Make sure undo stroke properly clears all the set pixels

CURA-12752
Otherwise, when merging the polygons and undo-ing the whole stroke, there may be some remaining pixels outside the mesh triangles that would not be cleared, because the rasterizing is not 100% identical

plugins/PaintTool/PaintClearCommand.py

@@ -42,6 +42,6 @@ class PaintClearCommand(PaintCommand):
         # There is actually nothing more to do here, both clear commands already have the same original texture
         return True
 
-    def _clearTextureBits(self, painter: QPainter):
+    def _clearTextureBits(self, painter: QPainter, extended = False):
         painter.setCompositionMode(QPainter.CompositionMode.RasterOp_NotSourceAndDestination)
         painter.fillRect(self._texture.getImage().rect(), QBrush(self._getBitRangeMask()))

plugins/PaintTool/PaintCommand.py

@@ -43,7 +43,7 @@ class PaintCommand(QUndoCommand):
         if self._original_texture_image is None:
             return
 
-        painter = self._makeClearedTexture()
+        painter = self._makeClearedTexture(extended=True)
         painter.setCompositionMode(QPainter.CompositionMode.RasterOp_SourceOrDestination)
         painter.drawImage(0, 0, self._original_texture_image)
         painter.end()
@@ -55,14 +55,14 @@ class PaintCommand(QUndoCommand):
         if self._sliceable_object_decorator is not None:
             self._sliceable_object_decorator.setPaintedExtrudersCountDirty()
 
-    def _makeClearedTexture(self) -> QPainter:
+    def _makeClearedTexture(self, extended = False) -> QPainter:
         painter = QPainter(self._texture.getImage())
         painter.setRenderHint(QPainter.RenderHint.Antialiasing, False)
 
-        self._clearTextureBits(painter)
+        self._clearTextureBits(painter, extended)
         return painter
 
-    def _clearTextureBits(self, painter: QPainter):
+    def _clearTextureBits(self, painter: QPainter, extended = False):
         raise NotImplementedError()
 
     @staticmethod

plugins/PaintTool/PaintStrokeCommand.py

@@ -17,6 +17,7 @@ class PaintStrokeCommand(PaintCommand):
     """Provides the command that does the actual painting on objects with undo/redo mechanisms"""
 
     PEN_OVERLAP_WIDTH = 2.5
+    PEN_OVERLAP_WIDTH_EXTENDED = PEN_OVERLAP_WIDTH + 0.5
 
     def __init__(self,
                  texture: Texture,
@@ -58,9 +59,9 @@ class PaintStrokeCommand(PaintCommand):
 
         return True
 
-    def _clearTextureBits(self, painter: QPainter):
+    def _clearTextureBits(self, painter: QPainter, extended = False):
         painter.setBrush(QBrush(self._getBitRangeMask()))
-        painter.setPen(QPen(painter.brush(), self.PEN_OVERLAP_WIDTH))
+        painter.setPen(QPen(painter.brush(), self.PEN_OVERLAP_WIDTH_EXTENDED if extended else self.PEN_OVERLAP_WIDTH))
         painter.setCompositionMode(QPainter.CompositionMode.RasterOp_NotSourceAndDestination)
         painter.drawPath(self._makePainterPath())