Fix writes for complementary angle constraint values. (hlorus#322)

Closes hlorus#310

model/angle.py

@@ -27,11 +27,6 @@ class SlvsAngle(DimensionalConstraint, PropertyGroup):
  The constraint's setting can be used to to constrain the supplementary angle.
  """
 
- def _set_value_force(self, value):
- DimensionalConstraint._set_value_force(
- self, HALF_TURN - value if self.setting else value
- )
-
  def assign_init_props(self, context: Context = None):
  # Updating self.setting will create recursion loop
  _value, _ = self.init_props()
@@ -71,6 +66,9 @@ def needs_wp(self):
  def to_displayed_value(self, value):
  return HALF_TURN - value if self.setting else value
 
+ def from_displayed_value(self, value):
+ return HALF_TURN - value if self.setting else value
+
  def create_slvs_data(self, solvesys, group=Solver.group_fixed):
  kwargs = {
  "group": group,
@@ -125,7 +123,6 @@ def _get_angle(A, B):
 
  x = A.dot(B) / divisor
  x = max(-1, min(x, 1))
-
  return math.degrees(math.acos(x))
 
  def init_props(self, **kwargs):

model/base_constraint.py

@@ -190,23 +190,23 @@ class DimensionalConstraint(GenericConstraint):
  value: Property
  setting: BoolProperty
 
- def _set_value(self, val: float):
+ def _set_value(self, displayed_value: float):
  # NOTE: function signature _set_value(self, val: float, force=False)
  # will fail when bpy tries to register the value property.
  # See `_set_value_force()`
  if not self.is_reference:
- self._set_value_force(val)
+ self._set_value_force(self.from_displayed_value(displayed_value))
 
- def _set_value_force(self, val: float):
- self["value"] = val
+ def _set_value_force(self, value: float):
+ self["value"] = value
 
  def _get_value(self):
  if self.is_reference:
  val, _ = self.init_props()
  return self.to_displayed_value(val)
- if not self.get("value"):
+ if self.get("value") is None:
  self.assign_init_props()
- return self["value"]
+ return self.to_displayed_value(self["value"])
 
  def assign_init_props(self, context: Context = None):
  # self.value, self.setting = self.init_props()
@@ -229,8 +229,22 @@ def init_props(self):
  raise NotImplementedError()
 
  def to_displayed_value(self, value):
+ """
+ Overwrite this function to convert the property value into 
+ something to display on the user interface.
+ NOTE: If the value is writeable, do not forget to change 
+ ``from_displayed_value()`` to apply the reverse operation.
+ """
  return value
 
+ def from_displayed_value(self, displayed_value):
+ """
+ Convert the displayed value of the property into 
+ a variable to store.
+ NOTE: See ``to_displayed_value()``
+ """
+ return displayed_value
+
  def py_data(self, solvesys, **kwargs):
  if self.is_reference:
  return []