Fixed a problem where in zooming in, stroke widths all grew

manimlib/camera/camera.py

@@ -392,7 +392,10 @@ class Camera(object):
             vmobject
         )
         ctx.set_line_width(
-            width * self.cairo_line_width_multiple
+            width * self.cairo_line_width_multiple *
+            # This ensures lines have constant width
+            # as you zoom in on them.
+            (self.get_frame_width() / FRAME_WIDTH)
         )
         ctx.stroke_preserve()
         return self