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

1 files changed, 6 insertions, 5 deletions

diff --git a/src/svg/qsvggraphics.cpp b/src/svg/qsvggraphics.cpp
index 6552b69..cc3c170 100644
--- a/src/svg/qsvggraphics.cpp
+++ b/src/svg/qsvggraphics.cpp
@@ -332,11 +332,12 @@ void QSvgText::draw(QPainter *p, QSvgExtraStates &states)
 
     // Force the font to have a size of 100 pixels to avoid truncation problems
     // when the font is very small.
-    qreal scale = 100.0 / p->font().pointSizeF();
+    const qreal scale = qreal(100.0) / p->font().pointSizeF();
+    const qreal inv_scale = p->font().pointSizeF() / qreal(100.0); // like '1/scale' but with less rounding errors
     Qt::Alignment alignment = states.textAnchor;
 
     QTransform oldTransform = p->worldTransform();
-    p->scale(1 / scale, 1 / scale);
+    p->scale(inv_scale, inv_scale);
 
     qreal y = 0;
     bool initial = true;
@@ -346,7 +347,7 @@ void QSvgText::draw(QPainter *p, QSvgExtraStates &states)
 
     if (m_type == TEXTAREA) {
         if (alignment == Qt::AlignHCenter)
-            px += scaledSize.width() / 2;
+            px += scaledSize.width() * qreal(0.5);
         else if (alignment == Qt::AlignRight)
             px += scaledSize.width();
     }
@@ -459,7 +460,7 @@ void QSvgText::draw(QPainter *p, QSvgExtraStates &states)
 
                 qreal x = 0;
                 if (alignment == Qt::AlignHCenter)
-                    x -= 0.5 * line.naturalTextWidth();
+                    x -= qreal(0.5) * line.naturalTextWidth();
                 else if (alignment == Qt::AlignRight)
                     x -= line.naturalTextWidth();
 
@@ -479,7 +480,7 @@ void QSvgText::draw(QPainter *p, QSvgExtraStates &states)
                     break;
                 }
 
-                y += 1.1 * line.height();
+                y += qreal(1.1) * line.height();
             }
             tl.draw(p, QPointF(px, py), QVector<QTextLayout::FormatRange>(), bounds);