JKQTMathText: optimized frac/sub/super spacing

doc/jkqtmathtext_docimages_frac.jkmt

@@ -33,7 +33,7 @@ MTFMunderbrace.png
 $f(x)=\underbrace{x+x+\ldots+x}{k\ \text{times}}$
 ---
 MTFMoverset.png
-$X\overset{=}{\text{def}}Y\ \ \ \ X\overset{=}{!}Y\ \ \ \ \ \frac{\Delta f}{\Delta x}\overset{\rightarrow}{\Delta x\rightarrow0}f^\prime$
+$X\overset{=}{\text{def}}Y\ \ \ \ X\overset{=}{!}Y\ \ \ \ \ \frac{\Delta f}{\Delta x}\overset{\longrightarrow}{\Delta x\rightarrow0}f^\prime$
 ---
 MTFMunderset.png
-$X\underset{=}{\text{def (5)}}Y\ \ \ \ X\underset{\Rightarrow}{f}Y\ \ \ \ \ \frac{\Delta f}{\Delta x}\underset{\rightarrow}{\Delta x\rightarrow0}f^\prime$
+$X\underset{=}{\text{def (5)}}Y\ \ \ \ X\underset{\Rightarrow}{f}Y\ \ \ \ \ \frac{\Delta f}{\Delta x}\underset{\longrightarrow}{\Delta x\rightarrow0}f^\prime$

examples/jkqtmathtext_test/mathtest.tex

@@ -49,6 +49,7 @@
 
 \begin{document}
 	 \begin{itemize}
+	 	\item $x_1^2 X_1^2 q_1^2$
 	 	\item\textbf{Text: Umlaute \& fonts: }\\ rm: \textrm{\"Aq{\"u}\"{a}t{\oe}r abcABC00, 123-45+6.0\%\S},\\
 	 	it: \textit{\"Aq{\"u}\"{a}t{\oe}r abcABC00, 123-45+6.0\%\S},\\
 	 	 sf: \textsf{\"Aq{\"u}\"{a}t{\oe}r abcABC00, 123-45+6.0\%\S},\\

lib/jkqtmathtext/jkqtmathtext.cpp

@@ -68,7 +68,7 @@ JKQTMathText::JKQTMathText(QObject* parent):
     brace_shrink_factor=0.45;
     brace_y_shift_factor=0.7;//-1;
 
-    subsuper_size_factor=0.7;
+    subsuper_size_factor=0.65;
     subsuper_mode_selection_by_size_factor=1.01;
     sub_shift_factor=0.4;
     super_shift_factor=0.7;

lib/jkqtmathtext/jkqtmathtext.h

@@ -755,14 +755,12 @@ class JKQTMATHTEXT_LIB_EXPORT JKQTMathText : public QObject {
          *
          */
         double bigmathoperator_font_factor;
-        /** \brief relative shift of text in superscript to normal text:
-         *         0= baseline kept, 1: baseline shifted to top of normal text
+        /** \brief relative shift of text in superscript to normal text, factor is multiplied by \c font.xHeight()
          *
          *  \image html jkqtmathtext_superscriptnode_getSizeInternal.png
          */
         double super_shift_factor;
-        /** \brief relative shift of text in subscript to normal text:
-         *         0= baseline kept, 1: baseline shifted to bottom of normal text
+        /** \brief relative shift of text in subscript to normal text, factor is multiplied by \c font.xHeight()
          *
          *  \image html jkqtmathtext_subscriptnode_getSizeInternal.png
          */

lib/jkqtmathtext/nodes/jkqtmathtextfracnode.cpp

@@ -149,11 +149,27 @@ void JKQTMathTextFracNode::getSizeInternal(QPainter& painter, JKQTMathTextEnviro
         ev2.fontSize=ev2.fontSize*getFracScalingFactor()*0.7;
     }
 
+    const QFontMetricsF fmev1(ev1.getFont(parentMathText), painter.device());
+    const QRectF AeTBR1=fmev1.tightBoundingRect("A");
+    const double asc1=AeTBR1.height();
+    const QFontMetricsF fmev2(ev2.getFont(parentMathText), painter.device());
+    const QRectF AeTBR2=fmev2.tightBoundingRect("A");
+    const double asc2=AeTBR2.height();
 
     double width1=0, baselineHeight1=0, overallHeight1=0, strikeoutPos1=0;
     double width2=0, baselineHeight2=0, overallHeight2=0, strikeoutPos2=0;
     child1->getSize(painter, ev1, width1, baselineHeight1, overallHeight1, strikeoutPos1);
     child2->getSize(painter, ev2, width2, baselineHeight2, overallHeight2, strikeoutPos2);
+    if (asc1>baselineHeight1) {
+        const double oldDescent=overallHeight1-baselineHeight1;
+        baselineHeight1=asc1;
+        overallHeight1=baselineHeight1+oldDescent;
+    }
+    if (asc2>baselineHeight2) {
+        const double oldDescent=overallHeight2-baselineHeight2;
+        baselineHeight2=asc2;
+        overallHeight2=baselineHeight2+oldDescent;
+    }
     const double descent1=overallHeight1-baselineHeight1;
 
 
@@ -176,7 +192,7 @@ void JKQTMathTextFracNode::getSizeInternal(QPainter& painter, JKQTMathTextEnviro
         const double top_ascent=line_ascent;
         const double newascent=overallHeight1+top_ascent;
         const double newdescent=qMax(overallHeight2-baselineHeight2, qheight-xheight);
-        width=width1+width2+xwidth/2.0;
+        width=width1+width2+xwidth*0.666;
         strikeoutPos=line_ascent;
 
         overallHeight=newascent+newdescent;
@@ -253,10 +269,27 @@ double JKQTMathTextFracNode::draw(QPainter& painter, double x, double y, JKQTMat
     }
 
 
+    const QFontMetricsF fmev1(ev1.getFont(parentMathText), painter.device());
+    const QRectF AeTBR1=fmev1.tightBoundingRect("A");
+    const double asc1=AeTBR1.height();
+    const QFontMetricsF fmev2(ev2.getFont(parentMathText), painter.device());
+    const QRectF AeTBR2=fmev2.tightBoundingRect("A");
+    const double asc2=AeTBR2.height();
+
     double width1=0, baselineHeight1=0, overallHeight1=0;//, strikeoutPos1=0;
     double width2=0, baselineHeight2=0, overallHeight2=0, strikeoutPos=0;
     child1->getSize(painter, ev1, width1, baselineHeight1, overallHeight1, strikeoutPos);
     child2->getSize(painter, ev2, width2, baselineHeight2, overallHeight2, strikeoutPos);
+    if (asc1>baselineHeight1) {
+        const double oldDescent=overallHeight1-baselineHeight1;
+        baselineHeight1=asc1;
+        overallHeight1=baselineHeight1+oldDescent;
+    }
+    if (asc2>baselineHeight2) {
+        const double oldDescent=overallHeight2-baselineHeight2;
+        baselineHeight2=asc2;
+        overallHeight2=baselineHeight2+oldDescent;
+    }
     const double ascent1=baselineHeight1;
     const double descent1=overallHeight1-baselineHeight1;
     const double ascent2=baselineHeight2;
@@ -286,7 +319,7 @@ double JKQTMathTextFracNode::draw(QPainter& painter, double x, double y, JKQTMat
         child1->draw(painter, x+(maxWidth-width1)/2.0, yline-xheight*(parentMathText->getFracShiftFactor())-descent1, ev1);
         child2->draw(painter, x+(maxWidth-width2)/2.0, yline+xheight*(parentMathText->getFracShiftFactor())+ascent2, ev2);
     } else if (mode==JKQTMathTextFracNode::MTFMstfrac || mode==JKQTMathTextFracNode::MTFMsfrac) {
-        deltaWidth=xwidth/2.0;
+        deltaWidth=xwidth*0.666;
         child1->draw(painter, x, yline, ev1);
         child2->draw(painter, x+width1+deltaWidth, y, ev2);
         const QLineF l(x+width1+deltaWidth, y-Mheight, x+width1, y+(qheight-xheight));

lib/jkqtmathtext/nodes/jkqtmathtextsubsupernode.cpp

@@ -53,7 +53,7 @@ void JKQTMathTextSuperscriptNode::getSizeInternal(QPainter& painter, JKQTMathTex
     double cStrikeoutPos=0, cWidth=0, cBaselineHeight=0, cOverallHeight=0;
     getChild()->getSize(painter, ev, cWidth, cBaselineHeight, cOverallHeight, cStrikeoutPos);
     const double childDescent=cOverallHeight-cBaselineHeight;
-    double shiftToChildBottom=parentMathText->getSuperShiftFactor()*tbr_of_letterM.height();
+    double shiftToChildBottom=parentMathText->getSuperShiftFactor()*fm.xHeight();
 
     if (prevNodeSize!=nullptr) {
         const double modifiedShift=prevNodeSize->baselineHeight-childDescent-parentMathText->getSpecialSuperShiftFactor()*cBaselineHeight-childDescent;
@@ -78,7 +78,7 @@ double JKQTMathTextSuperscriptNode::draw(QPainter& painter, double x, double y,
     const QFontMetricsF fm(currentEv.getFont(parentMathText), painter.device());
     QRectF tbr_of_letterM=JKQTMathTextGetTightBoundingRect(currentEv.getFont(parentMathText), "M", painter.device());
     const double childDescent=cOverallHeight-cBaselineHeight;
-    double shiftToChildBottom=parentMathText->getSuperShiftFactor()*tbr_of_letterM.height();
+    double shiftToChildBottom=parentMathText->getSuperShiftFactor()*fm.xHeight();
 
     if (prevNodeSize!=nullptr) {
         const double modifiedShift=prevNodeSize->baselineHeight-childDescent-parentMathText->getSpecialSuperShiftFactor()*cBaselineHeight-childDescent;
@@ -130,7 +130,7 @@ void JKQTMathTextSubscriptNode::getSizeInternal(QPainter& painter, JKQTMathTextE
     double cWidth=0, cBaselineHeight=0, cOverallHeight=0, cStrikeoutPos=0;
     getChild()->getSize(painter, ev, cWidth, cBaselineHeight, cOverallHeight, cStrikeoutPos);
     //const double childDescent=cOverallHeight-cBaselineHeight;
-    double shift_to_childBaseline=cBaselineHeight-parentMathText->getSubShiftFactor()*tbr_of_letterM.height();
+    double shift_to_childBaseline=cBaselineHeight-parentMathText->getSubShiftFactor()*fm.xHeight();
 
     if (prevNodeSize!=nullptr) {
         //qDebug()<<"oldshift="<<shift<<", prevNodeSize->overallHeight="<<prevNodeSize->overallHeight<<", prevNodeSize->baselineHeight="<<prevNodeSize->baselineHeight;
@@ -157,7 +157,7 @@ double JKQTMathTextSubscriptNode::draw(QPainter& painter, double x, double y, JK
 
     double cWidth=0, cBaselineHeight=0, cOverallHeight=0, cStrikeoutPos=0;
     getChild()->getSize(painter, ev, cWidth, cBaselineHeight, cOverallHeight, cStrikeoutPos);
-    double shift_to_childBaseline=cBaselineHeight-parentMathText->getSubShiftFactor()*tbr_of_letterM.height();
+    double shift_to_childBaseline=cBaselineHeight-parentMathText->getSubShiftFactor()*fm.xHeight();
 
     if (prevNodeSize!=nullptr) {
         //qDebug()<<"oldshift="<<shift<<", prevNodeSize->overallHeight="<<prevNodeSize->overallHeight<<", prevNodeSize->baselineHeight="<<prevNodeSize->baselineHeight;