[WWcvs] pg: Added line so that if the dot_radius on a vector arrow is 0 then the dot is not drawn at all.

[Mike G. v. a. <we...@ma...>]

Log Message:
-----------
Added line so that if the dot_radius on a vector arrow is 0 then the dot is not drawn at all.

Modified Files:
--------------
    pg/lib:
        VectorField.pm

Revision Data
-------------
Index: VectorField.pm
===================================================================
RCS file: /webwork/cvs/system/pg/lib/VectorField.pm,v
retrieving revision 1.4
retrieving revision 1.5
diff -Llib/VectorField.pm -Llib/VectorField.pm -u -r1.4 -r1.5
--- lib/VectorField.pm
+++ lib/VectorField.pm
@@ -271,7 +271,8 @@
     		my $dx = $dt*&{$self->dx_rule}($x,$y);
     		my $dy = $dt*&{$self->dy_rule}($x,$y);
     		$g->moveTo($x,$y);
-    		$g->stamps(new Circle($x, $y, $dot_radius,$dot_color,$dot_color) );
+    		$g->stamps(new Circle($x, $y, $dot_radius,$dot_color,$dot_color) ) if $dot_radius > 0; 
+    		    # setting the radius to zero omits the dot
     		$g->lineTo($x+$dx*&$rf_arrow_length($dx,$dy), $y+$dy*&$rf_arrow_length($dx,$dy),gdBrushed);
 
     	}