuple(ed); pa, pb = pos[a], pos[b]
-        ax.plot([pa[0], pb[0]], [pa[1], pb[1]], color="#e3e3e3", lw=0.8, zorder=0)
+    # medial graph only -- no base graph underneath
     for m, b in medges:
         pa, pb = mpos[m], mpos[b]
         ax.plot([pa[0], pb[0]], [pa[1], pb[1]], color="#c6c6c6", lw=0.8, zorder=1)
     if restored is not None:
         a, b = restored
-        ax.plot([pos[a][0], pos[b][0]], [pos[a][1], pos[b][1]], color="#d62728",
-                lw=1.8, ls=":", zorder=2)
         ax.plot(*mid(pos[a], pos[b]), "s", color=PAL[col[H.e(a, b)]], ms=13,
                 mec="#d62728", mew=2.0, zorder=7)
     halo = halo or set()