Using qreal more consistently in code (prevent misuse of double)

We want to force use of qreal where possible. This can lead to better
performance on platforms where qreal -> float (i.e. ARM). To achieve
this we:

1. changed from 'double' to 'qreal', where justified
2. using qreal() to intialize constants, where justified
3. adding helper functions that are overloaded for qreal
   like qAtan2(), qAcos(), qFabs() ...
4. defining QT_USE_MATH_H_FLOATS for Symbian platform

In addtion we used opportunity to improve code with some small things
5. converting divisions to multiplications
   (i.e. '/ 2.0' -> '* qreal(0.5)')
6. defining new constants (i.e. 'Q_PI / 180.0' -> 'Q_PI180')
7. declaring variables as 'const', where justified

Reviewed-by: Andreas Aardal Hanssen
Reviewed-by: Gunnar Sletta
Reviewed-by: Jan-Arve
Reviewed-by: Kim Motoyoshi Kalland
Reviewed-by: Alessandro Portale
Reviewed-by: Janne Koskinen

5 files changed, 35 insertions, 34 deletions

diff --git a/src/gui/styles/qcommonstyle.cpp b/src/gui/styles/qcommonstyle.cpp
index 4c9541b..4d3272c 100644
--- a/src/gui/styles/qcommonstyle.cpp
+++ b/src/gui/styles/qcommonstyle.cpp
@@ -3070,9 +3070,9 @@ static QPolygonF calcArrow(const QStyleOptionSlider *dial, qreal &a)
     int currentSliderPosition = dial->upsideDown ? dial->sliderPosition : (dial->maximum - dial->sliderPosition);
 
     if (dial->maximum == dial->minimum)
-        a = Q_PI / 2;
+        a = Q_PI2;
     else if (dial->dialWrapping)
-        a = Q_PI * 3 / 2 - (currentSliderPosition - dial->minimum) * 2 * Q_PI
+        a = Q_PI2 * 3 - (currentSliderPosition - dial->minimum) * Q_2PI
             / (dial->maximum - dial->minimum);
     else
         a = (Q_PI * 8 - (currentSliderPosition - dial->minimum) * 10 * Q_PI
@@ -3087,12 +3087,13 @@ static QPolygonF calcArrow(const QStyleOptionSlider *dial, qreal &a)
     int back = len / 2;
 
     QPolygonF arrow(3);
-    arrow[0] = QPointF(0.5 + xc + len * qCos(a),
-                       0.5 + yc - len * qSin(a));
-    arrow[1] = QPointF(0.5 + xc + back * qCos(a + Q_PI * 5 / 6),
-                       0.5 + yc - back * qSin(a + Q_PI * 5 / 6));
-    arrow[2] = QPointF(0.5 + xc + back * qCos(a - Q_PI * 5 / 6),
-                       0.5 + yc - back * qSin(a - Q_PI * 5 / 6));
+    const qreal five_div_by_six = 5 / 6;
+    arrow[0] = QPointF(qreal(0.5) + xc + len * qCos(a),
+                       qreal(0.5) + yc - len * qSin(a));
+    arrow[1] = QPointF(qreal(0.5) + xc + back * qCos(a + Q_PI * five_div_by_six),
+                       qreal(0.5) + yc - back * qSin(a + Q_PI * five_div_by_six));
+    arrow[2] = QPointF(qreal(0.5) + xc + back * qCos(a - Q_PI * five_div_by_six),
+                       qreal(0.5) + yc - back * qSin(a - Q_PI * five_div_by_six));
     return arrow;
 }
 
diff --git a/src/gui/styles/qs60style.cpp b/src/gui/styles/qs60style.cpp
index e0fcb92..016b6a7 100644
--- a/src/gui/styles/qs60style.cpp
+++ b/src/gui/styles/qs60style.cpp
@@ -579,7 +579,7 @@ void QS60StylePrivate::drawRow(QS60StyleEnums::SkinParts start,
 
 #if 0
     painter->save();
-    painter->setOpacity(.3);
+    painter->setOpacity(qreal(.3));
     painter->fillRect(startRect, Qt::red);
     painter->fillRect(middleRect, Qt::green);
     painter->fillRect(endRect, Qt::blue);
@@ -1624,7 +1624,7 @@ void QS60Style::drawControl(ControlElement element, const QStyleOption *option,
                     QS60StylePrivate::SF_PointNorth : QS60StylePrivate::SF_PointWest;
                 QS60StylePrivate::drawSkinPart(QS60StyleEnums::SP_QgnGrafBarWait, painter, progressRect, flags | orientationFlag);
             } else {
-                const qreal progressFactor = (optionProgressBar->minimum == optionProgressBar->maximum) ? 1.0
+                const qreal progressFactor = (optionProgressBar->minimum == optionProgressBar->maximum) ? qreal(1.0)
                     : (qreal)optionProgressBar->progress / optionProgressBar->maximum;
                 if (optionProgressBar->orientation == Qt::Horizontal) {
                     progressRect.setWidth(int(progressRect.width() * progressFactor));
@@ -1912,12 +1912,12 @@ void QS60Style::drawControl(ControlElement element, const QStyleOption *option,
                 if (focusFrame->widget() && focusFrame->widget()->hasEditFocus())
                     editFocus = true;
             }
-            const qreal opacity = editFocus ? 0.65 : 0.45; // Trial and error factors. Feel free to improve.
+            const qreal opacity = editFocus ? qreal(0.65) : qreal(0.45); // Trial and error factors. Feel free to improve.
 #else
-            const qreal opacity = 0.5;
+            const qreal opacity = qreal(0.5);
 #endif
             // Because of Qts coordinate system, we need to tweak the rect by .5 pixels, otherwise it gets blurred.
-            const qreal rectAdjustment = (penWidth % 2) ? -.5 : 0;
+            const qreal rectAdjustment = (penWidth % 2) ? qreal(-.5) : 0;
 
             // Make sure that the pen stroke is inside the rect
             const QRectF adjustedRect =
@@ -1941,7 +1941,7 @@ void QS60Style::drawControl(ControlElement element, const QStyleOption *option,
     case CE_Splitter:
         if (option->state & State_Sunken && option->state & State_Enabled) {
             painter->save();
-            painter->setOpacity(0.5);
+            painter->setOpacity(qreal(0.5));
             painter->setBrush(d->themePalette()->light());
             painter->setRenderHint(QPainter::Antialiasing);
             const qreal roundRectRadius = 4 * goldenRatio;
@@ -2019,8 +2019,8 @@ void QS60Style::drawPrimitive(PrimitiveElement element, const QStyleOption *opti
     case PE_IndicatorRadioButton: {
             QRect buttonRect = option->rect;
             //there is empty (a. 33%) space in svg graphics for radiobutton
-            const qreal reduceWidth = (qreal)buttonRect.width()/3.0;
-            const qreal rectWidth = (qreal)option->rect.width() != 0 ? option->rect.width() : 1.0;
+            const qreal reduceWidth = (qreal)buttonRect.width()/qreal(3.0);
+            const qreal rectWidth = (qreal)option->rect.width() != 0 ? option->rect.width() : qreal(1.0);
             // Try to occupy the full area
             const qreal scaler = 1 + (reduceWidth/rectWidth);
             buttonRect.setWidth((int)((buttonRect.width()-reduceWidth) * scaler));
diff --git a/src/gui/styles/qstyle.cpp b/src/gui/styles/qstyle.cpp
index ec238a9..6733209 100644
--- a/src/gui/styles/qstyle.cpp
+++ b/src/gui/styles/qstyle.cpp
@@ -2132,7 +2132,7 @@ int QStyle::sliderPositionFromValue(int min, int max, int logicalValue, int span
     uint p = upsideDown ? max - logicalValue : logicalValue - min;
 
     if (range > (uint)INT_MAX/4096) {
-        double dpos = (double(p))/(double(range)/span);
+        qreal dpos = (qreal(p))/(qreal(range)/span);
         return int(dpos);
     } else if (range > (uint)span) {
         return (2 * p * span + range) / (2*range);
diff --git a/src/gui/styles/qstylehelper.cpp b/src/gui/styles/qstylehelper.cpp
index af30f15..5b6f72f 100644
--- a/src/gui/styles/qstylehelper.cpp
+++ b/src/gui/styles/qstylehelper.cpp
@@ -117,15 +117,15 @@ static QPointF calcRadialPos(const QStyleOptionSlider *dial, qreal offset)
     const int currentSliderPosition = dial->upsideDown ? dial->sliderPosition : (dial->maximum - dial->sliderPosition);
     qreal a = 0;
     if (dial->maximum == dial->minimum)
-        a = Q_PI / 2;
+        a = Q_PI2;
     else if (dial->dialWrapping)
-        a = Q_PI * 3 / 2 - (currentSliderPosition - dial->minimum) * 2 * Q_PI
+        a = Q_PI2 * 3 - (currentSliderPosition - dial->minimum) * Q_2PI
             / (dial->maximum - dial->minimum);
     else
         a = (Q_PI * 8 - (currentSliderPosition - dial->minimum) * 10 * Q_PI
             / (dial->maximum - dial->minimum)) / 6;
-    qreal xc = width / 2.0;
-    qreal yc = height / 2.0;
+    const qreal xc = width * qreal(0.5);
+    const qreal yc = height * qreal(0.5);
     qreal len = r - QStyleHelper::calcBigLineSize(r) - 3;
     qreal back = offset * len;
     QPointF pos(QPointF(xc + back * qCos(a), yc - back * qSin(a)));
@@ -134,7 +134,7 @@ static QPointF calcRadialPos(const QStyleOptionSlider *dial, qreal offset)
 
 qreal angle(const QPointF &p1, const QPointF &p2)
 {
-    static const qreal rad_factor = 180 / Q_PI;
+    static const qreal rad_factor = Q_PI180;
     qreal _angle = 0;
 
     if (p1.x() == p2.x()) {
@@ -186,7 +186,7 @@ QPolygonF calcLines(const QStyleOptionSlider *dial)
     poly.resize(2 + 2 * notches);
     int smallLineSize = bigLineSize / 2;
     for (int i = 0; i <= notches; ++i) {
-        qreal angle = dial->dialWrapping ? Q_PI * 3 / 2 - i * 2 * Q_PI / notches
+        qreal angle = dial->dialWrapping ? Q_PI2 * 3 - i * Q_2PI / notches
                   : (Q_PI * 8 - i * 10 * Q_PI / notches) / 6;
         qreal s = qSin(angle);
         qreal c = qCos(angle);
@@ -215,7 +215,7 @@ void drawDial(const QStyleOptionSlider *option, QPainter *painter)
     const bool enabled = option->state & QStyle::State_Enabled;
     qreal r = qMin(width, height) / 2;
     r -= r/50;
-    const qreal penSize = r/20.0;
+    const qreal penSize = r/qreal(20.0);
 
     painter->save();
     painter->setRenderHint(QPainter::Antialiasing);
@@ -234,7 +234,7 @@ void drawDial(const QStyleOptionSlider *option, QPainter *painter)
     const qreal dx = option->rect.x() + d_ + (width - 2 * r) / 2 + 1;
     const qreal dy = option->rect.y() + d_ + (height - 2 * r) / 2 + 1;
 
-    QRectF br = QRectF(dx + 0.5, dy + 0.5,
+    QRectF br = QRectF(dx + qreal(0.5), dy + qreal(0.5),
                        int(r * 2 - 2 * d_ - 2),
                        int(r * 2 - 2 * d_ - 2));
     buttonColor.setHsv(buttonColor .hue(),
@@ -244,11 +244,11 @@ void drawDial(const QStyleOptionSlider *option, QPainter *painter)
 
     if (enabled) {
         // Drop shadow
-        qreal shadowSize = qMax(1.0, penSize/2.0);
+        const qreal shadowSize = qMax(qreal(1.0), penSize * qreal(0.5));
         QRectF shadowRect= br.adjusted(-2*shadowSize, -2*shadowSize,
                                        2*shadowSize, 2*shadowSize);
         QRadialGradient shadowGradient(shadowRect.center().x(),
-                                       shadowRect.center().y(), shadowRect.width()/2.0,
+                                       shadowRect.center().y(), shadowRect.width() * qreal(0.5),
                                        shadowRect.center().x(), shadowRect.center().y());
         shadowGradient.setColorAt(qreal(0.91), QColor(0, 0, 0, 40));
         shadowGradient.setColorAt(qreal(1.0), Qt::transparent);
@@ -260,7 +260,7 @@ void drawDial(const QStyleOptionSlider *option, QPainter *painter)
 
         // Main gradient
         QRadialGradient gradient(br.center().x() - br.width()/3, dy,
-                                 br.width()*1.3, br.center().x(),
+                                 br.width()*qreal(1.3), br.center().x(),
                                  br.center().y() - br.height()/2);
         gradient.setColorAt(0, buttonColor.lighter(110));
         gradient.setColorAt(qreal(0.5), buttonColor);
@@ -283,7 +283,7 @@ void drawDial(const QStyleOptionSlider *option, QPainter *painter)
                          qMin(160, highlight.saturation()),
                          qMax(230, highlight.value()));
         highlight.setAlpha(127);
-        p->setPen(QPen(highlight, 2.0));
+        p->setPen(QPen(highlight, qreal(2.0)));
         p->setBrush(Qt::NoBrush);
         p->drawEllipse(br.adjusted(-1, -1, 1, 1));
     }
@@ -302,7 +302,7 @@ void drawDial(const QStyleOptionSlider *option, QPainter *painter)
     dialGradient.setColorAt(1, buttonColor.darker(140));
     dialGradient.setColorAt(qreal(0.4), buttonColor.darker(120));
     dialGradient.setColorAt(0, buttonColor.darker(110));
-    if (penSize > 3.0) {
+    if (penSize > qreal(3.0)) {
         painter->setPen(QPen(QColor(0, 0, 0, 25), penSize));
         painter->drawLine(calcRadialPos(option, qreal(0.90)), calcRadialPos(option, qreal(0.96)));
     }
diff --git a/src/gui/styles/qstylesheetstyle.cpp b/src/gui/styles/qstylesheetstyle.cpp
index ae1d33a..ae84442 100644
--- a/src/gui/styles/qstylesheetstyle.cpp
+++ b/src/gui/styles/qstylesheetstyle.cpp
@@ -1252,20 +1252,20 @@ QPainterPath QRenderRule::borderClip(QRect r)
     const QRectF rect(r);
     const int *borders = border()->borders;
     QPainterPath path;
-    qreal curY = rect.y() + borders[TopEdge]/2.0;
+    qreal curY = rect.y() + borders[TopEdge]*qreal(0.5);
     path.moveTo(rect.x() + tlr.width(), curY);
     path.lineTo(rect.right() - trr.width(), curY);
-    qreal curX = rect.right() - borders[RightEdge]/2.0;
+    qreal curX = rect.right() - borders[RightEdge]*qreal(0.5);
     path.arcTo(curX - 2*trr.width() + borders[RightEdge], curY,
                trr.width()*2 - borders[RightEdge], trr.height()*2 - borders[TopEdge], 90, -90);
 
     path.lineTo(curX, rect.bottom() - brr.height());
-    curY = rect.bottom() - borders[BottomEdge]/2.0;
+    curY = rect.bottom() - borders[BottomEdge]*qreal(0.5);
     path.arcTo(curX - 2*brr.width() + borders[RightEdge], curY - 2*brr.height() + borders[BottomEdge],
                brr.width()*2 - borders[RightEdge], brr.height()*2 - borders[BottomEdge], 0, -90);
 
     path.lineTo(rect.x() + blr.width(), curY);
-    curX = rect.left() + borders[LeftEdge]/2.0;
+    curX = rect.left() + borders[LeftEdge]*qreal(0.5);
     path.arcTo(curX, rect.bottom() - 2*blr.height() + borders[BottomEdge]/2,
                blr.width()*2 - borders[LeftEdge], blr.height()*2 - borders[BottomEdge], 270, -90);