figures/asy/wtk_graph.asy: Add mcross for stepper graphs

A marker in the shape of a small cross.  With this marker, there's
less overlap between successive points that trend in horizontal or
vertical directions.

diff --git a/src/figures/asy/wtk_graph.asy b/src/figures/asy/wtk_graph.asy
index 8397d4923d45f30da5aa1bff96b0601a0bdfddce..c09733aecb0a4661cb7b2bf3a55dbaa77a8eacc0 100644 (file)
--- a/src/figures/asy/wtk_graph.asy
+++ b/src/figures/asy/wtk_graph.asy
@@ -218,6 +218,8 @@ m1 = scale(3mm)*shift(-.5,-.33)*m1;
 path m8=scale(2mm)*shift(-.5,-.5)*unitsquare;
 path m30=scale(1.5mm)*unitcircle;
 path mdot=scale(0.2pt)*unitcircle;
+path mcross = (0.5,0)--(0.5,1)--(.5,.5)--(0,0.5)--(1,0.5);
+mcross = scale(2mm)*shift(-0.5, -0.5)*mcross;
 
 markroutine marksize(string file="datafile", pen p=red, path mpath=scale(0.8mm)*unitcircle, real size=1) {
   return new void(picture pic=currentpicture, frame f, path g) {