Fix beam layout case

Multiple switches in a group should only have a slant if both stave's directions match.
Also rename misleading variables

Author: miiizen

src/engraving/rendering/score/beamtremololayout.cpp

@@ -1008,17 +1008,16 @@ bool BeamTremoloLayout::calculateAnchorsCross(const BeamBase* item, BeamBase::La
                     break;
                 }
             }
+
             const bool overallSlantFlat = overallDirection == 0;
-            const bool topSlantMatchesDirection = (topSlantDir != 0 && topSlantDir != overallDirection);
-            const bool bottomSlantMatchesDirection = (bottomSlantDir != 0 && bottomSlantDir != overallDirection);
-            const bool beamSideSwitchMatchesDirection = (beamSideSwitchDirection != 0 && beamSideSwitchDirection != overallDirection);
-            const bool staffSwitchMatchesDirection = (staffSwitchDirection != 0 && staffSwitchDirection != overallDirection);
-
-            forceHoriz = forceHoriz || overallSlantFlat
-                         || (topSlantMatchesDirection
-                             || bottomSlantMatchesDirection
-                             || beamSideSwitchMatchesDirection
-                             || staffSwitchMatchesDirection);
+            const bool topSlantOverallDiff = (topSlantDir != 0 && topSlantDir != overallDirection);
+            const bool bottomSlantOverallDiff = (bottomSlantDir != 0 && bottomSlantDir != overallDirection);
+            const bool beamSideSwitchOverallDiff = (beamSideSwitchDirection != 0 && beamSideSwitchDirection != overallDirection);
+            const bool staffSwitchOverallDiff = (staffSwitchDirection != 0 && staffSwitchDirection != overallDirection);
+            const bool flattenNeutralStaffSwitch = staffSwitchDirection == 0 && (topSlantDir != bottomSlantDir);
+
+            forceHoriz = forceHoriz || overallSlantFlat || flattenNeutralStaffSwitch
+                         || (topSlantOverallDiff || bottomSlantOverallDiff || beamSideSwitchOverallDiff || staffSwitchOverallDiff);
 
             if (!forceHoriz) {
                 int slant = 0;