1 files changed, 19 insertions, 11 deletions

diff --git a/Master/texmf/asymptote/graph3.asy b/Master/texmf/asymptote/graph3.asy
index 1357f3e7c87..32f66851e75 100644
--- a/Master/texmf/asymptote/graph3.asy
+++ b/Master/texmf/asymptote/graph3.asy
@@ -126,7 +126,7 @@ void labelaxis(picture pic, transform3 T, Label L, path3 g,
         locate1.dir(T,g,locate,t);
         triple pathdir=locate1.pathdir;
 
-        triple perp=cross(pathdir,P.vector());
+        triple perp=cross(pathdir,P.normal);
         if(align == O)
           align=unit(sgn(dot(sign*locate1.dir,perp))*perp);
         path[] g=project(box(T*m,T*M),P);
@@ -149,9 +149,11 @@ void labelaxis(picture pic, transform3 T, Label L, path3 g,
     },exact=false);
 
   path3[] G=path3(texpath(L));
-  G=L.align.is3D ? align(G,O,align,L.p) : L.T3*G;
-  triple v=point(g,relative(L,g));
-  pic.addBox(v,v,min(G),max(G));
+  if(G.length > 0) {
+    G=L.align.is3D ? align(G,O,align,L.p) : L.T3*G;
+    triple v=point(g,relative(L,g));
+    pic.addBox(v,v,min(G),max(G));
+  }
 }
 
 // Tick construction routine for a user-specified array of tick values.
@@ -509,7 +511,7 @@ real ztrans(transform3 t, real z)
 
 private triple defaultdir(triple X, triple Y, triple Z, bool opposite=false,
                           projection P) {
-  triple u=cross(P.vector(),Z);
+  triple u=cross(P.normal,Z);
   return abs(dot(u,X)) > abs(dot(u,Y)) ? -X : (opposite ? Y : -Y);
 }
 
@@ -964,7 +966,7 @@ void xaxis3(picture pic=currentpicture, Label L="", axis axis=YZZero,
   
   bool back=false;
   if(axis.type == Both) {
-    triple v=currentprojection.vector();
+    triple v=currentprojection.normal;
     back=dot((0,pic.userMax.y-pic.userMin.y,0),v)*sgn(v.z) > 0;
   }
 
@@ -1039,7 +1041,7 @@ void yaxis3(picture pic=currentpicture, Label L="", axis axis=XZZero,
   
   bool back=false;
   if(axis.type == Both) {
-    triple v=currentprojection.vector();
+    triple v=currentprojection.normal;
     back=dot((pic.userMax.x-pic.userMin.x,0,0),v)*sgn(v.z) > 0;
   }
 
@@ -1842,10 +1844,11 @@ path3 Arc(triple c, triple v1, triple v2, triple normal=O, bool direction=CCW,
 
   real phi1=radians(longitude(v1,warn=false));
   real phi2=radians(longitude(v2,warn=false));
-  if(phi1 >= phi2 && direction) phi1 -= 2pi;
-  if(phi2 >= phi1 && !direction) phi2 -= 2pi;
+  if(direction) {
+    if(phi1 >= phi2) phi1 -= 2pi;
+  } else if(phi2 >= phi1) phi2 -= 2pi;
 
-  real piby2=pi/2;
+  static real piby2=pi/2;
   return shift(c)*T*polargraph(new real(real theta, real phi) {return r;},
                                new real(real t) {return piby2;},
                                new real(real t) {return interp(phi1,phi2,t);},
@@ -1869,5 +1872,10 @@ path3 Arc(triple c, real r, real theta1, real phi1, real theta2, real phi2,
 // True circle
 path3 Circle(triple c, real r, triple normal=Z, int n=nCircle)
 {
-  return Arc(c,r,90,0,90,360,normal,n)&cycle;
+  static real piby2=pi/2;
+  return shift(c)*align(unit(normal))*
+    polargraph(new real(real theta, real phi) {return r;},
+               new real(real t) {return piby2;},
+               new real(real t) {return interp(0,2pi,t);},n,operator ..);
+
 }