Fix SVG export of torsions

Changelog.rst

@@ -14,6 +14,11 @@ This projects adheres to `Semantic Versioning <https://semver.org/spec/v2.0.0.ht
 Unreleased_
 ===========
 
+Fixed
+-----
+
+- [bug] The depiction of torsions now respects the sign convention.
+
 
 1.0b0_ -- 2019-01-04
 ====================
@@ -21,11 +26,11 @@ Unreleased_
 Added
 -----
 
-- [code] `core.Template` class is now the interface to manipulate templates.
-- [code] `core.convert_order_position` to convert an order vector into a
+- [code] ``core.Template`` class is now the interface to manipulate templates.
+- [code] ``core.convert_order_position`` to convert an order vector into a
   position vector, and vice-versa.
-- [code] `export` module to manage supported export formats.
-- [code] New external dependency `multiset`.
+- [code] ``export`` module to manage supported export formats.
+- [code] New external dependency ``multiset``.
 
 Changed
 -------
@@ -33,7 +38,7 @@ Changed
 - [code] Complete rewrite of the optimization logic to compute of a
   depth-optimal sequence of crossings.
 - [code] Complete refactor of the SVG export code.
-- [code] Public namespaces of each module have been cleaned of all unecessary
+- [code] Public namespaces of each module have been cleaned of all unnecessary
   objects.
 
 - [doc] Improve README.
@@ -41,13 +46,13 @@ Changed
 Removed
 -------
 
-- [code] Legacy optimization logic of `main` module:
-    - `all_subsets`, `createTree`, `detectDoubles`, `getNeighbours`,
-      `getPermutations`, `getTorsions`, `updatePermutationList` and
-      `updatePosition` functions.
-    - `Node` and `Tree` classes.
-- [code] Legacy drawing logic: `drawTemplate` module and `main.drawSVGTemplate`
-  function.
+- [code] Legacy optimization logic of ``main`` module:
+    - ``all_subsets``, ``createTree``, ``detectDoubles``, ``getNeighbours``,
+      ``getPermutations``, ``getTorsions``, ``updatePermutationList`` and
+      ``updatePosition`` functions.
+    - ``Node`` and ``Tree`` classes.
+- [code] Legacy drawing logic: ``drawTemplate`` module and
+  ``main.drawSVGTemplate`` function.
 
 Fixed
 -----

src/cate/_svg.py

@@ -97,7 +97,7 @@ class _SVGDrawer:
         self.dwg.defs.add(sprite)
         return sprite
 
-    def _create_pos_torsion_sprite(self):
+    def _create_neg_torsion_sprite(self):
         mask = self.dwg.mask()  # emulate the overlap of the boundaries with a mask
         sprite = self.dwg.g(class_='strand')
         mask.add(
@@ -137,7 +137,7 @@ class _SVGDrawer:
         self.dwg.defs.add(sprite)
         return sprite
 
-    def _create_neg_torsion_sprite(self):
+    def _create_pos_torsion_sprite(self):
         mask = self.dwg.mask()  # emulate the overlap of the boundaries with a mask
         sprite = self.dwg.g(class_='strand')
         mask.add(