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, 9 insertions, 9 deletions

diff --git a/src/gui/painting/qblendfunctions.cpp b/src/gui/painting/qblendfunctions.cpp
index f8dd424..76d50db 100644
--- a/src/gui/painting/qblendfunctions.cpp
+++ b/src/gui/painting/qblendfunctions.cpp
@@ -223,8 +223,8 @@ void qt_scale_image_16bit(uchar *destPixels, int dbpl,
     int h = ty2 - ty1;
     int w = tx2 - tx1;
 
-    const int dstx = qCeil((tx1 + 0.5 - qMin(targetRect.left(), targetRect.right())) * ix) - 1;
-    const int dsty = qCeil((ty1 + 0.5 - qMin(targetRect.top(), targetRect.bottom())) * iy) - 1;
+    const int dstx = qCeil((tx1 + qreal(0.5) - qMin(targetRect.left(), targetRect.right())) * ix) - 1;
+    const int dsty = qCeil((ty1 + qreal(0.5) - qMin(targetRect.top(), targetRect.bottom())) * iy) - 1;
 
     quint32 basex = quint32((sx < 0 ? srcRect.right() : srcRect.left()) * 65536) + dstx;
     quint32 srcy = quint32((sy < 0 ? srcRect.bottom() : srcRect.top()) * 65536) + dsty;
@@ -723,8 +723,8 @@ template <typename T> void qt_scale_image_32bit(uchar *destPixels, int dbpl,
     int h = ty2 - ty1;
     int w = tx2 - tx1;
 
-    const int dstx = qCeil((tx1 + 0.5 - qMin(targetRect.left(), targetRect.right())) * ix) - 1;
-    const int dsty = qCeil((ty1 + 0.5 - qMin(targetRect.top(), targetRect.bottom())) * iy) - 1;
+    const int dstx = qCeil((tx1 + qreal(0.5) - qMin(targetRect.left(), targetRect.right())) * ix) - 1;
+    const int dsty = qCeil((ty1 + qreal(0.5) - qMin(targetRect.top(), targetRect.bottom())) * iy) - 1;
 
     quint32 basex = quint32((sx < 0 ? srcRect.right() : srcRect.left()) * 65536) + dstx;
     quint32 srcy = quint32((sy < 0 ? srcRect.bottom() : srcRect.top()) * 65536) + dsty;
@@ -818,8 +818,8 @@ void qt_transform_image_rasterize(DestT *destPixels, int dbpl,
     qreal rightSlope = (bottomRight.x - topRight.x) / (bottomRight.y - topRight.y);
     int dx_l = int(leftSlope * 0x10000);
     int dx_r = int(rightSlope * 0x10000);
-    int x_l = int((topLeft.x + (0.5 + fromY - topLeft.y) * leftSlope + 0.5) * 0x10000);
-    int x_r = int((topRight.x + (0.5 + fromY - topRight.y) * rightSlope + 0.5) * 0x10000);
+    int x_l = int((topLeft.x + (qreal(0.5) + fromY - topLeft.y) * leftSlope + qreal(0.5)) * 0x10000);
+    int x_r = int((topRight.x + (qreal(0.5) + fromY - topRight.y) * rightSlope + qreal(0.5)) * 0x10000);
 
     int fromX, toX, x1, x2, u, v, i, ii;
     DestT *line;
@@ -996,7 +996,7 @@ void qt_transform_image(DestT *destPixels, int dbpl,
     if (det == 0)
         return;
 
-    qreal invDet = 1.0 / det;
+    qreal invDet = qreal(1.0) / det;
     qreal m11, m12, m21, m22, mdx, mdy;
 
     m11 = (u.u * w.y - u.y * w.u) * invDet;
@@ -1010,8 +1010,8 @@ void qt_transform_image(DestT *destPixels, int dbpl,
     int dvdx = int(m21 * 0x10000);
     int dudy = int(m12 * 0x10000);
     int dvdy = int(m22 * 0x10000);
-    int u0 = qCeil((0.5 * m11 + 0.5 * m12 + mdx) * 0x10000) - 1;
-    int v0 = qCeil((0.5 * m21 + 0.5 * m22 + mdy) * 0x10000) - 1;
+    int u0 = qCeil((qreal(0.5) * m11 + qreal(0.5) * m12 + mdx) * 0x10000) - 1;
+    int v0 = qCeil((qreal(0.5) * m21 + qreal(0.5) * m22 + mdy) * 0x10000) - 1;
 
     int x1 = qFloor(sourceRect.left());
     int y1 = qFloor(sourceRect.top());