implemented drawBoundary for spiral

hypgraph.cpp

@@ -1296,6 +1296,27 @@ void draw_boundary(int w) {
         return;
         }
       break;
+    
+    case mdSpiral: {
+      using namespace hyperpoint_vec;
+      if(euclid) return;
+      if(p == PPR::CIRCLE) p = PPR::OUTCIRCLE;
+      auto& sm = conformal::spiral_multiplier;
+      if(real(sm)) {
+        queuereset(mdUnchanged, p);
+        for(ld a=-10; a<=10; a+=0.1) {
+          cld z = exp(cld(a, a * imag(sm) / real(sm) + M_PI));
+          hyperpoint ret = hpxyz(real(z), imag(z), 0);
+          if(vid.skiprope) 
+            ret = mobius(ret, vid.skiprope, 1);
+          ret *= vid.radius;
+          curvepoint(ret);
+          }
+        queuecurve(ringcolor, 0, p);
+        queuereset(pmodel, p);
+        }
+      return;
+      }
 
     default: break;
     }