Improved distances and centering of cross-staff beams

src/engraving/dom/beam.cpp

@@ -220,6 +220,32 @@ const Chord* Beam::findChordWithCustomStemDirection() const
     return nullptr;
 }
 
+const BeamSegment* Beam::topLevelSegmentForElement(const ChordRest* element) const
+{
+    size_t segmentsSize = m_beamSegments.size();
+
+    IF_ASSERT_FAILED(segmentsSize > 0) {
+        return nullptr;
+    }
+
+    const BeamSegment* curSegment = m_beamSegments[0];
+    if (segmentsSize == 1) {
+        return curSegment;
+    }
+
+    for (const BeamSegment* segment : m_beamSegments) {
+        if (segment->level <= curSegment->level) {
+            continue;
+        }
+        Fraction elementTick = element->tick();
+        if (segment->startTick <= elementTick && segment->endTick >= elementTick) {
+            curSegment = segment;
+        }
+    }
+
+    return curSegment;
+}
+
 //---------------------------------------------------------
 //   move
 //---------------------------------------------------------

src/engraving/dom/beam.h

@@ -228,6 +228,8 @@ class Beam final : public BeamBase
 
     const Chord* findChordWithCustomStemDirection() const;
 
+    const BeamSegment* topLevelSegmentForElement(const ChordRest* element) const;
+
     inline int directionIdx() const { return (m_direction == DirectionV::AUTO || m_direction == DirectionV::DOWN) ? 0 : 1; }
 
 private:

src/engraving/dom/beambase.h

@@ -124,6 +124,8 @@ class BeamBase : public EngravingItem
         const StaffType* tab = nullptr;
         bool isBesideTabStaff = false;
         CrossStaffBeamPosition crossStaffBeamPos = CrossStaffBeamPosition::INVALID;
+        const Chord* limitingChordAbove = nullptr; // <-
+        const Chord* limitingChordBelow = nullptr; // <- For cross-staff spacing and centering
 
         void setAnchors(PointF startA, PointF endA) { startAnchor = startA; endAnchor = endA; }
         bool isValid() const override { return !(beamType == BeamType::INVALID); }

src/engraving/rendering/dev/beamtremololayout.cpp

@@ -846,9 +846,32 @@ bool BeamTremoloLayout::calculateAnchorsCross(const BeamBase* item, BeamBase::La
         }
     }
 
-    // Sets position for beams inbetween staves
-    ldata->startAnchor.setY((maxY + minY) / 2);
-    ldata->endAnchor.setY((maxY + minY) / 2);
+    double yMidPoint = (maxY + minY) / 2;
+    if (item->isBeam()) {
+        // Cross-staff beams may have segments both above and below the midline.
+        // Compute the y-difference between the top and bottom segment and aim for centering in between.
+        const Beam* beam = toBeam(item);
+        const std::vector<BeamSegment*>& beamSegments = beam->beamSegments();
+        const Chord* limitingChordAbove = beam->ldata()->limitingChordAbove;
+        const Chord* limitingChordBelow = beam->ldata()->limitingChordBelow;
+        if (!beamSegments.empty() && limitingChordAbove && limitingChordBelow) {
+            double yCenterSegment = 0.5 * (beamSegments.front()->line.y1() + beamSegments.front()->line.y2());
+
+            const BeamSegment* topBeamSegmentForChordAbove = beam->topLevelSegmentForElement(limitingChordAbove);
+            double yTopSegAbove = 0.5 * (topBeamSegmentForChordAbove->line.y1() + topBeamSegmentForChordAbove->line.y2());
+            double distAbove = yTopSegAbove - yCenterSegment;
+
+            const BeamSegment* topBeamSegmentForChordBelow = beam->topLevelSegmentForElement(limitingChordBelow);
+            double yTopSegBelow = 0.5 * (topBeamSegmentForChordBelow->line.y1() + topBeamSegmentForChordBelow->line.y2());
+            double distBelow = yTopSegBelow - yCenterSegment;
+
+            double averageDist = 0.5 * (distAbove + distBelow);
+            yMidPoint -= 0.5 * averageDist;
+        }
+    }
+
+    ldata->startAnchor.setY(yMidPoint);
+    ldata->endAnchor.setY(yMidPoint);
     ldata->startAnchor.setX(chordBeamAnchorX(ldata, startCr, ChordBeamAnchorType::Start));
     ldata->endAnchor.setX(chordBeamAnchorX(ldata, endCr, ChordBeamAnchorType::End));
 

src/engraving/rendering/dev/beamtremololayout.h

@@ -62,6 +62,8 @@ class BeamTremoloLayout
     static PointF chordBeamAnchor(const BeamBase::LayoutData* ldata, const ChordRest* chord, ChordBeamAnchorType anchorType);
     static int getMaxSlope(const BeamBase::LayoutData* ldata);
     static void extendStem(const BeamBase::LayoutData* ldata, Chord* chord, double addition);
+    static int minStemLength(const ChordRest* cr, const BeamBase::LayoutData* ldata);
+    static int strokeCount(const BeamBase::LayoutData* ldata, const ChordRest* cr);
 
 private:
 
@@ -93,10 +95,9 @@ class BeamTremoloLayout
     static void add8thSpaceSlant(BeamBase::LayoutData* ldata, PointF& dictatorAnchor, int dictator, int pointer, int beamCount,
                                  int interval, int middleLine, bool Flat);
     static bool noSlope(const Beam* beam);
-    static int strokeCount(const BeamBase::LayoutData* ldata, const ChordRest* cr);
+
     static bool calculateAnchorsCross(const BeamBase* item, BeamBase::LayoutData* ldata, const LayoutConfiguration& conf);
     static bool computeTremoloUp(const BeamBase::LayoutData* ldata);
-    static int minStemLength(const ChordRest* cr, const BeamBase::LayoutData* ldata);
 };
 } // namespace mu::engraving
 #endif

src/engraving/rendering/dev/systemlayout.cpp

@@ -65,6 +65,7 @@
 #include "alignmentlayout.h"
 #include "autoplace.h"
 #include "beamlayout.h"
+#include "beamtremololayout.h"
 #include "chordlayout.h"
 #include "harmonylayout.h"
 #include "lyricslayout.h"
@@ -2356,8 +2357,8 @@ void SystemLayout::layout2(System* system, LayoutContext& ctx)
                 }
             }
             dist = std::max(dist, d + minVerticalDistance);
+            dist = std::max(dist, minVertSpaceForCrossStaffBeams(system, si1, si2, ctx));
         }
-        dist = std::max(dist, minVertSpaceForCrossStaffBeams(system, si1, si2));
         ss->setYOff(yOffset);
         ss->setbbox(system->leftMargin(), y - yOffset, system->width() - system->leftMargin(), h);
         ss->saveLayout();
@@ -2382,7 +2383,7 @@ void SystemLayout::layout2(System* system, LayoutContext& ctx)
     SystemLayout::layoutInstrumentNames(system, ctx);
 }
 
-double SystemLayout::minVertSpaceForCrossStaffBeams(System* system, staff_idx_t staffIdx1, staff_idx_t staffIdx2)
+double SystemLayout::minVertSpaceForCrossStaffBeams(System* system, staff_idx_t staffIdx1, staff_idx_t staffIdx2, LayoutContext& ctx)
 {
     double minSpace = -DBL_MAX;
     track_idx_t startTrack = staffIdx1 * VOICES;
@@ -2401,33 +2402,56 @@ double SystemLayout::minVertSpaceForCrossStaffBeams(System* system, staff_idx_t
                     continue;
                 }
                 Beam* beam = toChord(item)->beam();
-                if (!beam || !beam->cross() || !beam->autoplace() || beam->elements().front() != item) {
+                if (!beam || !beam->autoplace() || beam->elements().front() != item) {
                     continue;
                 }
-                Note* highestOfBottomStaff = nullptr;
-                Note* lowestOfTopStaff = nullptr;
-                for (ChordRest* cr : beam->elements()) {
+                if (beam->ldata()->crossStaffBeamPos != BeamBase::CrossStaffBeamPosition::BETWEEN) {
+                    continue;
+                }
+                const Chord* limitingChordAbove = nullptr;
+                const Chord* limitingChordBelow = nullptr;
+                double limitFromAbove = -DBL_MAX;
+                double limitFromBelow = DBL_MAX;
+                for (const ChordRest* cr : beam->elements()) {
                     if (!cr->isChord()) {
                         continue;
                     }
-                    Chord* chord = toChord(cr);
+                    const Chord* chord = toChord(cr);
+                    double minStemLength = BeamTremoloLayout::minStemLength(chord, beam->ldata()) * (chord->spatium() / 4);
                     bool isUnderCrossBeam = cr->isBelowCrossBeam(beam);
                     if (isUnderCrossBeam && chord->vStaffIdx() == staffIdx2) {
-                        if (!highestOfBottomStaff || chord->upNote()->line() < highestOfBottomStaff->line()) {
-                            highestOfBottomStaff = chord->upNote();
+                        const Note* topNote = chord->upNote();
+                        double noteLimit = topNote->y() - minStemLength;
+                        if (noteLimit < limitFromBelow) {
+                            limitFromBelow = noteLimit;
+                            limitingChordBelow = chord;
                         }
+                        limitFromBelow = std::min(limitFromBelow, noteLimit);
                     } else if (!isUnderCrossBeam && chord->vStaffIdx() == staffIdx1) {
-                        if (!lowestOfTopStaff || chord->downNote()->line() > lowestOfTopStaff->line()) {
-                            lowestOfTopStaff = chord->downNote();
+                        const Note* bottomNote = chord->downNote();
+                        double noteLimit = bottomNote->y() + minStemLength;
+                        if (noteLimit > limitFromAbove) {
+                            limitFromAbove = noteLimit;
+                            limitingChordAbove = chord;
                         }
                     }
                 }
-                if (!highestOfBottomStaff || !lowestOfTopStaff) {
-                    continue;
+                if (limitingChordAbove && limitingChordBelow) {
+                    double minSpaceRequired = limitFromAbove - limitFromBelow;
+                    beam->mutldata()->limitingChordAbove = limitingChordAbove;
+                    beam->mutldata()->limitingChordBelow = limitingChordBelow;
+
+                    const BeamSegment* topBeamSegmentForChordAbove = beam->topLevelSegmentForElement(limitingChordAbove);
+                    const BeamSegment* topBeamSegmentForChordBelow = beam->topLevelSegmentForElement(limitingChordBelow);
+                    if (topBeamSegmentForChordAbove->above == topBeamSegmentForChordBelow->above) {
+                        // In this case the two opposing stems overlap the beam height, so we must subtract it
+                        int strokeCount = std::min(BeamTremoloLayout::strokeCount(beam->ldata(), limitingChordAbove),
+                                                   BeamTremoloLayout::strokeCount(beam->ldata(), limitingChordBelow));
+                        double beamHeight = ctx.conf().styleMM(Sid::beamWidth).val() + beam->beamDist() * (strokeCount - 1);
+                        minSpaceRequired -= beamHeight;
+                    }
+                    minSpace = std::max(minSpace, minSpaceRequired);
                 }
-                double bottomYOfTopStaff = lowestOfTopStaff->y() + lowestOfTopStaff->chord()->minStemLength();
-                double topYofBottomStaff = highestOfBottomStaff->y() - highestOfBottomStaff->chord()->minStemLength();
-                minSpace = std::max(minSpace, bottomYOfTopStaff - topYofBottomStaff);
             }
         }
     }

src/engraving/rendering/dev/systemlayout.h

@@ -83,7 +83,7 @@ class SystemLayout
     static void addBrackets(System* system, Measure* measure, LayoutContext& ctx);
     static Bracket* createBracket(System* system, LayoutContext& ctx, BracketItem* bi, size_t column, staff_idx_t staffIdx,
                                   std::vector<Bracket*>& bl, Measure* measure);
-    static double minVertSpaceForCrossStaffBeams(System* system, staff_idx_t staffIdx1, staff_idx_t staffIdx2);
+    static double minVertSpaceForCrossStaffBeams(System* system, staff_idx_t staffIdx1, staff_idx_t staffIdx2, LayoutContext& ctx);
 
     static bool elementShouldBeCenteredBetweenStaves(const EngravingItem* item, const System* system);
     static void centerElementBetweenStaves(EngravingItem* element, const System* system);

src/importexport/mei/tests/data/cross-staff-01.mscx

@@ -79,8 +79,8 @@
       <Measure>
         <voice>
           <Beam>
-            <l1>48</l1>
-            <l2>48</l2>
+            <l1>51</l1>
+            <l2>51</l2>
             </Beam>
           <Chord>
             <durationType>16th</durationType>
@@ -113,8 +113,8 @@
               </Note>
             </Chord>
           <Beam>
-            <l1>48</l1>
-            <l2>48</l2>
+            <l1>51</l1>
+            <l2>51</l2>
             </Beam>
           <Chord>
             <staffMove>1</staffMove>
@@ -147,8 +147,8 @@
               </Note>
             </Chord>
           <Beam>
-            <l1>48</l1>
-            <l2>48</l2>
+            <l1>51</l1>
+            <l2>51</l2>
             </Beam>
           <Chord>
             <durationType>16th</durationType>
@@ -181,8 +181,8 @@
               </Note>
             </Chord>
           <Beam>
-            <l1>48</l1>
-            <l2>48</l2>
+            <l1>45</l1>
+            <l2>45</l2>
             </Beam>
           <Chord>
             <staffMove>1</staffMove>
@@ -233,8 +233,8 @@
             <sigD>4</sigD>
             </TimeSig>
           <Beam>
-            <l1>-16</l1>
-            <l2>-8</l2>
+            <l1>-13</l1>
+            <l2>-5</l2>
             </Beam>
           <Chord>
             <staffMove>-1</staffMove>
@@ -267,8 +267,8 @@
               </Note>
             </Chord>
           <Beam>
-            <l1>-16</l1>
-            <l2>-8</l2>
+            <l1>-13</l1>
+            <l2>-5</l2>
             </Beam>
           <Chord>
             <staffMove>-1</staffMove>
@@ -301,8 +301,8 @@
               </Note>
             </Chord>
           <Beam>
-            <l1>-15</l1>
-            <l2>-9</l2>
+            <l1>-12</l1>
+            <l2>-6</l2>
             </Beam>
           <Chord>
             <staffMove>-1</staffMove>
@@ -332,8 +332,8 @@
             <durationType>16th</durationType>
             </Rest>
           <Beam>
-            <l1>-23</l1>
-            <l2>-21</l2>
+            <l1>-26</l1>
+            <l2>-24</l2>
             </Beam>
           <Chord>
             <staffMove>-1</staffMove>