Fix for [#36599] Freestyle: Line thickness modifier with certain blend types incorrectly calculated.

The inner/outer thickness values were separately blended by Multiply, Divide and other binary
operators, which resulted in the wrong thickness values reported in the issue.  The operations
must be applied to the sum of the inner and outer thickness values.

Also the Minimum and Maximum operators were not properly implemented (one of the two operands
were ignored by mistake).

1 files changed, 14 insertions, 13 deletions

diff --git a/release/scripts/freestyle/style_modules/parameter_editor.py b/release/scripts/freestyle/style_modules/parameter_editor.py
index 6a3d0efe2c2..371019ebe18 100644
--- a/release/scripts/freestyle/style_modules/parameter_editor.py
+++ b/release/scripts/freestyle/style_modules/parameter_editor.py
@@ -78,11 +78,11 @@ class ScalarBlendModifier(StrokeShader):
         elif self.__blend == 'DIFFERENCE':
             v1 = facm * v1 + fac * abs(v1 - v2)
         elif self.__blend == 'MININUM':
-            tmp = fac * v1
+            tmp = fac * v2
             if v1 > tmp:
                 v1 = tmp
         elif self.__blend == 'MAXIMUM':
-            tmp = fac * v1
+            tmp = fac * v2
             if v1 < tmp:
                 v1 = tmp
         else:
@@ -142,18 +142,19 @@ class ThicknessBlenderMixIn(ThicknessModifierMixIn):
         self.__ratio = ratio
 
     def blend_thickness(self, outer, inner, v):
+        v = self.blend(outer + inner, v)
         if self.__position == 'CENTER':
-            outer = self.blend(outer, v / 2)
-            inner = self.blend(inner, v / 2)
+            outer = v * 0.5
+            inner = v - outer
         elif self.__position == 'INSIDE':
-            outer = self.blend(outer, 0)
-            inner = self.blend(inner, v)
+            outer = 0
+            inner = v
         elif self.__position == 'OUTSIDE':
-            outer = self.blend(outer, v)
-            inner = self.blend(inner, 0)
+            outer = v
+            inner = 0
         elif self.__position == 'RELATIVE':
-            outer = self.blend(outer, v * self.__ratio)
-            inner = self.blend(inner, v * (1 - self.__ratio))
+            outer = v * self.__ratio
+            inner = v - outer
         else:
             raise ValueError("unknown thickness position: " + self.__position)
         return outer, inner
@@ -168,8 +169,8 @@ class BaseThicknessShader(StrokeShader, ThicknessModifierMixIn):
         StrokeShader.__init__(self)
         ThicknessModifierMixIn.__init__(self)
         if position == 'CENTER':
-            self.__outer = thickness / 2
-            self.__inner = thickness / 2
+            self.__outer = thickness * 0.5
+            self.__inner = thickness - self.__outer
         elif position == 'INSIDE':
             self.__outer = 0
             self.__inner = thickness
@@ -178,7 +179,7 @@ class BaseThicknessShader(StrokeShader, ThicknessModifierMixIn):
             self.__inner = 0
         elif position == 'RELATIVE':
             self.__outer = thickness * ratio
-            self.__inner = thickness * (1 - ratio)
+            self.__inner = thickness - self.__outer
         else:
             raise ValueError("unknown thickness position: " + self.position)