JKQTMathText: improved placement of sub-/superscript nodes by using JKQTMathtextNodeSize::baselineXCorrection to shift subscript to the left for e.g. preceding italic text or symbols that require such a shift

JKQTMathText: moved sub-/superscripts placed below/above a bit further apart from the central symbol/node

doc/jkqtmathtext_docimages_math.jkmt

@@ -58,7 +58,7 @@ jkqtmathtext_doc_subsuper_italiccorrection.png
 sub-/superscript:\\
 \begin{tabular}{c|c}
 italic-correction  &  no correction\\\hdashline
-$x_\textcolor{blue}{\leftarrow}^\textcolor{red}{0}$ & $\mathrm{M}_\textcolor{red}{0}^\textcolor{red}{0}$
+$x_\textcolor{blue}{\leftarrow}^\textcolor{red}{0}$\ \ \ $\alpha_\textcolor{blue}{\leftarrow}^\textcolor{red}{0}$\ \ \ $\nabla_\textcolor{blue}{\leftarrow}^\textcolor{red}{0}$ & $\mathrm{M}_\textcolor{red}{0}^\textcolor{red}{0}$\ \ \ $\upalpha_\textcolor{red}{0}^\textcolor{red}{0}$
 \end{tabular}
 ---
 jkqtmathtext_doc_subsuper_italiccorrection_boxes.png
@@ -66,5 +66,5 @@ jkqtmathtext_doc_subsuper_italiccorrection_boxes.png
 sub-/superscript:\\
 \begin{tabular}{c|c}
 italic-correction  &  no correction\\\hdashline
-$x_\textcolor{blue}{\leftarrow}^\textcolor{red}{0}$ & $\mathrm{M}_\textcolor{red}{0}^\textcolor{red}{0}$
+$x_\textcolor{blue}{\leftarrow}^\textcolor{red}{0}$\ \ \ $\alpha_\textcolor{blue}{\leftarrow}^\textcolor{red}{0}$\ \ \ $\nabla_\textcolor{blue}{\leftarrow}^\textcolor{red}{0}$ & $\mathrm{M}_\textcolor{red}{0}^\textcolor{red}{0}$\ \ \ $\upalpha_\textcolor{red}{0}^\textcolor{red}{0}$
 \end{tabular}

lib/jkqtmathtext/jkqtmathtext.cpp

@@ -63,7 +63,6 @@ JKQTMathText::JKQTMathText(QObject* parent):
     fontSize=10;
     fontSizeUnits=JKQTMathTextEnvironment::POINTS;
     fontColor=QColor("black");
-    italic_correction_factor=0.4;
     brace_factor=1.04;
     brace_y_shift_factor=0.7;//-1;
 
@@ -87,7 +86,7 @@ JKQTMathText::JKQTMathText(QObject* parent):
     decoration_separation_factor=0.1;
 
     operatorsubsuper_size_factor=0.65;
-    operatorsubsuper_distance_factor=0.25;
+    operatorsubsuper_distance_factor=0.35;
     operatorsubsuper_extraspace_factor=0.5;
     intsubsuper_xcorrection_factor=0.25;
     intsubbesides_xcorrection_xfactor=0.33;
@@ -206,7 +205,6 @@ void JKQTMathText::loadSettings(const QSettings& settings, const QString& group)
     brace_factor=settings.value(group+"brace_factor", brace_factor).toDouble();
     subsuper_size_factor=settings.value(group+"subsuper_size_factor", subsuper_size_factor).toDouble();
     subsuper_mode_selection_by_size_factor=settings.value(group+"subsuper_mode_selection_by_size_factor", subsuper_mode_selection_by_size_factor).toDouble();
-    italic_correction_factor=settings.value(group+"italic_correction_factor", italic_correction_factor).toDouble();
     super_shift_factor=settings.value(group+"super_shift_factor", super_shift_factor).toDouble();
     sub_shift_factor=settings.value(group+"sub_shift_factor", sub_shift_factor).toDouble();
     special_super_shift_factor=settings.value(group+"special_super_shift_factor", special_super_shift_factor).toDouble();
@@ -254,7 +252,6 @@ void JKQTMathText::saveSettings(QSettings& settings, const QString& group) const
     settings.setValue(group+ "brace_factor", brace_factor);
     settings.setValue(group+ "subsuper_size_factor", subsuper_size_factor);
     settings.setValue(group+ "subsuper_mode_selection_by_size_factor", subsuper_mode_selection_by_size_factor);
-    settings.setValue(group+ "italic_correction_factor", italic_correction_factor);
     settings.setValue(group+ "sub_shift_factor", sub_shift_factor);
     settings.setValue(group+ "super_shift_factor", super_shift_factor);
     settings.setValue(group+ "special_sub_shift_factor", special_sub_shift_factor);
@@ -711,16 +708,6 @@ double JKQTMathText::getSubsuperModeSelectionBySizeFactor() const
     return subsuper_mode_selection_by_size_factor;
 }
 
-void JKQTMathText::setItalicCorrectionFactor(double __value)
-{
-    this->italic_correction_factor = __value;
-}
-
-double JKQTMathText::getItalicCorrectionFactor() const
-{
-    return this->italic_correction_factor;
-}
-
 void JKQTMathText::setOperatorsubsuperSizeFactor(double __value)
 {
     this->operatorsubsuper_size_factor = __value;

lib/jkqtmathtext/jkqtmathtext.h

@@ -512,10 +512,6 @@ class JKQTMATHTEXT_LIB_EXPORT JKQTMathText : public QObject {
         void setSubsuperModeSelectionBySizeFactor(double __value);
         /** \copydoc subsuper_mode_selection_by_size_factor */
         double getSubsuperModeSelectionBySizeFactor() const;
-        /** \copydoc italic_correction_factor */
-        void setItalicCorrectionFactor(double __value);
-        /** \copydoc italic_correction_factor */ 
-        double getItalicCorrectionFactor() const;
         /** \copydoc operatorsubsuper_size_factor */ 
         void setOperatorsubsuperSizeFactor(double __value);
         /** \copydoc operatorsubsuper_size_factor */ 
@@ -721,14 +717,6 @@ class JKQTMATHTEXT_LIB_EXPORT JKQTMathText : public QObject {
          *  by \c \\sum,\\int,... .
          */
         double subsuper_mode_selection_by_size_factor;
-        /** \brief fraction of a whitespace by which to shift a sub-/superscript left/right when the previous text is italic
-         *
-         *  \image html jkqtmathtext/jkqtmathtext_doc_subsuper_italiccorrection.png
-         *
-         *  \image html jkqtmathtext/jkqtmathtext_doc_subsuper_italiccorrection_boxes.png
-         *
-         */
-        double italic_correction_factor;
         /** \brief like subsuper_size_factor, but for operators (\c \\sum , \c \\int , ...) where the text is placed above/below the symbol */
         double operatorsubsuper_size_factor;
         /** \brief for operators (\c \\sum , \c \\int , ...) where the text is placed above/below the symbol, this is the distance between the operator symbol and the sub-/super-text if multiplied by xHeight

lib/jkqtmathtext/jkqtmathtexttools.cpp

@@ -596,7 +596,9 @@ JKQTMathTextNodeSize::JKQTMathTextNodeSize():
     width(0),
     baselineHeight(0),
     overallHeight(0),
-    strikeoutPos()
+    strikeoutPos(),
+    baselineXCorrection(0),
+    topXCorrection(0)
 {
 
 }

lib/jkqtmathtext/jkqtmathtexttools.h

@@ -339,6 +339,15 @@ struct JKQTMATHTEXT_LIB_EXPORT JKQTMathTextNodeSize {
     double overallHeight;
     /** \brief strikeoutPos of whole block */
     double strikeoutPos;
+    /** \brief x-correction (<0 = move to the left) for subscripts, i.e. approximately at the height of the baseline
+     *
+     *  \image html jkqtmathtext/jkqtmathtext_doc_subsuper_italiccorrection.png
+     *
+     *  \image html jkqtmathtext/jkqtmathtext_doc_subsuper_italiccorrection_boxes.png
+     */
+    double baselineXCorrection;
+    /** \brief x-correction (>0 = move to the right) for superscripts, i.e. approximately at the top  of the box */
+    double topXCorrection;
     /** \brief calculate the descent */
     inline double getDescent() const { return overallHeight-baselineHeight; }
     /** \brief calculate the overall size in floating-point precision */

lib/jkqtmathtext/nodes/jkqtmathtextdecoratednode.cpp

@@ -164,6 +164,7 @@ JKQTMathTextNodeSize JKQTMathTextDecoratedNode::getSizeInternal(QPainter& painte
     s.baselineHeight=ascent;
     s.strikeoutPos=cs.strikeoutPos;
     s.width=std::max<double>(deco_miniwidth,cs.width);
+    s.baselineXCorrection=cs.baselineXCorrection;
     return s;
 }
 

lib/jkqtmathtext/nodes/jkqtmathtextlistnode.cpp

@@ -54,12 +54,14 @@ QString JKQTMathTextHorizontalListNode::getTypeName() const
 
 JKQTMathTextNodeSize JKQTMathTextHorizontalListNode::getSizeInternal(QPainter& painter, JKQTMathTextEnvironment currentEv) const {
     JKQTMathTextNodeSize outSize;
-    const QFontMetricsF fm(currentEv.getFont(parentMathText));
+    const QFont f=currentEv.getFont(parentMathText);
+    const QFontMetricsF fm(f);
     const double subsupershift=fm.xHeight()*parentMathText->getOperatorsubsuperDistanceFactor();
     const double subsuperextrawidth=fm.boundingRect('x').width()*parentMathText->getOperatorsubsuperExtraSpaceFactor();
     const double subsuperSpecialModeAscent=fm.ascent()*parentMathText->getSubsuperModeSelectionBySizeFactor();
     const double subsuperSpecialModeDecent=fm.descent()*parentMathText->getSubsuperModeSelectionBySizeFactor();
     const double spaceWidth=fm.boundingRect(' ').width();
+
     //QRectF tbr=parent->getTightBoundingRect(currentEv.getFont(parent), "M", painter.device());
 
 
@@ -81,6 +83,7 @@ JKQTMathTextNodeSize JKQTMathTextHorizontalListNode::getSizeInternal(QPainter& p
             if (shouldUseSpecialSubscriptMode)  prevNodeSizePtrForSubscript=&prevNodeSize;
             if (shouldUseSpecialSuperscriptMode)  prevNodeSizePtrForSuperscript=&prevNodeSize;
         }
+        const double subscript_xcorrection=prevNodeSize.baselineXCorrection+fm.lineWidth()*0.5;
 
         JKQTMathTextSuperscriptNode* nodeI_SuperScript=dynamic_cast<JKQTMathTextSuperscriptNode*>(nodes[i]);
         JKQTMathTextSubscriptNode* nodeI_SubScript=dynamic_cast<JKQTMathTextSubscriptNode*>(nodes[i]);
@@ -116,7 +119,7 @@ JKQTMathTextNodeSize JKQTMathTextHorizontalListNode::getSizeInternal(QPainter& p
                         outSize.overallHeight=outSize.baselineHeight+ns2.getDescent();
                         outSize.strikeoutPos=ns2.strikeoutPos;
                     }
-                    xnew+=qMax(ns.width+spaceWidth, ns2.width+prevNodeSize.subBesidesXCorrection);
+                    xnew+=qMax(ns.width+spaceWidth, ns2.width+subscript_xcorrection);
 
                     doDraw=false;
                     //qDebug()<<"### super+sub";
@@ -149,7 +152,7 @@ JKQTMathTextNodeSize JKQTMathTextHorizontalListNode::getSizeInternal(QPainter& p
                         outSize.overallHeight=outSize.baselineHeight+ns2.overallHeight-ns2.baselineHeight;
                         outSize.strikeoutPos=ns2.strikeoutPos;
                     }
-                    xnew+=qMax(ns.width+prevNodeSize.subBesidesXCorrection, ns2.width+spaceWidth);
+                    xnew+=qMax(ns.width+subscript_xcorrection, ns2.width+spaceWidth);
 
 
                     doDraw=false;
@@ -167,7 +170,7 @@ JKQTMathTextNodeSize JKQTMathTextHorizontalListNode::getSizeInternal(QPainter& p
                     outSize.overallHeight=outSize.baselineHeight+ns.getDescent();
                     outSize.strikeoutPos=ns.strikeoutPos;
                 }
-                xnew+=ns.width-prevNodeSize.subBesidesXCorrection;
+                xnew+=ns.width+subscript_xcorrection;
                 doDraw=false;
 
             }
@@ -201,7 +204,7 @@ JKQTMathTextNodeSize JKQTMathTextHorizontalListNode::getSizeInternal(QPainter& p
                     //double d1=ns.overallHeight-ns.baselineHeight;
                     //double d2=oh2-bh2;
                     //double d3=oh3-bh3;
-                    const double neww=qMax(qMax(ns.width, sub.width+prevNodeSize.subSuperXCorrection), sup.width+prevNodeSize.subSuperXCorrection)+subsuperextrawidth;
+                    const double neww=qMax(qMax(ns.width, sub.width+prevNodeSize.subSuperAboveBelowXCorrection), sup.width+prevNodeSize.subSuperAboveBelowXCorrection)+subsuperextrawidth;
                     const double newBaselineHeight=ns.baselineHeight+sup.overallHeight+subsupershift;
                     if (newBaselineHeight>outSize.baselineHeight) {
                         const double extraBaselineHeight=newBaselineHeight-outSize.baselineHeight;
@@ -244,7 +247,7 @@ JKQTMathTextNodeSize JKQTMathTextHorizontalListNode::getSizeInternal(QPainter& p
                         outSize.overallHeight=outSize.overallHeight+(nodeSize.baselineHeight-outSize.baselineHeight);
                         outSize.baselineHeight=nodeSize.baselineHeight;
                     }
-                    const double neww=qMax(nodeSize.width, sub.width+nodeSize.subSuperXCorrection)+subsuperextrawidth;
+                    const double neww=qMax(nodeSize.width, sub.width+nodeSize.subSuperAboveBelowXCorrection)+subsuperextrawidth;
                     i++;
                     doDraw=false;
                     xnew+=neww;
@@ -274,7 +277,7 @@ JKQTMathTextNodeSize JKQTMathTextHorizontalListNode::getSizeInternal(QPainter& p
                         outSize.overallHeight=outSize.baselineHeight+descent1;
                     }
 
-                    const double neww=qMax(nodeSize.width, sup.width+nodeSize.subSuperXCorrection)+subsuperextrawidth;
+                    const double neww=qMax(nodeSize.width, sup.width+nodeSize.subSuperAboveBelowXCorrection)+subsuperextrawidth;
                     i++;
                     doDraw=false;
                     xnew+=neww;
@@ -300,6 +303,8 @@ JKQTMathTextNodeSize JKQTMathTextHorizontalListNode::getSizeInternal(QPainter& p
                 outSize.overallHeight=outSize.baselineHeight+cDescent;
                 outSize.strikeoutPos=ns.strikeoutPos;
             }
+            outSize.baselineXCorrection=ns.baselineXCorrection;
+            outSize.topXCorrection=ns.topXCorrection;
             //qDebug()<<"### subsupop: else   overallHeight="<<overallHeight<<" baselineHeight="<<baselineHeight;
 
             xnew+=ns.width;
@@ -343,6 +348,7 @@ double JKQTMathTextHorizontalListNode::draw(QPainter& painter, double x, double
             if (shouldUseSpecialSubscriptMode)  prevNodeSizePtrForSubscript=&prevNodeSize;
             if (shouldUseSpecialSuperscriptMode)  prevNodeSizePtrForSuperscript=&prevNodeSize;
         }
+        const double subscript_xcorrection=prevNodeSize.baselineXCorrection+fm.lineWidth()*0.5;
 
         JKQTMathTextSuperscriptNode* nodeI_SuperScript=dynamic_cast<JKQTMathTextSuperscriptNode*>(nodes[i]);
         JKQTMathTextSubscriptNode* nodeI_SubScript=dynamic_cast<JKQTMathTextSubscriptNode*>(nodes[i]);
@@ -361,7 +367,7 @@ double JKQTMathTextHorizontalListNode::draw(QPainter& painter, double x, double
                     i++;
                     //painter.setPen(QPen("magenta"));
                     //painter.drawEllipse(xnew-4,ynew-4,8,8);
-                    const double xnew2=nodeISucc_SubScript->drawWithSpecialPlacement(painter, xnew-prevNodeSize.subSuperXCorrection, ynew, currentEv, prevNodeSizePtrForSubscript);
+                    const double xnew2=nodeISucc_SubScript->drawWithSpecialPlacement(painter, xnew+subscript_xcorrection, ynew, currentEv, prevNodeSizePtrForSubscript);
                     //i++;
                     xnew=qMax(xnewidth, xnew2);
                     doDraw=false;
@@ -373,7 +379,7 @@ double JKQTMathTextHorizontalListNode::draw(QPainter& painter, double x, double
                 if (nodeISucc_SuperScript) { // is this subscript?
                     //painter.setPen(QPen("red"));
                     //painter.drawEllipse(xnew-4,ynew+shift-(ccOverallHeight-ccBaselineHeight)-4,8,8);
-                    double xnewidth=nodeI_SubScript->drawWithSpecialPlacement(painter, xnew-prevNodeSize.subSuperXCorrection, ynew, currentEv, prevNodeSizePtrForSubscript);
+                    double xnewidth=nodeI_SubScript->drawWithSpecialPlacement(painter, xnew+subscript_xcorrection, ynew, currentEv, prevNodeSizePtrForSubscript);
                     i++;
                     //painter.setPen(QPen("magenta"));
                     //painter.drawEllipse(xnew-4,ynew-4,8,8);
@@ -383,7 +389,7 @@ double JKQTMathTextHorizontalListNode::draw(QPainter& painter, double x, double
                     doDraw=false;
                 }
             } else {
-                xnew=nodeI_SubScript->drawWithSpecialPlacement(painter, xnew-prevNodeSize.subBesidesXCorrection, ynew, currentEv, prevNodeSizePtrForSubscript);
+                xnew=nodeI_SubScript->drawWithSpecialPlacement(painter, xnew+subscript_xcorrection, ynew, currentEv, prevNodeSizePtrForSubscript);
                 doDraw=false;
             }
         } else {
@@ -427,10 +433,10 @@ double JKQTMathTextHorizontalListNode::draw(QPainter& painter, double x, double
                     const double xn1=nodes[i]->draw(painter, xnew+(neww-nodeSize.width)/2.0, ynew, currentEv);
                     i++;
                     //double xnew2=
-                    const double xnsub=subn->getChild()->draw(painter, xnew+(neww-sub.width)/2.0-nodeSize.subSuperXCorrection, ynew+sub.baselineHeight+descent1+subsupershift, ev);
+                    const double xnsub=subn->getChild()->draw(painter, xnew+(neww-sub.width)/2.0-nodeSize.subSuperAboveBelowXCorrection, ynew+sub.baselineHeight+descent1+subsupershift, ev);
                     i++;
                     //double xnew3=
-                    const double xnsup=supn->getChild()->draw(painter, xnew+(neww-sup.width)/2.0+nodeSize.subSuperXCorrection, ynew-nodeSize.baselineHeight-descent3-subsupershift, ev);
+                    const double xnsup=supn->getChild()->draw(painter, xnew+(neww-sup.width)/2.0+nodeSize.subSuperAboveBelowXCorrection, ynew-nodeSize.baselineHeight-descent3-subsupershift, ev);
                     doDraw=false;
                     xnew=qMax(qMax(xn1, xnsub), xnsup)+subsuperextrawidth/2.0;
                 } else if (subn) { // is this subscript and no following superscript?
@@ -452,7 +458,7 @@ double JKQTMathTextHorizontalListNode::draw(QPainter& painter, double x, double
                     const double xn1=nodes[i]->draw(painter, xnew+(neww-nodeSize.width)/2.0, ynew, currentEv);
                     i++;
                     //double xnew2=
-                    const double xnsub=subn->getChild()->draw(painter, xnew+(neww-sub.width)/2.0-nodeSize.subSuperXCorrection, ynew+sub.baselineHeight+descent1+subsupershift, ev)+subsupershift;
+                    const double xnsub=subn->getChild()->draw(painter, xnew+(neww-sub.width)/2.0-nodeSize.subSuperAboveBelowXCorrection, ynew+sub.baselineHeight+descent1+subsupershift, ev)+subsupershift;
                     doDraw=false;
                     //xnew+=w;
                     xnew=qMax(xnsub, xn1)+subsuperextrawidth/2.0;
@@ -476,7 +482,7 @@ double JKQTMathTextHorizontalListNode::draw(QPainter& painter, double x, double
                     const double xn1=nodes[i]->draw(painter, xnew+(neww-nodeSize.width)/2.0, ynew, currentEv);
                     i++;
                     //double xnew3=
-                    const double xnsup=supn->getChild()->draw(painter, xnew+(neww-sup.width)/2.0+nodeSize.subSuperXCorrection, ynew-nodeSize.baselineHeight-descent3-subsupershift, ev);
+                    const double xnsup=supn->getChild()->draw(painter, xnew+(neww-sup.width)/2.0+nodeSize.subSuperAboveBelowXCorrection, ynew-nodeSize.baselineHeight-descent3-subsupershift, ev);
                     doDraw=false;
                     xnew=qMax(xn1, xnsup)+subsuperextrawidth/2.0;
                 }
@@ -485,7 +491,7 @@ double JKQTMathTextHorizontalListNode::draw(QPainter& painter, double x, double
 
         if (i<nodes.size() && doDraw) {
             if (nodeI_SuperScript) xnew=nodeI_SuperScript->drawWithSpecialPlacement(painter, xnew, ynew, currentEv, prevNodeSizePtrForSuperscript);
-            else if (nodeI_SubScript) xnew=nodeI_SubScript->drawWithSpecialPlacement(painter, xnew-prevNodeSize.subBesidesXCorrection, ynew, currentEv, prevNodeSizePtrForSubscript);
+            else if (nodeI_SubScript) xnew=nodeI_SubScript->drawWithSpecialPlacement(painter, xnew+subscript_xcorrection, ynew, currentEv, prevNodeSizePtrForSubscript);
             else xnew=nodes[i]->draw(painter, xnew, ynew, currentEv);
         }
     }

lib/jkqtmathtext/nodes/jkqtmathtextlistnode.h

@@ -36,9 +36,19 @@ class JKQTMathText; // forward
 /** \brief subclass representing a list of nodes in the syntax tree, layed out horizontally
  *  \ingroup jkqtmathtext_items
  *
- *  \note This type of node also implements typesetting sub-/superscript above/below the previous node (if
- *        JKQTMathTextNode::is() is \c true for that previus node. The drawing is done as defined in the
- *        following image \image html jkqtmathtext_subsuper_with_limits.png
+ *  This type of node also implements typesetting sub-/superscript above/below the previous node (if
+ *  JKQTMathTextNode::is() is \c true for that previus node. The drawing is done as defined in the
+ *  following image:
+ *    \image html jkqtmathtext_subsuper_with_limits.png
+ *
+ *  In addition this node also ensures that subscripts are moved to the left for italic previous
+ *  text or nodes that require such a shift (e.g. \c \\nabla or \c \\int ):
+ *
+ *  \image html jkqtmathtext/jkqtmathtext_doc_subsuper_italiccorrection.png
+ *
+ *  \image html jkqtmathtext/jkqtmathtext_doc_subsuper_italiccorrection_boxes.png
+ *
+ *  This is implemented using JKQTMathTextNodeSize::baselineXCorrection .
  *
  *  \see JKQTMathTextVerticalListNode
  */

lib/jkqtmathtext/nodes/jkqtmathtextsubsupernode.cpp

@@ -64,7 +64,6 @@ JKQTMathTextNodeSize JKQTMathTextSuperscriptNode::getSizeWithSpecialPlacement(QP
     s.width=cs.width;
     if (prevNodeSizeForSpecialPlacement!=nullptr) s.strikeoutPos=prevNodeSizeForSpecialPlacement->strikeoutPos;
     else s.strikeoutPos=fm.strikeOutPos();
-    if (currentEv.italic && prevNodeSizeForSpecialPlacement==nullptr) s.width=s.width+double(fm.boundingRect(' ').width())*parentMathText->getItalicCorrectionFactor();
     return s;
 }
 
@@ -91,7 +90,6 @@ double JKQTMathTextSuperscriptNode::drawWithSpecialPlacement(QPainter& painter,
     }
 
     double xx=x;
-    if (currentEv.italic && prevNodeSizeForSpecialPlacement==nullptr) xx=xx+double(fm.boundingRect(' ').width())*parentMathText->getItalicCorrectionFactor();
 
     return getChild()->draw(painter, xx, y-(shiftToChildBottom+childDescent), ev);//+0.5*fm.boundingRect("A").width();
 }
@@ -137,7 +135,6 @@ JKQTMathTextNodeSize JKQTMathTextSubscriptNode::getSizeWithSpecialPlacement(QPai
     ev.fontSize=ev.fontSize*parentMathText->getSubsuperSizeFactor();
     const QFontMetricsF fm(ev.getFont(parentMathText), painter.device());
     //const QRectF tbr_of_letterM=JKQTMathTextGetTightBoundingRect(currentEv.getFont(parentMathText), "M", painter.device());
-    const double italic_xshift=qMax(0.0,-fm.rightBearing('x'));// double(fm.boundingRect('x').width())*parentMathText->getItalicCorrectionFactor();
 
     const JKQTMathTextNodeSize cs=getChild()->getSize(painter, ev);
     //const double childDescent=cs.overallHeight-cs.baselineHeight;
@@ -156,7 +153,6 @@ JKQTMathTextNodeSize JKQTMathTextSubscriptNode::getSizeWithSpecialPlacement(QPai
     if (prevNodeSizeForSpecialPlacement!=nullptr) s.strikeoutPos=prevNodeSizeForSpecialPlacement->strikeoutPos;
     else s.strikeoutPos=fm.strikeOutPos();
     s.width=cs.width;
-    if (currentEv.italic && prevNodeSizeForSpecialPlacement==nullptr) s.width=s.width-italic_xshift;
     return s;
 }
 
@@ -174,7 +170,6 @@ double JKQTMathTextSubscriptNode::drawWithSpecialPlacement(QPainter& painter, do
 
     const JKQTMathTextNodeSize cs=getChild()->getSize(painter, ev);
     double shift_to_childBaseline=cs.baselineHeight-parentMathText->getSubShiftFactor()*fm.xHeight();
-    const double italic_xshift=qMax(0.0,-fm.rightBearing('x'));// double(fm.boundingRect('x').width())*parentMathText->getItalicCorrectionFactor();
 
     if (prevNodeSizeForSpecialPlacement!=nullptr) {
         //qDebug()<<"oldshift="<<shift<<", prevNodeSize->overallHeight="<<prevNodeSize->overallHeight<<", prevNodeSize->baselineHeight="<<prevNodeSize->baselineHeight;
@@ -187,10 +182,6 @@ double JKQTMathTextSubscriptNode::drawWithSpecialPlacement(QPainter& painter, do
     //qDebug()<<"baselineHeight="<<baselineHeight<<", overallHeight="<<overallHeight<<", strikeoutPos="<<strikeoutPos;
     //qDebug()<<"shift="<<shift<<", yshift="<<yshift;
     double xx=x;
-    if (currentEv.italic && prevNodeSizeForSpecialPlacement==nullptr) {
-        //std::cout<<"italic_xshift="<<italic_xshift<<"\n";
-        xx=xx-italic_xshift;
-    }
     return getChild()->draw(painter, xx, y+shift_to_childBaseline, ev);//+0.5*fm.boundingRect("A").width();
 }
 

lib/jkqtmathtext/nodes/jkqtmathtextsymbolnode.cpp

@@ -160,7 +160,7 @@ double JKQTMathTextSymbolNode::draw(QPainter& painter, double x, double y, JKQTM
     const double xShift=(s.width-tbr.width())/2.0;
     const QPointF x0(x+xShift-tbr.x(), y+yShift);
     double italic_xcorrection=fabs(tbr.width()-tbrNonItalic.width());
-    if (fabs(italic_xcorrection)<1e-6) italic_xcorrection=double(fm.boundingRect(' ').width())*parentMathText->getItalicCorrectionFactor();
+    if (fabs(italic_xcorrection)<1e-6) italic_xcorrection=double(fm.boundingRect(' ').width())*0.4;
 
     //qDebug()<<"SYMB::draw(): symbolName="<<symbolName<<" font="<<f<<" sym="<<sym<<" yShiftFactor="<<symprops.yShiftFactor;
 
@@ -246,6 +246,7 @@ JKQTMathTextSymbolNode::NodeSize JKQTMathTextSymbolNode::getSymbolSize(QPainter
     const QRectF br=getBoundingRect(fm, sym, globalFlags);
     const QRectF tbrNoSymbol=JKQTMathTextGetTightBoundingRect(f, "X", painter.device());
     const QRectF mintbr=JKQTMathTextGetTightBoundingRect(f, "(", painter.device());
+    const QRectF dottbr=JKQTMathTextGetTightBoundingRect(f, ".", painter.device());
     //const double yShift=symprops.yShiftFactor*tbr.height();
 
     if (currentEv.insideMath) {
@@ -280,8 +281,14 @@ JKQTMathTextSymbolNode::NodeSize JKQTMathTextSymbolNode::getSymbolSize(QPainter
     s.strikeoutPos=fm.strikeOutPos();
 
     if (has(globalFlags, IntLikeSymbolCorrection)) {
-        s.subSuperXCorrection=parentMathText->getIntSubSuperXCorrectionFactor()*tbr.width();
-        s.subBesidesXCorrection=parentMathText->getIntSubBesidesXCorrectionXFactor()*JKQTMathTextGetTightBoundingRect(f, "X", painter.device()).width();
+        if (has(globalFlags, SubSuperscriptBelowAboveSymbol)) {
+            s.subSuperAboveBelowXCorrection=parentMathText->getIntSubSuperXCorrectionFactor()*tbr.width();
+        }
+        s.baselineXCorrection=-parentMathText->getIntSubBesidesXCorrectionXFactor()*JKQTMathTextGetTightBoundingRect(f, "X", painter.device()).width();
+        s.topXCorrection=dottbr.width();
+    }
+    if (has(globalFlags, SubscriptCorrection) && sym.size()>0) {
+        s.baselineXCorrection=fm.rightBearing(sym[sym.size()-1]);
     }
 
     return s;
@@ -410,7 +417,7 @@ JKQTMathTextSymbolNode::SymbolFullProps JKQTMathTextSymbolNode::UprightGreekLett
 
 void JKQTMathTextSymbolNode::addGreekLetterVariants_WinSymbol_Unicode_Html(const QString &baseInstructionName, const QString &letterWinSymbol, const QString &letterUnicode, const QString &html)
 {
-    symbols[baseInstructionName]=MathGreekLetter_WinSymbol_Unicode_Html(letterWinSymbol, letterUnicode, html);
+    symbols[baseInstructionName]=MathGreekLetter_WinSymbol_Unicode_Html(letterWinSymbol, letterUnicode, html).addGlobalFlags(SubscriptCorrection);
     symbols["text"+baseInstructionName]=AsOutsiudeGreekLetter_WinSymbol_Unicode_Html(letterWinSymbol, letterUnicode, html);
     symbols["up"+baseInstructionName]=UprightGreekLetter_WinSymbol_Unicode_Html(letterWinSymbol, letterUnicode, html);
 }
@@ -533,7 +540,7 @@ void JKQTMathTextSymbolNode::fillSymbolTables()
     { auto s=UnicodeSymbol(QChar(0x2103)).addUprightStd("°C").addUprightHtml("&deg;C");
         symbols["celsius"]=s; symbols["degC"]=s; symbols["degreeCelsius"]=s; }
     symbols["ell"]=UprightSymbolUnicode(QChar(0x2113), "&ell;");
-    symbols["wp"]=UprightSymbolUnicode(QChar(0x2118), "&wp;");
+    symbols["wp"]=UprightSymbolUnicode(QChar(0x2118), "&wp;").addGlobalFlags(SubscriptCorrection);
     symbols["mho"]=UprightSymbolUnicode(QChar(0x2127), "&mho;");
     symbols["lozenge"]=UprightSymbolUnicode(QChar(0x25CA), "&loz;");
     symbols["cent"]=SimpleTextSymbol(QChar(0xA2), "&cent;");
@@ -574,7 +581,7 @@ void JKQTMathTextSymbolNode::fillSymbolTables()
     symbols["glqq"]=UnicodeSymbol(QChar(0x201C)).addHtml("&OpenCurlyDoubleQuote;").addStd("\"");
     symbols["grq"]=UnicodeSymbol(QChar(0x2019)).addHtml("&CloseCurlyQuote;").addStd("'");
     symbols["grqq"]=UnicodeSymbol(QChar(0x201D)).addHtml("&CloseCurlyDoubleQuote;").addStd("\"");
-    symbols["hbar"]=UprightSymbolUnicode(QChar(0x210F)).addUprightHtml("&hbar;").addStd("h", ItalicOn|DrawLeftHBar);
+    symbols["hbar"]=UprightSymbolUnicode(QChar(0x210F)).addUprightHtml("&hbar;").addStd("h", ItalicOn|DrawLeftHBar).addGlobalFlags(SubscriptCorrection);
     symbols["hexagon"]=UprightSymbolUnicode(QChar(0x2394));
     symbols["ii"] = SymbolFullProps(SymbolProps("i", Upright|BoldOff), "i", Upright|BoldOff);
     symbols["infty"]=UnicodeSymbol(QChar(0x221E)).addHtml("&infin;").addWinSymbol(QChar(0xA5)).addStd("8", RotateSymbol90);
@@ -662,8 +669,8 @@ void JKQTMathTextSymbolNode::fillSymbolTables()
     symbols["lb"] = NarrowMathOperatorText("lb");
     symbols["ld"] = NarrowMathOperatorText("ld");
     symbols["lim"] = NarrowMathOperatorText("lim").addGlobalFlags(SubSuperscriptBelowAboveSymbol);
-    symbols["liminf"] = NarrowMathOperatorText("lim inf", "lim&thinsp;inf").addGlobalFlags(SubSuperscriptBelowAboveSymbol);
-    symbols["limsup"] = NarrowMathOperatorText("lim sup", "lim&thinsp;sup").addGlobalFlags(SubSuperscriptBelowAboveSymbol);
+    symbols["liminf"] = NarrowMathOperatorText("lim inf", "lim&thinsp;inf").addGlobalFlags(SubSuperscriptBelowAboveSymbol).addGlobalFlags(SubscriptCorrection);
+    symbols["limsup"] = NarrowMathOperatorText("lim sup", "lim&thinsp;sup").addGlobalFlags(SubSuperscriptBelowAboveSymbol).addGlobalFlags(SubscriptCorrection);
     symbols["ln"] = NarrowMathOperatorText("ln");
     symbols["log"] = NarrowMathOperatorText("log");
     symbols["max"] = NarrowMathOperatorText("max");
@@ -731,7 +738,7 @@ void JKQTMathTextSymbolNode::fillSymbolTables()
         symbols["emptyset"]=s; symbols["varnothing"]=s; }
     symbols["equiv"]=MathOperatorSymbolUnicode(QChar(0x2261)).addMathOperatorHtml("&equiv;").addMathOperatorWinSymbol(QChar(0xBA));
     symbols["exists"]=NarrowMathOperatorSymbolUnicode(QChar(0x2203)).addMathOperatorHtml("&exist;").addMathOperatorWinSymbol(QChar(0x24)).addStd("E", ItalicOff|BoldOff|FlipSymbolLeftRight);
-    symbols["forall"]=NarrowMathOperatorSymbolUnicode(QChar(0x2200)).addMathOperatorHtml("&forall;").addMathOperatorWinSymbol(QChar(0x22)).addStd("A", ItalicOff|BoldOff|FlipSymbolUpDown);
+    symbols["forall"]=NarrowMathOperatorSymbolUnicode(QChar(0x2200)).addMathOperatorHtml("&forall;").addMathOperatorWinSymbol(QChar(0x22)).addStd("A", ItalicOff|BoldOff|FlipSymbolUpDown).addGlobalFlags(SubscriptCorrection);
     { auto s=MathOperatorSymbolUnicode(QChar(0x2265)).addMathOperatorHtml("&GreaterEqual;").addMathOperatorWinSymbol(QChar(0xB3));
         symbols["geq"]=s; symbols["ge"]=s; }
     symbols["geqq"]=MathOperatorSymbolUnicode(QChar(0x2267)).addMathOperatorHtml("&GreaterFullEqual;");
@@ -765,7 +772,7 @@ void JKQTMathTextSymbolNode::fillSymbolTables()
     symbols["mid"]=MathOperatorSymbolUnicode(QChar(0x2223)).addMathOperatorHtml("&VerticalBar;").addMathOperatorWinSymbol(QChar(0xBD)).addMathOperatorStd("|");
     symbols["mp"]=MathOperatorSymbolUnicode(QChar(0x2213)).addMathOperatorHtml("&mp;").addWinSymbol(QChar(0xB1),ItalicOff|BoldOff|FlipSymbolUpDown).addStd(QChar(0xB1),ItalicOff|BoldOff|FlipSymbolUpDown);
     symbols["multimap"]=MathOperatorSymbolUnicode(QChar(0x22B8)).addMathOperatorHtml("&mumap;");
-    symbols["nabla"]=NarrowMathOperatorSymbolUnicode(QChar(0x2207)).addMathOperatorHtml("&nabla;").addMathOperatorWinSymbol(QChar(0xD1));
+    symbols["nabla"]=NarrowMathOperatorSymbolUnicode(QChar(0x2207)).addMathOperatorHtml("&nabla;").addMathOperatorWinSymbol(QChar(0xD1)).addGlobalFlags(IntLikeSymbolCorrection);
     symbols["ne"]=NarrowMathOperatorSymbolUnicode(QChar(0x2260)).addMathOperatorHtml("&ne;").addMathOperatorWinSymbol(QChar(0xB9));
     symbols["nearrow"]=UprightSymbolUnicode(QChar(0x2197)).addUprightHtml("&UpperRightArrow;");
     { auto s=MathOperatorSymbolUnicode(QChar(0x00AC)).addMathOperatorHtml("&not;").addMathOperatorWinSymbol(QChar(0xD8));
@@ -1201,24 +1208,21 @@ QPair<QFont, JKQTMathTextSymbolNode::SymbolProps> JKQTMathTextSymbolNode::Symbol
 
 JKQTMathTextSymbolNode::NodeSize::NodeSize():
     JKQTMathTextNodeSize(),
-    subSuperXCorrection(0.0),
-    subBesidesXCorrection(0.0)
+    subSuperAboveBelowXCorrection(0.0)
 {
 
 }
 
 JKQTMathTextSymbolNode::NodeSize &JKQTMathTextSymbolNode::NodeSize::operator=(const JKQTMathTextNodeSize &other)
 {
-    subSuperXCorrection=0;
-    subBesidesXCorrection=0;
+    subSuperAboveBelowXCorrection=0;
     JKQTMathTextNodeSize::operator=(other);
     return *this;
 }
 
 JKQTMathTextSymbolNode::NodeSize &JKQTMathTextSymbolNode::NodeSize::operator=(const NodeSize &other)
 {
-    subSuperXCorrection=other.subSuperXCorrection;
-    subBesidesXCorrection=other.subBesidesXCorrection;
+    subSuperAboveBelowXCorrection=other.subSuperAboveBelowXCorrection;
     JKQTMathTextNodeSize::operator=(other);
     return *this;
 }

lib/jkqtmathtext/nodes/jkqtmathtextsymbolnode.h

@@ -71,9 +71,7 @@ class JKQTMATHTEXT_LIB_EXPORT JKQTMathTextSymbolNode: public JKQTMathTextNode {
         struct NodeSize : JKQTMathTextNodeSize {
             NodeSize();
             /** \brief x-correction as described for JKQTMathParser::intsubsuper_xcorrection_factor for placing sub-/superscript below/above the symbol, e.g. for integral signs, where the subscript is slightly shifted to the left (from center) and the superscript slightly to the right */
-            double subSuperXCorrection;
-            /** \brief x-correction as described for JKQTMathParser::intsubbesides_xcorrection_xfactor for placing sub-/superscript besides the symbol */
-            double subBesidesXCorrection;
+            double subSuperAboveBelowXCorrection;
 
             NodeSize& operator=(const JKQTMathTextNodeSize& other);
             NodeSize& operator=(const NodeSize& other);
@@ -144,6 +142,7 @@ class JKQTMATHTEXT_LIB_EXPORT JKQTMathTextSymbolNode: public JKQTMathTextNode {
             MakeWhitespaceHalf= 1 << 2,    /*!< \brief symbol uses whitespaces in its text (SymbolProps::symbol). These should be typeset as half-spaces */
             IntLikeSymbolCorrection= 1 << 3, /*!< \brief symbols, like \c \\int,\\iint,... require a correction in x-direction for subsequent sub-/superscripts ... this flag marks such symbols */
             SubSuperscriptBelowAboveSymbol= 1 << 4, /*!< \brief symbols, like \c \\int,\\iint,... if appearing in math-mode cause typesetting following sub-/superscripts below/above the symbol, not besides it. */
+            SubscriptCorrection= 1 << 5, /*!< \brief symbols, like \c \\nabla,... require a subscript correction in x-direction for subsequent subscripts ... this flag marks such symbols */
         };
 
         friend inline GlobalSymbolFlags operator~ (GlobalSymbolFlags a) { return (GlobalSymbolFlags)~static_cast<uint64_t>(a); }

lib/jkqtmathtext/nodes/jkqtmathtexttextnode.cpp

@@ -149,12 +149,15 @@ JKQTMathTextTextNode::LayoutInfo JKQTMathTextTextNode::calcLayout(QPainter &pain
     double ascent=0;
     double descent=0;
     for (int i=0; i<l.textpart.size(); i++) {
+        l.baselineXCorrection=0;
+        l.topXCorrection=0;
         QRectF br, tbr;
         switch(l.fontMode[i]) {
             case FMasDefined:
             case FMasDefinedOutline:
                 br=fm.boundingRect(l.textpart[i]);
                 tbr=JKQTMathTextGetTightBoundingRect(f, l.textpart[i], painter.device());
+                if (f.italic() && l.textpart[i].size()>0) l.baselineXCorrection=fm.rightBearing(l.textpart[i].operator[](l.textpart[i].size()-1));
                 break;
             case FMasDefinedForceUpright:
                 br=fmUpright.boundingRect(l.textpart[i]);
@@ -163,10 +166,12 @@ JKQTMathTextTextNode::LayoutInfo JKQTMathTextTextNode::calcLayout(QPainter &pain
             case FMroman:
                 br=fmRoman.boundingRect(l.textpart[i]);
                 tbr=JKQTMathTextGetTightBoundingRect(fRoman, l.textpart[i], painter.device());
+                if (fRoman.italic() && l.textpart[i].size()>0) l.baselineXCorrection=fmRoman.rightBearing(l.textpart[i].operator[](l.textpart[i].size()-1));
                 break;
             case FMfallbackSymbol:
                 br=fmFallbackSym.boundingRect(l.textpart[i]);
                 tbr=JKQTMathTextGetTightBoundingRect(fFallbackSym, l.textpart[i], painter.device());
+                if (fFallbackSym.italic() && l.textpart[i].size()>0) l.baselineXCorrection=fmFallbackSym.rightBearing(l.textpart[i].operator[](l.textpart[i].size()-1));
                 break;
         }
         l.textpartXPos.append(l.width);